The common rabbit pinworm (Passalurus ambiguus) is an intestinal parasite. It does not pose a serious health threat and often lives unnoticed in rabbits, but it can cause uncomfortable itching and skin inflammation or redness around their hind ends and anus. P.ambiguus is a species-specific parasite, meaning that it only lives in rabbits.
Pinworms live in the small intestines, cecum (large intestine), and colon of rabbits. They pass their eggs into the environment through the rabbit's feces.
How did my rabbit get infected with pinworms?
Rabbits become infected with pinworms by eating feces that contain pinworm eggs. Your rabbit can get pinworms if they eat the contaminated feces of another infected rabbit. Most likely, your rabbit was exposed to pinworm-infected feces from its parents, at the pet store, breeder, or shelter.
How are pinworms diagnosed?
You or your veterinarian may see your rabbit scratching or biting at their hind end and you may possibly see small white worms around the anus or in the feces. If you or your veterinarian see any of these signs, a pinworm diagnosis may be confirmed with a fecal analysis.
Your veterinarian will analyze a sample of your rabbit’s feces in a fecal smear under a microscope or through a “fecal flotation” test. Your veterinarian or a veterinary technician can identify the presence of pinworm eggs by a microscopic examination of the fecal flotation test.
How are pinworms treated?
Pinworms are challenging to treat because rabbits are coprophagic (meaning they eat their own feces). Rabbits frequently reinfect themselves during treatment by repeatedly ingesting infected feces.
If your rabbit is diagnosed with pinworms, they will be prescribed anti-parasitic drugs. Also, you will need to be diligent about cleaning and eliminating all feces in and around your rabbit's cage and other areas where they play, sleep, and roam. If there is more than one rabbit in the house or pen, all rabbits must be treated to prevent repeated pinworm infections. If you are careful to treat your rabbit and keep the habitat super-clean, you can prevent reinfection.