Flea Infection in Mammals (with special reference to Hedgehogs, Bears and a note on Elephants)

Disease Summary

Alternative Names (Synonyms)

Disease Type

Infectious/Non-Infectious Agent associated with the Disease

• There are many species of Flea within the order Siphonaptera, which infect a wide variety of mammal and bird species. (B24, B46)
• The Erinaceus europaeus - West European Hedgehog is host to Archaeopsylla erinacei - Hedgehog flea (B156.7.w7, B228.9.w9, J15.21.w1, J18.38.w1, B291.12.w12)
• Other flea species recorded on European hedgehogs (Erinaceus spp.) include Pulex irritans (human flea), Nosopsyllus fasciatus (rat flea), Ctenocephalides canis (dog flea), Ctenocephalides felis (cat flea) and others. (B228.9.w9)
• Ctenophthalamus agyrtes in Europe. (J18.38.w1)
• Echidnophaga gallinacae (stick-tight flea) has been recorded on the central African hedgehog (Atelerix albiventris - Four-toed hedgehog) in Kenya and Nigeria. (B228.9.w9)
• The European rabbit (Oryctolagus cuniculus - European rabbit) is host to Spilopsyllus cuniculi - Rabbit flea (B46)
• In Elephants:
  • "A flea, Echindnophaga larina has occasionally been encountered on elephants." (B411)
• In Bears:
  • Pulicidae fleas have been found in cubs or captive bears in contact with domestic animals, such as cat or dog. (B16.9.w9)

Infective "Taxa"

• Siphonaptera - Fleas (Order)

Non-infective agents

Physical agents

References

Disease Author

Major References / Reviews

Code and Title List

In Hedgehogs:
B156.7.w7, B228.9.w9, B259.w7, B258.w9, B284.6.w6, B291.12.w12, B337.3.w3, J15.21.w1, J18.38.w1, P23.1999S.w8

In rabbits:
B156.7.w7, J15.21.w1

In Elephants: 
B411

In Bears:

B16.9.w9
D274
J30.56.w4, J345.3.w2, J417.24.w1

Other References

Code and Title List

Detailed Clinical and Pathological Characteristics

• Fleas are laterally flattened wingless jumping insects which may be found on a wide variety of mammals and birds. (B24, B46)
• Fleas are of veterinary importance due to:
  • the effects on their host
  • their capacity to act as vectors of a wide range of diseases. (e.g. see: Myxomatosis). (B24, B46)
  • their role as intermediate host for other parasites
• In many cases fleas are an incidental finding.

Clinical Characteristics

• Fleas may be visible on the host, as may their droppings.
• The host may scratch.
• Raised, slightly inflamed papules may be present where fleas have bitten the host.
• In dogs with flea-bite allergy there may be severe pruritus associated with discrete crusted papules, with self-inflicted trauma leading to areas of alopecia or moist dermatitis. 
• In cats with flea-bite allergy marked pruritus is associated with numerous small brown crusty papules palpable through the fur.

(B46, B)

• Fleas are easily visible on hedgehogs. (J15.21.w1, B284.6.w6)
• Fleas are considered normally not to harm hedgehogs. (B156.7.w7)
• Heavy infections, particularly in conjunction with other parasites, may cause anaemia due to blood loss and therefore weakness. (B259.w7, B284.6.w6, B291.12.w12, B337.3.w3)
• The main areas affected are the neck, chest, front legs, abdomen and between the spines. (B291.12.w12)

• Fleas visible moving through the hair, particularly near the eyes and axillae. (B16.9.w9) 

Incubation

• Fleas hatch two days to two weeks after eggs are laid; the whole life cycle may take as short a time as three weeks or as long as two years. (B46)

• Hedgehog fleas have a short pupation period to ensure that nestling hoglets are parasitised. (B228.9.w9)

Mortality / Morbidity

• Flea infection may be incidental or may cause significant distress to the host. (B46)

