Treatment and Care (LARGE PAGE - wait to load)

For information on manipulation of the population and environment see Environmental and Population Management

• Where disease in wild waterfowl is concerned, manipulation of the population and the environment are most commonly employed to reduce the effect of disease outbreaks. However, treatment and care of individual waterfowl or groups of waterfowl may also be appropriate, for example in the cleaning of birds affected by Oiling, Hook and Line Injuries or Avian Botulism.
• In captive waterfowl, the treatment and care of individual birds is employed more commonly, although consideration must also be given as to the role of the population and the environment in the development of the disease, and the possible effect on disease incidence of manipulating these.

For information on manipulation of the population and environment see Environmental and Population Management

• In zoo and wildlife rehabilitation settings, usually treatment will involve a single bear. However, group control of disease may be required for infectious diseases, including parasite infestations, and environmental management may also be required, particularly for parasite control. 
• In rescue situations, large numbers of bears may require individual treatment to repair damage caused by years of abuse. (P503.1.w7)

For information on manipulation of the population and environment see  Environmental and Population Management

• Chapter 4 - B36 Field Manual of Wildlife Diseases - Disease control operations

• The appropriate route for administration of medication will vary depending on factors including the severity and site of disease, type, volume and formulation of medication, and the size, number, feeding habits and temperament of the animals to be treated. Economic factors, requirements for dosing by the owner (rather than by a veterinarian) and legal registration requirements must also be considered.
• Topical medication is appropriate for use on the skin, and for ocular treatment.
• Most medications are given orally or by parenteral routes - mainly by subcutaneous, intramuscular or intravenous injection. Other routes such as intraosseous, intraperitoneal, intratracheal or intracardiac are used less commonly.

Further information about the uses and limitations of the main routes of drug administration is provided in Routes of Drug Administration in Ruminants (Techniques Overview)

• Oral medication is indicated when there is normal gastro-intestinal tract motility, and offers the widest range of options with regard to administration and formulation. Medicated feed and water (Food / Water Medication for Birds) have their main advantages in treating diseases on a flock basis. Capsules and tablets (Capsule / Tablet Administration in Birds) can be easily administered to handleable birds and can be used to deliver precise amounts of medication. Administration by gavage (Gavage / Tubing of Birds) is an excellent way to initially improve gastro-intestinal tract motility in a debilitated animal, and provide longer term hydration and nutrition.
• Parenteral administration is any mode other than topical or through the gastrointestinal tract. This usually means delivering medication through a needle to a specific anatomic site. Action at site, or circulating blood levels of drug are achieved more rapidly than oral medications. The potential for introducing septic agents is higher, so cleanliness is much more important. Tissues to which agents are delivered may be damaged. Needle sizes and volumes delivered must be chosen carefully, according to the size of the bird. (B11.5.w18, V.w5, V.w7).

Oral medication

• Oral medication is advantageous where possible, to remove the stress and risks associated with physical restraint (e.g. in a squeeze cage, see: Mammal Handling & Movement) for hand or pole injection, or with remote injection (darting). However, this can only be used when both (a) the bear will consume the required medication (usually hidden inside a food treat) and (b) it is possible to ensure that the correct individual will eat the medicated food.
• Oral medications can be mixed into foods such as milk, honey, cod liver oil, meat or fish, or placed inside a small treat which will be eaten whole. Liquids or powders can be placed inside a gelatin capsule which is then hidden in the treat. (P6.6.w3, B16.9.w9)
• Bears have an excellent sense of smell and may detect medicines and refuse to eat food containing medication. (D247.8.w8)
• Individual bears vary greatly in what they will be willing to eat. (D247.8.w8)
• In general, sweet foods can be used to camouflage drugs for bears. Powders or ground up pills may be given inside thick honey sandwiches; similarly liquid medications may be mixed with honey. (D247.8.w8)
• It may be possible to conceal medication inside the carcass of a rabbit or chicken.  (D247.8.w8)
• When a group of bears is to be medicated orally, the bears need to be separated into individual dens to ensure that all animals can consume the medicated food, rather than dominant animals being overdosed and subordinate animals not getting any of the medication. (B16.9.w9)

Parenteral medication

• Parenteral administration by remote injection (darting) is required in many circumstances, including for medicating free-living bears.
  • For intramuscular injections it is important to be aware of the anatomy of bears, in particular the large quantities of subcutaneous fat which may be present over the rump and hind legs of hibernating species in late summer and winter, and polar bears at any time of year. Therefore injecting into the shoulder or neck muscles is preferable. (B16.9.w9, D156.w2)
    • When delivering drugs by remote injection (darting), the rifle must be powered correctly; if a charged dart hits with too low velocity, the cushioning effect of the bear's thick fur and fat may be such that the firing cap fails to fire due to insufficient impact. (B16.9.w9)
    • Needle lengths of at least 7.5 cm (3 inches) are required for intramuscular injections into adult bears. (B10.48.w43, B16.9.w9)
    • See: Intramuscular Injection of Bears
    • Note: bears can be trained to allow injections by hand or using a pole syringe, without physical restraint. See: Mammal Handling & Movement - Husbandry Training
  • For intravenous access (in anaesthetised bears), the sublingual vein is most accessible; fat layers make the jugular and femoral veins more difficult to access. (B10.48.w43) Various veins can be used and different individuals prefer different veins for intravenous access.
    • See: Intravenous Injection in Bears
• See below, anaesthesia and chemical restraint, for more information on the use of anaesthetic agents.

Topical medication

• Topical medication is needed for treatment of a number of skin diseases. Depending on the bear's cooperation, the precision needed in application and the volume of medication, it may be necessary to treat the bear while it is physically or chemically restrained, or it may be possible to apply topical medication to an unrestrained individual.
  • For example, treatment of wound myiasis (Myiasis (with special reference to Waterfowl, Hedgehogs, Elephants and Bears)) in an Ursus arctos - Brown bear was possible by throwing a volume of an organophosphate insecticide in appropriate dilution over the affected wound. (J196.54.w1)

• Capsule / Tablet Administration in Birds
• Gavage / Tubing of Birds
• Food / Water Medication for Birds
• Intramuscular Injection of Birds
• Intraosseus Injection of Birds
• Intraperitoneal Injection for Birds
• Intratracheal Medication for Birds
• Intravenous Injection of Birds
• Nebulization of Birds
• Subcutaneous Injection of Birds
• Topical Medication of Birds

Mammals

• Mammal Handling & Movement
• Intramuscular Injection of Bears
• Intravenous Injection in Bears
• Subcutaneous Injection of Mammals

• Accommodation Design for Birds - Temporary / Hospital Accommodation
• Accommodation Design for Mammals - Temporary / Hospital Accommodation
• Wildlife Casualty Accommodation (with special reference to UK Wildlife)
• Wildlife Casualty & Convalescent Feeding (with special reference to UK Wildlife)

GENERAL

• Supportive care is frequently a vital part of the treatment of individuals and groups and may vary from simple provision of a safe quiet place for recuperation to force feeding and parenteral fluid administration.
• In all dealings with sick or injured wild animals minimizing stress is very important. It is important to remember that the proximity of humans and human-associated noises are likely to be extremely stressful to the animal. Every effort should be made to minimize this stress.
• Provision of appropriate accommodation is an important part of supportive care. See:
  • Accommodation Design for Birds: Temporary / Hospital Accommodation
  • Accommodation Design for Mammals - Temporary / Hospital Accommodation
  • Wildlife Casualty Accommodation (with special reference to UK Wildlife)
• Wild animals should be handled only when necessary for their treatment (B11.4.w17, V.w5). Sick dogs, cats and other pets frequently benefit from being fussed over and patted or stroked: wild animals generally do not. For most wild animals the best "tender loving care" which can be given is to be left alone. Handling should also be minimized to reduce the chance of a wild animal which is to be released back into the wild becoming unwary of humans, which could be dangerous both to the animal and to the people it may approach after release. (P19.1.w10)

