Allergies are on top of the most common clinical conditions that affect cats. An allergy happens when the cat's immune system is oversensitive or overreacts to foreign bodies called allergens.
Allergens are proteins that the body's immune system tries to eliminate. The most common allergens that affect humans are pollen, dirt, mold, and pet hair.
This hypersensitivity to allergens in felines can usually manifest in three ways: itch (when it affects the skin), difficulty in breathing (when it affects the respiratory system), vomiting, and/or diarrhea (when it affects the gastrointestinal system).
Six Types of Allergies
Experts recognize six different kinds of allergies in cats:
- Flea allergy;
- Atopic dermatitis (or environmental allergies);
- Food allergy;
- Contact dermatitis;
- Cutaneous medication eruptions; and
- Allergic bronchitis, or feline bronchial asthma.
Let's discuss each of these below.
Symptoms of Allergies in Cats
All allergic reactions can trigger similar, overlapping symptoms. However, these signs and symptoms may have different intensities and develop over time.
A flea allergy is the most common allergic reaction in cats. Despite popular belief, the average cat experiences only minor skin irritability due to fleabites. On the other hand, cats that have flea allergies can have severe reactions to a single fleabite. This reaction is caused by the immune system's response to antigens in the flea's saliva. When a flea bites a cat to suck blood, it injects saliva into its skin. One fleabite is enough to cause extreme itching and trigger hair loss.
In flea allergies, there can be scabs or open sores on the skin, resulting in a second microbial skin infection (pyoderma). These scabs are typically called miliary dermatitis, a term coined since the scabs look like millet seeds. These scabs will be seen on the skin—especially on the head, neck, inner thighs, the base of the tail, and abdomen.
Most cats with flea allergies have a history of either poor or no flea control.
In humans, atopy is often called 'hay fever.' Atopic dermatitis or atopy generally describes allergies to ecological allergens such as plant pollens, yards, mold and mildew, and house allergens. Several of these allergic reactions, such as ragweed, cedar, and lawn pollens, occur seasonally. Nevertheless, others are non-seasonal, like molds, mildew, and house allergens.
This allergy can have similar symptoms to food allergies. Itching is also the most reported sign, along with ear infections, hair loss, skin plaques, and pustules. Frequently, cats suffer from relapsing secondary microbial and/or yeast infections. Atopic allergies can likewise have asthma-like breathing difficulties, as well as conjunctivitis.
Treatment for Atopic Dermatitis
The first approach entails utilizing corticosteroids and improving the health coat, using a therapeutic 'spot-on' spray and/or shampoo. In most cases, steroids will dramatically block allergies, and a rapid improvement in the symptoms will be observed. Depending on the feline's condition, steroids might be offered orally or by injection.
Another drug that can be used is antihistamines. Some cats react well to certain antihistamines, while others can be ineffective. Antihistamines can take 7-10 days to take effect. Therefore, they are not ideal for abrupt flare-ups. Similarly, essential fatty acids such as fish oils are inadequate during short episodes because they need several weeks to take effect. Cats susceptible to atopic dermatitis may be given fatty acid supplements that can help reduce future flare-ups.
Another treatment for felines with atopy is immunosuppressive drug therapy. These medicines especially target the immune cells involved in atopic dermatitis to minimize the hypersensitivity response that the body is experiencing. The effect can take up to one month. Therefore, it is not used for abrupt flare-ups.
Food allergies have very comparable symptoms to environmental allergies. They are usually reactions to the protein part of the food (e.g., beef, pork, hen, or turkey). Proteins in vegetables like those found in corn and wheat, food additives, and chemicals may also cause food allergies. A food allergic reaction might create any of the medical indicators previously discussed. However, not all cats with food allergies will have intestinal signs like vomiting, diarrhea, gassiness, and hypersalivation. Many will instead show skin symptoms, including itching around the face, head, and neck. Food allergies will typically be non-seasonal, meaning they happen all year round.
Your vet may suggest food allergy testing if symptoms have been persistent for numerous months, if the cat does not respond well to steroids, or if a kitten cat itches without other noticeable reasons. The process will be a trial and error of elimination or feeding a hypoallergenic diet. The cat will be fed ingredients they never had before (like duck, rabbit, etc.). Because it takes eight weeks for all other food to be totally out of the body, the cat must eat the special diet regimen for 8 to 12 weeks.
Allergic Contact Dermatitis
This type of allergy usually shows up as lesions on the skin after direct exposure to triggers such as pollen, yeast, or mites. The area affected is determined by direct contact. Most cats with contact dermatitis will show symptoms such as redness, swelling, bumps, and crusting where the skin is exposed. Itching on the areas of contact may be moderate or severe.
Cutaneous Drug Eruptions
These are allergic reactions to any type of medicine. They vary in symptoms, location, and extent. Cats commonly experience itchiness, rashes, inflammation, swelling, hives, and, in serious situations, cellular death and also sloughing of the skin. But do not worry; this kind of severe allergic reaction is rare.
Allergic bronchitis is also called bronchial asthma. Felines usually hiss, cough, and struggle to breathe.