• Erinaceus europaeus - West European Hedgehog may commonly have relatively heavy infestations of fleas. (J18.38.w1, B214.3.26.w11, B259.w7)
  • Heavy infestations of fleas may indicate the hedgehog is in poor condition. (J15.21.w1)
• N.B. Hedgehog fleas are absent from Erinaceus europaeus in New Zealand. (J10.22.w1)

• Flea infection is common in free-ranging bears. (J417.24.w1)

Pathology

Human Health Considerations

• Hedgehog fleas Archaeopsylla erinacei rarely, but occasionally, bite humans. (B228.9.w9, J3.128.w2, J184.48.w1, P23.1999S.w8)

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

• Erinaceus spp. (B228.9.w9)
• Archaeopsylla erinacei on most wild hedgehogs. (B258.w9)
• Pulex irritans were found on the long-eared hedgehog Hemiechinus auritus (Hemiechinus auritus - Long-eared hedgehog) in Iraq; it was noted that Archaeopsylla erinacei, Ctenocephalides felis, Echidnophaga gallinacea, Xenopsylla nubica and other flea species had been recorded previously on hedgehogs in Iran and the Arab world. (J177.18.w1)
• In New Zealand, infection with Nosopsyllus fasciatus (rat flea) and Ctenocephalides felis (cat flea) on Erinaceus europaeus. (J10.22.w1)
• Echidnophaga gallinacae (stick-tight flea) has been recorded on the central African hedgehog Atelerix albiventris (Atelerix albiventris - Four-toed hedgehog) in Kenya and Nigeria and on the Algerian hedgehog Atelerix algirus (Atelerix algirus - Algerian hedgehog) in Algeria. (B228.9.w9)
• Ctenocephalides felis strongylus on the central African hedgehog Atelerix albiventris near Nairobi (Kenya) and on the Ivory coast. (B228.9.w9)
• Ctenocephalides crataepus on several central African hedgehogs  Atelerix albiventris examined during a study in Nigeria. (J183.23.w1)
• Synosternus paliidus and Xenopsylla cheopis in hedgehogs in Nigeria. (B228.9.w9)
• Pulex irritans on a long-eared hedgehog Hemiechinus auritus in northern Iraq. (B228.9.w9)
• Archaeopsylla erinacei on Erinaceus concolor (Erinaceus concolor - East European hedgehog) and Hemiechinus auritus - Long-eared hedgehog in Israel. (B228.9.w9)
• In Ireland, almost all fleas (1024/1025) collected from hedgehogs Erinaceus europaeus around Dublin were Archaeopsylla erinacei. (J3.119.w4)
• Archaeopsylla erinacei and Ctenophthalmus agyrtes are commonly found on hedgehogs. (B214.3.26.w11)
• Hedgehogs Erinaceus europaeus in Germany were found to be infested with Archaeopsylla erinacei commonly (70/74 hedgehogs), Ctenocephalides felis (12/76 hedgehogs) and also Ceratophyllus gallinae (1/76 hedgehogs). (J184.48.w1)
• Hedgehogs Erinaceus europaeus in Ireland were found to be infected with Archaeopsylla erinacei erinacei, with a mean burden of 55.9 fleas per hedgehog (from 19 hedgehogs). Two juveniles carried 65 and 114 fleas. Additionally one adult carried a single Ctenophthalmus nobilis. (J186.22.w1)
• Hedgehogs Erinaceus europaeus in the UK. (B259.w7)

In Elephants:

• "A flea, Echindnophaga larina has occasionally been encountered on elephants." (B411)