FOOD AND WATER

• Intake of sufficient food and water is vital. Within a given class of animals, smaller animals have a higher metabolic rate than larger animals. Birds have a higher metabolic rate than similarly sized mammals. In calculating nutritional requirements, whether for voluntary food intake or force-feeding, it is important to remember the requirements for healing wounds, in the case of injured animals, and for regaining weight which may have been lost in the period prior to admission. Monitoring of weight and body condition is essential to ensure that adequate nutrients are being ingested and absorbed. See: 
  • Food and Feeding for Birds - Convalescent diets / Nutritional Support
  • Food and Feeding for Mammals - Convalescent diets / Nutritional Support
  • Wildlife Casualty & Convalescent Feeding (with special reference to UK Wildlife)
• Fresh water should always be available, with due consideration for the risks involved when an animal is recovering from anaesthetic or is unable to lift its head properly due to illness (e.g. while recovering from Avian Botulism).
• Fluid therapy should be given to dehydrated individuals and those unable to drink voluntarily. Depending on the degree of dehydration and the general state of the animal, fluids may be given by the oral, subcutaneous, intravenous or intraosseous routes.
• Appropriate food should be provided. 
  • It is important to remember when dealing with wild animal casualties that the food available for feeding animals during hospitalization is frequently very different from what they would eat in the wild and may not be recognized as food, at least initially.
  • Force-feeding may be required if an animal cannot or will not eat voluntarily. This procedure is likely to be stressful to the animal and should be discontinued as soon as adequate voluntary intake develops. 
  • In birds, depending on the species, age and condition of the bird, solid food items (e.g. pieces of meat, fish) may be pushed into the esophagus or a liquid mixture may be given by tube (see: Gavage / Tubing). The ingredients of liquid diets fed by tube should be based on the normal diet of the species.

WARMTH

• Provision of a warm environment will decrease the energy expenditure required for the animal to maintain its body temperature.
• This is particularly important for:
  • Small animals, which have a large surface area to volume ratio and a high metabolic rate;
  • Neonates, especially altricial birds and mammals;
  • Individuals unable to behaviourally regulate temperature due to illness or during anaesthesia and recovery from anaesthesia.
• Note: It is also important to ensure that animals are not becoming hyperthermic. Hyperthermia is more likely to occur in:
  • Individuals which have lost some of their normal insulation (fur, feathers, subcutaneous fat) or in which fur or feathers are contaminated;
  • Individuals unable to behaviourally regulate temperature due to illness or during anaesthesia and recovery from anaesthesia.
  • Individuals being kept in a confined space.

• N.B. Waterfowl, particularly wild waterfowl, hospitalized for treatment are susceptible to the development of diseases such as Aspergillosis and Bumblefoot. Prevention of the development of such diseases in hospitalized waterfowl includes reducing stress and designing hospital accommodation to avoid or minimize known factors associated with their development. Particular care should be taken with species known to have high susceptibility to these diseases.
• Species with strong pair-bonds (e.g. swans) may be stressed and pine if separated from their mate during treatment. If possible, it may be best to hospitalize both birds, keeping the pair together.
• N.B. It is very important to maintain and if necessary restore the waterproofing of waterfowl during treatment. Provision of water for bathing and swimming is important in maintaining waterproofing.
• Providing the opportunity for hospitalized waterfowl to spend much of their time on water is particularly important in species which normally spend most of their time afloat, such as swans, seaducks and stifftails, and for any individual recovering from a leg or foot problem, as it minimized the amount of time spent weight-bearing on the affected limb.
• For most hospitalized wild waterfowl, food such as wheat, brown/wholemeal bread and green food should be provided, both dry and in a bowl covered with water. Consideration should be given as to the natural diet and nutritional requirements of the individual species and information from the "Natural Diet" "Feeding Behaviour" and "Aviculture" sections of the relevant species page should be consulted. (see also: Food and Feeding for Birds).
• Tube feeding may be required if hospitalized waterfowl are not taking food voluntarily (see: Gavage / Tubing of Birds).
• It is important to remember that waterfowl which have lost the normal insulation properties of their feathers, such as may be seen with Oiling, will have greatly increased calorific (energy) requirements.

(B11.4.w17)

• Accommodation Design for Mammals - Temporary / Hospital Accommodation
• Food and Feeding for Mammals - Convalescent diets / Nutritional Support

Fluids

• Bears may require fluids as supportive treatment for bears which have diarrhoea and vomiting and/or are refusing food and water, (J3.145.w4, J11.83.w1, J142.19.w1), when obviously dehydrated (B16.9.w9, B64.26.w5, P62.18.w1),  or while undergoing prolonged surgical procedures. (P3.2006a.w1, P62.18.w1)

Temperature regulation

• Bears have a thick fur coat. In most circumstances, adult bears of northern species are likely to be more at risk of hyperthermia than of hypothermia. 
  • Heating may be required for tropical species, particularly Helarctos malayanus - Sun bear but also Melursus ursinus - Sloth bear and Tremarctos ornatus - Spectacled bear. (D254, D247.2.w2)
  • Bears may overheat during chemical immobilization, particularly in high ambient temperatures. It is important that the bear's temperature is monitored carefully during anaesthesia.
  • In cold temperatures, anaesthetised bears should be given protection from the cold. 
    • Wrap the bear in a space blanket or place it on an insulating pad. (D249.w13)
    • During surgery in cold conditions, place hot water bottles along the sides of the bear. (V.w89, V.w90)
• Very young bears have a poor coat and a greatly reduced ability to thermoregulate. It is important to ensure that young bear cubs are kept warm. (B288.w11, B16.9.w9, B64.26.w5)
• Further information on general care for young cubs is provided in:
  • Rearing of Mammals (Mammal Husbandry and Management) - Hand-rearing
  • Hand-rearing American Black Bears (Techniques)
  • Hand-rearing Brown Bears (Techniques)
  • Hand-rearing Polar Bears (Techniques)
  • Hand-rearing Spectacled Bears (Techniques)
  • Hand-rearing Sun Bears (Techniques)

Food and water

• Water should be accessible except in the eight hours prior to anaesthesia or if the bear may be in danger of drowning (e.g. during seizures).
• For wild bears undergoing temporary captivity for rehabilitation, high-quality named-brand complete dry dog food or omnivore food may be used. (B468.8.w8p)
• See: Food and Feeding for Mammals - Convalescent diets / Nutritional Support

• Accommodation Design for Birds - Temporary / Hospital Accommodation
• Accommodation Design for Mammals - Temporary / Hospital Accommodation
• Wildlife Casualty Accommodation (with special reference to UK Wildlife)
• Wildlife Casualty & Convalescent Feeding (with special reference to UK Wildlife)
• Food and Feeding for Birds - Convalescent diets / Nutritional Support
• Food and Feeding for Mammals - Convalescent diets / Nutritional Support
• Wildlife Casualty & Convalescent Feeding (with special reference to UK Wildlife)
• Food / Water Medication for Birds
• Gavage / Tubing of Birds
• In Food / Water
• Bandaging & Splinting in Birds

• Get all necessary equipment ready before starting treatment. (P62.23.w1)
• When treating wild animals, maintain a warm, quiet environment. (P62.23.w1)
• Ensure sufficient personnel are available for appropriate restraint and treatment, (P62.23.w1) or use chemical restraint. (V.w5)
• In general, treatment of wounds is likely to require sedation or general anaesthesia of the animal.
  • This is particularly true if extensive cleaning and debridement (surgical removal of dead and severely damaged tissue) is necessary.
• Note: the stress and pain involved in wound management must be remembered: just because it is possible to hold a conscious animal of a particular species sufficiently immobile for wound management to take place does not mean that treatment of the conscious animal without sedation and analgesia is appropriate.

