Bacterial Mastitis in Rabbits 

Disease Summary

• Septic mastitis in rabbits is a bacterial infection of the lactating glands. This can be the result of trauma, ascending infection via dirty bedding, or haematogenous spread. (B603.3.w3, B609.2.w2)
• It is most commonly found in heavily lactating does (B602.19.w19)
• It is a potentially life-threatening infection and can lead to septic shock. (B602.19.w19, B609.2.w2)
• Mammary gland abscesses can occur in non-lactating does as a result of trauma or haematogenous spread. (B609.2.w2)

Alternative Names (Synonyms)

• Blue breast (B600.9.w9, B604.5.w5)
• Caked udder (B604.5.w5)
• Septic mastitis.

See also: 

• Cystic Mastitis in Rabbits
• Staphylococcosis

Disease Type

Infectious/Non-Infectious Agent associated with the Disease

• Commonly Streptococcus spp., Staphylococcus spp. or Pasteurella spp. (B602.18.w18)
• Staphylococcus aureus - this is the most common organism involved in this condition. (B64.22.w8, B601.9.w9, B602.19.w19, B603.3.w3, B609.2.w2, J34.24.w3)
• Streptococcus sp. (B64.22.w8, B601.9.w9, B602.19.w19, B603.3.w3, B609.2.w2, J34.24.w3)
• Pasteurella sp. (B601.9.w9, B602.19.w19, B603.3.w3, B609.2.w2, J34.24.w3)
• Trauma to the teats may allow secondary bacterial infection. (B602.19.w19, B609.2.w2)
  • Sharp projections in nest boxes. (B10.45.w47)
  • Rough bedding (B10.45.w47)
  • Nipple injuries due to the teeth of suckling offspring. (B10.45.w47)
• Poor hygiene (B602.19.w19, B609.2.w2, J29.10.w2)

Infective "Taxa"

• Pasteurella multocida
• Staphylococcus aureus
• Staphylococcus spp.
• Streptococcus sp.

Non-infective agents

Physical agents

• Non-specific physical trauma
• Faecal - Urine contamination of substrate

References

Disease Author

Referees

Major References / Reviews

Code and Title List

Other References

Code and Title List

Detailed Clinical and Pathological Characteristics

Clinical Characteristics

• Depression, anorexia, lethargy (B601.9.w9, B602.19.w19, B609.2.w2, J34.24.w3, J213.5.w1)
• Polydipsia, polyuria (B609.2.w2)
• Fever. (J34.24.w3, J213.5.w1)
• There may have been pseudopregnancy, e.g. signs of nest building and hair pulling. (B609.2.w2)
• Rejection of young. (B601.9.w9)
• Illness or death in the suckling young. (B609.2.w2, J34.24.w3)
• Sometimes progressing to septicaemia and death of the doe. (J34.24.w3, J213.5.w1)

Clinical examination findings

• Exudation and suppurative inflammation around the teats. (J3.114.w9)
• Warm, swollen, firm, erythematous, painful mammary gland(s) - one or multiple glands can be affected. (B601.9.w9, B609.2.w2, J29.10.w2, J213.5.w1)
  • May be localised abscesses or more diffuse infection. (J34.24.w3)
• The affected teat will initially be pink from hyperaemia and then may turn blue or purple due to vascular stasis. (B602.19.w19, B609.2.w2)
• Haemorrhagic or purulent fluid can be expressed from the affected glands. (B609.2.w2)
• Fever. (J29.10.w2, J34.24.w3)
  • Fever and dehydration if there is systemic involvement. (B601.9.w9, B609.2.w2)
• Abscessation of the gland(s). (B609.2.w2)
• "An outbreak of S. aureus infection in a rabbitry was associated with a pustular, exudative dermatitis in the young and mastitis in lactating does". (B608.21.w21)
• Note: Abscessation may lead to loss of the gland, septicaemia and death. (B603.3.w3, B609.2.w2)

CBC and Biochemistry

• CBC: 
  • Often this is normal or there is a lymphopenia. 
  • A neutrophilia and left shift are not common. 
• Azotaemia, electrolyte disturbances, and increase in ALT:
  • These can all be abnormal in rabbits that have septicaemia or severe dehydration. 
• See: Clinical Pathology of Lagomorphs

