Infectious/Non-Infectious
Agent associated with the Disease
|
- Anoplura (sucking lice) on mammals, and Mallophaga (chewing lice) on mammals and birds.
- Lice tend to be fairly host-species specific.
In Elephants
- Elephants have their own louse,
Haematomyzus elephantis. (J4.169.w3,
J12.45.w1, B24,
B451.10.w10, B453.7.w7, P64.1.w3,
P501.2001.w4,
P502.1.w5)
- This louse is in the order Mallophaga, suborder Rhynchophthirina (J4.169.w3)
- It is described as 1 to 2 mm long, reddish brown, and difficult to remove from the skin. Eggs are found firmly adherent to hair shafts.
(J4.187.w2)
- Unusually for Mallophaga, elephant lice have their mouthparts on the end of a thin projection, and are obligate blood feeders.
(J4.187.w2)
- "The head is prolonged anteriorly in a rostrum, the
mandibles are at the apex of the rostrum. The thoracic segments are
fused." (B24)
- Adults can live off the host for up to 21 days; eggs take 21 days to
hatch. (J4.169.w3)
In Bears
- Mallophaga (chewing lice):
- Trichodectes spp. are common on free-ranging Ursus americanus - American black bear.
(B22.32.w15)
- Trichodectes pinguis pinguis. (B208.1.w1,
J345.3.w2,
J412.87.w1)
- Trichodectes pinguis euarctidos. (B208.1.w1,
J1.14.w9,
J1.16.w13, J412.87.w1)
- Males length 1.9-2.2 mm (average 2.08 mm); females 2.1-2.5
mm (average 2.28 mm). Males head breadth 0.67-0.80 mm 9average
0.74 mm), females 0.67-0.78 mm 9average 0.74 mm). (J412.87.w1)
- Differentiated from Trichodectes pinguis pinguis by
the fact that small pigmented pleural plates present in Trichodectes
pinguis pinguis are absent or unpigmented in Trichodectes pinguis
euarctidos. (J412.87.w1)
In Lagomorphs
- Hoplopleura lice have been reported to occur on pikas. (B208.1.w1)
|
Infective
"Taxa" |
|
Non-infective agents |
-- |
Physical agents |
-- Indirect /
Secondary |
|
|
Disease Author |
Debra Bourne MA
Vet MB PhD MRCVS (V.w5),
Nikki Fox BVSc MRCVS (V.w103),
Gracia Vila-Garcia
BVSc, MSc,
MRCVS (V.w67)
|
 |
Referees |
Anna Meredith MA VetMB CertLAS DZooMed (Mammalian) MRCVS (V.w128);
Richard Saunders BVSc BSc CertZooMed MRCVS (V.w121) |
Major References /
Reviews
|
Code and Title List |
B24,
B46,
B208.1.w1
Elephants:
B212.w26, B451.10.w10
J4.169.w3, J12.45.w1
P64.1.w3, P502.1.w5
Bears:
B16.19.w9,
B22.32.w15, B208.1.w1,
B336.51.w51
J345.3.w2
D270.VII.w7,
D274
Lagomorphs:
B142, B208.1.w1, B284.10.w10, B600.9.w9, B601.13.w13,
B602.19.w19, B604.5.w5,
B609.2.w2,
B608.21.w21, B610.23.w23,
B614.11.w11,
B615.6.w6
J29.5.w1
|
Other References
|
Code and Title List |
Bears:
J1.11.w11, J1.14.w9,
J1.16.w13, J1.26.w11,
J30.56.w4, J412.87.w1,
J413.7.w1Lagomorphs:
J1.11.w13, J1.36.w10,
J11.93.w2, J62.60.w3,
J62.62.w4, J469.288.w1,J469.457.w1,J469.495.w1,
J469.530.w1
|
Detailed Clinical and Pathological Characteristics
|
| General |
- Lice are usually present in small numbers with no apparent detrimental effect to the
host.(B208.1.w1)
- Lice are of veterinary importance due to:
- the potential to affect their host
- their capacity to act as vectors of diseases.