• Chaetopsylla setosa on wild Ursus americanus - American black bear in southern British Columbia (Canada) and Montana (USA). (J345.3.w2)
• Chaetopsylla setosa on wild Ursus arctos - Brown bear in British Columbia. (J345.3.w2)
• Chaetopsylla (Arctopsylla) tuberculaticeps ursi from wild Ursus arctos - Brown bear in southern Alberta, southern British Columbia and Alaska. (J345.3.w2)
• Chaetopsylla (Arctopsylla) tuberculaticeps ursi from wild Ursus americanus - American black bear in south-central Alaska and in Montana. (J345.3.w2)
• Chaetopsylla tuberculaticeps tuberculaticeps from wild Ursus arctos - Brown bear from Norway, Russia, the Italian Alps and Japan. (J345.3.w2)
• Thrassis spenceri (normally found on marmots) from a wild Ursus arctos - Brown bear from British Columbia. (J345.3.w2)
• Pulex irritans from four wild Ursus americanus - American black bears in northern California. (J345.3.w2)
• Orchopeas caedens (normally found on Tamiasciurus sp. red squirrels) found in a bear's den a few days after the bear left the den. (J345.3.w2)
• Unidentified fleas on a wild Ursus americanus - American black bear in Michigan. (J345.3.w2)
• Pulex sp. fleas were found on one of 30 bears during a study of Ursus americanus - American black bears from Montana and Wyoming. . [1976](J345.3.w3)
• Oropsylla arctomys (primarily a parasite on woodchuck, Marmota monax) were found (eight fleas) on one of five bears examined during a survey of Ursus americanus - American black bears in central Ontario, Canada, 1975-1977. (J30.56.w4)
• Chaetopsylla hiberculaticeps ursi in 2% of Ursus americanus - American black bears from Montana. (J417.24.w1)
• Fleas were present on free-ranging Ursus americanus - American black bears in Louisiana and on all of five individuals presented to the Louisiana State university Wildlife Hospital. (J417.24.w1)
• A study of 177 wild Ursus americanus - American black bear in spruce-fir forest noted that two bears in the main Big Creek study area had fleas Arctopsylla ursi and two bears collected from outside the study area had heavy flea infestations (and heavy lice and tick infestations). (D274)

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

• Erinaceus europaeus - West European Hedgehog
• Elephants (Elephantidae - Elephants (Family))
• Bears (Ursidae - Bears (Family))
• Ursus americanus - American black bear
• Ursus arctos - Brown bear

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

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

• Erinaceus spp. (B228.9.w9)
• Archaeopsylla erinacei on most wild hedgehogs. (B258.w9)
• Pulex irritans were found on the long-eared hedgehog Hemiechinus auritus  (Hemiechinus auritus - Long-eared hedgehog) in Iraq; it was noted that Archaeopsylla erinacei, Ctenocephalides felis, Echidnophaga gallinacea, Xenopsylla nubica and other flea species had been recorded previously on hedgehogs in Iran and the Arab world. (J177.18.w1)
• In New Zealand, infection with Nosopsyllus fasciatus (rat flea) and Ctenocephalides felis (cat flea) in Erinaceus europaeus. (J10.22.w1)
• Echidnophaga gallinacae (stick-tight flea) has been recorded on the central African hedgehog Atelerix albiventris (Atelerix albiventris - Four-toed hedgehog) in Kenya and Nigeria and on the Algerian hedgehog Atelerix algirus (Atelerix algirus - Algerian hedgehog) in Algeria. (B228.9.w9)
• Ctenocephalides felis strongylus on the central African hedgehog Atelerix albiventris near Nairobi (Kenya) and on the Ivory coast. (B228.9.w9)
• Ctenocephalides crataepus on several central African hedgehogs  Atelerix albiventris examined during a study in Nigeria. (J183.23.w1)
• Synosternus paliidus and Xenopsylla cheopis in hedgehogs in Nigeria. (B228.9.w9)
• Pulex irritans on a long-eared hedgehog Hemiechinus auritus in northern Iraq. (B228.9.w9)
• Archaeopsylla erinacei on Erinaceus concolor (Erinaceus concolor - East European hedgehog) and Hemiechinus auritus in Israel. (B228.9.w9)
• In Ireland, almost all fleas (1024/1025) collected from hedgehogs Erinaceus europaeus around Dublin were Archaeopsylla erinacei. (J3.119.w4)
• Archaeopsylla erinacei and Ctenophthalmus agyrtes are commonly found on hedgehogs. (B214.3.26.w11)
• Hedgehogs Erinaceus europaeus in Germany were found to be infested with Archaeopsylla erinacei commonly (70/74 hedgehogs), Ctenocephalides felis (12/76 hedgehogs) and also Ceratophyllus gallinae (1/76 hedgehogs). (J184.48.w1)
• Hedgehogs Erinaceus europaeus in Ireland were found to be infected with Archaeopsylla erinacei erinacei, with a mean burden of 55.9 fleas per hedgehog (from 19 hedgehogs). Two juveniles carried 65 and 114 fleas. Additionally one adult carried a single Ctenophthalmus nobilis. (J186.22.w1)
• Hedgehogs Erinaceus europaeus in the UK. (B259.w7)