(V.w5, V.w6, V.w26)

Initial inspection and cleaning

• Careful inspection should be carried out for the presence of fly eggs or maggots (which may not be superficially visible) and action taken to remove these. See: Myiasis.
• Maintain sterile technique while cleaning and managing the wound, even if it is already infected. (P62.23.w1)
  • This reduces exposure of the wound to additional and nosocomial (hospital-associated) pathogens. (P62.23.w1)
• If wound are superficial and mild, with minimal contamination and no infection, minimise clipping of hair (or feathers, in birds) to preserve insulation, and manage by simple first aid. (P62.23.w1)

Hair clipping and skin preparation

• Clip the area around the wound to allow full evaluation of the area affected, and to prevent additional contamination of the wound. (P62.23.w1)
• Clipping of hair around the wound should be carried out using curved, blunt-ended scissors. If these are damped or dipped in mineral oil, cut hare will stick to the blades rather than fall into the wound. (J15.17.w4)
• Further from the wound, clippers can be used; these must be sharp and whole, without any missing teeth, to minimise further trauma to the skin. (J15.17.w4)
• Sterile swabs, a water-soluble jelly (e.g. K-Y Jelly, Johnson & Johnson) (J15.17.w4) or moist cotton wool may be placed in/over/along the edge of the wound to minimise clipped hair contaminating the wound by falling into it. (P19.2.w5)
  • Large wounds might be temporarily closed with towel clips or a continuous suture while the hair is being clipped. (J15.17.w4)
• Note: The area clipped should not be excessive, as hair normally provides the animal with protection from cold, some trauma etc. Loss of hair from a large area will increase the risk of the animal becoming chilled, particularly in small animals. (P19.2.w5, V.w5)
  • For information on preparation around the wound in birds see below: Wound Management for Birds
• Surgically prepared the skin around the wound using povidone-iodine or chlorhexidine diacetate. (P62.23.w1)

Lavage

• For contaminated wounds, thorough flushing with an isotonic solution such as sterile normal (0.9%) saline or lactated Ringer's solution is recommended. (J15.17.w4, P19.2.w5, P62.23.w1,)
  • Large volumes of lavage/irrigation solution help to dilute contaminating bacteria in the wound. (P62.23.w1)
  • A substitute saline solution [not a precise substitute] may be produced if necessary by dissolving one teaspoon of salt in a pint of water (preferably boiled and cooled). (B337.A6.w12, P19.2.w5)
  • For grossly contaminated wounds, tap water directed using a hand shower head can be used for initial lavage, but it should be followed by use of physiological saline to give an appropriate environment for healthy tissue. (J15.17.w4, P62.10.w2, P62.23.w1)
  • Optimum pressure for lavage of wounds is 8 psi. This can be carried out by using an 18-gauge needle attached to a 20 or 35 mL syringe. (J15.17.w4, P62.23.w1)
    • Higher pressures should not be used as they may cause deeper contamination, or oedema in adjacent, undamaged, tissues. (J15.17.w4)
  • During lavage, make sure the wound can drain freely and that the patient is protected from the fluids, not becoming soaked. (J15.17.w4)
• Contaminated or infected wounds should be cleaned using a non-irritant antiseptic solution. 
  • If an antiseptic solution is used, it is necessary to balance the beneficial anti-bacterial effects with the potential toxic effects of the antiseptic on tissue. (J15.17.w4, P62.23.w1)
  • Chlorhexidine can be used at a 0.05% final solution. This has good residual activity, but Staphylococcus aureus is often resistant. It is toxic to fibroblasts. (J15.17.w4, P62.23.w1) 
  • Povidone iodine can be used as a 1% solution; this is broad spectrum, but inactivated by debris, pus or blood. It does not have as good residual activity as chlorhexidine and is toxic to host cells. (J15.17.w4, P62.23.w1)
  • Hydrogen peroxide, cetrimide/chlorhexidine (Savlon Veterinary Concentrate, Mallinckrodt) and hypochlorite (Dakin's solution) have all been shown to be irritant and highly toxic to host cells and should not be used. (J15.17.w4)
  • Note: use of products such as Dettol and TCP should be avoided; they are irritant and sting severely on open wounds. (P19.2.w5)
• Do NOT cleanse deep wounds with hydrogen peroxide or alcohol, as this may cause tissue injury and increase the chance of infection developing. (D249.w13)
  • Hydrogen peroxide does not have any antibacterial properties, and it injures capillary beds. It should not be used for cleaning wounds. (P62.23.w1)
  • Avoid using alcohol; this may cause pain and also cool the animal excessively. (P62.23.w1)

Surgical debridement

• This aims to remove foreign material and devitalised, contaminated and infected tissue, reducing the need for debridement of the wound by macrophages and thereby allowing rapid onset of the proliferative phase of wound healing, as well as helping to control infection. (J15.17.w4)
• Considerable debriding of wounds may be necessary to remove contaminated and devitalised tissue. Anaesthesia will often be necessary for this process as it will often be appropriate to remove the damaged tissue as far back as to where there is an effective blood supply (and thereby usually pain sensors) to encourage healing.
• If the wound is contaminated but not infected (in the first six hours, the "golden period"), it can be debrided once to give a surgically clean wound; infected wounds require further stages of debridement. (J15.17.w4)
• During surgical debridement, the wound should be draped and prepared as for surgery. Viable tissue must be handled gently; handle skin edges with skin hooks (bent 20-gauge needles can substitute), not retractors. (J15.17.w4)
• Ensure haemostasis to avoid development of a haematoma, but note that multiple ligatures of necrotic tissue plus from electrocautery can delay healing. (J15.17.w4)
• Explore the wound carefully; check there are no deep punctures complicating an apparently simple surface laceration. (J15.17.w4)
• Handle different tissue types appropriately: (J15.17.w4)
  • Trim the skin edges; note that initial vascular spasm may cause mistakes in assessment of skin viability. Preserve as much skin as possible.
  • Debride muscle which is dark, friable, or does not contract.
  • Debride exposed fatty tissue back to a clean plane.
  • Conserve and protect nerves whenever possible.
  • Preserve tendons as much as possible. Note that anastomosis will fail if infection is present, and that strength will begin to develop only after three to five days.
  • Exposed joints should be lavaged thoroughly, repaired and immobilised.

  (J15.17.w4)

(B13.16.w11, B14, J15.17.w4, P19.2.w5, P62.23.w1, V.w5, V.w26, V.w6)

Suturing

• Puncture wounds should never be sutured.
• Suturing (primary closure) may be appropriate with fresh lacerations or with older lacerations if the tissue deficit following debridement is not too extensive.
  • In wild animals, absorbable sutures should be used for closure of the skin as well as deeper tissues, so that there is no need for additional handling to remove the sutures. 
    • It is particularly important to use absorbable sutures in field situations when the animal will be released immediately. (B345.4.w4)
    • Use a tapered needle to suture internal muscle layers on a deep wound. (B345.4.w4)
    • Use a cutting needle to suture the skin. (B345.4.w4) 
  • Consideration should be given to wound drainage; the placement of a drain may be required (not in the field).
  • Care must be taken to avoid attempting to suture wounds with a large tissue deficit which would place excessive pressure on the wound.
• Tissue glue or bandage strips can also be used to close clean fresh wounds. (P62.23.w1)

Delayed primary closure

• Wounds which are grossly contaminated, infected (contain pus), contain necrotic tissue or involve defects which wound produce excessive tension at the wound edges cannot be closed.
• Control of infection and management of the wound with bandaging may allow surgical debridement and delayed primary closure three to five days later. (P62.23.w1)

Encouraging healing by secondary intention

• In many cases (e.g. old, contaminated wounds) it may be necessary to leave the wound to close by secondary intention.
• These wounds are kept open and managed to promote the establishment of a healthy bed of granulation tissue. (P62.23.w1)
• Granulation tissue should develop at the wound edges and progress across the wound, with contracture and epithelialisation. (P62.23.w1)
• The application of topical preparations that encourage epitheliogenesis (stimulate healing) may be useful, e.g. Intrasite Gel (Smith and Nephew).
• Note: healing by secondary intention is slower, often with more scarring and loss of skin pliability. (P62.23.w1)
• Where possible, the use of dressings which promote healing may be used. 
  • Note: Many wild animal casualties, particularly adult mammals, may not tolerate dressings and bandages.

