This month, Dr Mtry takes an in-depth look at allergens and allergies in pets – what to look for, how to diagnose the condition, and importantly ways to treat and manage the condition effectively …

By Dr Irene Mitry
Head Veterinarian, Clyde Veterinary Hospital – Melbourne

Our pets are really not all that different from us, at a biological level – and they can be just as prone to suffer from allergic reactions – not a pleasant prospect, as any pet owner who suffers from an allergy themselves can testify.

Allergic reactions often operate in a cycle, with irritation of the affected area becoming a stimulus for your dog or cat to itch, which in turn can worsen any infection.

A slew of other health conditions can often develop as a result of your pet’s scratching the affected area, including hair loss, scabbing of the skin, and overall discomfort and associated irritation.

For these reasons, diagnosing the condition and identifying the allergen as quickly as possible is vital for their effective treatment.

Unfortunately, most allergies do not have a “cure” per se – in most cases, management of allergic conditions comes down to simply managing the symptoms and reducing contact with the offending allergen as much as possible.

As we move into the summer months downunder, we begin to see more and more dogs (and to a lesser extent, cats) presenting at the hospital with allergic reaction symptoms, and one recent study showed that skin conditions are actually rated as the #2 overall reason for pet trips to the vet.

So I thought now would be a good time to take a look at what you can do as a pet owner to help prevent your dog or cat from getting stuck in an allergic cycle, and maintain their quality of health if they do.

Allergic Reactions – Signs to Watch For

Because our pets can be masters at avoiding displaying any sign of disease or weakness (remember they are genetically wired this way), it is important for pet owners to always keep a close eye on their pet’s daily behaviour, and take careful note of any changes that persist for more than 24 hours.

The main way for owners to differentiate allergies in their pets from regular influenza or a ‘cold’ is the itch factor.

Owners should look for signs of itching and irritation, typically in the form of redness, sensitivity, or inflammation of their dog or cat’s skin.

If you notice your pet is excessive scratching, licking or chewing at one particular area, it’s a good sign that some form of allergic reaction may be present.

Importantly, take note of the actual area that are tending to itch at – is it one particular area of skin, or maybe one or the other of their ears?

This can indicate the presence of an ear infection, which requires a very different treatment to allergic dermatitis of the outer skin, while a dog itching their back near the base of the tail is oftentimes a sign of flea allergy.

Try and give your vet as much information as possible about any allergic response – how long they have been experiencing it, where exactly it is located, and exactly what behaviour is being exhibited.

The most common areas affected by allergens in dogs and cats are the face, ears, feet, belly and armpit area.

Acute Allergic Reactions

Perhaps the most alarming of all pet allergies is an acute allergic reaction. Pets can go into anaphylactic shock if they have a severe reaction to an allergen, which can be fatal if not treated quickly. Fortunately there are quite rare and usually caused by bee stings or responses to vaccines.

The most troubling anaphylactic symptoms to watch for are

• Cold limbs
• Wheezing and difficulty breathing
• Increased heart rate or a weak pulse
• Seizures
• Excessive salivating or drooling
• Vomiting
• Diarrhea
• Pale gums

If your pet is showing one or more of these symptoms, this should be a red flag that you need to get them to their veterinarian urgently and without delay.

In some cases, your pet may also develop hives or facial swelling in response to an allergen. Swelling of the face, throat, lips, eyelids, or earflaps may look serious but is rarely fatal, and your veterinarian can readily treat it with an antihistamine.

Atopic Dermatitis

Pets that continually itch without relief may have allergen-induced atopic dermatitis. Atopic dermatitis is a condition that involves severe irritation of the skin usually due to inhaled or been in contact with the allergens.

If atopic dermatitis is left untreated, it can then lead to secondary infections due to an overgrowth of yeast or bacteria, so again you should see your vet as soon as possible with any concerns.

In general, the following are the most common symptoms associated with allergic reactions in pets

• Itchiness
• Hives
• Swelling of the face, ears, lips, eyelids, or earflaps
• Red, inflamed skin
• Sneezing
• Itchy ears
• Chronic ear infections
• Itchy, runny eyes
• Constant licking
• Diarrhea
• Vomiting

Readers will note that many of these symptoms could also be a sign of another veterinary condition. For this reason, only your vet can give you an effective diagnosis and treatment plan for the condition.

Types of Allergies

Allergies in pets generally fall under one of three main categories according to their cause – skin allergies, food allergies, and environmental allergens.

Skin Allergies

Skin allergies, also known as allergic dermatitis, are the most common type of allergic reactions in dogs and cats.

Flea allergy dermatitis is a specific form of allergy caused by an allergic reaction to fleabites. Some animals are allergic to flea saliva, which can make affected animals extremely itchy, especially at the base of the tail, and their skin may become red, inflamed, or scabbed.

You may also notice signs of fleas infesting your pet, such as flea dirt, or even see the fleas themselves if you brush their fur “against the grain” and inspect their fur closely. Flea allergies are most effectively treated by treating your dog or cat with a regular flea treatment.

Food Allergies

Food allergies and sensitivities can cause itchy or irritated skin, so don’t assume that just because your pet is scratching that the condition in necessarily skin-related.

The most common places dogs or cats with food allergies will tend to itch are their ears and their paws, and this may or may not be accompanied by gastrointestinal symptoms. Again, make sure your vet has all the required information about all changes in their food in order to make an effective diagnosis.

Environmental Allergens

Environmental allergens, such as dust, pollen, and mold, can cause an atopic allergic reactions or atopic dermatitis in pets.

In most cases, these allergies are seasonal, so you may only notice your dog or cat itching during certain times of the year. As with food allergies, the most commonly affected areas are the paws and ears (but also include the wrists, ankles, muzzle, underarms, groin, around the eyes, and in between the toes).

Diagnosing Allergies in Pets

If you have ever undergone allergy testing yourself, then you know that diagnosing allergies is an often complicated process, even with the best modern medical science has to offer.

But without an effective diagnosis of the actual allergen present, a tailored and therefore effective veterinary response is impossible.

The first thing your veterinarian may choose to do is rule out any other underlying condition that could be causing your pet’s symptoms.

If your veterinarian feels an allergy is the likely cause, they may propose allergy testing to try and determine the cause of the allergen that is causing the reaction.

However, keep in mind that even the best formal tests do not always return a positive response – diagnosis of allergic conditions is most usually an exercise in elimination and trial and error

Food allergies are often diagnosed using an elimination diet. A food trial consists of feeding your pet strictly one singular source of protein and carbohydrate for 12 weeks.

Veterinary Cytology – the ‘Gold Standard’ Test

Cytology involves examination of  the cells  from the affected area of the skin under a microscope.

Sampled fluid/ tissue from a patient is smeared onto a slide and stained. This is then examined for the number of cells on the slide, what types of cells they are, how they are grouped together and what the cell details are (shape, size, nucleus etc).

Fortunately, at Clyde Veterinary Hospital, we are equipped with the necessary tools for performing cytological exams right here on-site, allowing for the speediest possible diagnosis of your pet’s skin infection.

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