Why Pets Itch and Scratch and Chew and Lick!

March 28, 2013

What Causes Itchiness?| Diagnosis| Treatments| Products| Contact Us

Dr. Messina

by Dr. Abigail Messina D.V.M

One of the most common calls made to any animal hospital in America goes something like this: “Doctor, I’ve got to get this dog in right away. He’s driving us nuts. All he does is itch and scratch, bite and lick and he’s keeping us up all night!” In reality there is a wide spectrum of causes and severity of pruritus (pruritus means itching) in dogs with skin and coat trouble. Some dogs and cats can spend hours romping through fields, digging holes, and rolling in the grass and still have no after-effects at all. Others, kept indoors and fed an excellent diet, may have severe skin disorders.


10595965_sThere are six main reasons why pets develop dermatitis (skin inflammation). The difficulty with determining a diagnosis for dermatitis arises because very different causes can display identical signs in the patient. Itching can be caused by many different factors, and can be further complicated by the fact that the constant biting, licking, and scratching can then cause secondary bacterial or yeast infections. It is very important for the doctor and client to be on the same page regarding the pathway of tests and therapeutic strategies required to sort out the different reasons for itching.

  1. Environmental… airborne pollens, carpeting, wool, grass, ferns and other vegetation, plastic crates, hay, ingredients in shampoos and ear cleaners
  2. Nutritional… food intolerances cause some dogs to react with skin itching, blisters, reddened skin patches, or facial swelling from common ingredients in foods, treats or supplements. The most common allergens we see in cases of food intolerances are chicken, beef, wheat, and dairy.
  3. Parasitic… flea saliva can cause itchiness all over the dog from the bite of a single flea! FAD is the abbreviation for flea allergy dermatitis and is a very common source of severe itching. Many owners find it difficult to believe the existence of an ongoing allergic dermatitis caused by only occasional flea bite.
  4. Infectious… on occasion infections from staph bacteria can cause skin itchiness; more common is dermatitis from overgrowth of skin yeast organisms. Usually the infections seen with itchy skin is secondary to the physical damage done through scratching and chewing.
  5. Allergic… an allergy is an over-reaction to a substance where the body’s defense mechanisms go overboard in attempts to protect the body from that substance. Dogs and cats can be allergic to oral and topical medications, vaccine antigens, food ingredients, and inhaled substances. Allergies and autoimmune diseases result when the defense mechanisms turn against the individual’s own tissue. Any tissue in the body could be the victim of self-destruction and when the skin is involved itching, redness, scabs and sores are the result.
  6. Neurogenic… scratching and chewing at various skin locations on occasion are triggered by neurologic factors such as boredom, psychological frustration, discomfort or pain. Even though initially the skin involved is normal, the persistent chewing, licking and scratching damage the skin. This damage triggers local stress that creates a vicious cycle of skin damage-chewing-more damage-more chewing.

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You might think the diagnosis should be easy, the dog scratches therefore he is itchy. It is finding the initial cause of pruritus that can become somewhat tedious. When your pet is examined for pruritus, we will do various small tests to try and determine whether there is yeast, bacteria, mites, parasites (fleas, ticks) etc. present on the skin’s surface. These tests may help us to better pinpoint the inciting cause of your pets itchiness.

The most common diagnostics you may see us perform are:

  • Flea combing
  • Skin scrapes – a scalpel blade is used to superficially scrape the surface of the skin to help us look for microscopic mites that may be living in the skin
  • Double-sided tape – the tape is stuck repeatedly to the affected skin on your pet, and then adhered to a slide for viewing under the microscope. This helps us to easily identify the presence of yeast and bacteria on the skin’s surface
  • Impression smear – by pressing a slide onto affected skin, especially if it is oozy or has any discharge, we can sometimes get a sample of any organisms or abnormal cells
  • Environmental allergy testing (VARL testing) – when we suspect that your pet suffers from environmental allergies we may suggest doing VARL testing. This test involves taking blood samples from your pet, and sending it to a specialized lab where they analyze the possible environmental stimuli your pet may be allergic to, including various pollens, grasses, trees, and molds. Those allergens are then made into “vaccines” we can use to desensitize your pet against these stimuli.
  • Biopsy – in extreme cases we may suggest taking a biopsy of your pet’s skin. This may help when diagnosing more significant skin problems such as autoimmune diseases or certain cancers.

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As you have probably guessed, the treatment for itchy skin varies depending on the cause. Most infections will be treated with a short-term course of antibiotics and possibly steroids. These medications serve to treat the current infection as well as stop the itching to immediately make your pet more comfortable and avoid further damage to the skin. Long-term treatments will depend on the underlying cause, either aiming at better parasite control or addressing an underlying allergy.

An easy way to avoid skin problems that may arise secondary to fleas and ticks is to use an oral (for fleas only) or topical (fleas and ticks) preventative every month. We rely on the top-rated products to prevent flea and tick problems with your dog or cat. Topicals such as Frontline Plus and Vectra are easily applied to your pet’s skin to help prevent infestation and irritation from both fleas and ticks. Oral medications, such as Trifexis and Comfortis are easily digested tablets that attack the flea cycle and provide month-long coverage.  Check out our Current Promotions on these safe and effective products!

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Contact Us

If your pet is itchy, please make an appointment where we can examine his or her skin and make a tailored treatment plan for your pet.  If you have any further questions about this topic, or any concerns about your pet, please don’t hesitate to call us at Chase Farm Veterinary Hospital (508) 995-9935.

Not a client here? That’s ok! We are always happy to add new members to our Chase Farm family. Please call if you are interested in scheduling an appointment – or fill out our New Client Form – and we would be happy to accommodate you and your pets’ needs as best we can. If you would like a complimentary hospital tour before, or at the time of your appointment, one of our friendly receptionists are always happy to show you around.

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