In Elephants:

• "A flea, Echindnophaga larina has occasionally been encountered on elephants." (B411)

In Bears:

• In Bears:
  • Chaetopsylla setosa on wild Ursus americanus - American black bear in southern British Columbia (Canada) and Montana (USA). (J345.3.w2)
  • Chaetopsylla setosa on wild Ursus arctos - Brown bear in British Columbia. (J345.3.w2)
  • Chaetopsylla (Arctopsylla) tuberculaticeps ursi from wild Ursus arctos - Brown bear in southern Alberta, southern British Columbia and Alaska. (J345.3.w2)
  • Chaetopsylla (Arctopsylla) tuberculaticeps ursi from wild Ursus americanus - American black bear in south-central Alaska and in Montana. (J345.3.w2)
  • Chaetopsylla tuberculaticeps tuberculaticeps from wild Ursus arctos - Brown bear from Norway, Russia, the Italian Alps and Japan. (J345.3.w2)
  • Thrassis spenceri (normally found on marmots) from a wild Ursus arctos - Brown bear from British Columbia. (J345.3.w2)
  • Pulex irritans from four wild Ursus americanus - American black bears in northern California. (J345.3.w2)
  • Orchopeas caedens (normally found on Tamiasciurus sp. red squirrels) found in a bear's den a few days after the bear left the den. (J345.3.w2)
  • Unidentified fleas on a wild Ursus americanus - American black bear in Michigan. (J1.11.w11, J345.3.w2)
  • Pulex sp. fleas were found on one of 30 bears during a study of Ursus americanus - American black bears from Montana and Wyoming. . [1976](J345.3.w3)
  • Chaetopsylla hiberculaticeps ursi in 2% of Ursus americanus - American black bears from Montana. (J417.24.w1)
  • Fleas were present on free-ranging Ursus americanus - American black bears in Louisiana and on all of five individuals presented to the Louisiana State university Wildlife Hospital. (J417.24.w1)
  • A study of 177 wild Ursus americanus - American black bear in spruce-fir forest noted that two bears in the main Big Creek study area had fleas Arctopsylla ursi and two bears collected from outside the study area had heavy flea infestations (and heavy lice and tick infestations). (D274)

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

• Erinaceus europaeus - West European Hedgehog
• Elephants (Elephantidae - Elephants (Family))
• Bears (Ursidae - Bears (Family))
• Ursus americanus - American black bear
• Ursus arctos - Brown bear

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

General Information on Environmental Factors/Events and Seasonality

• There are seasonal variations in flea burdens; newly-emerged fleas are abundant of hedgehogs in late summer/autumn. (B228.9.w9)
• In the southeastern USA, fleas may be found on bears year-round, while in northern areas they will be found late spring to early fall (autumn), when temperatures are higher than 15 °C (60 °F) and humidity is over 50%. (J417.24.w1)

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

In bears:  

• North America. (J417.24.w1)
• Fleas may be less common on bears in eastern North America than further west in North America. (J345.3.w2)

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

In bears:  

• North America. (J417.24.w1)
• Fleas may be less common on bears in eastern North America than further west in North America. (J345.3.w2)

General Information on Investigation / Diagnosis

• Fleas (laterally flattened wingless insects) may be visible directly on the animal or in its immediate environment.
• Flea dropping may be visible on the animal or following combing. These appear dark brown or black but when placed on moist tissue a spreading red stain will appear.
• The host or its environment may be examined by using a vacuum cleaner with fine gauze inserted behind the nozzle so that any fleas are retained on the gauze.

