August 24, 2022 Dermatology

Why does my pet keep itching? Allergies, infections, and ectoparasites in pets

A cat with allergies

Why does my pet keep itching? Allergies, infections, and ectoparasites in pets

August is itchy pet awareness month. August is a good month to discuss itchy pets since nearly all the patients I am seeing these days are itchy and scratching at themselves. This blogpost will focus on some of the more common causes of itching and scratching in our favorite fur persons.

Ear Mites in Kittens

Young pets with itching and scratching symptoms often suffer from different conditions than their adult counterparts. Kittens will commonly have ear mites resulting in a brown discharge from the ears that vaguely resembles coffee grounds. Scratching may be aimed at the ears, but in uncoordinated kittens, you might just see back legs scratching the air and missing their mark. Fortunately, ear mites are easily treated with medication. Keep in mind that ear mites from your new kitten can easily be transferred to the other pets in your household, so it’s best to treat this ear mites as soon as possible.

Itchy Puppies and Collars

In my experience, ear mites are much less common in puppies than kittens. But puppies may display frequent scratching of their head, ears and neck for a far less concerning reason: they’re not used to wearing their collar. Take the collar off for a few hours and if the scratching subsides, then your puppy is likely fine. If the skin under the collar is red or scabby, then it might be an allergy to the collar and a different collar is in order.

Fleas, Ticks, Lice and Mites

A Golden Retriever with demodectic mange

Another common cause of scratching is an ectoparasite, meaning a parasite in or on the skin. Fleas, ticks, lice and mites are all ectoparasites. Flea infestations are much less common than when I began practicing veterinary medicine thanks to excellent monthly and trimonthly preventive medications. Fleas are easy to see crawling around on your pet. Mites are not easy to see and require a skin scrape for diagnosis. Another name for a mite infestation is mange. Demodex mange mites live in the hair follicles and sarcoptic mange mites live under the surface of the skin. The photo of a Golden retriever accompanying this blogpost has a bad case of demodectic mange. Both types of mange make a dog extremely itchy, worse than a bad case of fleas. Keep in mind, fleas will bite people and some types of mange can be shared between a dog and their person. Be sure to tell your veterinarian if you and your dog are both itchy.

Which Comes First: the Itch or the Infection?

Itching, allergies and skin infections (pyoderma) are a common trio of related problems in veterinary patients. In pet allergies, the barrier function of the skin is impaired allowing allergens to set off an allergic reaction and itching. Itching causes breaks in the skin and the skin’s microbiome, which causes an infection in the injured skin. One type of  skin infection secondary to allergies is called a “hot spot.” A skin infection, without underlying allergies, will also cause itching in dogs and cats.

The photo included in this blogpost is one of my Abyssinian patients with allergies. You can see how the itching has resulted in big sores on his chin. A number of purebred cats are prone to allergies including Somali cats, Ocicats, Siamese, Persian and Maine Coon cats. Allergies in cats have similar causes to those in dogs and include allergies to fleas or other ectoparasites, food and environmental allergens.

Allergies are such a common cause of itching and scratching in pets that AMC’s Usdan Institute for Animal Health Education hosted a lecture on the treatment of seasonal allergies in pets with AMC’s Senior Veterinarian in Dermatology, Dr. Mark Macina.

Tags: allergies, Dermatology, ectoparasites, fleas, itching, lice, mites, scratching, skin conditions, skin infections, skin issues, ticks,

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