Understanding Allergies in Dogs and Cats

by Lorna Orchard

Causes

Allergies occur when a pet’s immune system overreacts to substances that are normally harmless. In dogs, the most common types of allergies include environmental allergies and food allergies, whereas cats are mostly commonly prone to flea allergies, followed by environmental and food allergies.

  • Environmental allergies (atopy) are triggered by things like pollen, mould, dust mites, or grass. These allergies can be seasonal, worsening during spring and summer when pollen counts are high, or in the winter when house dust mites are more problematic
  • Food allergies are triggered by certain proteins in their diet, such as beef, chicken or fish
  • Flea allergic dermatitis is caused by a reaction to flea saliva. Even a single flea bite can trigger severe itching and irritation

Common Symptoms

Allergic reactions in pets often manifest through skin problems. Itching (pruritus) is the most frequent sign. Pets may excessively lick, chew, or scratch their skin, particularly their feet and ears leading to redness, hair loss, or scabbing. Other symptoms include recurrent ear infections or chronic gastrointestinal issues like having a ‘sensitive tummy’ and having regular soft poos. Cats may also develop over-grooming habits, leading to bald spots and skin lesions on their tummy.

Diagnosis and Treatment

Diagnosing allergies in pets can be a complex process, often involving a combination of veterinary examination, allergy testing, and elimination diets. Your vet may recommend ruling out parasites, conducting blood tests to check for environmental allergens, or trialling a hydrolysed diet to identify the food culprit. Equally some pets suffer from a combination of allergies making diagnosis more challenging.

While allergies cannot be cured, treatment aims to manage symptoms effectively. Below is a summary of treatment options

  • Atopy: reducing exposure alongside medicated shampoos, antihistamines, anti-itch therapies (Apoquel, Cytopoint Zenrelia), corticosteroids, or immunotherapy and your vet will be able to guide you on the most appropriate treatment for your pet
  • Food allergies: dietary adjustments are essential involving switching to a hydrolysed diet such as Purina HA, Royal Canin Anallergenic/Hypoallergenic or Hills z/d
  • Flea allergic dermatitis: strict flea control for both the pet and its environment

Early detection and consistent management are key to improving your pet’s quality of life. Allergies can be frustrating for pets, owners and vets but by staying vigilant and working closely with your vet, you can ensure that your dog or cat leads a happy, comfortable life—free from the constant irritation of allergies.