What is the deal with all that itching and scratching?

As an owner of an itchy dog, I was so excited to attend a lecture called “20 minute approach to Pruritus” at this year’s AVMA Veterinary conference in Denver. The presenter was Dr. John Angus, a veterinary dermatologist practicing out of Pasadena, CA. His presentation was not only interesting to me because of my personal experience, but also because it seems like this spring at the clinic we were inundated with case after case of itchy dogs.

This can be such a frustrating problem because while there are several treatment options to relieve the itch, there technically is no cure. In his lecture, Dr. Angus explained 5 reasons for itchy pets. Atopic Dermatitis occurs in dogs that have a hypersensitivity reaction to allergens inhaled or absorbed into the skin. They can be seasonal or year- round. In minor cases, we commonly see scratching of the ears or belly, licking of feet (brown staining), sneezing, runny nose, watery eyes, and rubbing of the face. In more severe cases, dogs are scratching so violently they cause deep excoriations (scratches) on their skin, hair loss, scabs, crusts, and secondary bacterial or fungal infections. Their skin may become thick, darkened, or greasy but flakey at the same time. These dogs are absolutely miserable. Often they need long term management with shampoos, antihistamines, antibiotics to clear secondary infections, short courses of corticosteroids, or medications to try and desensitize their body to these allergens.

Food allergies account for at least 10-15% of all itchy animals. It is like any other allergy, but in these cases the dogs’ body responds to an ingredient in his food. Dogs most commonly form an allergy to ingredients like chicken, beef, lamb, pork, dairy, wheat, egg, and soy. These dogs can exhibit chronic ear inflammation or infections, gastrointestinal problems, gassiness, and itchy feet or rear end. Most dogs live their whole life eating the same food and never have any issues; however some will form an allergy over time. If we suspect a food allergy, the best thing to do is try and eliminate the source by performing a food trial. We may recommend switching from, for example, a chicken and rice diet to a fish and sweet potato or duck and pea. We do this for 6-8 weeks and see if the symptoms resolve. Sometimes we may even challenge the food trial by reintroducing the previous food and monitoring for flare-ups. Food allergy testing can also be a helpful tool to identify certain allergens.

Parasitic infestations of the skin can also cause major itching. The most common players are fleas, ticks, mites, or lice. Fleas, ticks and lice can be seen by the naked eye, but mites need to be identified microscopically. Parasites can cause generalized itching, or itching/hair loss in localized regions of the skin. If we ever suspect parasitic involvement of an itchy dog, we perform a test called a skin scraping. It’s exactly what it sounds; we take the affected part of the skin and scrape off a small sample of dead skin and hair, then transfer it to a slide and identify the creeper. The medication type and length of treatment depends on the type of parasite, but it’s fairly straight forward once identified. Prevention is widely available for flea and tick control. Bacterial and fungal infections often fall into the category of “Secondary Infections”, in other words they are caused by the allergies. A lot of the time we see infections in the ears, on the feet, or belly, but in severe cases it can be widespread all over the body. We can identify the infection much like we identify parasites, but now we are looking for bacteria or yeast. Sometimes it can be a combination of both. These patients are very itchy, can have a rash with pustules (pus filled bumps), crusty skin, hair loss, or a musky-foul smell to the skin. Many of these infections will clear up with the appropriate antibiotic or antifungal, but it’s important to continually maintain treatment for their allergies or else the infection can reoccur.

Just like with people, a small amount of itching of the skin is completely normal. However, if you feel you are constantly telling Fido to “Stop licking!” or he is shaking the bed so violently in the middle of the night by scratching that you’re losing sleep…Don’t worry, you’re not alone! There are so many options to help relieve the itch and give your pet (and you) some peace.