Just as allergies have become more common in children these days compared to several generations ago, veterinarians are seeing far more allergies in pets too. It is difficult to explain this phenomenon, theories range from alterations in the content of pet foods to the use of modern day household cleaning products or simply genetic evolution. The dog or cat that exhibits itchiness is often first thought by their owners to have a flea problem. According to Dr. Marina Tal of VCA Brown Animal Hospital on Williston Road in South Burlington,"This has been the worst flea year I've seen in my ten years of practice." When asked for her opinion as to why this would be the case, Tal suggested that one explanation could be that pets (cats as well as dogs) are being plagued by fleas that are becoming resistant to current topical treatments, making the treatments less effective. She went on to explain that itching in dogs is often allergy, and not directly flea related. Whatever the cause, allergic dogs benefit hugely from avoiding the offending allergen or, if that is impossible, appropriate treatment to minimize the itchiness.

But allergies can be trying to diagnose and treat in pets. "It is very much a trial and error process," Tal said. "It can be really frustrating for the pet owner and the veterinarian...and same for the animal, who is apt to be extremely uncomfortable."

Itchiness can manifest itself not only as obvious scratching at the neck and flanks, but also as chewing, face rubbing, foot licking and over grooming. Foot licking, for example, is often perceived by owners as normal, when in fact the dog is responding to itchy feet in the only way it can, by licking them. The skin between the toes may turn red and sore due to the compulsive licking, and in dogs with lighter colored coats such as white, champagne, or apricot, the fur is stained brown by saliva.

Ear infections are another common sign of an underlying allergy. Though general waxiness, hair in the ear canals, lack of ventilation, bacteria, and yeast may trigger the infection, an underlying allergy is often the root cause of the itchiness. If your dog gets recurrent ear infections, by eliminating an underlying allergen you may prevent your dog from going over the 'itchiness threshold' and developing full blown ear infections.

So, what are the common allergies in dogs?

For convenience they are best separated into four categories.

1) Flea bite hypersensitivity

2) Adverse food reaction

3) Atopic dermatitis

4) Contact dermatitis

Flea bite hypersensitivity is relatively straight forward to cure. It is a simple case of eliminating every single flea on the dog and his/her environment. The itchiness is caused by an allergic reaction to the flea saliva, and so even a solitary flea can trigger a scratching frenzy. Dr. Tal points out that vacuuming is a typical preliminary step in removing fleas from the household environment, but make sure to use a bagless vacuum, or make sure to throw out the bag immediately after vacuuming since there stands a good chance of having flea eggs collected there that will go on to hatch while in the bag.

Dr. Tal also shared that some of the lower cost over-the-counter topical flea treatments contain ingredients that can be toxic to cats, causing tremors, seizures and possibly death: these ingredients are "Pyrethrin," and "Permethrin."

Adverse food reactions are more difficult to treat as it can be difficult to isolate the precise ingredient responsible for causing itchiness in your dog. Treatment requires owners to be exceptionally disciplined and motivated in preventing their pet having even a single treat unless the exact ingredients are known to be safe.

Dr. Tal recommends a dietary trial to diagnose an adverse food reaction. This involves picking a prescriptive diet or home cooked diet and feeding your dog exclusively that for a period of 6 to 8 weeks. She offers that it is typically a protein and not a grain that causes reactions in dogs. Remember if you are doing one of these trials, then your dog must not be given any treats, especially not pigs ears, chews, bones, dental sticks or any rawhide products.

Once flea bite hypersensitivity and adverse food reactions have been ruled out, the next step is to consider an environmental allergy, also known as atopic dermatitis. Symptoms of atopic dermatitis usually begin between one and three years of age, though any age is possible. The itchiness is often seasonal, which is consistent with a pollen allergy, though some dogs are itchy all year round. There are certain breeds which are predisposed to this condition: Boxers, Dalmations, English Bulldogs, Golden Retrievers, Labrador Retrievers, and West Highland White Terriers are more commonly affected. Diagnosis is usually made based on the history and ruling out all the other causes of itchiness, and many vets will treat the condition on these presumptions. The treatment is often a course of oral medications/shots to suppress the dogs immune system.

Contact dermatitis is a skin reaction caused by your dog coming into contact with a chemical that is an irritant. It therefore only tends to affect the stomach, groin, and feet of the dog, and is characterized by reddening and drying of the skin in these areas. It can also be seen when owners shampoo their dogs with a product that is not intended for use in dogs. Contact dermatitis is rare, but easily ruled out by careful use of cleaning products around the household. Just think, did the itchiness coincide with the introduction of a new carpet cleaner, washing powder, or fabric softener?

By far the best treatment for any allergy is avoidance of the cause. By careful investigation and following the steps above this is often possible, especially for flea bite hypersensitivity, adverse food reactions, and contact dermatitis. If avoidance is impossible though, as is the case for many cases of atopic dermatitis, then seasonal or lifelong treatment may be indicated. Dr. Tal acknowledges that treatments can be expensive, but VCA Brown Animal Hospital will try to work with pet owners on developing a sensible treatment plan that will make a pet substantially more comfortable.