Honey

• Honey is recognised to be beneficial applied topically to infected wounds:
  •  The high osmolarity of honey and its consequent and ability to minimise water available to bacteria gives an antibacterial action.
  • Some types of honey such as manuka honey, have a slow, sustained production of hydrogen peroxide at very low concentration, producing an antimicrobial effect.
  • Some types of honey also have other components with demonstrable antimicrobial effects.
  • The low pH and high glucose content also may be stimulatory to macrophages.

  (J128.14.w1)

Antibiotics

• All wounds in wild animals should be considered to be contaminated and appropriate antibiotic treatment instigated.
  • In the field, commonly, penicillins are given, since these are effective against many of the microbes found on skin (and likely to contaminate wounds) and are available in long-acting preparations. (B345.4.w4)
  • When giving a single dose of procaine penicillin/benzathine penicillin, give 22,000 IU/kg of the benzathine penicillin G to ensure an adequate repository effect giving antibiotic cover for 5-7 days. (B345.4.w4)
  • Give no more than 5 mL at any one site, subcutaneously or into the large muscle masses of the hind legs. (B345.4.w4)
• With "cat-caught" puncture wounds it is particularly important to ensure that antibiotics  are likely to be effective against Pasteurella multocida.

(B345.4.w4, J15.17.w4, V.w5, V.w6, V.w26)

WOUND MANAGEMENT FOR BIRDS

GENERAL PRINCIPLES

It is important when managing wounds to recognize that a variety of factors may impede wound healing including:

• Severe protein deficiency.
• Chronic anaemia.
• Dehydration.
• Poor nutritional status.
• Presence of necrotic tissue (may physically impede migration of epithelial cells, and may harbour bacteria).
• Presence of blood clots (may physically impede migration of epithelial cells, and may harbour bacteria).
• Presence of foreign bodies, including e.g. non-viable bone as well as dirt etc.
• Sutures causing foreign body reaction (minimized by selection of appropriate suture material).
• Tissue destruction (due to desiccation, severe trauma or poor surgical technique).
• Poor vascular supply.
• Lack of immobilization of wounds over joint surfaces.
• Continual abrasion.
• Infection by pathogenic bacteria.

INITIAL ASSESSMENT OF SOFT TISSUE WOUNDS

• Take the history and perform a general physical examination.
• Take care to locate wounds, e.g. by parting the feathers.
• Note the location and extent of the injury.
• Estimate / record the age of the injury (e.g. skin discolouration due to bruising develops after 2-3 days and may persist for a week or longer.
• Note any associated fractures or luxations.
• Check blood supply and nervous supply to the affected area, particularly for wounds of the limbs.

TREATMENT OF FRESH UNCOMPLICATED WOUNDS

• May be treated by primary closure to produce first intention healing. (B13.40.w13, B14, P4.1990.w2)
• Haemorrhage must be controlled, e.g. by direct pressure. (B14)
• Primary closure should not be attempted on open contaminated wounds (B13.40.w13).
• N.B. Puncture wounds should not be sutured due to the risk of bacterial contamination.

TREATMENT OF OLDER AND/OR UNCONTAMINATED WOUNDS

These should be managed to allow secondary intention healing. Once infection has been controlled and a healthy granulation bed established it may be appropriate to suture the wound in some cases.

1) WOUND PREPARATION: Aim is to remove foreign material, devitalized tissues and potentially pathogenic microorganisms.

• Carefully pluck feathers, or trim feathers with fine sharp scissors to avoid tearing skin, to produce a 2-4cm healthy feather-free area of skin around the wound.
  • Plucking will encourage regrowth of feathers; if feathers are cut they will not regrow until the next normal moult. The minimum area should be plucked and great care is required to avoid tearing the skin.
  • N.B. plucking of feathers is painful; this may be best carried out on an anaesthetised bird if more than a few feathers are to be plucked.
  • N.B. Care should be taken not to damage the feather follicles and thereby prevent proper regrowth of feathers. This is imperative for the flight and tail feathers of birds of prey, and any other species with a high dependency on flight such as swifts and swallows. If there is any doubt, such important feathers should not be plucked until absolutely necessary (which could be due to damage to blood feathers or the proximity of physical damage). (V.w6)

  (B13.16.w11, B14, P19.2.w5, V.w5, V.w26)

• Gently irrigate with warm water or sterile isotonic saline to remove debris, blood clots and gross contaminants.
• N.B. in warm months check carefully for fly eggs/maggots: myiasis may lead to large quantities of soft tissue being consumed in just a few hours.
• Take samples for bacterial culture after removal of surface contaminants but before application of any antiseptics if bacterial infection is suspected.
• Lavage with 0.05% chlorhexidine diacetate solution or 0.5-1.0% povidone iodine solution, will provide antibacterial activity
• Hydrogen peroxide may be used for initial cleaning of dirty wounds, or as a sporicide if clostridial infection is suspected.
• Surgically debride non-viable and necrotic tissue, until viable, vascularized tissue is visible. (N.B. may have to debride several times over a period of days with old or complicated wounds).
• Achieve haemostasis.
• It is important to minimise the area of feathers removed when treating birds as these provide the bird with its protection against weather and water and loss of feathers may delay release until the feathers regrow. (P19.2.w5, V.w5)
•  

2) TOPICAL MEDICATION:

• Use as appropriate. See: Topical medication of Birds.

3) BANDAGING:

• If properly applied, bandages work "to provide an optimal environment for epithelialization and wound contraction with the fewest complications."  (P4.1990.w2). The functions of bandaging are to provide:

• Pressure to reduce dead space, swelling, oedema, haemorrhage.
• Protection from pathogenic microorganisms.
• Immobilization of the wound.
• Protection from desiccation.
• Protection from self mutilation or abrasion.
• Absorption of exudate.
• Debridement of the wound surface.
• Comfort for the bird.

• Three layers of bandaging are usually used, the different layers having different functions.

PRIMARY / CONTACT LAYER:

This is the most important layer for wound healing and may be adherent or non-adherent. The contact layer should be sterile, remain in place despite patient movement, provide a moist environment for the wound, be comfortable and assist in debridement.

a) Adherent dressings

• open weave or fine mesh gauze pads may be useful for the initial phase of treatment where excessive amounts of necrotic debris need to be removed by a process other than surgical debridement, or for wounds in which there is excessive exudate production. Wet -to-dry dressings, using sterile, saline-soaked gauze pads may be used to mechanically remove exudate and necrotic tissue.
• Adherent dressings disrupt the surface of the healing wound at each dressing change, and the very moist environment produced by wet-to-dry dressings may lead to tissue maceration.

b) Non-adherent dressings are used in the granulation and epithelialization phase of wound healing.

• Traditional non-adherent dressings - cotton dressings with a non-adherent film, and petroleum-impregnated fine-mesh gauze dressings:

• These are widely available and inexpensive.
• Allow excess fluid to be absorbed into the secondary layer.
• Cotton non-adherent film dressings in practice do stick to wounds if left in place for more than 2-3 days; as a result when the dressing is removed disruption of the healing surface and bleeding may occur.
• Petroleum-impregnated fine-mesh gauze dressings are not ideal for use in birds as they soil the feathers; work in dogs also indicates they can slow the rate of wound epithelialization.
• Both types may slip from the wound despite careful bandaging.

