Why did my dog start to get itchy during the first 2 weeks of August?

Over the past two to three weeks, area veterinary clinics have seen quite a few itchy dogs. Most of these dogs were reported to be normal until the first or second week of August, and then to become rapidly itchy. Many of these dogs also have sores, scabs, or small pus containing skin bumps called pustules. Most of these dogs are generally itchy, but have areas such as the face, ears, legs, feet, abdomen, and/or arm pits that seem much worse. I regularly have clients tell me, or look back in the record and find, that last year the dog had a very similar problem at the same time of the year.

There are several disease possibilities that can cause these symptoms. With this history, one of the most likely problems to consider is an allergy. The allergens usually come from plant blossoms. This time of year, ragweed pollen is a common culprit.

While humans usually have upper respiratory symptoms like sneezing and itchy eyes, the skin is the main reactive organ in dogs with allergies. As the skin becomes inflamed and traumatized from scratching, hair is lost, and often sores develop. Commonly, a secondary bacterial skin infection develops. With chronic inflammation and trauma, the skin often becomes thickened and pigmented.

Allergies are relatively common in dogs. Most of these allergic dogs have some seasons that are worse than others. It all depends on what they are allergic to. If it is ragweed, the season is usually late summer until fall. If the allergies are to things like house dust mites, then the symptoms are usually worst when the furnace or air conditioner are running.

Often, dogs will start to have problems seasonally, and then gradually the season lengthens to year-round. Many dogs have multiple allergies with problems throughout the year and seasonal variations.

Exactly what triggers allergy development is still being debated. However, the mechanisms of the reactions are understood. Essentially, the immune system responds to non-threatening antigens, like ragweed pollen, inappropriately. The response triggers the release of histamine and other mediators, and the inflammatory cascade is triggered.

Allergies are treated by three main methods. The first is to eliminate exposure to the allergen. For flea allergy, eliminating flea exposure works very well. When the allergen is something like ragweed pollen, this becomes nearly impossible on a year-round basis.

The second method of treatment is symptom management. This is usually accomplished by use of medications such as antihistamines, corticosteroids, and immune modulators. Antibiotics are used to treat secondary bacterial infections if present. Additionally, dietary supplements, such as certain fatty acids, some foods and shampoos can help alleviate symptoms. Allergy management often changes in this dynamic disease process.

The third method of treatment is called hyposensitization. Essentially, this involves determining what the allergies are to, and then retraining the immune system to respond normally. There are two methods of allergy testing. The gold standard is intradermal skin testing. The second testing method involves a blood sample sent to a laboratory where levels of the immunoglobulin IgE are measured. Once it is determined what the offending allergens are, a cocktail of those allergens is produced and the dog is given a series of injections to try to retrain the immune system.

While allergies are the most likely problem based on the history, it is important to rule out other problems. This is a time of year when many dogs are exposed to things such as fleas, swimming, and wild animals. Flea numbers in the environment are at their highest numbers in the late summer and early fall. Swimming can contribute to skin itchy skin infections and ear infections. Mites such as sarcoptes cause an incredibly itchy skin irritation.

If your dog seems significantly itchy, I recommend you have it seen by a veterinarian. Veterinarians can determine what the problem is, and then help you manage the condition. This will improve your dog’s quality of life and overall health.

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