(B609.2.w2)

Incubation

• --

Mortality / Morbidity

• --

• Can be fatal. (J34.24.w3)
  • Abscessation may lead to loss of the gland, septicaemia and death. (B603.3.w3, B609.2.w2)
  • Prognosis is fair to guarded with treatment but it does depend on the severity of disease. (B609.2.w2)

Pathology

• Histopathology: congestion, haemorrhage and dense polymorphonuclear leucocyte infiltration of mammary tissue. (B614.15.w15)

Human Health Considerations

Disease has been reported in either the wild or in captivity in:

• Domestic rabbits. (B601.9.w9, B602.19.w19, B609.2.w2, J34.24.w3, J213.5.w1)

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Host species with further information available are listed below:

Host Species List

• Oryctolagus cuniculus domesticus - Domestic European rabbit

(List does not contain all other species groups affected by this disease)

Disease has been specifically reported in Free-ranging populations of:

• --

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Host species with further information available are listed below:

Host Species List

• --

(List does not contain all other species groups affected by this disease)

General Information on Environmental Factors/Events and Seasonality

• Often asociated with poor hygiene. (B602.19.w19, B609.2.w2, J29.10.w2)

Regions / Countries where the Infectious Agent or Disease has been recorded

• --

Regions / Countries where the Infectious Agent or Disease has been recorded in Free-ranging populations

• --

General Information on Investigation / Diagnosis

• A presumptive diagnosis is often made based on the clinical signs. (B601.9.w9)

Express the fluid or milk from the teats

• In septic mastitis, macrophages or degenerate neutrophils with intracellular bacteria may be found. (B609.2.w2)

Bacterial culture and sensitivity 

• A sample should be taken from expressed fluid/milk or from the wall of the abscess. (B601.9.w9, B609.2.w2)

Firm needle aspirate of firm masses 

• Useful to differentiate abscess from mammary neoplasia although it may give misleading results if the tumour has necrotic, septic foci. (B609.2.w2) 

Serology for Pasteurella

• Unfortunately, the usefulness of this test is severely limited and often not helpful in diagnosing pasteurellosis in the pet rabbit. (B609.2.w2)
• An ELISA is available and will report results as high positive, low positive, or negative:
  • Positive result: even if the result is high, it only indicates a prior exposure to the bacteria and then the development of antibodies. It does not confirm active infection. Low positive results can occur due to a cross-reaction with another nonpathogenic bacteria giving a false-positive result. (B609.2.w2)
  • Negative result: false negative results are common if it is early infection or if there is immunosuppression. (B609.2.w2)

CBC and Biochemistry

• CBC: 
  • Often there is a normal or lymphopenia. (B609.2.w2)
  • A neutrophilia and left shift are not common. (B609.2.w2)
• Azotaemia, electrolyte disturbances, and increases in ALT:
  • These can all be abnormal in rabbits that have septicaemia or severe dehydration. (B609.2.w2)

See: Clinical Pathology of Lagomorphs

• Environmental Assessment
• History & Documentation
• Physical Examination of Mammals
• Necropsy of Mammals
• Imaging in Lagomorph Diagnosis and Treatment
• Clinical Pathology of Lagomorphs
• Chapter 2 - B36 Field Manual of Wildlife Diseases - Specimen Collection and Preservation
• Chapter 3 - B36 Field Manual of Wildlife Diseases - Specimen shipment
• Appendix A - B36 Field Manual of Wildlife Diseases - Sample specimen history form

Similar Diseases (Differential Diagnosis)

• Cystic Mastitis in Lagomorphs
• Mammary gland hyperplasia
  • This has been reported to occur secondary to a pituitary tumour. (B609.2.w2)
• Inflammatory mammary adenocarcinoma (Uterine Neoplasia in Rabbits)
  • Differentiate by biopsy (B609.2.w2)
  • There may be a concurrent mammary abscess. (B609.2.w2)
• Subcutaneous abscess (Abscessation in Lagomorphs)
  • This may or may not involve the mammary gland. (B609.2.w2)

Specific Medical Treatment

Prognosis

• Fair to guarded with treatment but it does depend on the severity of disease. (B609.2.w2)

