Mites

Mites are small arachnids (very closely related to spiders and ticks). They can live on your pet’s skin or in their fur. Clinical symptoms associated with mite infestation are usually a result of an underlying condition causing immune suppression.

The main types of mites discussed in this factsheet are burrowing mites, fur mites and demodex mites. Burrowing mites burrow under the skin and generally cause more severe clinical symptoms than fur mites which live on the surface of the skin. Demodex mites are elongated mites which live on the hair follicles, certain types of demodex mites can burrow into the hair follicles.

Small pets can become infested with mites through direct contact with other infested pets or through indirect contact with contaminated bedding or objects in the animal’s environment. Small pets may pick up mites, especially demodex mites, through contact with their mother during suckling.

Guinea pigs can suffer from Trixacarus caviae, a type of burrowing mite commonly known as mange. They can also suffer from a type of fur mite called Chirodiscoides caviae.

Trixacarus caviae mites (mange) in guinea pigs can remain latent (without clinical symptoms) for months, but stress or underlying disease can trigger clinical symptoms as the mites begin to breed. They cause intense itchiness and pain. Affected guinea pigs may also experience convulsions (seizures), especially when handled. Small bumps may appear on the skin of affected guinea pigs where the mites have burrowed. Thinning or loss of fur and scratches or sores where the guinea pig has bit or scratched themselves may also be noticeable. The skin can look yellowish or crusty, and sometimes secondary skin infections can occur. Affected areas of skin are usually seen around the neck, shoulders, back and inner thighs. Affected guinea pigs may also experience weight loss and appear lethargic and depressed.

Hamsters can become infested with demodex mites. There are two species of demodex mites which affect hamsters. Demodex criceti do not cause any clinical signs and in the majority of cases are not a concern. Demodex aurati are cigar-shaped mites which can borrow into the hair follicle and cause clinical signs. Less commonly they can be infested with Notoedres mites, a type of burrowing mite which can also affect rats.

Demodex usually affects older hamsters (over 1.5 years old). Clinical signs of demodex include dry and scaly skin with patches of hair loss. It usually begins over the hamster’s back but it can spread to other places on the body as the condition progresses. Usually, the condition does not cause itchiness. In most cases too, the mites are secondary to some other underlying condition, which has impaired the hamster’s immune system.

Notoedres mites, which can affect hamsters and rats, burrow under the skin in order to create tunnels to lay eggs. In hamsters they cause severe itching, crusting, sores and hyperpigmentation (when the skin becomes darker). They are often found on the ear pinnae, face, genitalia, tail, and limbs, although they can be more generalised (spread over the body) in nature.

Rats are most commonly affected by fur mites called Radfordia ensifera, but can also rarely be infested with burrowing Notoedres mites, as can hamsters.

Rats affected by fur mites can show no clinical signs or they can develop severe itching and small scaly lesions around the head and shoulders. It is possible for affected rats to develop secondary infection of the skin.

Much like hamsters, gerbils can also become infested with demodex mites. The demodex mite affecting gerbils is known as Demodex merioni.

Clinical symptoms of demodex are usually only seen in young, old, diseased, pregnant or under-nourished gerbils. Typical clinical signs include hair loss, scaliness of the skin, and skin ulceration affecting the back legs and tail.

If you suspect your small pet has mites you should take them to a veterinary surgeon for diagnosis and treatment. If your vet suspects your pet is suffering from a type of burrowing mite they may wish to perform skin scrapings. This involves scraping the skin in a small area or several small areas with a blunt scalpel, and then transferring the scrapings to a microscope slide. The scrapings are visualised under a microscope and the vet will look for any mites that may be under the surface of the skin.

Fur mites are usually diagnosed through hair plucks. This is when your vet plucks some of your pets fur onto a microscope slide in order to look for the mites.

Demodex mites are usually diagnosed by skin scrapings, hair plucks or via both techniques.

There are a range of treatment options for mites in small pets, your vet will be able to recommend the best treatment option based on the clinical symptoms your pet is exhibiting and their normal lifestyle. The most common treatment option is ivermectin, an anti-parasitic drug, given as a spot-on, orally, or by injection. Two to three treatments are often required to eliminate all mites and the animal's home environment should be regularly disinfected, and their bedding replaced during treatment. Certain types of mites may be treated with topical solutions (applied to the skin).

If your pet is diagnosed with mites it’s also important to check for any underlying disease or causes of stress. You should think about any changes to your pet’s environment or routine which might be causing them stress and rectify where possible. Your vet may wish to run further diagnostic tests, such as blood tests, if they suspect your pet has an underlying disease such as an hormone imbalance, kidney problems, or a tumour.