Demodectic Mange in Cats

Demodicosis can be localized in specific areas or generalized all over the body. A thorough medical evaluation is indicated for cats with generalized demodicosis because of its association with immune system disorders. In most cases, D gatoi or D. cati are the species of mites associated with demodectic mange in cats.

In some cases, especially with D. gatoi, the condition may lead to lip ulcers and scabs across the body.

Severe cases of D. cati might lead to recurrent ear infections. D. cati is part of the normal biome of a cat. This mite only becomes pathogenic in overgrowth numbers, or if an immune system condition is present. D. gatoi is always considered pathogenic.

Demodicosis is very rare in cats. Normally the mites are present on the skin in low numbers and a healthy immune system keeps the parasite population in check. Sometimes, the mite population grows excessively because of a compromised immune system.

While Demodex mites do cause a rash, it’s more of a concern as an indicator of immunosuppression. Immunosuppressive conditions, such as feline leukemia virus, feline immunodeficiency virus, or diabetes mellitus put cats at higher risk for developing demodicosis.

Demodicosis is more likely to occur or become serious in immunocompromised and senior cats. Kittens are also more likely to develop this condition, but they often outgrow it, especially in mild cases.

Demodicosis is caused by a parasitic infestation with D. cati and D. gatoi mange mites. D. cati mites normally live on feline skin in small numbers, but may multiply excessively and cause mange. D. gatoi are not part of a cat’s normal biome and can cause skin irritation even when only present in small numbers.

Symptoms vary depending on the species of Demodex infesting the cat.

D. cati normally lives on hair follicles and may not cause any symptoms at all.

Skin lesions might be itchy but it’s not always the case.

D. gatoi lives on the surface of the skin.

The most common test to diagnose demodicosis is the skin scrape. The vet uses a scalpel to scratch and collect superficial skin cells for microscopic examination. The presence of adult mites or their eggs is conclusive for diagnosing demodex. Another common testing method is to apply acetate tape to the skin to remove superficial parasites and skin cells for microscopic analysis. Samples of hair may also be assessed microscopically to look for mites. Skin biopsy is a more invasive test and is less common.

Not finding traces of Demodex mites doesn’t exclude the possibility of demodicosis.

If diagnosis of mange caused by D. cati is confirmed, additional testing for immunosuppressive conditions is indicated.

Treatment includes oral and topical medications to kill the mites. Other procedures may prove necessary depending on any underlying conditions affecting the immune system.

Prognosis depends on the presence or absence of any underlying immune system disorder, especially in cases of D. cati infestation. Generally, if no other condition is present, the prognosis is good. Some cases resolve spontaneously. All in-contact cats in the same household require treatment to prevent recurrence. Always consult a veterinarian before administering topical medication to cats. Many topical medications are toxic to cats and can be fatal even in low doses.

Demodicosis is potentially contagious between animals of the same species. Demodex mites are species-specific so transmission between different species doesn’t occur. Quarantine is important for any animal suspected of having any form of mange. D. cati is ubiquitous and therefore not considered contagious, while D. gatoi potentially is. Carriers who show no signs of a skin condition but are capable of infecting other cats may exist.

Demodicosis is rare in cats.

Treatment involves medication to kill Demodex mites. Treatment is only successful as long as any underlying immune system disorders are addressed or ruled out. Treating secondary skin infections (bacterial or fungal) is also critical for treatment to work.