Allergies in dogs can be triggered just like humans, with a previously exposed substance that causes a reaction which makes the body believe it is being attacked. The immune system then sends out histamines to fight the “bad” substance that it believes is attacking the body. This produces swelling, itching, and redness to name a few. Therefore, the medication to treat your dog’s ear itching may actually make the problem worse. In extreme cases, some dogs can develop anaphylaxis, which can trigger a severe swelling of the airway and death from suffocation within minutes. This is a rare occurrence, but with medication allergies it can be especially bad, because the medication the veterinary experts suggest you give your dog for the allergy can be the worst thing to use.

Over the counter ear drops for dogs can actually cause your dog more itching and irritation than the condition you used the ear drops for. This can happen if your dog is allergic to one (or more) of the ingredients in the ear drops, such as sulfates, cortisone, antibiotic, antifungal, or antibacterial medications. The problem with many of these ear drops products is that they have so many different ingredients in them that it is hard to tell what your dog may be having a reaction to. However, the most often culprit is neomycin, which is an antibacterial medication. An allergic reaction to this or any other ingredient in ear drops can produce redness, irritation, itching, and inflammation (swelling). A serious complication, anaphylaxis, can also be triggered by the ear drops, which is fatal if you do not get help immediately. Anaphylaxis makes the blood vessels in your dog’s airway constrict, which can then cause suffocation and death. The best thing to do is to only use medications that are prescribed or referred by your veterinarian.

The possible symptoms of an ear drop allergy in your dog can vary depending on the health and size of your dog as well as which medication in the ear drops your dog is allergic to. Some of the most common signs of ear drop allergy are:

All dogs of any species, gender, and age can develop an allergy to ear drops, but it most often is seen in:

Ear drop allergies in dogs can be caused by any ingredient in the ear drops, whether they are active or inactive ingredients. Some of the most common are:

Your veterinarian will do a complete physical examination, taking special care to check the ears. Although it is hard to determine the exact cause of the allergic reaction, the veterinarian will use the information from you as well as the symptoms noted during the examination. Medical history and recent illnesses, injuries, and medications are essential to the diagnosis. Your veterinarian will also perform some laboratory tests, such as a complete blood count, biochemistry analysis, urinalysis, and fecal exam. There are also a couple of allergy tests the veterinarian can perform that may be helpful.

If you suspect your dog has had an allergic reaction to ear drops, you may have to ask your veterinarian to do a serum allergy test to find out for sure. This is done by taking a small blood sample and testing it under a microscope for signs of allergic response. If the test is positive, your veterinarian will send you to a dog dermatologist to do an intradermal allergy test.

This test is done by the dermatologist and costs a bit more than other tests, but it is considered to be the most accurate test for allergens. In this procedure, your dog will be sedated and they will shave the area to be tested (usually the abdomen or side). The dermatologist will use a small needle to inject your dog with different allergens (usually about 50 of them) and wait to see which ones become inflamed and red. This usually only take a few minutes.

First, the veterinarian will flush the ear and the ear canal with sterile saline solution to remove as much of the ear drops as possible. Anti-inflammatory wash with glucocorticoids will be used to reduce swelling and irritation. The veterinarian will also send you home with a prescription for this ear wash or the instructions to make your own with vinegar and water. A corticosteroid shot and antihistamines may also be given if necessary.

Usually, your dog will show improvement within the first 24 hours, and will continue to get better as long as you follow the instructions given to you by the veterinarian. Sometimes, you may have to return for more tests if the irritation and swelling have not cleared up or if the condition returns. While it is rare, your dog could be sensitive to the ear wash the veterinarian prescribed, so be sure to watch carefully for any signs of allergy and call your veterinarian if necessary.