Friday, July 14, 2006

Mites & Fleas

If your rabbit has dandruff-like flaky skin, this could indicate mites

Rabbits can have a number of external parasites that can cause discomfort, hair loss and often disease. You should regularly check your rabbit’s coat to make sure there are no signs of mites or fleas and it is recommended that all outside rabbits are regularly treated for fleas as they can carry disease.

Hair loss, although often a sign of mites or flea infestation, can sometimes be due to over grooming caused by hormonal imbalances, especially in entire females. So if your doe is not responding to treatment for fleas or mites please have her checked out by a rabbit savvy veterinarian as it might be due to uterine cancer or ovarian cysts.

There are two types of fleas seen in rabbits. The common flea (Ctenocephalides canis or C. felis) is often seen on rabbits and if your rabbit lives closely with a feline or canine companion then they are very likely to get fleas occasionally. Fleas can cause skin irritation and over grooming and can predispose the skin to bacterial infections once the skin’s protective barrier is damaged with scratching and biting.

Rabbits can also get the Spanish Flea (Xenopsylla cunicularis smit). This is a flea that is specific to rabbits. It was released into Australia in 1993 to try and aid the spread of Myxomatosis in the wild rabbit population. This is a very real threat to our outside rabbits and I would strongly recommend regular monthly flea treatments to help prevent infection.

Ear mites
Psoroptes cuniculli are a small microscopic mite that lives in the ears of rabbits. Because rabbits have very long narrow ear canals it can often be difficult to see these creatures even though they are visible to the naked eye. These mites cause severe irritation and large numbers of crusty painful scabs that can be seen in the ear. Your vet can find these mites by examining the wax and crusting from the ear under the microscope. The damage that is caused in the ear of rabbits with an infection of Psoroptes cuniculli can predispose them to ear infection that can extend into the inner ear. Ear mites are treated with ivomec injections by your vet. Alternatively, monthly Revolution, a spot-on active against fleas and mites, has also been used to control ear mite infections.

Rabbit lice (Haemodipsus ventricosus) are rarely found on domestic rabbits, but can be occasionally found in their wild counterparts. They are quite large and at 1.5 – 2 mm in length are easily seen with the naked eye.

Cheyleteilla parasitovorax is commonly called walking dandruff, as the mites themselves can be visible to the naked eye. They live on the surface of the skin around the hair shaft and cause damage to the shaft. Hair loss, especially on the tail base can be a sign that you rabbit has mites. Cheyleteilla is a common condition in rabbits and is often brought into the home on hay and straw. If you are concerned that your rabbit might have mites then see your veterinarian as they will be able to check the presence of these tiny insects under the microscope. Treatment is often straightforward with an application of Revolution.
Burrowing mites that live in the hair follicles rather than the hair shaft can occasionally be found on rabbits. They are not very common and their presence can be diagnosed with a deep skin scraping or more often with a skin biopsy.

Unfortunately there are no treatments that are registered for use in rabbits, although there are a few products that have been used extensively and are known to be safe.

Revolution is a monthly flea treatment for cats and dogs and is helpful in treating fleas, mites and ear mites in rabbits. It should not be used in kits younger then 12 weeks. Please see your veterinarian for the correct dose.

Advantage is also safe for use in rabbits; again see your veterinarian for the correct dose. Be careful not to use in kits under 12 weeks of age. Advantage is only effective against fleas.

DO NOT use Frontline on rabbits, as it has been known to cause fatal seizures, even 5-7 days after application.

Other flea products such as washes, powders and collars should not be used in rabbits as some can cause severe illness and death. If in any doubt at all, do not use it until you have talked to a veterinarian.

Article written by Dr Narelle Walter, BVSc, MRCVS Hallam Veterinary Clinic, 55 Belgrave-Hallam Road, Hallam, Vic, 3803 Ph: (03) 9703 1776