• Modern non-adherent dressings have been developed which keep the wound surface moist, prevent scab formation and increase the rate of re-epithelialization (in comparison to traditional dressings):

i) Occlusive hydrocolloid or hydroactive dressings.

• These dressings adhere to skin but not to wounds, are semi-flexible, opaque, and impermeable to moisture vapour and oxygen.
• They absorb fluid and exudate, producing a moist gelatinous cover over the surface of the wound. 
• Despite their adhesive qualities, additional bandaging is usually required to hold these dressings in place.
• May leave a slightly sticky residue on skin and feathers.
• Some hydrophilic dressings may be sufficiently rigid to be sutured lightly into position, and may assist granulation of quite large areas.
• Dressing should be changed every 2-3 days initially, once a week when a healthy granulation bed has been established.
• Dressing must be changed if quantity of exudate results in leakage around the edge of the dressing (to prevent bacterial invasion).
• Useful for e.g. slow-healing, granulating wounds over the keel and carpal joints, and for granulating bumblefoot lesions, also for extensive wounds with considerable exudate production and wounds requiring debridement.

ii) Semi-occlusive moisture-vapour permeable dressings.

• Thin, transparent flexible polyurethane membrane.
• Stick to clean, dry, detergent-free skin but not to the wound.
• May be conformed to even difficult-to-bandage areas (e.g. head).
• Permeable to oxygen and moisture vapour.
• Impermeable to water and bacteria.
• Allow fluid and exudate to accumulate under the dressing.
• Maintain a moist, aerobic environment
• Maintain a sterile surface (if wound aseptically cleaned beforehand) while margins remain sticking to surrounding skin.
• Prevent desiccation and scab formation, reduce pain associated with the desiccation of nerve endings
• Promote leukocyte debridement of the wound surface, and migration of epithelial cells from the wound edges (epithelialization), and thereby speed healing.
• Allow visual monitoring of the wound and both qualitative and quantitative assessment of the production of exudate.
• Dressing should be changed every 2-3 days initially, once a week when a healthy granulation bed has been established.
• Dressing must be changed if quantity of exudate results in leakage around the edge of the dressing (to prevent bacterial invasion).
• Use should be discontinued if excessive redness, swelling and/or odour indicates gross infection.

SECONDARY / MIDDLE LAYER:

Functions:

• absorption of fluids and wound exudate
• protection of the wound from additional trauma
• immobilization of the wound while healing occurs

Conforming gauze bandages are usually used as the secondary bandage layer. N.B. figure - of -eight wing bandages should provide padding and immobilization due to their bulk, not by using a very tight bandage. Joint damage, vascular compromise and delayed healing may all be seen if bandages are improperly applied.

TERTIARY / OUTER LAYER:

Function: to hold the bandages in place. May also be used to protect the bandages from the attentions of the patient.

• Self-adhesive bandages are commonly used. These are light-weight, breathable, conform well to avian anatomy e.g. limbs, and are generally well tolerated. White adhesive tape may be used in patients with a tendency to remove their bandages.

(P4.1990.w2, B11.3.w10, B13.16.w1, B14, B116.30.w3)

• There may be a conflict between the indications for bandaging a wound and the requirement of the birds for access to water for swimming.
• If wound management precludes constant access to water, the possibility of daily access to clean water prior to application of a new bandage should be considered.

(B11.36.w4, B13.19.w12, V.w5)

• If the wound is still bleeding, control bleeding by applying direct pressure to the wound or to the appropriate pressure point. (D249.w13)
• Clip the hair around the wound. (B64.26.w5, D249.w13)
• Flush the wound thoroughly with a weak solution of povidone iodine or chlorhexidine. (D249.w13)
  • It is particularly important to ensure that any pus (in an infected wound) or maggots (in a wound with myiasis) are flushed out of the wound. (D249.w13)
    • See Myiasis (with special reference to Waterfowl, Hedgehogs, Elephants and Bears) (Parasitic Disease)
  • Do NOT cleanse deep wounds with hydrogen peroxide or alcohol, as this may cause tissue injury and increase the chance of infection developing. (D249.w13)
• Debride any dead tissue. (B64.26.w5, D249.w13)
• Apply topical antibiotics. (B64.26.w5)
• Parental or oral antibiotics are recommended for five to seven days. (B16.9.w9)
• If necessary, suture the wound using an absorbable suture material (B64.26.w5, D249.w13)
  • Absorbable sutures should be used for closure of the skin as well as deeper tissues, so that there is no need to remove the sutures. (B345.4.w4)
  • It is particularly important to use absorbable sutures in field situations when the animal will be released immediately. (B345.4.w4)
  • Use a tapered needle to suture internal muscle layers on a deep wound. (B345.4.w4)
  • Use a cutting needle to suture the skin. (B345.4.w4) 
• Note: 

  • Even quite large and infected wounds in adult polar bears (e.g. a suppurating wound more than 30 cm² and another 18 cm² open wound on one male, and a 50 cm long 6 cm deep wound on the upper thigh of another male, may heal well with minimal scarring. (J30.64.w1)

• Note:

  • Note: Many wild animal casualties, particularly adult mammals, may not tolerate dressings and bandages.
  • Bears are strong and may interfere with external devices. (B64.26.w5)
  • Cubs may be prevented from interfering with casts etc. by fitting an Elizabethan collar. (B16.9.w9) 

• History and Documentation - General
• Physical Examination of Birds
• Physical Examination of Mammals
• Accommodation Design for Birds - Temporary / Hospital Accommodation
• Accommodation Design for Mammals - Temporary / Hospital Accommodation
• Wildlife Casualty Accommodation (with special reference to UK Wildlife)
• Topical Medication of Birds
• Bandaging & Splinting in Birds

FOR BIRDS

"It has been suggested that all birds suffering from trauma and disease can be assumed to be at least ten percent dehydrated." (B13.39.w16)

Fluid therapy is a vital part of initial patient stabilization, whatever the presenting problem of the patient in question. Dehydration and electrolyte losses may be severe and even life-threatening in an ill or injured bird.

AIMS

• Correct any existing fluid deficit.(B119.w2)
• Correct and existing electrolyte disorders.(B119.w2)
• Provide daily requirements.(B119.w2)

CONSIDER

• Hydration status.(B119.w2)
• Electrolyte balance.(B119.w2)
• Acid-base status.(B119.w2)
• Haematology and biochemistry.(B119.w2)
• Caloric balance.(B119.w2)

SIGNS OF DEHYDRATION

• Ulnar artery and vein easily compressible, with small diameter and slow (more than 1-2 seconds) filling time indicates dehydration of more than 7% (B119.w2).
• Dry mucous membranes (B119.w2).
• Sunken eyes. (B119.w2)
• Reduced skin elasticity (B12.39B.w9)
• General: weakness, reluctance to move, signs of central nervous system depression (B119.w2).
• Serum osmolarity (B119.w2)
• Plasma urea (may be greatly increased)(B119.w2)
• Packed cell volume. May not reflect acute changes in hydration status (B119.w2)

ROUTE

• Oral, subcutaneous, intravenous or intraosseous. (B119.w2)
• Oral fluids are appropriate in an individual which is conscious and able to perch/stand and keep its head up. Stressed individuals may tolerate the administration of only small volumes e.g. 5-10ml/kg initially. The frequency of administration may be decreased, and the volume increased gradually. (B119.w2) (See: Gavage / Tubing of Birds)
• Subcutaneous fluids are appropriate for individuals which are not critically compromised. (See: Subcutaneous Injection of Birds).
• Intravenous fluids are appropriate for birds with hypotensive or hypovolaemic shock, and for critically ill individuals (See: Intravenous Injection of Birds). (B119.w2)
• Intraosseous fluids are appropriate e.g. for individuals with very small or collapsed veins (P3.1999b.w2, B119.w2).
• Intraosseous and intravenous routes provide rapid expansion of circulatory volume and rapid kidney perfusion: these routes should be used in shock or haemorrhage (P3.1999b.w2).