Intravenous fluids

• Use if the rabbit is dehydrated or has sepsis. (B602.19.w19, B609.2.w2)

Antibiotics

• Ideally should be based on the results of culture and sensitivity. (B601.9.w9, B609.2.w2, J29.10.w2)
• N.B. Start treatment with broad-spectrum antibiotics while waiting for culture and sensitivity results. (J213.5.w1)
• Enrofloxacin (J29.10.w2)
  • 5 - 20 mg/kg orally or by subcutaneous or intramuscular injection every twelve to twenty four hours. (B609.2.w2)
• Trimethoprim-Sulphonamide (J29.10.w2)
  • 30 mg/kg orally every twelve hours. (B609.2.w2)
• Chloramphenicol
  • 50 mg/kg orally every eight hours. 
  • Avoid human contact with this drug due to potential blood dyscrasia.
    (B609.2.w2)
• Penicillin G
  • 40,000 to 60,000 IU/kg by subcutaneous injection every two to seven days.
  • Use if Pasteurella or Streptococcus is cultured. 
  • Not usually effective against Staphylococcus. 
    (B609.2.w2)
  • Note: 
    • Fatal antibiotic-associated enterotoxaemia can occur, sometimes even with a single dose of penicillin given subcutaneously. (V.w127)
    • There have been reports of kits dying after nursing does had received procaine penicillin. The deaths are thought to be due to toxic effects of the procaine. (B600.9.w9)
• Streptomycin (B64.22.w8)

Pain management (analgesia)

• NSAIDs: these can be used to reduce inflammation and pain. (B609.2.w2, J29.10.w2)
  • Meloxicam
    • 0.2 - 0.6 mg/kg orally every 24 hours. (B609.2.w2, V.w128)
    • Use with caution in patients with compromised renal function. (B609.2.w2)
  • Carprofen (J29.10.w2)
    • 2.2 mg/kg orally every twelve to twenty four hours. (B609.2.w2)
  • Flunixin meglumine. (J296.62.w2)
• Opioid analgesics may be used: butorphanol or bupernorphine. (J296.62.w2)

Prolactin inhibitors

• "Galastop" may be used to reduce lactation. (B603.3.w3)

DO NOT USE

• Oral antibiotics that select against Gram-positive bacteria:
  • Penicillins, macrolides, lincosamides and cephalosporins. (B609.2.w2)
  • These may cause a fatal enteric dysbiosis and enterotoxaemia. (B609.2.w2)
    • See: Clostridial Enteritis and Enterotoxicosis in Rabbits
• Corticosteroids
  • Systemic or tropical preparations may severely exacerbate an infection due to heightened susceptibility to infection and delayed wound healing. Gastrointestinal ulceration and haemorrhage may also occur. (B609.2.w2)

• Treatment and Care

General Nursing and Surgical Techniques

• The animal should be kept as an inpatient until stable. (B609.2.w2)

• Warm compress: hot packing of affected teats is useful and also milking out the affected gland several times a day. (B10.45.w47, B601.9.w9, B602.19.w19, B603.3.w3, B609.2.w2, J34.24.w3)
• Surgical debridement or drainage of abscess: This may be necessary for abscessed or necrotic glands. (B602.19.w19, B603.3.w3, B609.2.w2, J34.24.w3)
• Assist feed anorexic or inappetant rabbits to prevent secondary gastrointestinal disorders. (B609.2.w2)
• Clean and disinfect the environment. (B609.2.w2)

Care of the young

• Early weaning of young: this is usually necessary in lactating does and will prevent the kits starving or suffering bacterial enteritis. (B601.9.w9, B603.3.w3)
• Hand-rearing of the young. (J29.10.w2) See: Rearing of Mammals - Hand-rearing
• Note: Do not foster young of the affected doe to a surrogate doe as they may transmit the infection to the surrogate. (B10.45.w47, B609.2.w2, J29.10.w2, J296.62.w2)

• Clinical Pathology of Lagomorphs

Preventative Measures

--

• Preventative Medicine for Mammals

Environmental and Population Control Measures

Lagomorphs

• Keep the environment clean. (B609.2.w2)

• Environmental and Population Management - General