Some of the most frustrating cases that I see include the itchy dog. The itchy dog can be difficult to diagnose and even when a diagnosis is made, treatment can often be frustrating and un-rewarding. It is difficult to watch a dog stop what it is doing to scratch or to stay awake all night scratching because it just can't get relief. When these cases aren't resolved, I'm not happy, the owner isn't happy and the dog definitely isn't happy.
In this article I will discuss some of the symptoms, causes and treatments for the itchy dog. With patience and a good veterinary relationship it is possible to find some relief for these poor suffering dogs.
The medical term for itching is pruritus and it occurs in the skin when nerve endings are stimulated creating a tingling sensation. Just as it is annoying to us it must be to our dogs as well; as we know that they do all that they can to relieve it. We obviously know that a dog is itchy when he scratches at himself with his hind paw. We often hear the tell tale "bang, bang" as his leg hits the floor and some dogs will moan as they try to relieve the itch. However, this isn't the only way that dogs can exhibit pruritus. These are the signs that indicate that your dog is itchy:
- Scratching
- Chewing or licking at himself
- Licking other objects
- Rubbing paws on head and face
- Rubbing head or body on the ground
If your pet exhibits these signs it is time to visit your veterinarian. Most often these signs are a result of pruritus but they are not exclusive to pruritus and so you should have your veterinarian take a look.
All of this scratching, licking and chewing can damage the skin which in turn makes it more prone to further damage, creating a viscous cycle. So by the time I see some of these patients they actually have more than one inciting factor. My role as a veterinarian is to aid in diagnosing the factors involved and to treat the underlying causes. In general the main causes of itching are:
- Parasites
- Allergies
- Infections
By looking at the above list it appears that diagnosis should be simple, however this is rarely the case. Each of these causes can be have several factors and they can all be present at the same time. For example the initial cause of the pruritus may have been fleas. The scratching ensuing from the parasites could lead to damage of the skin barrier resulting in infections and allergic reactions. Allergies can be a consequence of environmental allergies or food allergies and infections can come in the form of parasites, yeast fungus or any combination of these three. All of these things will need to be determined and treated.
In order to determine the reasons for your dog's scratching your veterinarian will need to ask you many questions about your dog, your dog's environment and its habits. A thorough examination of your dog and its skin will need to be completed and diagnostic tests will need to be performed. Some of the most common tests include:
- Skin Scraping - The skin is scraped and cells are examined under a microscope for abnormalities and parasites
- Impression Smear - A slide is pressed to the skin and examined under a microscope.
- Fur Pluck - A few strands of fur are plucked to check for fungus
- Wood's Lamp Evaluation - A special UV lamp is used to look for evidence of fungus
- Acetate Tape Preparation- Tape is applied to the fur and examined under a microscope for parasites
- Skin Biopsy - Multiple areas of the skin are biopsied and sent to a lab for evaluation
- Allergy Testing - This can be done through blood testing or skin testing by a qualified veterinary dermatologist.
Once a diagnosis is made the goal is to treat the underlying cause. Parasites and infections are treated with the correct medications. The skin is several layers deep making it difficult to penetrate and making treatment tedious and time consuming. It is not unusual for the treatment course to be prolonged for several months.
Allergies can be even more trying to treat. An allergy is an over-reaction of your dog's immune system to a foreign protein. The immune system of most animals will notice foreign proteins such as dust mites and rid them from their systems. In a dog that is allergic to dust mites, the immune system will work even harder to rid the body of the protein and this in turn causes redness, swelling and the itching that we see.
The ideal course of treatment in allergies is avoidance. However, sometimes this is impossible and therefore, other avenues must be explored. At this point we want to decrease the body's immune response to the particular allergens. Hypo-Sensitization is one avenue that can be explored. This is when your dog receives "allergy shots". These shots include very small amounts of the protein to which your dog is allergic. This in effect creates "resistance" in your dog so that he will not react as strongly to a given allergen. Sometimes this is not effective or is not an option and at this time medications can be used to control the symptoms and decrease the itching. These medications include:
- Antihistamines
- Omega Fatty Acids
- Glucocorticoids or other drugs which suppress the immune system
Please note that it is important to NEVER give your dog any medication without the advice of your veterinarian. As much as dogs are a part of our family, they are not small humans. Some human medications can be toxic to dogs, or have severe side effects. The dose of medication that is appropriate to a dog is not related to that in humans; even small ones.
In the event that your regular veterinarian is not able to help you find relief for your itching dog, it may be time for a referral to a board certified veterinary dermatologist who specializes in such cases.
Although having an itchy dog can seem exasperating; a patient, persistent relationship with your veterinarian can help you and your dog find relief.