- their role as intermediate host for other parasites
- (B46)
- May be present in large numbers on debilitated individuals.(B208.1.w1)
- May be present in larger numbers in winter and spring on deer (B208.1.w1)
- Detrimental effects of lice may include dermatitis, pruritus, intense grooming, fur
matting, alopecia (hair loss), skin inflammation or scaling, allergic reactions,
anaemia,
secondary infections at bite sites, unthriftiness, decreased growth rate, secondary
infection, pathogen transmission (B208.1.w1).
(B24,
B46,
B208.1.w1)
|
Clinical
Characteristics |
- The presence of large numbers of lice may indicate debility such as senility or illness,
immunocompromise, nutritional deficiency or inability of the host to groom. (B208.1.w1)
|
| ELEPHANTS |
- Affected Elephas maximus
- Asian Elephant may show signs of dermatitis, with severe pruritus
(shown by frequent rubbing of the body on trees or other
objects), dryness of the skin, and scaling of the skin of e.g. the neck, ears, abdominal areas and near the tail.
(B212.w26, J12.45.w1, P502.1.w5)
- Nervousness, vigorous movements of the ears and frequent scratching the abdomen and neck were seen.
(J12.45.w1)
- Some elephants may develop cuts and bruises from scratching. Development of papules, considered to be associated with louse infection, have also been described.
(J4.169.w3)
- Restlessness and actions to relieve pruritus are common signs. (P64.1.w3)
- Frequent rubbing due to irritation caused by lice may case sores. (B451.10.w10)
|
| BEARS |
|
| LAGOMORPHS |
- Distribution of lice:
- Lice are most frequently found along the lateral and dorsal aspects of the
body and also around the perineum.
- Eggs: laid on the host and are found firmly attached to the
hair.
- Clinical signs (more likely to be seen in the debilitated or immunosuppressed host)
- anaemia
- pruritus
- erythematous papules
- alopecia
- weakness, emaciation and death in debilitated animals.
(B600.9.w9, B601.13.w13,
B602.19.w19,
B604.5.w5,
B608.21.w21,
B609.2.w2,
B610.23.w23,
B615.6.w6,
J29.5.w1)
|
Incubation |
-- |
| ELEPHANTS |
--
|
| BEARS |
--
|
| LAGOMORPHS |
- Life cycle:
- takes two to five weeks depending on the
environmental conditions. (B600.9.w9)
- 30 days. (B604.5.w5)
- Lice seldom leave a living host. (B604.5.w5)
- Eggs:
- laid on the host and are found firmly attached to the hair; (B600.9.w9,
B604.5.w5)
- oval shaped with an operculum which is quite distinctive and
from which the larvae emerge. (B600.9.w9)
- The eggs hatch seven days after they are laid. (B604.5.w5)
- Young lice are similar to the adults; they undergo three
ecdysis before they become an adult. (B600.9.w9)
|
Mortality / Morbidity |
--
|
| ELEPHANTS |
--
|
| BEARS |
- Pediculosis has been commonly reported in free range Ursus americanus - American black bear
in United States and Canada.
(B16.9.w9)
- Trichodectes pinguis euarctidos in moderate to heavy infestations were found on four of 113
Ursus americanus - American black
bears captured in Northern Wisconsin, 1974-1975. (J1.14.w9)
- One 2.5-year-old male was infested with about 5000 lice and was in
poor physical condition with low body weight (17.6 kg). (J1.14.w9)
|
| LAGOMORPHS |
- Lice are common in wild rabbits but they are only occasionally found on domestic rabbits
(in particular those in breeding
establishments if the husbandry standards are poor). (B600.9.w9)
- Haemodipsus setoni ticks were found on 12 (22 %)
black-tailed jackrabbits (Lepus californicus)
in one study in Northern California. (J1.36.w10)
- Lice can act as a vector for myxomatosis. (B284.10.w10)
|
Pathology |
-- |
| ELEPHANTS |
-- |
| BEARS |
-- |
| LAGOMORPHS |
-- |
Disease has been reported in either the wild or in captivity
in:
|
In elephants
- Elephant lice were found clinically affecting Elephas maximus
- Asian Elephant in Nehru Zoological Park, Hyderabad, India. (J12.45.w1)
- Elephant lice were found on both Elephas maximus
- Asian Elephant and Loxodonta africana
- African Elephant) in San Diego Zoo, California, USA;
infection was known to be present also in elephants from San Diego
Wild Animal Park. (J4.187.w2)
- The elephant louse was detected on camp elephants all over Thailand,
but was considered to have only "minor
clinical importance" as a parasite of elephants. (P501.2001.w4)
- Infection was found to be quite widely prevalent in both captive and
wild elephants in Kerala, India. (P64.1.w3,
P502.1.w5)
- Elephant lice were found on elephants in the Kruger National Park,
South Africa. (J377.27.w1)
- Elephant lice were found in moderate numbers on an Elephas maximus
- Asian Elephant recently arrived in the USA from Thailand. (J11.55.w1)
In bears
- Pediculosis has been reported commonly in free-ranging Ursus americanus - American black bear
in the United States and Canada.
