Cat Allergies: Types and Symptoms

An allergy is an immune response sensitivity to certain substances that cause allergic reactions. These are classified as antigens or allergens.

Typically, allergens are inherently harmless (like pollen, foods, or dust), but in certain individuals, the body overreacts and stimulates an inflammatory response that causes allergy symptoms.

Can Cats Have Allergies?

Yes! Cats can have allergies. In fact, they are extremely common in cats.

Cats with multiple types of allergies are more difficult to diagnose, treat, and manage.

Allergies are typically a life-long condition that can impact a cat and pet parent’s quality of life.

While some breeds may be more prone to allergies, they can occur in all cats. Purebred cats are more likely to have airborne allergies than domestic short hairs.

Siamese cats tend to be more likely to have food allergies

Early intervention is critical to long-term success. As soon as you notice your cat may be suffering from allergies, call your veterinarian for an exam.

Types of Allergies in Cats

Veterinarians recognize these six major types of allergies in cats. These different types of cat allergies include:

• Food allergies

• Atopic dermatitis, or environmental allergies

• Flea allergy dermatitis

• Allergic contact dermatitis—when an allergen comes into direct contact with the skin to cause a rash

• Cutaneous drug eruptions—skin reaction to a medication

• Allergic bronchitis (feline asthma)

Signs and Symptoms of Allergies in Cats

Common symptoms of allergies in cats include:

• Excessive scratching or licking, including overgrooming

• Sores, scabs, crusting, tiny lumps/bumps, or acne

• Areas of flat, reddened, swollen skin (eosinophilic plaques)

• Areas of hair loss or thinning hair, poor or unkempt hair coat

• Coughing, wheezing

• Shortness of breath/trouble breathing

• Sneezing

• Watery nasal discharge

• Upset stomach (vomiting, diarrhea, change in appetite)

• Blood in stool

• Weight loss

• Facial swelling (most common around the lips, nose, and eyes)

• Hives

• Anaphylaxis

Difficulty breathing in cats is a veterinary emergency. If your cat is breathing with his mouth open or has labored breathing, seek veterinary care immediately.

What Are Cats Allergic To?

Cats can be allergic to a variety of things—so let’s look at the most common allergens to affect cats.

Food

The cause of food allergies in cats is poorly understood. Any protein, carbohydrate, preservative, additive, or dye can be potentially allergenic.

Typically, a cat’s immune system is overstimulated by a protein. The most frequently reported allergies are beef, fish, and chicken.

While cats can have allergies to grains, corn, or gluten, it is far less common than the main protein sources.

Some studies indicate Siamese cats and cats under 6 months old may have higher rates of developing food allergies.

Their Environment

Atopy, or environmental allergies, is characterized by inflamed, itchy skin disease. Genetic causes are not well documented in cats, but atopy occurs more often in Abyssinian, Devon Rex, and domestic short-haired cats less than 3 years old.

The most common causes of atopy are:

• Pollen

• Mold spores

• Yeast

• Dust and storage mites

• Animal or human dander

Allergic contact dermatitis is rare in cats and involves a delayed hypersensitive reaction at the site of contact with:

• Plants (pollen, grasses, trees)

• Medications (topical drugs, ear medications, soaps, shampoos, insecticides)

• Home furnishings (fibers, dyes, polishes, cleansers)

• Other (rice flour, chlorinated water)

Fleas

Flea allergic dermatitis occurs as a hypersensitive reaction to the flea’s saliva.

Cutaneous Drug Eruptions

Any drug can cause a cutaneous drug reaction. It can happen after one dose or multiple doses.

More common drugs that cause a drug eruption include antibiotics, anticonvulsants, antihypertensives, NSAIDs, and antiarrhythmic drugs.

Allergic Bronchitis

Asthma occurs when a cat’s immune system overreacts to allergen in the air causing airway inflammation and constriction of the airway.

Potential inciting allergens include:

• Cigarette smoke

• Poor environmental hygiene

• Dusty cat litter

• Hair spray

• Molds

• Pollen

• Powders

• Household chemicals

• Air fresheners

Allergy Tests for Cats

Allergy tests for cats vary. Tests may include:

• Skin cytology

• Skin biopsy

• Patch test for contact dermatitis

• Intradermal skin testing

• Radiographs (chest X-ray)

• Elimination diet trial

  • Novel protein diet

  • Hydrolyzed diet

• Using a flea comb

• Blood work to look at white blood cells

Treatment for Allergies in Cats

Depending on the cause of your cat’s allergies, treatment may include:

• Eliminating the offending food from your cat’s diet.

• Steroids (prednisolone/prednisone)

• Anti-diarrheal protocols including probiotics, a bland diet, and fiber and/or pectin supplementation

• Anti-nausea medication like Cerenia or Ondansetron

• Immunotherapy, or allergy vaccines

• Immunosuppressive therapy or drugs, like cyclosporine 

• Immunomodulating drugs like oclacitinib (Apoquel)

• Antibiotics and antifungals for secondary infections (Convenia or itraconazole)

• Pain medications (Onsior or gabapentin)

• Topical therapy

• Antihistamines (chlorpheniramine)

• Flea and tick treatment

• Hypoallergenic shampoos and wipes

• Hospitalization

• Oxygen supplementation

Recovery and Management for Allergies in Cats

With time, the commitment of loving pet parents, and a close relationship with a veterinarian, cat allergies can be managed. Your cat can enjoy a good quality of life.

Cat allergies can’t be cured, but with monitoring and early intervention if flare-ups do occur, cats can quickly return to normal.

Risk factors, especially with cats with atopy, include environments with long allergy seasons and high pollen levels.

Some allergies like flea allergies and contact dermatitis, become more severe and chronic as cats age. You can work with your vet to determine the best treatments to manage your cat’s allergies, given the specific diagnosis and their personality.