Passaluriasis in rabbits is parasitic infestation with the pinworm Passalurus ambiguus. These small worms may inhabit caecum, small and large intestine. Pinworms are usually considered non-pathogenic, rarely cause clinical signs, and may be incidental necropsy findings. Transmission is faecal–oral: eggs are shed in faeces and ingested by the same or other rabbits. The rabbit pinworm is host-specific.
Any animal may be affected regardless of age, sex, or breed.
Clinical signs
Usually asymptomatic; moderate or severe perianal pruritus may occur. Worms may be visible in faeces.
Examination may reveal perianal dermatitis, poor coat, weight loss, or rectal prolapse with heavy infestation.
Passaluriasis may be found incidentally at abdominal surgery or necropsy.
Differential diagnoses
- with pruritus/dermatitis of perineum — urine scald;
- ectoparasite infestation;
- contact dermatitis.
Tests
Imaging is not used. Blood counts are usually normal.
Faecal flotation or direct smears detect eggs and adults (sexual dimorphism).
Treatment
Asymptomatic passaluriasis does not require treatment. Treat if clinical signs are present — for example owners see worms around the anus.
Clean the perineum of adult worms and treat secondary perianal pyoderma if present.
Relapse is common — even solitary rabbits reinfect themselves by coprophagy.
Medications:
- fenbendazole: 10–20 mg/kg once, repeat in 10–14 days;
- thiabendazole: 50 mg/kg PO once, repeat in 10–14 days;
- piperazine: 200 mg/kg PO, repeat in 14 days.
Treat all rabbits in the environment.
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