(B16.9.w9)
- Trichodectes pinguis pinguis. (J412.87.w1)
- Trichodectes pinguis euarctidos first described from the
American black bear (Euarctos americanus) Ursus americanus - American black bear
(J412.87.w1)
- Trichodectes pinguis pinguis has been reported from Ursus arctos - Brown bear
in Europe and from a Himalayan black bear (Ursus thibetanus - Asiatic black bear)
in a zoo in Paris. (J345.3.w2)
- Trichodectes pinguis euarctidos were found on 21/241 black bears examined live in New York (Adirondacks, plus five from Allegany State Park),
1956-1958. No external parasites were found on 17 Ursus americanus - American black
bears from zoos in New York State. (J413.7.w1)
- Unidentified lice were detected on a Himalayan black bear (Ursus thibetanus - Asiatic black bear)
in southeastern USSR. (J345.3.w2)
- Trichodectes pinguis euarctidos has been described from Ursus americanus - American black bear
in Canada (Ontario, British Columbia) and USA (Michigan, Minnesota, New York, Montana.
(J345.3.w2)
- An unidentified Trichodectes sp. was detected on one of 30 Ursus americanus - American black bear
from Montana and Wyoming. (J345.3.w3)
- Trichodectes pinguis were detected on the ventral body hairs of
a male Ursus thibetanus - Asiatic black bear
shot on Kyushu Island, Japan. (J1.26.w11)
- Trichodectes pinguis euarctidos was found on an adult male Ursus americanus - American black bear
killed in Michigan, USA in 1968. (J1.11.w11)
- Trichodectes pinguis euarctidos in moderate to heavy infestations were found on four of 113 bears captured in Northern Wisconsin, 1974-1975.
(J1.14.w9)
- Trichodectes pinguis euarctidos were found in large numbers
all over a wild Ursus americanus - American black bear
in Idaho in 1976; the bear also had audycoptic mange. (J1.16.w13)
- Trichodectes pinguis euarctidos on two of five Ursus americanus - American black bear
(40%) examined from central Ontario, Canada. (J30.56.w4)
- Trichodectes pinguis pinguis on Ursus arctos - Brown bear
in Western North America. (B208.1.w1)
- Trichodectes pinguis euarctidos on Ursus americanus - American black bear
across North America. (B208.1.w1)
- A study of 177 wild Ursus americanus - American black bear
in spruce-fir forest noted that two bears collected outside the main
Big Creek study area had heavy Trichodectes pinguis euarctidos
infestations (thousands of lice) as well as heavy flea and tick
infestations. (D274)
In Lagomorphs
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)
|
Disease has been specifically reported in Free-ranging
populations of:
|
|
In elephants
- Infection was found to be quite widely prevalent in both captive and
wild elephants in Kerala, India. (P64.1.w3,
P502.1.w5)
- Elephant lice were found on elephants in the Kruger National Park,
South Africa. (J377.27.w1)
In bears
- Pediculosis has been reported commonly in free-ranging Ursus americanus - American black bear
in the United States and Canada.