CALCULATION OF REQUIREMENTS

• Fluid deficit in millilitres may be calculated as equal to normal body weight in grams, times 0.1 (i.e. one tenth of body weight) for estimated 10% dehydration.
• Maintenance fluids required may be estimated at 50ml/kg/day (40-60ml/kg/day).
• Fluid therapy should be given to correct 1/4 to1/2 of the deficit within the first 4 to 6 hours, with the remaining replacement volume given over the following 20 to 28 hours (B119.w2); correction of 50% of the estimated deficit in the first 24 hours and the remainder of the deficit over the following 48 hours (together with the maintenance requirement) (B11.3.w10).
• "Rule of thumb": 3% of body weight three times daily (allows for 10% dehydration plus maintenance requirements (P7.1.w6). Normal saline warmed to 39 °C may be given by subcutaneous injection at 20.5ml/kg body weight four to five times daily (B14).
• N.B. Maximum acute fluid load tolerated by a healthy individual is 90ml/kg/hour, but most avian patients cannot tolerate such a high rate.
• Lactated Ringer's solution is the fluid of choice, protecting renal function better than do sugar solutions. 5% dextrose is not considered a satisfactory replacement solution since free water is left as the dextrose is metabolized.
• Fluids should be warmed to 96 °F (37 °C) before being administered to anaesthetized birds, to avoid hypothermia. (B13.39.w16); (38-39 °C (100.4-102.2 °F)) (P3.1999b.w2).

TYPE OF FLUIDS

Crystalloids are used much more commonly than colloids.

• Lactated Ringer's solution (LRS) (Hartmann's solution): Useful general-purpose fluid replacer - fluid replacer of choice for most situations. Rapidly restores vascular volume. 0.1-0.3 mEq/kg bodyweight potassium (as concentrated potassium chloride) should be added if LRS is used for maintenance. Most drugs may be added to LRS, but sodium bicarbonate should not be added (B119.w2, P3.1999b.w2).
• Normal saline (0.9% sodium chloride): Useful for initial fluid deficit restoration and for support of an individual with regurgitation. Not good for fluid maintenance in birds. Must add 0.1-0.3 mEq/kg/day supplemental potassium chloride salts when used for re-expansion of circulatory volume. Most drugs may be added. Improves diuresis and therefore promotes the excretion of potassium. Restores sodium deficit in individuals with hyponatraemia. For individuals with hypernatraemia, half-strength saline (0.45%) with 2.5% dextrose or 5% dextrose should be used (B119.w2).
• Dextrose solution: 5%, 10% or 50%. 5% dextrose is rapidly absorbed if given orally. N.B. 5% dextrose is a hypotonic solution (252 mOsm/L), therefore must be used with caution if given by intravenous, subcutaneous or intraperitoneal routes.  Once the dextrose is absorbed (leaving the water) a shift in electrolytes will occur to restore osmolar balance. 10% or 50% solution may be used to treat hypoglycaemia. Initial dose of 1ml/kg 50% dextrose may be used intravenously. N.B. Disadvantage of dextrose is the promotion of cellular acidosis (B119.w2).
• Bicarbonate: Acidosis is usually corrected by rehydration. Severe acidosis may require use of bicarbonate. Ideally, dose is calculated on the basis of blood gas analysis. In the absence of a blood gas reading, 0.5-1.0 mEq/kg sodium bicarbonate diluted in 10 to 20 ml/kg fluids may be given (subcutaneous or intraperitoneal). (B119.w2, P7.1.w6).
• Hypertonic saline: 4-5 mL/kg, followed by normal crystalloids may be used in an emergency (P3.1999b.w2).
• Colloids: e.g. Dextrans, hetastarch.

• Little work has been done on the use of colloids in birds.
• Have been used safely in raptors at approximately 10 mL/kg/hour.

(P3.1999b.w2).

• Bears may require fluids when obviously dehydrated (B16.9.w9, B64.26.w5, P62.18.w1) or while undergoing prolonged surgical procedures. (P3.2006a.w1, P62.18.w1)
  • Intravenous catheters may be placed in the cephalic (P62.18.w1) or medial saphenous (V.w6) veins to give fluids intravenously. 
  • Lactated Ringer's solution and 5% dextrose may be given as fluid support during surgery. (P62.18.w1)
• Fluids may be given as supportive treatment for bears which have diarrhoea and vomiting and/or are refusing food and water. (J3.145.w4, J11.83.w1, J142.19.w1) 
  • Cubs with bacterial gastroenteritis [Bacterial Gastroenteritis in Bears] may need intravenous or subcutaneous fluid therapy with lactated Ringer's solution (Hartmann's Solution). (B64.26.w5)
  • In cases of severe dehydration with gastritis, supportive fluid therapy intravenously: (B16.9.w9, B64.26.w5) isotonic saline or saline dextrose, 50-100 mL/kg body weight (B64.26.w5). 7.5-10 mL per kg body weight. (B16.9.w9)

• Gavage / Tubing of Birds
• Intraosseus Injection of Birds
• Intravenous Injection of Birds
• Subcutaneous Injection of Birds
• Subcutaneous Injection of Mammals
• Intravenous Injection of Bears

• N.B. Whenever an anaesthetic is undertaken, the anaesthetist must be familiar with emergency protocols. Consideration must be given as to the availability of equipment required to monitor the anaesthetic plane of the animal being anaesthetized and any equipment/drugs required for revival. It is advisable to calculate the doses of any revival agents which may be required in an emergency BEFORE COMMENCING the anaesthetic. An accurate body weight should be determined to allow accurate dosage. (P3.1999b.w2, V.w6).

• Always consider whether the risks of the anaesthetic are outweighed by the benefits gained by the immobilization. (P106.2007.w5)
• The ideal anaesthetic produces a smooth, reliable induction, provides relief of the patient from fear and anxiety, produces appropriate levels of restraint, analgesia and relaxation for the procedure to be performed, for the length of time required for the procedure, and a rapid, uneventful and full recovery.
• The required degree of restraint and relaxation may vary from minimal, e.g. for radiography, to considerable for orthopaedic or abdominal surgery. Both intra-operative and post-operative analgesia are usually required for surgery, and anaesthetic agents which provide good analgesia often allow better muscle relaxation and restraint; they may also allow maintenance on a lower (and safer) anaesthetic plane.
• In many circumstances it is necessary to anaesthetise the animal without performing a pre-anaesthetic physical examination or any other tests to determine health status.
• During anaesthesia, the animal should be placed in a position which promotes respiration and minimises the risk of aspiration of saliva or regurgitated material.
• The limbs should be positioned to minimise the development of circulatory impairment. 

(B11.9.w20, B13.49.w16, B14, B121, B486.11.w11, J1.5.w5, P3.1999b.w2, P106.2007.w5, V.w5, V.w6)

Further information is available in this section on WATERFOWL Anaesthesia and BEAR Anaesthesia (see below).

HANDLING AND RESTRAINT

• See also Manual Restraint information in the Bird Handling & Movement - Holding & Carrying.
• Waterfowl show a very variable response to stimuli; feather follicles are sensitive and there may be violent reaction to feather plucking, but little reaction to suturing or cutting the skin, or even handling viscera. The bill, head and feet are also sensitive. (B10.26.w3, B11.9.w20, B13.46.w1, B14).

