Managing Pet Allergies & Sensitivities

“Allergies” are one of the most commonly misunderstood conditions seen in veterinary practice. Many pet owners don’t realise their pet has an allergy or sensitivity at first, even though the signs themselves are often very noticeable.

Common symptoms include:

1. licking or chewing paws (often in the evening or at rest)
2. frequent scratching,
3. recurrent ear infections
4. rubbing the face on furniture
5. hair loss
6. red, inflamed skin

Over time, untreated allergies can lead to thickened, darkened skin and secondary bacterial or yeast infections.

While these signs are usually recognised early, understanding what they actually mean, and what’s causing them, can be confusing. This is where knowing the difference between an allergy and a sensitivity becomes important.

Allergy vs Sensitivity: What’s the Difference?

True Allergies

A true allergy is an immune system reaction. Your pet’s body overreacts to something that is normally harmless, triggering inflammation, itchiness, and skin or ear problems. Because the immune system is involved, true allergies tend to be persistent and recurring unless properly managed.

Sensitivities or Intolerances

Sensitivities (sometimes called intolerances) do not involve the immune system. They are usually related to digestion or irritation and may cause symptoms like loose stools, mild itching, or discomfort, but typically without severe inflammation or chronic skin disease.

This distinction matters because allergies require a different diagnostic and treatment approach. Treating a true allergy as a simple sensitivity often leads to frustration and ongoing symptoms.

Are Allergies for Pets the Same as Allergies for Humans?

This is a really good question, and it is where a lot of confusion can arise. What we are familiar with calling allergies in humans is not the same as allergies in pets.

In simple terms, when we talk about allergies in dogs and cats, we are referring to immune-mediated responses. These are inappropriate reactions of the immune system to things like food proteins (beef, chicken, pork, lamb, salmon etc) or environmental allergens. In pets, these immune responses most commonly show up as chronic skin and ear disease (itching, recurrent ear infections, licking/chewing, skin infections), and sometimes ongoing gastrointestinal signs. They are usually long-term conditions rather than sudden reactions. These are not sensitivities.

Acute reactions such as hives, facial swelling or anaphylaxis can occur in pets, but they are relatively uncommon and are most often associated with things like insect stings, vaccines or medications, rather than food or everyday environmental allergens. These acute reactions are what we might commonly refer to as allergies in people, or an allergic reaction, but this is not what we are talking about in animals.

Food intolerances in our pets are not immune-based. They tend to relate to difficulty digesting or processing certain ingredients and are generally less clinically significant from a veterinary perspective. While they may cause intermittent digestive upset, they aren’t classified as a disease and they result in very transient signs. You may have an animal where a type of food doesn’t agree with them and they have some diarrhoea, but they are absolutely fine on a different type of food. This would be an intolerance or a sensitivity to a type of food. So this isn’t a disease or a medical issue, just a simple switch of food will solve the problem. You would also not expect to get any other signs with a sensitivity other than some mild Gastro Intestinal upset.

The Three Main Types of Allergies in Pets

In general, allergies in pets fall into three main categories: parasitic allergies, food allergies, and environmental allergies.

Finding the cause requires a clear approach guided by a veterinarian, as expert advice is essential for accurate diagnosis and effective treatment.

1. Parasitic Allergies: Always the First Step

The most important allergy category to rule out first is parasites.

Fleas, mites, lice, and even hookworms can irritate the skin or trigger allergic reactions. Some pets are so sensitive that a single flea bite can cause intense itching, redness, and hair loss. This reaction is known as flea allergy dermatitis.

Because parasites are such a common trigger, effective parasite control is always the first step in any allergy investigation. Without addressing this, other treatments are unlikely to work.

This is why visiting your veterinarian is essential, as they can ensure your pet receives the correct treatment for the specific parasite involved.

2. Food Allergies: Less Common, Often Misunderstood

True food allergies are immune-mediated reactions to specific dietary proteins, most commonly meats such as chicken, beef, pork, or lamb. They can develop at any age, but often appear in young pets, sometimes before one year of age.

Common signs of food allergy include:

• Persistent itching or scratching
• Red, inflamed skin
• Recurrent ear infections
• Smelly skin or skin infections
• Sometimes chronic or recurring diarrhoea

How Are Food Allergies Diagnosed?

The only reliable way to diagnose a food allergy is through a strict veterinary-guided food trial.

It’s important to see your vet before starting a trial, as any existing skin infections or inflammation need to be treated first. The trial must use a veterinary-prescribed hypoallergenic or novel protein diet. Over-the-counter “sensitive skin” or “sensitive digestion” foods are not suitable, as they do not contain the required hydrolysed proteins.

Food trials are challenging because they must be 100% strict:

• No treats
• No table scraps
• No chews or flavoured medications

Most trials last six to eight weeks. Even a single treat can invalidate the results and mean starting again from the beginning.

3. Environmental Allergies: Atopic Dermatitis

If parasites and food allergies are ruled out, the final category is environmental allergies, often diagnosed as atopic dermatitis.

These allergies are triggered by substances in the environment such as:

• Pollens
• Grasses
• Dust mites
• Moulds

Environmental allergies may start as seasonal but often become year-round over time. While they cannot be cured, they can usually be managed very successfully with the right combination of:

• Medical treatment
• Lifestyle adjustments
• Ongoing supportive care

Managing Allergies: There’s No Quick Fix

Allergy management is rarely about a single treatment. Instead, it focuses on:

• Identifying the trigger where possible
• Reducing the overall allergic load on the body
• Treating secondary infections and inflammation

Most importantly, knowing when to involve your veterinarian is crucial.

Persistent itching, repeated ear infections, hair loss, skin redness, or ongoing discomfort should never be considered “normal,” even if they’ve been happening for a long time.

Final Takeaway

Pet allergies can be complex, but they are manageable.

By understanding the difference between allergies and sensitivities, recognising early warning signs at home, and working closely with your veterinary team, you can significantly improve your pet’s comfort and quality of life.

A less itchy, more comfortable pet isn’t just possible; it’s achievable with the right approach!