(B16.9.w9)
- Trichodectes pinguis euarctidos were found on 21/241 black bears examined live in New York (Adirondacks, plus five from Allegany State Park),
1956-1958. No external parasites were found on 17 Ursus americanus - American black
bears from zoos in New York State. (J413.7.w1)
- Trichodectes pinguis pinguis has been reported from Ursus arctos - Brown bear
in Europe and from a Himalayan black bear (Ursus thibetanus - Asiatic black bear)
in a zoo in Paris. (J345.3.w2)
- Unidentified lice were detected on a Himalayan black bear (Ursus thibetanus - Asiatic black bear)
in southeastern USSR. (J345.3.w2)
- Trichodectes pinguis euarctidos has been described from Ursus americanus - American black bear
in Canada (Ontario, British Columbia) and USA (Michigan, Minnesota, New York, Montana.
(J345.3.w2)
- An unidentified Trichodectes sp. was detected on one of 30 Ursus americanus - American black bear
from Montana and Wyoming. (J345.3.w3)
- Trichodectes pinguis were detected on the ventral body hairs of
a male Ursus thibetanus - Asiatic black bear
shot on Kyushu Island, Japan in 1987. (J1.26.w11)
- Trichodectes pinguis euarctidos was found on an adult male Ursus americanus - American black bear
killed in Michigan, USA in 1968. (J1.11.w11)
- Trichodectes pinguis euarctidos in moderate to heavy infestations were found on four of 113 bears captured in Northern Wisconsin, 1974-1975.
(J1.14.w9)
- Trichodectes pinguis euarctidos were found in large numbers
all over a wild Ursus americanus - American black bear
in Idaho in 1976; the bear also had audycoptic mange. (J1.16.w13)
- Trichodectes pinguis euarctidos on two of five Ursus americanus - American black bear
(40%) examined from central Ontario, Canada. (J30.56.w4)
- Trichodectes pinguis pinguis on Ursus arctos - Brown bear
in Western North America. (B208.1.w1)
- Trichodectes pinguis euarctidos on Ursus americanus - American black bear
across North America. (B208.1.w1)
- A study of 177 wild Ursus americanus - American black bear
in spruce-fir forest noted that two bears collected outside the main
Big Creek study area had heavy Trichodectes pinguis euarctidos
infestations (thousands of lice) as well as heavy flea and tick
infestations. (D274)
In Lagomorphs
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 Investigation / Diagnosis
|
| -- |
| ELEPHANTS |
Diagnosis of ectoparasite
infections is by observation of clinical signs together with
identification of the parasite involved. (B10.49.w21)
On examination, lice may be found, particularly on the ears but also
elsewhere on the body. (J12.45.w1)
- Elephant lice are found mainly on the head and neck, under the
abdomen and the tail head. (B212.w26)
- The highest concentrations of both lice and eggs were found behind the
ears of Elephas maximus
- Asian Elephant in one outbreak. (J4.169.w3)
- On infected Elephas maximus
- Asian Elephant and Loxodonta africana
- African Elephant in one zoo, lice were found on the posterior surface of the
pinna, the head and neck caudal to the
ears; in more severely infected individuals, they were more widespread.
(J4.187.w2)
- Lice are found mainly on the head, in folds of the skin, and in
the external ear canal. (P80.1.w1)
- The proboscis of the louse may be very firmly attached to the skin.
(J12.45.w1)
See also the description in Elephants and their Diseases- A Treatise on Elephants - Part IV - Chapter VIII
- Diseases of the Skin (continued) - External Parasites
|
| BEARS |
- Trichodectes pinguis euarctidos on Ursus americanus - American black bear
from central Ontario, Canada, were not detected on external
examination but were found when hides were softened in a 5-10%
potassium hydroxide solution. (J30.56.w4)
|
| LAGOMORPHS |
- Detection of lice. (J29.5.w1)
- Identification of the louse with the naked eye:
- 1.5 - 2.5 mm
in length with an oval abdomen. (B600.9.w9,B604.5.w5)
- If the animal is dead then observation of the lice is
facilitated by cooling the pelt in the refrigerator for 30
minutes. Remove the pelt from the fridge for 10 minutes and then
examine with a hand lens- the lice usually migrate from the cool
skin up toward the warmer hair tips. By placing the pelt on a
piece of dark paper within a frame of petroleum jelly or
cellophane tape, lice will become trapped, making detection easier. (B604.5.w5)
- Alternatively, "gently vacuuming the animal with a
pipette attached to a suction unit or small commercial vacuum
works very well. A small piece of milk filter paper placed in the
line traps debris which can be examined microscopically. Pruritic
animals especially seem to enjoy the motion of the pipette and the
technique is atraumatic and efficient for recovering ectoparasites".