PRE-ANAESTHETIC PREPARATION

• Pre-anaesthetic handling should be minimal, as gentle as possible and as stress-free as possible. (B11.9.w20)
• A bird should be in as good a state of health as possible before being anaesthetized  (B11.9.w20). A blood sample should be taken if there is any doubt as to the health status of the bird, if time allows. Minimum clinical profile of AST, bile acids, LDH, urea, uric acid, full haematology and clotting time is suggested (B14).
• Hydration status should be considered: fluid therapy should be given before anaesthetic if the PCV is above 55%. If isoflurane anaesthesia is used, fluid therapy may be started immediately after induction, rather than prior to induction. (B11.9.w20, B14)
• Possible hypoglycaemia: intravenous 5% glucose should be given before, during and following surgery if the blood glucose level is below 16mmol per litre. (B11.9.w20)
• Liver and kidney functions should be considered: halothane is contra-indicated with liver dysfunction (and in debilitated birds); ketamine is contraindicated with kidney dysfunction.
• Starvation for two to six hour prior to surgery has been suggested to reduce the risk of oesophageal reflux and inhalation prior to surgery (B37.x.w1).
• Weight should be determined accurately prior to anaesthetic for dose calculation with injectable agents. If inhalation induction is to be used, weight may be determined after induction, but is still required e.g. for fluid therapy calculations (B11.9.w20).
• The number of contour feathers removed to provide a clean surgical site should be minimized to retain waterproofing and allow an early return to water.
• Birds must be kept warm before, during and after anaesthetic. Cooling may lead to hypothermia, which may be fatal, and may predispose to cardiac arrhythmias, as well as increasing recovery time. Vetbed, towels or similar materials, or a heating pad, should be placed under the bird. The use of wetting agents such as surgical spirit should be minimized due to their chilling effect. Consideration should be given to the use of disposable adhesive drapes such as Opsite (Smith & Nephew) to minimize the area which must be prepared for surgery while maintaining an adequate clear surgical site. N.B. cool anaesthetic gases flowing through the respiratory tract also act to cool the bird.(B11.9.w20, B14)
• Profuse salivation is common in anaesthetized waterfowl. The use of an anticholinergic agent such as atropine or glycopyrrolate is not recommended, as this results in thicker secretions.

(B11.9.w20, B13.39.w16, B14, B37.x.w1)

ANAESTHETIC MONITORING

Constant monitoring of depth of anaesthesia, heart, respiration and if possible oxygenation is important; temperature should also be monitored.

• Cardiac: doppler probe under tongue, against carotid artery or on recurrent ulnar artery, or oesophageal stethoscope, or ECG (leads placed over distal lateral tarsometatarsus and carpal joint of each wing, with atraumatic clamps or silver needles); pulse - e.g. radial artery. Normal heart rate in waterfowl is quite variable, e.g. 180-230bpm in the Pekin duck (Anas platyrhynchos domesticus - Domestic duck). Changes in heart rate may give more information than absolute rate (B11.9.w20, B13.46.w1, B14).
• Oxygenation: Oximeter may be used over tibiotarsal bone (appears most consistent and reliable), wing web, toe or tongue.  Arterial oxygen saturation should be maintained well over 85%: level under 80% may be dangerous.  Pulse oximeter will also give pulse rate (B13.39.w16, B14).
• Temperature: rectal or oesophageal thermometer. Normal body temperature of waterfowl is approximately 39-41.6°C. N.B. Longer recovery time with lower body temperature, as well as myocardial depression. (B11.9.w20, B13.46.w1, B14).
• Tube patency should be checked regularly - may become blocked by secretions. Changing the tube every 20 minutes during anaesthesia has been suggested (B37.x.w1).
• Respiration - rate and excursion should be noted; respiration should be slow and regular. Normal respiratory rate is quite variable in waterfowl - may be e.g. 13-40 breaths per minute in geese and swans, or e.g. 30-95 breaths per minute in ducks (B11.33.w1, B13.46.w1). Depth, rate and pattern of respiration should be noted, particularly any changes. Rapid, jerky respiration or hyperventilation indicate ensuing problems. Slow irregular respiration with too deep anaesthesia. Increased respiratory rate/depth may indicate lightening of anaesthetic plane, stimulation (pain), difficulty in breathing (e.g. due to a blocked tube) or elevated paCO2. Rapid, shallow or intermittent respiration may also indicate too deep anaesthesia.  N.B. Drapes may make visual monitoring difficult - clear surgical drapes facilitate monitoring, as does the use of a small anaesthetic bag. Apnoea monitors may be used (e.g. Imp respiratory monitor, IMP Electronics; apALERT apnoea monitor, MBM Enterprises, Australia) but may not register respiration, especially in small birds. They can only be used if the bird is intubated, and care must be taken that the monitor does not kink the tube. Respiratory rate should not fall below 12-15 breaths per minute for large birds such as swans, or below 25-50 breaths per minute for birds weighing less than 500g (should be not less than half of normal resting rate), or hypercapnoea may develop (B11.9.w20, B13.39.w16, B14, B37.x.w1).
• Reflexes: loss of voluntary motion, but retained palpebral, corneal and pedal reflexes in light anaesthetic plane (B13.49.w16), slow to absent pedal reflex and wing reflex in surgical plane of anaesthesia, loss of corneal reflex indicates deep anaesthesia (B13.49.w16). Wing flutter may indicate the bird is becoming light (B13.39.w16).
• Capnography - measurement of end tidal carbon dioxide level may be useful, but is not standard at present (B14).

ORAL SEDATION

• In certain circumstances sedation with an orally absorbed drug may be an appropriate means of waterfowl capture. This method may be used to capture an individual bird (e.g. one duck in a park situation), using a bait which can be targeted at that individual, such as a piece of bread, or a group of waterfowl, for example by using baited grain.
• In using oral bait to sedate/anaesthetize waterfowl for capture it is particularly important to ensure that the bird(s) are watched closely with rapid intervention to prevent drowning or attack by other individuals. This method must be used with extreme caution if the possibility exists that the birds may fly away from the site between ingestion of the drug and it having its effect. Other potential hazards include a lack of control over the amount of drug consumed by each individual, variability in the responses of different individuals to a given dose (possible effects of age, sex, health status and degree of stress), and effects on non-target species consuming the bait. Additionally, there is little data on the effects of orally administered immobilizing agents on behaviour, physiology and survival. The possibility of residues must also be considered if birds may be used for human consumption.
• Drugs which have been used or tested for use as oral immobilization agents include alpha-chloralose, methoxymol, metomidate, pentobarbital sodium, secobarbital sodium, thiopental sodium and tribromoethanol. A combination of alpha-chlorulose and tribromoethanol has also been used successfully.
• (See: Oral Sedation of Waterfowl).

(J2.8.w1, J4.161.w1, B13.46.w1, B36.4.w4, B123).

LOCAL ANAESTHESIA

• Frequently sufficient for superficial procedures.
• Safe if dose is carefully calculated (B14).
• Gross overdose may occur in small birds if dose not calculated.
• Lidocaine (Lignocaine) hydrochloride (2%) usually safe and effective, although general depression may occur with high doses. 1-3 mL may be used in birds greater than 2kg body weight, and up to 1 mL in a 400 g bird. Solution may be diluted to give 0.5% solution. Preparations with adrenaline are recommended to limit absorption rate. Lignocaine ointment may be used around the vent following cloacal prolapse (B14). Maximum dose 4 mg/kg (B23.39.w3).
• Use of 2% procaine, 1ml in ducks, 3ml in swans reported to provide good local anaesthesia with few problems. (B13.46.w1). Narrow safety margin, recommended dilution to produce 0.2% solution, after which 1-2 mL/kg may be used (B14).
• Xylocaine hydrochloride has also been considered a safe local anaesthetic for use in waterfowl (B10.26.w3).

