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itchy dog

We frequently hear these statements and questions from our pet parents: “My dog is constantly scratching or licking and even wakes me up at night! What can I do about it!?” Or “My cat is always scratching his face!” Everyone is miserable and it seems like there is no end in sight. In order to ditch the itch, we must figure out the cause, so let’s explore some common causes of pet itching:


Allergies are the most common cause of itching in dogs and cats. With an allergic patient, the immune system inadvertently learns to respond to an otherwise harmless substance and tries to fight the insulting substance (like pollen or mold). This abnormal response creates inflammation and stimulates the nerves in the skin – thus the itch! Between the inflammation and the traumatic itching, the skin barrier breaks down allowing moisture to escape and bacteria to get in. This causes even more inflammation and nerve sensation – thus more itching!
Allergies come in 3 broad categories:

Environmental Allergies

Environmental allergies also called “atopic dermatitis” is an irregular response to pollens, dander, mites, molds, etc. in the environment. They may be seasonal triggers like ragweed pollen, year-round triggers like the dust mites in our homes, or sporadic triggers like the molds that form after rain and snow. Patients usually develop atopic dermatitis between 6 months and 6 years of age. Dogs will lick mostly at the feet, bite at their legs, and scratch at their face and sides. Cats typically scratch their face and develop baldness and sores around their face and neck. Environmental allergies are nothing to sneeze at (pardon the pun) and can become
extremely severe and can even cause kidney failure if not treated aggressively enough.

Food Allergies

Food allergies develop with a gradual increase in sensitivity to proteins in food (or in some cases, starches, but it’s rare). Over time, repeated exposure to the protein causes the body to begin reacting. In some cases you can see gastrointestinal symptoms however, most of the time you see symptoms develop in the skin of our pets. Dogs can experience ear infections (usually one sided), feet licking (usually underneath the paws) and bottom scooting or licking. Some dogs will have generalized scratching as well. Cats experience very similar symptoms to environmental allergies.

Although any protein can create an allergic response, the most common proteins are beef/bison, chicken, fish (in cats) and wheat and soy. Pets can develop a food allergy at any time in life.

Flea Bite Hypersensitivity

Some pets will itch simply because a flea is feeding on their skin and this causes a local histamine response – like when we are bitten by a mosquito. Flea bite hypersensitivity is a bit different however. An exuberant response to the saliva of the female flea causes lesions which are far worse for your pet. Luckily, here in Colorado we don’t see flea problems too often but when we do, the lesions are most often over the pet’s lumbar or pelvic region and can occur at any age.

Acral Lick Dermatitis – that’s quite the mouth full

Most commonly seen in dogs, it is better known as a Lick Ganuloma. This is a slowly progressive, self-trauma-induced skin lesion that is created from excessive licking or chewing at one area of a limb. This licking is a response to some underlying cause such as allergies, nerve or joint pain, boredom or anxiety, trauma, foreign material (like a fox tail in the skin) or a skin infection.

Skin Infections

Skin infections also called pyoderma develop from bacteria and yeast that is naturally occurring on our skin, our pets are no different. Some pets develop an overgrowth of these nasty pathogens which can cause intense itching.


Parasites on the skin such as ringworm, lice, fleas, and mites can also cause itching and sores. Some of these can be contagious to us, so make sure your veterinarian looks for these.

Endocrine Disease

Endocrine diseases such as Cushing’s syndrome or hypothyroidism or even diabetes mellitus. Blood work is indicated to help your veterinarian rule out these common disease processes and begin appropriate therapy.

Epitheliotropic lymphoma

Epitheliotropic lymphoma is a form of skin cancer that can create dry, flaky and itchy skin that looks like allergies. This is luckily a rare condition.

So, What should I do about excessive itching in my pet?

As you can see, there are many reasons why your pet may be keeping you up at night while they itch, scratch, or lick. So, before you reach for that bottle of Benadryl or ask the stock boy at the local pet store what to use to ditch the itch, call your veterinarian! A proper diagnosis is needed to rule out more severe problems. Simple diet changes may be indicated, medication for parasites might be needed, or we may have to start therapy for allergies!