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Reasons Dogs Itch or Scratch Themselves

Have a dog scratching an itch unrelated to fleas or ticks? There are many possible reasons unrelated to surface parasites.

Melvin Peña  |  Oct 6th 2015


Scenario: Your dog’s hind legs are constantly working at an area behind her ear, trying to scratch an unfathomable itch. Perhaps she’s rubbing against a piece of furniture, focusing on a bit of her side that she cannot reach with her fore or hind claws, trying to find some relief. You are puzzled because she regularly takes medication to prevent fleas and ticks from flourishing, wears a treated collar, or just had a bath last week. Like any good dog owner, you want to do something, but don’t know where to start.

Take heart! There are plenty of reasons dogs itch or scratch themselves that do not involve fleas or ticks. We’re going to examine symptoms beyond itching and scratching that you can look for and their possible causes. Narrowing down the list of suspects can help you and your veterinarian isolate the issue and relieve your dog’s suffering. Some may be environmental, some are medical, and still others may be so obvious that you overlook them completely. Determining the cause of your dog’s irritation is the first step to addressing the problem!

reasons dogs itch or scratch themselves

No fleas or ticks, but the dog is still scratching? (Photo by Taro on Flickr)

Today we’re looking at:

  • Allergies
  • Dry skin
  • Fungal infection
  • Hot spots
  • Mange
  • Boredom and stress

Allergic reactions can cause scratching

When we think of our own allergic reactions — to external stimuli or other triggers — our minds may first turn to respiratory responses, things like sneezing, stopped-up noses, trouble breathing, and the like. Dogs can sneeze, too, but any number of allergens can cause dogs to scratch themselves uncontrollably. For dogs who spend much of their lives indoors, exposure in the springtime to outdoor stimuli such as pollen can irritate a dog’s skin. Environmental allergies are not limited to the world beyond your home; dogs can have adverse physical reactions to everything from household cleaning products and mold to automotive chemicals and even ingredients in a newly introduced food or treat.

Dry skin on dogs

Perhaps you are bothered by your dog’s natural musk, that certain, undefinable dog smell that seems to assault your nostrils mere days after bathing. You may think there’s no such thing as a dog who’s too clean, but if your freshly bathed dog is itching despite having her third bath this month, excessive grooming might just be the reason. Sources differ on frequency, but for normal domestic dogs, one bath every one to three months should be more than sufficient. This gives a dog’s natural oils time to regroup and redistribute themselves in the normal course of daily self-grooming. Stripping these oils dries out a dog’s skin, leading to physical discomfort and itching. The shampoo itself might be an allergen for your dog — consider dry baths or products that are labeled safe for sensitive dogs.

Fungal infections

Many people mistake ringworm in dogs for a parasite, when it is, in fact, a fungus. Like most fungi, the kind of ringworm that afflicts dogs — microsporum canis — takes root under the right conditions. Look to the dog’s extremities for hair loss and the small pinkish-red lesions that give the infection its name. Moisture and heat provide the right environment, and it feeds on keratin found in a dog’s skin. The summer months are a prime time for fungal infections, but so too is winter, when your heater is working overtime. Ringworm’s spores can remain dormant for months, so cleaning and disinfecting your dog’s bed, clothing, and dishes is essential for prevention. It’s zoonotic, meaning that contact with the fungus can spread by contact to you and your family.

reasons dogs itch or scratch themselves

Environmental changes can cause a dog’s constant itching. (Photo via Wikimedia Commons)

Hot spots on dogs

Excess heat can foster dog skin irritations and scratching beyond those caused by fungi. Bacterial infections also thrive and can be exacerbated when it’s too warm. Even a minor cut, wound, or abrasion is a perfect site for what’s known as a hot spot to form. Hot spots are not only caused by external injuries, but also by too much biting or scratching at skin until the surface is broken by your dog’s attentions to it. Many of the other factors we’ve looked at, and those we have yet to examine, can also give an opportunistic bacterium, like staph, room to grow and multiply. Look for pus, bleeding, and matted hair, all of which may arise suddenly.

Mange

We have very negative and extreme impressions of the word “mange,” but it has a number of causes, symptoms, and solutions. Every living body, including a dog’s, is its own complex ecosystem, complete with beneficial mites, bacteria, and other microscopic organisms. The most common form of mange is demodetic and tends to affect puppies, senior dogs, and those who are immunodeficient. Demodex mites are perfectly common, pass to puppies while nursing, and are normally harmless, kept in check as their immune systems develop. Along with scratching and biting, look for characteristic balding spots around the head and face. These lesions are not caused by the mites, but by secondary infections when the mite population explodes.

Boredom and stress can cause scratching, too

This seems counterintuitive, or, at the very least, strange. If there’s no physical ailment, why would a dog be scratching, itching, or biting at himself repeatedly? Are you out of the house for extended periods of time each day, leaving a single dog at home alone? Do you employ a dog walker to tend to the dog’s needs for exercise, attention, and routine? Does the dog have ready access to toys, puzzles, fresh water, and food while you or the family are away at work or school? Separation anxiety and boredom can certainly lead a dog to finding ways to keep herself entertained. In the absence of other alternatives, and when destroying pillows or chewing on shoes are no longer satisfactory, she may turn to scratching.

reasons dogs itch or scratch themselves

What can you do when your dog won’t stop itching? (Photo by Shutterstock)

Alternately, anxiety may also prompt an otherwise healthy dog to turn to scratching invisible itches. A dog who is unaccustomed to car or air travel, being placed in a restrictive environment like a kennel or crate when she’s used to being at liberty, or the introduction of something new into the home can all cause a dog undue stress. If the repeated itching is accompanied by sudden hair loss or by digestive upset — diarrhea, vomiting, and/or not eating — then any of these stressors may be at the root of her problem. Giving her time to readjust to a stable environment should resolve it.

What’s causing your dog to keep itching?

If  your dog seems to have an itch that she just can’t scratch, there may be any number of potential reasons and causes. One we didn’t even glance at is a nagging internal injury. Dogs might scratch at the site of a sore bump or bruise inside because they have no other way of expressing the discomfort it’s causing them. Is it too cold inside or outside? A lack of moisture in the air can lead to dry skin and repetitive scratching.

Itching when there are no fleas or ticks does not mean that external stimuli are not involved. In most all of the cases we’ve addressed, the source of a dog pawing at herself is almost always something new in a dog’s environment. Determine what that element is and you’re that much closer to providing your dog relief!

About the author: Melvin Peña trained as a scholar and teacher of 18th-century British literature before turning his research and writing skills to puppies and kittens. He enjoys making art, hiking, and concert-going, as well as dazzling crowds with operatic karaoke performances. He has a one-year-old female Bluetick Coonhound mix named Idris, and his online life is conveniently encapsulated here.