INJECTABLE ANAESTHESIA

• Often marked inter-species and intra-species variability in response. (J13.51.w1, B13.39.w16).
• Accurate weighing important for correct dose calculation (B11.9.w20, B14).
• Anaesthetic dose may be difficult to control, and irreversible after administration. (J13.51.w1, B13.39.w16).
• Predispose to intraoperative hypothermia and hypoglycaemia: further exacerbated by prolonged recovery time (J13.51.w1, B13.39.w16).
• Injectable anaesthetic drugs and drug combinations which have been used in waterfowl include propofol (Rapinovet), alphaxolone/alphadolone (Saffan), ketamine, ketamine/xylazine, ketamine/medetomidine, ketamine/diazepam.
• Propofol (8mg/kg) may be induction agent of choice if mask induction with isoflurane is not possible (B37.x.w1), and it has been suggested that it may be preferable to isoflurane in some field situations (J1.36.w1), although it also has been suggested that the duration of action of propofol is too short to be of practical use in birds (B11.9.w20).
• Details of the use of individual injectable anaesthetic agents are given in:

• Alphaxolone / Alphadolone Anaesthesia in Waterfowl
• Ketamine Anaesthesia in Waterfowl
• Ketamine/Diazepam Anaesthesia in Waterfowl
• Ketamine/Medetomidine Anaesthesia in Waterfowl
• Ketamine/Xylazine Anaesthesia in Waterfowl
• Propofol Anaesthesia in Waterfowl

• N.B. Injectable anaesthetic agents may provide a health hazard for the anaesthetist and other people exposed to these anaesthetic agents. Care should be taken to avoid self-injection. Several drugs may be absorbed through the skin and/or mucous membranes and care should be taken to avoid splashing of drugs onto the skin, lips or eyes. If such contact does occur the relevant area should be irrigated with copious amounts of water (B121).

GASEOUS ANAESTHESIA

• Precisely controllable, little species variation, little or no metabolism required.
• Should always be used with precision vapourizer.
• N.B. greater efficiency of avian lungs produces greater sensitivity to small changes in anaesthetic gas concentration (B11.9.w20).
• Carrier gas flow 3-5 litres/minute.
• Relatively high level for induction (e.g. isoflurane at 4.0 to 5.0%), allows rapid induction (may be within four to five breaths) (B11.9.w20).
• Lower level for maintenance.
• Intermittent positive pressure ventilation  may be required to maintain adequate oxygenation (B11.9.w20, B13.39.w16)
• Isoflurane is generally considered to be the anaesthetic agent of choice for birds for both induction and maintenance. N.B. it has been suggested that propofol may be more suitable for some field situations (J1.36.w1).
• Always leave on oxygen for a time after turning off anaesthetic agent at the end of the procedure (B14).
• Details of the use of individual gaseous anaesthetic agents are given in:

• Halothane Anaethesia in Waterfowl
• Isoflurane Anaesthesia in Waterfowl
• Methyoxyflurane Anaesthesia in Waterfowl

• N.B. Exposure to gaseous anaesthetic agents may have health implications for the anaesthetist and other people exposed to the anaesthetic agents. It is suggested that "reasonable measures should be taken both to reduce the risk of serious contamination of the atmosphere with inhalation anaesthetics and to remind operating theatre staff of possible hazards" (B121).
• The "reasonable measures" include filling vapourizers using proper filling apparatus or funnels, outside the operating theatre and preferably out-of-doors, turning vapourizers off when not in use, taking care when handling anaesthetic agents, using low flow systems when possible, using scavenging of waste gases/vapours, using endotracheal intubation rather than a face mask when possible and checking breathing circuits regularly for leaks (B121).

(B11.9.w20, B13.39.w16, B13.46.w1, B14, B37.x.w1).

ANAESTHETIC EQUIPMENT AND USE

Circuits:

• Non-rebreathing circuit with small dead-space and low resistance recommended, e.g. modified Ayres T-piece or mini-Bain system.
• Bain co-axial circuit may warm inflow gases and provide humidification using expired gases of patient.
• IPPV (intermittent Positive Pressure Ventilation) may be provided with reservoir bag. Important to maintain high oxygen flow rate during bird anaesthesia.
• Flow rate should be at least three times normal minute volume for the individual: minute volume of 2.5 kg chicken is 770 mL/minute, suggested flow rate 3 litres per minute for birds of this general size. Minute volume of American black duck (Anas rubripes - American black duck) at rest 815.4 mL/minute (body weight 1.026 kg).
• Scavenging system should be used to protect operating room personnel from exposure to anaesthetic gases.

(B11.9.w20, B14, B13.39.w16).

Ambu bag:

• Self-inflating resuscitation apparatus
• May be used for ventilation during anaesthesia in the field.
• Paediatric size may be suitable e.g. for ducks; neonatal size may be required for small birds.
• Squeeze to give visible expansion of the thorax, twenty times a minute (every five seconds).

(J1.36.w1, P3.1999.w2)

Face mask: 

• Used for induction and may be used for maintenance in very short procedures (up to 10-15 minutes) (B11.9.w20, B13.39.w, B13.46.w1). Choose to fit comfortably with minimal dead space. Commercially-available transparent masks or a mask created e.g. from a 60ml syringe case may be modified using a latex glove or tape to reduce leakage.

Intubation:  (Used once the bird has been induced, although may not be required for very short procedures.)

• Reduces dead space, maintains airway.
• Glottis is visible just behind the tongue.
• Intubation is easier if the tongue is pulled forwards.
• Usually soft uncuffed tube, but cuffed tube, inflated with care, may be chosen for waterfowl, to avoid inhalation of regurgitated fluids, particularly for e.g. flushing oesophagus and gizzard.
• Care not to over-inflate due to risk of pressure necrosis (birds have complete tracheal rings and fragile tracheal mucosa).
• Care to ensure neck extended in long-necked birds to avoid risk of trachea folding over the edge of the tube with resultant partial or complete obstruction of the airway.
• Risk of blockage of tube with mucus (copious secretions by waterfowl during anaesthesia). Risk of blockage is greatest in small birds, due to small diameter tube. Tube should be checked regularly throughout anaesthesia. Changing the tube every 20 minutes has been suggested (B37.x.w1).
• Allows scavenging of waste gases.
• Facilitates artificial ventilation.

(B11.9.w20, B13.46.w1, B37.x.w1, P3.1999b.w2, P7.1.w4)

AIR SAC INTUBATION

• Useful for surgery of the mouth/bill, or in a bird with tracheal obstruction.
• Usually placed in an anaesthetized bird. May be placed in an unanaesthetised bird with tracheal obstruction.
• Placement similar to normal site for endoscopic examination e.g. for surgical sexing.

• Surgically prepare site. (Minimal skin preparation with alcohol may be used in an emergency).
• Extend leg caudally.
• Stab incision of skin over sternal notch, or snick incision with scissors, with points then spread to enlarge hole.
• Thrust straight artery forceps (haemostats)  through muscle into abdominal cavity, then opened slightly to allow insertion of cannula, or trochar may be used, to gain access to air sacs.
• Place large tube of inert material (e.g. French 14G silastic tubing, or commercially available air sac cannula - Cook Instrumentation) into airsac to maximum depth of 1cm (to minimize risk of liver or spleen damage by the tube).1-2.5 inches 2.5-7cm (P3.1999.w2)
• Suture in place using purse-string suture transfixing the tube (monofilament non-adsorbing suture material).
• Attach end of tube to anaesthetic circuit.

• Intermittent positive pressure ventilation recommended while anaesthetized: may stop breathing due to hypocapnoea, and not restart spontaneous breathing until airsac perfusion is stopped and blood paCO₂ rises.
• Tube may be removed postoperatively, or may be left in place e.g. if syringeal aspergillus plug or other dyspnoic problem.

(B11.9.w15, B13.39.w16,