"April showers bring May flowers."
Most of us are familiar with this saying. But April showers also bring pollen and mold, and for those with allergies that means runny noses, puffy eyes, sinus pain, sneezing and headaches. Allergies can also be problematic for our pets -- except that, in addition to exposure from inhaled molds and pollens (allergens), pets also absorb many allergens through their skin. The process of absorbed allergens to allergy response and symptoms is a complex one.
WHAT ARE ALLERGIES?
The genetic tendency to develop allergic diseases is called atopy, a term which refers to the way susceptible individuals experience a heightened immune response to common, usually harmless, allergens. The important point to understand is that these allergens are only harmless to those who are not allergic to them.
There are several features of atopy:
It is typically seasonal, with Spring and Fall being the most problematic times for symptoms to flare up. However, over time, the allergic "season" for most pets increases and can even become year-round.
The onset of atopy symptoms in 70% of pets is in the first 1-3 years of life.
Inhalant allergies respond rapidly to steroids. In comparison, food allergies are more variable and frequently do not respond at all to steroids.
HOW ARE ALLERGIES DIAGNOSED?
The diagnosis of atopy is a clinical one, not based on testing. Symptoms in pets are primarily itchy skin. Dogs chew, lick or rub their feet, legs, around the eyes, muzzle, arm pits, ventral abdomen and anus. In cats, the pattern of irritation is not as characteristic and will mimic those found in several conditions. Some 25% of cats have more than one type of allergy. Genetically predisposed canine breeds include:
West Highland White Terrier
After a diagnosis is made, intradermal skin testing or serum antibody testing is used to find what your pet is allergic to. Intradermal skin testing involves shaving the area of skin, injecting small amounts of antigen, and watching for a skin reaction -- usually swelling or redness. Serum testing doesn't aim for a direct skin response; instead it measures antibody levels in the blood relative to specific antigens.
HOW ARE ALLERGIES TREATED?
Once a diagnosis is made, there are several options for treatment. Many pets with allergies have secondary skin infections which need to be addressed at the same time. Secondary infections are either bacterial (Staphylococcus) and/or yeast (Malasezzia). Yeast and bacteria are micro-organisms that normally live on the skin but penetrate deeper tissues because of damage to the skin as a result of chewing and scratching. These secondary infections can amplify the allergic response and the prevent resolution of symptoms until they are addressed.
Direct treatment options for the allergy include the following:
Omega 3 Fatty Acids. Omega 3 fatty acids alone are not a treatment for allergies. However, increasing the amount of omega 3 fatty acids in your pet’s diet can decrease the production of inflammatory mediators and decrease the body’s reactivity. They take about 6 weeks to become effective, and their use can decrease the amount of other medications needed.
Antihistamines. These can be effective in mildly affected patients. A 10-20% response is expected for any given antihistamine. Fortunately, there are many to choose from. Cats tend to respond better to antihistamines, but cats can also be difficult to medicate orally. Antihistamines and omega 3 fatty acids are synergistic; each helps the other work better.
Steroids. These have been the workhorse for the treatment of allergies for years. They work well in the short term to quickly and effectively control atopy. Steroids are started at a higher frequency and then tapered down to the lowest effective dose, usually every other day or every third day. They can produce short-term side effects like increased drinking, appetite, and urination. Steroids can also suppress the immune system and bring out latent urinary or upper respiratory infections. In cats, long-acting injectable steroids are frequently used, but these may cause diabetes in susceptible cats. Short-term use of steroids (less than 90 days’ worth in a calendar year) usually produce no long-term health effects. Long-term side effects on the body usually occur in patients with year-round atopy, or whose atopy gets worse with time.
Cyclosporine. This is an immune modulator commonly used in organ transplants. Cyclosporine is a safe, effective, and reliable treatment for atopy without the side effects of steroids. It has the down side of a 1-2 month onset of action, however, making it unsuitable for short-term atopy.
Oclacitinib. This is a relatively new treatment for atopy. Oclacitinib is a Janus kinase inhibitor that targets proinflammatory cytokines involved in itch and inflammation. It has a minimal negative impact on the immune system.
Monoclonal antibodies. Monoclonal antibodies are designed to target a specific compound in the body. In this instance, the antibody targets a cytokine called Interleukin-31 (IL-31). This is the cytokine primarily responsible for itch and inflammation associated with allergies. By blocking IL-31’s effects, antibodies minimize allergy symptoms.
Desensitization. Pets can be desensitized against particular allergens just as people can be. Once these allergens are identified, an injectable or oral vaccine can be made. These can take 4 to 12 months to help, but 50% of patients will experience significant enough improvement to no longer require medication. Some 25% of patients will still require some medication during their worst times of year, and another 25% will not benefit from desensitization at all. Allergy injections are tapered to once a month for life, and oral vaccination is given twice a day for life.
Finally, reducing your pet’s allergen exposure can also improve your pet's symptoms. Weekly bathing, for instance, can dramatically reduce allergens on your pet’s skin. This is because pets with atopy have abnormal attachments between their skin cells, allowing allergens to get in. (Picture a brick wall where the mortar between the bricks is damaged and rain water can seep in.) Using a therapeutic shampoo containing phytosphingnosine can help rebuild the skin’s natural barrier (like repairing the cracked mortar between the bricks). Exposure can also be reduced by removing stuffed toys and regularly washing pet bedding. Air conditioners with a good filter system can also decrease airborne allergens, particularly when pets are kept indoors during high-allergen activities like mowing the lawn.
The right treatment, of course, will depend on the severity and seasonality of your pet's symptoms. As always, you'll want to consult your veterinarian before beginning any treatment plan.
In the meantime, be sure to stop by our stores for all your pet care needs! We're in the process of expanding our pet lines, and our friendly staff will be happy to help you find just what you're looking for.