Author TB Thompson DVM has been a licensed, practicing veterinarian since 2000.
When the techs told me my next appointment was for a cat having an allergic reaction, I felt a surge of adrenaline.
I didn’t know whether to expect a cat in a life-threatening situation or a healthy cat with red spot on its skin. There is such a huge range of severity with these cases!
Today, I want to help you recognize the symptoms of allergic reactions in cats and understand how to help them.
KEY POINTS
- Allergic reactions are an over-reaction of the immune system.
- Most allergies are mild and may only require minimal treatment.
- Severe allergic reactions can cause weakness, vomiting, and diarrhea. They require immediate veterinary treatment.
What Is an Allergic Reaction?
Think of your cat’s body as a castle and their immune system as soldiers guarding a castle.
Normally, these soldiers protect against real threats like viruses and bacteria. However, during an allergic reaction, they mistakenly attack harmless visitors like pollen or flea saliva, thinking they’re deadly invaders.
This overreaction releases histamine, leading to symptoms such as skin swelling or redness. While mild reactions may only cause discomfort, severe cases can significantly impact your cat’s health and require urgent veterinary attention.
[VIDEO]
Katie the cat had an allergic reaction to a vaccine.
Common Allergens
Identifying what triggers an allergic reaction can aid in a cat’s care. Below is a table of common allergens:
| Allergen Type | Examples |
|---|---|
| Foods | Beef, fish and chicken are most common (1) |
| Environmental | Pollen, mold, dust mites |
| Fleas & Other Parasites | Flea saliva (flea allergy dermatitis) |
| Household Items | Perfumes, cleaning products, certain cat litter |
| Drugs/Medication | Certain antibiotics, vaccines, flea drops or other medications |
Symptoms of Allergic Reactions in Cats
Allergic reactions produce a range of symptoms from very mild to extremely severe.
Mild to Moderate Symptoms
The most common type of allergic reaction in cats involves only the skin and produces mild symptoms.
- Itching and Scratching: Excessive itching, licking, or chewing of the skin.
- Skin Changes: Swelling, redness, pain, bumps, hair loss, or open sores from scratching.
- Respiratory Issues: Sneezing, coughing, breathing fast or wheezing, especially with environmental allergens.
- Behavioral Changes: Withdrawn or irritable behavior due to discomfort.
Severe Allergic Reaction: Anaphylaxis
The most severe form of allergic reaction in cats is called anaphylaxis and fortunately, it doesn’t occur very often.
An anaphylactic reaction is a severe and rapid allergic response in cats. (2) It can cause
- Collapse
- Vomiting and/or diarrhea
- Very pale gums
- Difficulty breathing
- Swelling, redness or bruising of the skin
This type of reaction is extremely urgent and can be life-threatening without immediate veterinary care.
Diagnosing Allergies in Cats
Diagnosing allergies in cats often starts with your observations and a vet’s expertise.
Your vet may suggest skin or blood tests to identify specific allergens. Sometimes, an elimination diet is recommended to pinpoint food allergies. Your role in relaying information about possible allergy triggers and patterns of symptoms is vital in helping your vet make an accurate diagnosis.
Treating Mild to Moderate Allergic Reactions
Once an allergic reaction in a cat is diagnosed, the next step is treatment. The goal is to relieve symptoms and prevent future reactions. Here are some common treatment approaches:
- Avoidance: The best treatment is to avoid the allergen. For example, if your cat is allergic to a specific food, removing it from their diet can prevent reactions.
- Medications: Depending on the severity, your vet might prescribe medications. These can include antihistamines to control itching or steroids to reduce inflammation.
- Topical Treatments: For skin-related allergies, special shampoos or creams can help soothe irritated skin.
- Immunotherapy: Allergy shots (immunotherapy) can train your cat’s immune system to stop over-reacting. Immunotherapy gradually desensitizes the cat’s immune system to the allergen.
- Flea Control: For flea allergies, maintaining a strict flea control regimen is essential.
- Environmental Modifications: For environmental allergies, changes like air purifiers, regular cleaning, and hypoallergenic bedding can help.
First Aid for Allergic Reactions in Cats
If you suspect your cat is having an allergic reaction, you can use first aid while preparing to see a vet. Here are some steps:
- Stay Calm: Take a deep breath and prepare to help your cat. Make sure the kitty is indoors, restrained in a cat carrier or leashed.
- Remove Allergens: If you suspect an insect sting or contact allergy from something like flea/tick preventive drops, remove the offending material. Look for a small stinger (1/16th inch long or so), especially around the paws and face. Pull it out with tweezers if you find one. Use mild soap and water to wash any chemicals from the fur and skin.
- Monitor Symptoms: Observe for any worsening signs like difficulty breathing or swelling.
When to See a Vet
Moderate to severe allergic reactions can progress very quickly. Take your cat to a vet clinic immediately if you notice
- Weakness
- Unusual breathing pattern (too fast or too slow)
- Bruising or bleeding
- Unconsciousness or seizures
If your cat had a mild allergic reaction that has not improved significantly with home care and first aid after 24 hours, you should see a vet.
FAQs
How long does an allergic reaction last in cats?
The duration of an allergic reaction in cats can vary. Mild reactions may last a few hours to a couple of days. However, if the allergen continues to be present, or if the reaction is severe, symptoms can persist longer. It’s important to identify and remove the allergen and consult a vet for proper guidance.
Can I give my cat Benadryl for an allergic reaction?
Yes, Benadryl (diphenhydramine) is often used to treat mild allergies in cats. However, it’s important to consult your vet before giving your cat any medication. They will provide the correct dosage and instructions based on your cat’s specific needs and health condition.
Can a cat become allergic to something suddenly?
Yes, cats can suddenly develop allergies to substances they’ve been exposed to for a long time without any issues. This sudden onset can be due to changes in the cat’s immune system. If you notice any allergic symptoms in your cat, it’s best to have them evaluated by a vet.
