Amoxicillin Allergies in Cats

Amoxicillin allergies can be detected through an allergy skin test performed by a vet. But unfortunately, many cat owners do not realize their cat has amoxicillin allergies until a reaction occurs after exposure to the medication. At this point, your cat will need immediate medical attention. If an allergic reaction is left untreated, it can quickly become fatal, so it’s important to take your cat to a vet as soon as possible.

Amoxicillin is an antibiotic that is widely used to treat bacterial infections in cats. The most common brand names of amoxicillin are Clavamox and Augmentin. This medication is effective in treating respiratory, bladder, skin, ear, and tooth infections. However, some cats are allergic to amoxicillin, and if they are exposed to it, can experience a wide range of symptoms including skin rashes, fever, swelling, difficulty breathing, vomiting, and diarrhea. The exact cause of allergies—in cats and in humans—is unknown, so any cat could have amoxicillin allergies. 

If your cat is allergic to amoxicillin, any exposure to this medication will produce a reaction. Unfortunately, you may not know your cat is allergic to amoxicillin until he has one of these reactions. The severity of the reaction will vary from cat to cat, however the symptoms remain the same. Some of the symptoms you may observe include:

• Skin rashes
• Fever
• Facial swelling
• Swelling of the limbs
• Difficulty breathing
• Elevated heartbeat
• Vomiting
• Diarrhea
• Unsteadiness

Some cats have amoxicillin allergies, while others do not. There is no known cause for allergies, so it’s impossible to determine why your cat is allergic to amoxicillin. If your cat is allergic to amoxicillin, he will experience an allergic reaction after any kind of exposure to it. These reactions can be dangerous, so it’s important to work with a vet to determine if your cat has allergies early on in his life.

Your cat will not exhibit any symptoms of having amoxicillin allergies unless he has come into contact with the medication. If he has, bring him into a veterinarian as soon as possible. After the vet has stabilized his condition, he may suggest having your cat tested to determine what caused the reaction.

To identify allergens, a vet will perform a series of skin tests on your cat. The vet will administer a very small amount of any suspected allergens, including amoxicillin, foods, pollen, and dust, to the cat’s skin using a tiny needle that scratches the skin’s surface. After an allergen is applied to the cat’s skin, the vet will look for a reaction in the form of a red bump. If no bumps occur, the cat is not allergic to that allergen. 

These skin tests are usually only performed after your cat has experienced an allergic reaction to something. However, allergic reactions can be life-threatening. If you want to be safe and determine if your cat has allergies prior to a reaction occurring, talk to your vet about whether or not a skin test can be done in the absence of symptoms.

If skin testing reveals that your cat has an amoxicillin allergy, immunotherapy treatment may be performed. After the skin testing, the vet will create a special serum containing small amounts of the amoxicillin allergen. The serum will be injected into your cat in small quantities over time. The first injection will have the smallest quantity of amoxicillin, and the amount will gradually increase in every injection after the initial one. As a result of this treatment, your cat will experience less severe symptoms if he is ever exposed to amoxicillin again. 

The first injection will likely be administered in the vet’s office so the vet can closely monitor your cat’s reaction to the serum. But after the initial injection, the vet may ask if you are comfortable administering the next treatments on your own. If you don’t feel comfortable, you can make appointments to bring your cat into the vet for his injections.

Most cats will respond very well to immunotherapy, and will no longer exhibit any severe symptoms if they are exposed to amoxicillin. To get the desired results, it’s important that you closely follow your vet’s instructions and administer all injections as required. 

While your cat is being treated, or if you choose not to do immunotherapy, you will need to prevent any exposure to amoxicillin to avoid an allergic reaction. Amoxicillin is often prescribed when your cat has an infection, so you will need to ensure your cat is never given amoxicillin when being treated. Make sure you always remind your vet that your cat has an amoxicillin allergy so he knows never to administer this medication when your cat is sick.