Veterinarian-written / veterinarian-approved articles for your dog.

Flea Allergy Dermatitis in Dogs

One flea bite can cause a big reaction in an allergic dog.

Your dog is scratching a lot all of a sudden. You don't think much about it until you suddenly see that she's developing a bald spot on her rump. That's when you decide to look closely, and you see it: a tiny, dark insect running for cover under the nearby hair.

Your dog has fleas.

Fleas Don't Always Cause Excessive Scratching in Dogs

You might be surprised to learn that fleas don't really cause that much itchiness in some dogs. The problem occurs in dogs that are allergic to flea saliva. For those dogs, even a few flea bites can trigger a full-body, prolonged, itchy reaction.

Flea allergic dogs can scratch like crazy, lose hair, develop secondary bacterial or yeast infections, and generally feel miserable.

What Are the Signs of Canine Flea Allergy?

Signs of flea allergy in dogs include:

  • Extreme scratching, licking, and biting at skin
  • Hair loss including the development of bald spots
  • Hot spots
  • Rump and tail head are often affected
  • Fleas or flea dirt may be found on the pet

How Is Flea Allergy Diagnosed in Dogs?

Your veterinarian will take a complete history of your dog's signs and do a thorough physical examination to diagnose flea allergy. Other conditions that can cause similar signs include:

However, the pattern of hair loss and scratching is often different for these conditions, and the history will likely be different, as well.

What Is the Treatment for Flea Allergy Dermatitis in Dogs?

Flea allergy is treated by getting rid of as many fleas as possible in your dog's environment (your home) and using a good flea preventative on all of the animals in your home.

Your veterinarian will help you decide the best, safest products for your home and each of your pets. Don't use any products in your home or on your pets without talking with your veterinarian first.

While you work on getting rid of the fleas, your dog may require medications to control the itchiness associated with flea allergy or to treat secondary infections. These medications may include antihistamines, steroids, antibiotics, and antifungal medications. Don't give your dog any medicine without checking with your veterinarian first.

Prevention Is Key for Flea Allergic Dogs

Once you determine that your dog has a flea allergy, prevention is the key to controlling it. Your dog may need to be on year-round flea preventative, and all of the other pets in your house will need to be on it, too. This will keep fleas from getting a foothold in your home, where they multiply and can become a difficult problem to solve.

You can learn more about fleas and dogs in these articles:

"Flea Control for Dogs"

"Dog Fleas: How to Look for Fleas on Your Dog"

"How to Treat Fleas in Puppies"

"Apple Cider Vinegar as Flea Control for Dogs"

"How to Apply Topical Flea Medications to Dogs"

You can also learn about other causes of canine scratching here: "Dealing With Canine Scratching and Licking."

You May Also Like These Articles:

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Food Allergies in Dogs

Hotspots in Dogs

Dog Fleas: How to Look for Fleas on Your Dog

Otitis Externa: Ear Infections in Dogs

Pediculosis: Lice in Dogs

Apple Cider Vinegar as Flea Control for Dogs

Lick Granuloma: Causes, Treatments, and Prevention of Acral Lick Granuloma in Dogs

Flea Control for Dogs


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