(B615.6.w6)
- Identification of the eggs with the naked eye:
- lice eggs are firmly attached to the hair of the host;
- oval shaped with an operculum which is quite distinctive and
from which the larvae emerge.
(B600.9.w9)
- See: Clinical Pathology of Lagomorphs
- Skin Testing
|
| Related Techniques |
|
 |
Specific Medical Treatment
|
- Ectoparasiticide compounds, if treatment is required. (B208.1.w1)
- e.g. Avermectins such as ivermectin, abamectin, doramectin,
orally, topically or parentrally. (B208.1.w1)
- Pediculicidal dusts, powders, sprays etc. containing carberyl,
cypermethrin, deltamethrin, malathion
etc. are usually effective.
Use weekly for two to four weeks, and treat bedding/cage at the same
time. (B208.1.w1)
|
| ELEPHANTS |
- Topical or orally administered Ivermectin is effective against
elephant louse infection. (B336.53.w53)
- Elephants (Elephas maximus
- Asian Elephant and Loxodonta africana
- African Elephant) were treated with ivermectin given orally at 0.059 - 0.087 mg/kg, repeated after five to six weeks. No lice were found by seven days after the first
treatment. At the time of the second treatment, a few lice but no eggs were present. Lice were not detected at any time following the second treatment.
(J4.187.w2)
- Oral ivermectin was preferred since, while intramuscular injections had been effective against
these lice, they had also lead to development of local inflammation and soreness at the injection sites.
(J4.187.w2)
- Systemic treatment is very effective because, unlike most Mallophaga,
the elephant louse is an obligate blood feeder. (J4.187.w2)
- Topical permethrin has been used. (B450.17.w17)
- A wash or dip using an organophosphorus
compound (Sumithion) at 1% concentration has been found very
effective. (P64.1.w3,
P502.1.w5)
- Other older recorded treatments include:
- Dusting with Gammexene [BHC - organochlorine], which was washed off by bathing the
following day. (J12.45.w1)
- Scrubbing with a lindane-based (organochlorine)
shampoo, left on the skin for ten
to 15 minutes before being rinsed off, and repeated on two further
occasions at one week intervals (i.e. to cover the time during
which the louse can survive off the host, and the time to hatching
of the eggs). (J4.169.w3)
|
| BEARS |
|
| LAGOMORPHS |
|
| Related Techniques |
|
|
|
Environmental
and Population Control Measures
|
| General Environment Changes, Cleaning and
Disinfection |
The cage/beddings
should be treated at the same time that an animal with lice is treated. (B208.1.w1)
|
BEARS |
|
| LAGOMORPHS |
Formaldehyde fumigation of the premises and equipment is useful in the
elimination of the parasites from the environment. (B604.5.w5)
|
| Population Control Measures |
Ensure uncrowded
conditions to avoid rapid spread of lice between individual hosts. (B208.1.w1) |
| BEARS |
- Maintain clean, dry conditions, particularly for orphaned cubs. (D270.VII.w7)
|
| LAGOMORPHS |
- Colonies of domestic rabbits should be well separated from any wild
rabbits to prevent transmission of disease to the domestic colony. (B604.5.w5)
|
| Isolation, Quarantine and Screening |
Isolate incoming
individuals which have lice until they have been treated and are no longer
infested. (B208.1.w1) |
| BEARS |
- Quarantine newly-arrived bears. (D270.VII.w7)
|
| LAGOMORPHS |
- For prevention of lice infestation in a colony, place parasite-free
stock in a parasite-free facility and then quarantine new arrivals. (B604.5.w5)
|
| Related Techniques |
|
|
|