(B46)

• Fleas are easily seen. (J15.21.w1, B259.w7, B337.3.w3)

• On physical examination, the presence of fleas moving through the hair. (B16.9.w9)

• History & Documentation
• Physical Examination of Mammals
• Necropsy of Mammals
• Environmental Assessment
• 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)

Specific Medical Treatment

• A variety of insecticides may be used if treatment is required.
  • Care must be taken to avoid toxicity.
  • Pyrethrum-based dusting powder appears to be safe in most species (V.w5).
• Organophosphorus compounds (e.g. dichlorvos/fenitrothion combination, iodofenphos), pyrethrum, pyrethroids such as permethrin and organochlorines (bromocyclen in cats and dogs, gamma HCH in dogs) have been used. (B46)

• Treatment is often not required for wildlife casualties, unless there is a heavy infestation (J15.21.w1).
• For Erinaceus europaeus - West European Hedgehog:
  • Pyrethrum dusting powder, with or without piperonyl butoxide (B156.7.w7, B228.11.w11, B259.w7, B284.6.w6, B337.3.w3, J15.21.w1); e.g. Rid-mite (Johnson's Veterinary Products)
    • Treat any bedding with same powder. (B156.7.w7)
  • Synthetic pyrethroids. (J15.21.w1)
  • Bromocyclen powder (Alugan, Hoechst). (B156.7.w7) (This is no longer available in the UK)
  • Permethrin (B284.6.w6); N.B. permethrin may be toxic, even fatal. (B228.11.w11)
  • Fipronil may be used; it should be sprayed sparingly and it is essential to ensure that the hedgehog is kept in a well ventilated environment during and after treatment. (B284.6.w6) 
  • Fenthion (Tiguvon 10%, Bayer) one drop per 100 g bodyweight onto the back of the hedgehog: all fleas should be eliminated within 24 hours and the effect should last for four weeks. (B228.11.w11, B291.12.w12)
  • The use of insecticidal baths (followed by rinsing, then drying in a warm room) has been described, with a suggestion that very weak or hypothermic individuals should not be treated immediately. (B291.12.w12)
  • Avoid using aerosol sprays as the noise involved may cause stress to the hedgehog. (B228.11.w11)
• For hoglets a very mild flea or mite powder (Pyrethrum based) should be used, e.g. Johnson's Rid-mite (Johnson's Veterinary Products), designed for birds. (B337.2.w2)

• Commercial flea powder/spray, to treat the affected bear(s) and any in-contact animals. (B16.9.w9)
  • Keep bears from swimming for 24 hours after treatment. (B16.9.w9)
• The bedding and housing must be treated also. (B16.9.w9)
• Fipronil (Frontline®, Merial Animal Health Ltd.) is used on Ursus americanus - American black bear. (J417.24.w1)

• Treatment and Care - General

General Nursing and Surgical Techniques

• Treatment and Care - General

Preventative Measures

Several products are available which are designed for regular (monthly) administration to dogs and/or cats for control and prevention of flea infections. These may be available (depending on the product) as tablets, injections, sprays or "spot-on" solutions for application to the skin. (B504)

• Treatment and Care - General

Environmental and Population Control Measures

• It is important to treat all the susceptible animals in contact with the known host even if they show no signs of infection. 
• Insecticidal sprays designed for environmental (house) use may be used.
• Sprays containing methoprene (insect growth regulator) may be used; this can prevent development of fleas to adults for up to four months after application.
• Thorough cleaning with a vacuum cleaner is important to remove fleas, eggs and flea droppings from the environment.

(B46, B504)

HEDGEHOGS

• Clean the bear's environment to eliminate eggs and larvae. (J417.24.w1)

• Environmental and Population Management - General