Paracitology

Parasitology of Rabbits

This section provides an overview of important external and internal parasites of rabbits, including their causes, clinical signs, and treatment/prevention options. References are included where available.

Etiology (cause)

Fleas are ectoparasites that feed on rabbit blood. The most common species in rabbits is the cat flea, Ctenocephalides felis felis.

Clinical Signs

• Intense pruritus (itching)
• Alopecia (hair loss) from scratching
• Papules, scabs, and dermatitis
• Anemia in severe infestations
• Flea dirt (black specks) visible on skin/fur

Treatment, Prevention, and Control

• **Selamectin (Revolution for kittens)**: safe and effective for fleas, ear mites, and mange mites (off-label use).
• **Imidacloprid (Advantage 40)**: 0.4 mL for rabbits <4 kg; 0.8 mL for >4 kg, applied to skin at neck.
• Treat environment with insect growth regulators (IGRs) and insecticidal sprays.
• Avoid permethrin/pyrethrin due to toxicity and flea resistance.

References:

• Hutchinson MJ, Jacobs DE, Bell GD, et al. Evaluation of imidacloprid for the treatment and prevention of cat flea infestations on rabbits. Vet Rec. 2001;148:695-696. doi:[10.1136/vr.148.22.695](https://doi.org/10.1136/vr.148.22.695)

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Etiology (cause)

Fur mites are surface-dwelling mites often called "walking dandruff."

Clinical Signs

• Dandruff-like scaling, especially along the back
• Mild to severe pruritus
• Alopecia in severe infestations

Treatment, Prevention, and Control

• Selamectin or ivermectin (0.2–0.4 mg/kg SC, repeat in 14 days).
• Treat all in-contact rabbits.
• Clean/disinfect housing and grooming tools.

References:

• Paterson S. Skin diseases of rabbits. Semin Avian Exot Pet Med. 2006;15(2):94-99. doi:[10.1053/j.saep.2006.04.005](https://doi.org/10.1053/j.saep.2006.04.005)

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Etiology (cause)

Psoroptes cuniculi is a common ear mite in rabbits, living in the external ear canal.

Clinical Signs

• Crusty, thick brown debris in ears
• Intense scratching and head shaking
• Secondary bacterial infections
• Pain and head tilt in severe cases

Treatment, Prevention, and Control

• Selamectin (Revolution) topical application.
• Ivermectin (SC injection or topical).
• Avoid oil-based ear cleaners, which can worsen inflammation.

References:

• Swindle MM, Adams RJ. Psoroptic ear mange in rabbits: treatment with ivermectin. Lab Anim Sci. 1988;38(1):109–111. PMID: 3351435

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Etiology (cause)

Coccidiosis in rabbits is caused by protozoan parasites of the genus Eimeria. Over 11 species infect rabbits; E. stiedae affects the liver (hepatic coccidiosis), while others affect the intestines.

Clinical Signs

• Diarrhea (may be watery or bloody)
• Weight loss and poor growth
• Dehydration
• In hepatic coccidiosis: hepatomegaly, icterus, poor body condition

Treatment, Prevention, and Control

• Sulfonamides (sulfadimethoxine, trimethoprim-sulfa).
• Toltrazuril (Baycox®) effective against multiple Eimeria spp.
• Strict sanitation (removal of feces, disinfection of cages).

References:

• Pakandl M. Coccidia of rabbit: a review. Folia Parasitol (Praha). 2009;56(3):153-166. doi:[10.14411/fp.2009.020](https://doi.org/10.14411/fp.2009.020)

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Etiology (cause)

Pinworms are common in laboratory and pet rabbits but usually non-pathogenic.

Clinical Signs

• Often asymptomatic
• Occasional perianal pruritus
• Rarely: mild enteritis

Treatment, Prevention, and Control

• Fenbendazole (20 mg/kg PO for 5 days, repeat in 10 days).
• Good sanitation to break life cycle.

References:

• Kondo H, et al. Pathology of pinworm infection in rabbits. Exp Anim. 1981;30(3):305-310. doi:[10.1538/expanim1978.30.3_305](https://doi.org/10.1538/expanim1978.30.3_305)

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Etiology (cause)

A microsporidian parasite transmitted via urine spores or vertically. Infects the kidneys, brain, and eyes.

Clinical Signs

• Neurological signs: head tilt, ataxia, seizures
• Ocular lesions: phacoclastic uveitis, cataracts
• Renal disease: chronic renal failure

Treatment, Prevention, and Control

• Fenbendazole (20 mg/kg PO daily for 28 days).
• Prevent contamination by infected urine.
• Test and cull in commercial colonies.

References:

• Künzel F, Fisher PG. Clinical signs, diagnosis, and treatment of Encephalitozoon cuniculi infection in rabbits. Vet Clin Exot Anim. 2018;21(1):69-90. doi:[10.1016/j.cvex.2017.08.007](https://doi.org/10.1016/j.cvex.2017.08.007)

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Summary

Parasites in rabbits can cause mild to severe disease depending on the species involved, host immune status, and environmental management. Control relies on accurate diagnosis, proper antiparasitic treatment, and strict hygiene measures.