Cat allergies are one of the most troublesome health concerns our best friends face. While allergic reactions are not all fatal, they can affect our cat’s comfort and overall well-being.

These reactions happen when the cat’s immune system overreacts to an allergen, leading to various symptoms specific to the cause. 

Unfortunately, allergies in cats can appear out of nowhere, and sometimes, they might not always be known. To help you get a good idea of what allergies are and what to do, here’s a quick guide.

What are the Common Types of Allergies in Cats?

Cats can develop allergies to many different substances, many of which can be present in homes and outdoor spaces. Here are the common types of allergies in cats:

Flea Allergy Dermatitis

Cat fleas are a troublesome pest. Flea allergy dermatitis is the most frequently diagnosed type of allergy in cats. Unlike a standard reaction to fleas, this condition is caused by a hypersensitivity to proteins in flea saliva. 

Just a single flea bite can result in an intense immune response in sensitive cats. 

FAD can occur even with minimal exposure to fleas, since their immune systems can react disproportionately to the allergen. If these are left untreated, the resulting skin irritation can worsen and serve as a breeding ground for secondary infections like bacteria and fungi. 

It’s important to be cautious all year round, but most especially during the warmer months. Here are the common signs you can expect: 

• Skin Irritation. Intense itching and scratching are the common signs of flea allergies in cats. The affected areas are often localized around the base of the tail, neck, and head.

• Hair Loss. Patches of hair loss and balding often result from overgrooming, which can also be seen as too much chewing, scratching, and biting. 

• Redness and Inflammation. Your cat’s skin may appear red and inflamed, especially in areas most affected by the flea bites. 

• Scabs and Crusty Lesions. Small, raised scabs or crusty sores, commonly referred to as "miliary dermatitis," are a common sign of an allergic reaction to flea saliva. 

• Secondary Infections. Too much scratching and biting can break the skin, which increases the risk of bacterial or fungal infections in cats. 

Food Allergies

Food allergies in cats come from an immune response to specific proteins and ingredients in their diet. These allergies are not the same as food intolerances. Cats can develop specific food allergies at any stage in their lives, even to foods they have consumed for years.

Some of the common triggers include ingredients such as beef, chicken, eggs, dairy, and grains. Even fillers and artificial additives in cat food can cause an allergic reaction. Common symptoms of a food allergy in cats include:

• Digestive Symptoms. Digestive issues such as vomiting, diarrhea, and flatulence are common when cats are allergic to the food they eat. Some cats may exhibit abdominal pain or discomfort.

• Itchy and Irritated Skin. Itchiness is often concentrated around the neck and head. You might notice this when your cat starts to scratch these areas or feels overly uncomfortable. 

• Redness and Crusty Skin. Redness may be a result of food allergies in cats. Small crusts around the skin can also be another result.

• Poor Coat Quality. The fur may become dull, brittle, or patchy due to the impact of the allergy on overall health. Hair loss can also be present.

Environmental Allergies

Environmental allergies occur when a cat’s immune system reacts to allergens in its environment. These allergies may be seasonal or year-round. These include dust mites, mold spores, pollen, and dirt. 

Cats with environmental allergies often have heightened sensitivity, meaning multiple allergens can cause symptoms simultaneously. These include: 

• Persistent Scratching. You can observe persistent scratching or itching that worsens during specific seasons or can be constant throughout the year.

• Respiratory Symptoms. Sneezing, coughing, and nasal discharge are possible symptoms of an allergen that has irritated the airways. Feline asthma is a common condition that results from this..

• Skin Issues. Redness, rashes, or scaly patches are often present on the face, belly, and paws. 

• Behavioral Changes. Your cat will tend to groom more, become visibly irritated, or appear stressed.

Contact Allergies

Although less common than other types, contact allergies arise when a cat’s skin comes into direct contact with an irritating substance. Unlike environmental allergies, which are usually airborne, contact allergies require physical exposure to the allergen.

For cats, some observed contact allergens include fabrics, shampoos, and bowls. Basically, anything your cat touches can be a contact allergen if your cat is allergic to it. These allergies cause localized reactions, depending on where they hit.

Symptoms of contact allergies in cats include:

• Localized Irritation. A clear sign is localized irritation. You can see red, inflamed skin in areas that were touched by the allergen, often the paws, chin, or belly.

• Swelling or Bumps. Small, raised bumps or hives may develop where the allergen made contact.

• Persistent Scratching. Too much itching and scratching can be observed, which will ultimately lead to hair loss if left to progress.

• Behavioral Indicators. Cats may avoid areas where they notice the start of the irritation or may hide in secluded areas.