What are they?
Rabbit fur mites, also known as Cheyletiella or ‘walking dandruff’ are a type of tiny, spider-like parasite which lives on the skin surface. The mites survive by feeding on dead skin cells and debris within the fur. Cheyletiella mites are zoonotic, meaning that they can be transmitted to humans as well as other animal species.What are the symptoms?
The most common symptom of rabbit fur mites is flaky skin especially along the back. Dry, white, dandruff-like flakes appear in clumps within the fur and often result in patchy fur loss (alopecia). These flakes can sometimes be seen moving within the coat due to the movement of the parasite, hence the name ‘walking dandruff’. The mites sometimes cause mild itching but many affected rabbits seem unaware of the problem. In small numbers these parasites can be considered normal, however when present in large enough numbers to produce these scaling lesions or hair loss this usually indicates an underlying problem that allows the mites to multiply.How does my rabbit catch them?
Cheyletiella mites can be passed from rabbit to rabbit directly or on contaminated materials such as bedding, and are often present in small numbers on the skin and fur of healthy rabbits. The natural grooming behaviour of rabbits prevents mite numbers from building up and causing disease. However, in some individuals the mites are allowed to proliferate, causing damage to the fur and skin which results in the typical hair loss and scaling lesions. This is often due to an underlying illness or other reason preventing the rabbit from grooming effectively and suppressing the immune system of the rabbit.
Dental problems can allow mite infestations to develop as rabbits use their tongue and incisors (front teeth) to groom the fur. If these teeth are growing abnormally or the rabbit is experiencing dental pain, they may be reluctant or unable to groom the fur effectively. Other sources of pain, illness or stress such as spinal or hindlimb arthritis, gut problems or respiratory disease can deter the rabbit from expressing normal behaviours including grooming. Additionally, obesity can prevent rabbits from stretching around to groom the back and hindquarters.
How are they diagnosed?
Diagnosis is based on observation of the characteristic appearance of the white scaling skin lesions coupled with microscopic examination of the skin debris. Scale is collected from the lesions using a clear tape strip which is then applied to a microscope slide or by gently scraping material from the lesion using a scalpel blade.
The mites can often be readily viewed under a microscope moving within this debris or the eggs may be found attached to the fur.
The underlying cause of the mite infestation must also be identified based on clinical examination to assess the teeth, mobility, body condition and general health of the affected rabbit. In some cases, further diagnostic testing such as blood tests or x-rays will be advised in order to check for evidence of underlying illness or other reasons for poor grooming.
How are they treated?
Treatment of the mites is usually straightforward by use of an effective anti-parasite medication. This is usually in the form of injections or ‘spot-on’ treatments applied topically to the skin and may need to be repeated several times over a number of weeks. In addition to treating the mites themselves, it is necessary to treat any predisposing factors exacerbating the infestation. This may include treatment of dental disease, medications for spinal or hindlimb pain or addressing obesity if present.
It is also important to thoroughly clean the enclosure on a regular basis throughout treatment to minimise contamination and re-infestation from the environment. In rabbits with long-term grooming problems, such as with chronic arthritis or those undergoing a weight loss programme, it is helpful to assist with their grooming by brushing the fur regularly to keep mite numbers to a manageable level.