Sometimes a dog’s itchiness becomes so relentless that the incessant scratching, biting, licking, and rubbing in an effort to relieve the problem leads to hair loss, wearing away of the skin, nasty bumps, scaly red spots, crusty areas forming over scabs, and the skin’s thickening and hardening. In addition, as part of the itch-scratch cycle, the dog will often develop secondary bacterial or yeast infections.
The cause: in many cases, it’s atopic dermatitis, a disease that affects up to three in 10 dogs. Atopic dermatitis in dogs appears to have a complex genetic background, which, together with environmental factors, predisposes pets to developing symptoms. Any dog can develop the condition, but there is strong breed predilection. Labrador and golden retrievers, many types of terriers, German shepherd dogs, cocker spaniels, boxers, and French and English bulldogs have been the most commonly reported breeds in studies looking at the genetic background. The disease usually takes hold between the ages of one and three and lasts the dog’s entire life.
How the disease causes damage
Atopic dermatitis is considered to be an allergy — an excessive and inappropriate response of the immune system — to otherwise harmless allergens, such as pollen, dust, mites, or mold. The allergens take advantage of genetic defects in the structure and function of a dog’s skin, which allow for increased penetration of the offending substances from the environment that cause aberrant inflammatory reactions in turn. The compromised skin also allows harmful bacteria or yeast to colonize there, laying the groundwork for the secondary infections that further complicate disease severity.
Other skin ailments can look like atopic dermatitis. These include sarcoptic mange (scabies) or other skin parasites; flea allergy; inflammation of hair follicles due to bacterial infection; Malassezia dermatitis, a skin condition whose root cause is fungi; and other allergies such as contact dermatitis, food intolerances or allergies, even skin lymphoma, a type of cancer. A diagnosis needs to be made by a veterinarian, and it can be tricky because atopic dermatitis makes it easier for a number of these other conditions to develop. She or he will also get a history from the owner, which is an extremely important piece of the puzzle.
Multi-pronged treatment approach
Every dog diagnosed with atopic dermatitis should receive personalized, supportive, long-term treatment, and you are a big part of that.
Flea control. Dogs in general should be administered appropriate flea and tick prevention, but it becomes even more important for a pet with atopic dermatitis since an affected dog will likely be allergic to one or more allergens present in the flea saliva, which can trigger a flare-up. Your home must be flea-free, and other pets in your household must be on strict flea prevention.
Treatment of secondary infections. Afflicted dogs so often end up with secondary infections. Otitis (ear infection) and skin infections result from colonization of bacteria or yeast. It’s important to get on top of them by applying medicine prescribed by the veterinarian.
Frequent baths. A dog with atopic dermatitis should be bathed on a regular basis scheduled to the needs of the particular patient. The silver lining here is that while many dogs don’t like baths, your pet will appreciate the bathing because it provides relief from the itching. It also helps treat secondary infections without the need of oral antibiotics by restoring the already damaged skin barrier.
Diet by prescription. A reliable food will be available by prescription from the dog’s doctor for conducting a food trial to rule out food allergy. True, most allergens responsible for the symptoms of atopic dermatitis are airborne. But a number of affected dogs are also allergic to various proteins and/or carbohydrates in food. Foods prescribed for food trials should not trigger an immune response.
Specific treatments for atopic dogs
In addition to the above-mentioned approaches, most dogs will also benefit from certain prescribed medicines, depending on the severity of the disease.
Steroids. These are very effective for controlling or preventing flare-ups or more chronic cases. Anti-inflammatory doses of a type of steroid called prednisone, for instance, are usually enough to quell symptoms. But they can’t be used for long periods. They cause serious side effects like liver or pancreas damage, in addition to excessive thirst and untoward increases in appetite.
Cyclosporine. This drug suppresses the immune system, which is what causes the inflammation and other unwanted reactions in the skin. It is highly effective, controlling atopic dermatitis in more than three out of four cases. (It usually takes 4 to 6 weeks to see results.) It is also safe over the long term and easy to administer. The dog simply gets a capsule with food. That said, there can be side effects. One in four dogs vomits, and cyclosporine can also cause diarrhea and loss of appetite, so it’s not always an option.
Allergen specific immunotherapy (ASIT). These are allergy vaccines, and a dog with atopic dermatitis who gets them needs to be tested beforehand for specific allergies to make sure he’s getting the right shots. Each contains small quantities of the offending allergen, and the dog’s immune system becomes desensitized to it over time. It takes roughly 9 months to a year to work. ASIT is not as good as cyclosporine for severe disease and has a somewhat lower success rate (60 percent, as opposed to 75 percent). But for dogs who have a bad reaction to cyclosporine, it’s certainly worth a try.
Oclacitinib. This represents a novel treatment. It’s given by mouth and has anti-itch and anti-inflammatory properties and could prove more effective than cyclosporine. It is a safe drug but can have some adverse effects, including a decrease in red or white blood cells, so close monitoring by your vet is recommended.
Lokivetmab. A cutting-edge treatment, Lokivetmab is administered as an injection in the skin similar to vaccinations, usually every month or two. It’s a very safe treatment to relieve itching, with an efficacy close to 80 percent.
If you stay with it, you and your veterinarian will come up with a treatment regimen that works. Better still: New treatments are in the pipeline and may be available within the next year or so to help to give relief to our pets with more efficacy and fewer adverse effects.