By: Sarah Thatcher-Mason, DVM
Almost every day I am presented with an itchy dog or a scratchy cat. Many owners have tried multiple products and methods to relieve the scratching, often to achieve only marginal improvement. Persistent pruritis (itching) is most often due to an underlying allergy. They can be brought on by fleas, food sensitivities, or allergens in the environment – both indoor and outdoor. Immediate relief can be provided with medication but will not provide a long-term solution. Determining the cause of the allergy can be challenging, but is the key to controlling and relieving the itch for good!
One of the more common causes of allergies is a flea allergy. Even one flea can cause severe generalized itching! Symptoms include crusting, redness, hair loss, and pruritis over the rump, thighs, abdomen and flanks. Episodes can be seasonal in temperate regions or non-seasonal in tropical and subtropical regions where fleas are present year-round. It is important to keep your dogs and cats on a flea preventive product all year long in this area – remember, even one flea can cause them to react! Make sure that you check with your veterinarian when choosing flea-control products for your cats – some over the counter products can be toxic!
Food allergies are also a common culprit. I treat allergies in young dogs and in older dogs that have been on the same type of food for years. Two of the most common allergens in dogs are beef and milk, however, chicken, soy, eggs, wheat and corn can also cause allergic reactions. Food additives and dyes can be the culprit as well. Dogs with food allergies may also have chronic ear infections and concurrent GI issues such as diarrhea, flatulence, and vomiting. Long-term treatment consists of eliminating the offending allergen (if known) from the diet, providing a manufactured hypoallergenic diet or feeding a balanced homemade diet if food dyes or additives are the suspected allergen. It is important that once your vet prescribes a specific diet that you keep your pet on that diet only. Any extra treats can cause breakouts and negate the beneficial effects of the hypoallergenic food. Bear in mind that it can take up to 4 months so patience and tenacity is important!
Canine and feline atopy is a reaction to allergens in the environment. It is thought that there is a genetic predisposition in affected animals. Diagnosis is based on ruling out more obvious causes such as food or flea-bite allergies and response to treatment. Allergy testing and immunotherapy can be performed as well. The goal of immunotherapy is to desensitize the animal the allergens that they are susceptible to by exposing them to diluted doses over time. Dogs and cats with atopy tend to itch and lick the feet, groin, flanks, face and ears. Itching may be seasonal or nonseasonal. If atopic dermatitis is confirmed, treatment is generally lifelong.
There are many different reasons for pruritis. Often the cause is multifactorial and the diagnosis can take time. It is also important to consult with your veterinarian before changing any aspect of treatment.