Common Skin Allergies in Cats and Dogs

Skin allergies are something that we see in both our feline and canine patients. While many pet owners are familiar with the issue, you might have a few unanswered questions. Let’s explore some of the most common types of skin allergies, how they might affect your pet and also what we can do to help them feel more comfortable again.

What are the most common skin allergies in cats and dogs?

Flea allergy

One of the most frequently diagnosed allergies in pets is flea allergies. Flea allergic dermatitis (FAD) is an allergy (also known as a “hypersensitivity reaction”) to flea saliva. Whilst a normal flea bite can be a bit irritating to any pet, animals with flea allergies will react more severely. Affected animals may overgroom, have widespread itchiness or develop multiple small scabs (miliary dermatitis, one of the main symptoms in cats).

Environmental allergies (atopic dermatitis)

Affected animals may react to an array of different allergens in the environment, in just the same way that people with asthma or hay fever do. Some can cause skin problems all year round (such as house dust mites) whereas others may only cause seasonal flare-ups (pollens).

Food allergies

Food allergies can develop in pets, even if they have been eating the same food for a long period. Hypersensitivity (allergic) reactions occur most frequently to the proteins in food, with beef, chicken and dairy being common triggers. Food allergies appear to be much less common than environmental allergies in pets.

It is also important to note that many pets with skin allergies, could have a combination of the above, all contributing to their symptoms.

What are the symptoms of skin allergies in cats and dogs?

The most common symptoms of skin allergies in cats and dogs include:

· Increased itchiness (pruritus)

· Red and inflamed skin (erythema)

· Scabs or sores

· Areas of hair loss or thinning (alopecia)

· Recurrent skin or ear infections

· Licking at their paws

· Hives (a raised rash)

· Rubbing their face or ears excessively

· Discoloration of the fur from licking (saliva staining)

Other types of reaction

It is also important to note that some animals may show other symptoms from their allergies.

For example, cats are prone to a condition called eosinophilic granuloma complex. This is an allergy-related disorder that causes persistent sores or ulcers. These commonly appear on the lips and inside the mouth, but may be seen in other locations of the body. Studies show that in most cats a hypersensitivity (allergic) reaction is the underlying cause, but cases can be complex.

Diarrhoea and vomiting may occasionally be seen in animals with food allergies. Respiratory symptoms are sometimes seen in cats, with conditions like feline asthma having an underlying hypersensitivity (allergic) component too.

Most people have heard of anaphylactic shock, which may occur in pets with severe allergies. This extreme reaction to an allergen is an emergency with affected animals having breathing difficulties, extreme swelling and collapse. Fortunately, it’s very rare in pets!

How are skin allergies diagnosed in pets?

To begin with, our vets will discuss your pet’s symptoms with you and take a history. That includes discussing your pet’s diet and current parasite control regime. In general, we can’t diagnose allergies until we’ve ruled out parasites – because the symptoms are so similar. So, if we seem to be focussing on fleas and mites rather than allergies to begin with – there is a reason for it, it’s not that we don’t believe you!

The following steps may need to be taken to try and reach a diagnosis –

· Testing and/or treating to rule out parasites – this may include looking at coat brushings for evidence of flea dirt and taking hair pluck or skin scrape samples to look at under the microscope for mites.

· Testing to identify any secondary infections – Bacterial and fungal skin infections need to be treated. Dogs and cats with allergies are much more prone to secondary infections, and these can add to their itchiness.

· Biopsies or cytology – sometimes samples of tissue are taken, or cells are collected and sent to the laboratory for analysis. This may be needed if any suspicious lesions are not responding to usual treatments.

· Dietary trials – To diagnose food allergies, a strict dietary trial is required. This involves gradually stopping your pet’s current diet and introducing them to a vet-approved hypoallergenic diet. Your pet will remain on this for 6-8 weeks to see if their itchiness improves. The diet can then be re-challenged to see if the itchiness reoccurs when your pet’s old diet is given.

· Allergy blood tests – In animals with suspected environmental allergies, blood can be taken and sent to the laboratory to be tested against common triggers like grass pollens, tree pollens, dust mites and parasites.

· Allergy skin tests – these are usually performed by a specialist dermatologist, who injects small amounts of allergens into the surface of the skin to assess whether a reaction occurs.

Your vet will discuss the most appropriate tests for your dog or cat and explain each one as they go along.

How are skin allergies treated in cats and dogs?

Long-term treatment is usually required for most pets with allergies. Each animal is different so treatment plans will vary but could include any combination of the following:

· Medications to reduce itchiness – Some form of medication to stop pets from feeling itchy is often prescribed. There are many different options and types available, including steroids (prednisolone), oclacitinib, cyclosporin, monoclonal antibodies and (less commonly) antihistamines. Our vets will be able to talk you through the various options to work out what might suit you and your pet the best.

· Topical treatments of shampoos – A prescription shampoo may be required, or medicated wipes, to help counteract secondary infections and soothe inflamed skin.

· Anti-parasite treatment – Preventative flea or mite treatments are usually advised, not only to deal with any current infections but to stop future ones too. This is extremely important, especially in animals with flea-allergic dermatitis (FAD).

· Antibiotics – Courses of antibiotics may be required if your pet has secondary bacterial skin infections.

· Immunotherapy – If your pet has had allergy testing, then immunotherapy can be explored. Liquid medication is made which contains small quantities of the allergens that your pet reacts to. These are then administered to your cat or dog via injection or sometimes by mouth over time, to gradually desensitise them to their allergens.

· Change of diet – A long-term change of diet is required in animals with food allergies. This diet should be strictly followed, as even an occasional treat or table scrap containing one of your pet’s known triggers could cause a skin flare-up. · Supplementation with essential fatty acids (EFAs) – EFAs can help in the management of allergies, by improving the skin barrier and coat condition. These can be given as a supplement or may be found in some skincare/allergy diets.

It is important to stick with the plan that your vet recommends, as stopping medication suddenly or not dosing accurately can lead to problems with your pet’s management.

Final thoughts

If you are concerned about your pet’s skin, or think they may have an allergy, then contact us to make an appointment. Our vets will be able to talk you through the steps needed for your pet and give you advice on the management of their condition. As with all health issues, the sooner treatment is started the sooner your pet can be made more comfortable, so don’t hesitate to give us a call.

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