7 Signs of an Allergic Reaction in Dogs

Dr. Casey Smallwood

Oct 7, 2020

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Do you think your dog might have allergies? Have you noticed your pet suffering from acute allergic reactions or from long-term seasonal allergies? If you think there’s a chance your dog is dealing with any type of allergy, it’s important to speak to your vet about this problem sooner rather than later.

However, you can also read up on the different types of dog allergies and what to do in case you notice symptoms in the article below.

Types of Dog Allergies 

Below, we’ve gathered a list of the four most common types of allergies in dogs. Each of these allergies has its own causes and treatments, but understanding the categories can make a big difference in how well you recognize your dog’s allergic reaction.

Food Allergies

This is usually apparent when they have a sick stomach (most commonly seen as vomiting and diarrhea) after eating certain types of food.

However, food allergies may also present as skin conditions or fur loss, so be on the lookout for skin and hair problems in your dog to determine whether or not your pet may have this problem.

Skin Allergies

Skin allergies are often caused by exposure to flea/ticks, plants or yard treatment chemicals that cause your dog’s skin to become irritated.

Clinical signs seen most commonly with this are redness of skin itself, itchiness, or even the presentation of hives (small raised red bumps over the skin). There may be other causes such as a new detergent, but you’re likely to see the problem resolve itself quickly when you remove the irritant from your dog’s common areas.

Your dog and cat should also be on regular flea/tick preventative as well which you can get through your primary veterinarian.

Seasonal Allergies

Some dogs suffer allergic reactions from seasonal allergies, just like people do.

If you notice your dog getting sick (ear infections, licking or chewing at their feet, sneezing, etc) around the same time every year or notice him sneezing more often when he’s been outside all day, there’s a chance he has seasonal allergies. It’s important to rule out other factors, however, to make sure this is the case.

Acute Allergies

Dogs who have sudden allergic reactions to irritants have acute allergies. These are most commonly caused by insect bites or stings, but they may have other causes as well. You will often see facial swelling, vomiting, or even more severe signs of trouble breathing and collapse if they undergo a true anaphylaxis reaction.

Acute allergies may need immediate vet treatment and will require you to keep an eye on your dog.

Symptoms of Allergic Reactions in Dogs and What to Do

If you are ever in any doubt about the severity of your dog’s condition, contact your vet or go to an emergency vet immediately.

Here are some of the most common allergic reactions in dogs and what you should do if you notice them:

Itchiness and Hives

If you notice your dog scratching a lot or see hives or redness on his skin, then he may have an allergy. These reactions are common in all types of allergies.

If they are the only symptoms you notice, you can wait a day or two before scheduling a vet visit. However, if they’re coupled with any other symptoms, plan to get to the vet soon.

While it does not always work in dogs/cats, you can also administer Benadryl to help with clinical signs and irritation. Call your local VEG for instructions on giving Benadryl to dogs.

Diarrhea, Vomiting, and Upset Stomach

If your dog is having diarrhea or is vomiting, it’s best to schedule a vet visit as soon as possible so your dog can get the care he needs right away as this may be a sign of an early anaphylactic reaction.

Itchy Ears

Itchy ears can usually wait until your next vet visit for attention, as they aren’t usually a sign of anything life-threatening.

However, if your pet is increasingly uncomfortable and/or starts to have any trouble walking or a tilted head to one side, head to the vet for treatment as soon as possible.

Sneezing and Runny Nose

When sneezing and runny nose are accompanied by fever or by any other symptoms on this list, they require vet treatment right away.

They may be signs of seasonal allergies and could be very benign, but it’s important for your vet to check for the cause of your dog’s allergic reaction.

Runny Eyes

Runny eyes need to be checked out by a vet even if you think they’re just an allergic reaction in dogs.

Many upper respiratory infections in dogs present with runny eyes early on, and this can also be a symptom of damage to the eye itself (scratch or ulceration of the cornea). Rule out these potential issues by taking your dog to the vet to find out what’s causing his eyes to be runny.

Licking Frequently or Skin Chewing

If your dog chews or licks his skin—especially his feet—frequently or seemingly nonstop, this is a sign he’s dealing with some form of allergies.

The problem could come from exposure to irritants in the backyard or on walks, but it may also be a symptom of food allergies in your dog. Although the problem isn’t an emergency, you’ll need to go to the vet in the coming weeks to determine how to treat it and what the underlying cause might be.

Swollen Face

A dog with a swollen face is suffering from an acute allergy, most likely related to an insect bite or sting. This may also be a sign your dog has breathed in an allergen, such as a large amount of pollen.

If you see a swollen face or snout, this is a sign that your dog may be headed into anaphylactic shock. Although dogs with a swollen face don’t always suffer anaphylaxis, it is common. We recommend bringing your dog in to be seen by an emergency vet if there is any facial swelling so that it can be treated and prevented from getting worse, which could lead to other signs such as trouble breathing if there is enough swelling.

See a Vet for Allergic Reactions in Dogs

Now that you know a little bit more about what to expect from your dog’s allergic reactions, you can determine whether or not to schedule a vet appointment right away or wait until the next scheduled checkup.

Either way, it’s important to talk to your vet about your dog’s allergies and find out the best course of action for treatment. If there’s ever a doubt on how you think you should proceed, it’s always best to call a veterinarian right away so you can get your dog the help he needs for his allergic reactions. 

The veterinarians at VEG are here and ready to answer and questions and help with any allergic reaction in a dog’s situation. There are expert and compassionate emergency vets at every one of our VEG locations, so you never have to wait until your next appointment to seek immediate veterinary advice and care.