My next patient was Scratchie the pit bull. It was Scratchie’s sixth visit this year for itchy, infected skin. His “seasonal” allergies now extended from spring through fall, and our various treatments hadn’t seemed to give the poor guy much relief.
Statistics show that 10% to 15% of dogs have allergies, but sometimes it seems closer to 75% in our practice. That’s because when pollen levels start to go up in the early spring, itchy dogs start filling up the appointment calendar until frost. Most allergic dogs can be controlled with topical treatments and oral medications, but for some unfortunate critters, that just isn’t enough to keep them from being miserable. Those patients usually need immunotherapy, in the form of allergy shots.
Before beginning allergy shots, the dog must first be tested. That requires a trip to the dermatologist for intradermal testing or a visit to our hospital for blood testing. Once the test is done, a serum is made specifically for that dog, using small amounts of allergens (the proteins that cause the dog to itch). The patient periodically receives injections with gradually increasing amounts of allergens until a maintenance level is reached.
Although immunotherapy has very good efficacy, this option hasn’t been popular with owners for a number of reasons. The cost of going to the dermatologist and having the skin testing done is one drawback. Then there is the issue of having to inject your dog -- not a great option if either owner or pooch is needle-shy.
Some dogs can have adverse reactions to the serum. Allergy shots can take months to start working. Finally, it can be difficult to remember to give the injections at certain time intervals.
But now there’s a better way to deliver allergens to our patients: sub-lingual immunotherapy. The procedure is simple. First, we draw blood from your dog and send it to Heska Veterinary Diagnostic Laboratory. The serum that is formulated from the allergens is then administered by drops given in the mouth instead of by injection.
About half of dogs receiving allergy immunotherapy will have an excellent response, about 25% will have a so-so response, and about 25% will have no response at all. When sub-lingual immunotherapy first came out, there was skepticism over whether the drops would be as effective as injections. It turns out that not only do they work just as well, in many cases they work better! In fact, dermatologists often find that dogs that fail to respond to injections have success with sub-lingual therapy. Many dermatologists are using oral therapy from the get-go almost exclusively now.
Besides its good efficacy and the no-needle thing, there are more advantages. There is much less chance of anaphylaxis (a severe and life-threatening allergic reaction) with the oral drops. Even dogs who had anaphylaxis with the injections tolerate sub-lingual immunotherapy. The drops, which are delivered by a pump, are easy to administer by the pet owner. With injectable therapy, mold serum must be injected in a syringe separate from the pollen serum, but with sublingual therapy the two can be combined in one vial. And the sublingual treatment seems to work slightly faster than the injections. Heska says it takes three to four months to see a response, but many dermatologists say they see a reduction in scratching more quickly than that. With either method, though, it’s best to expect to see results during the next allergy season, so pet owners need to plan ahead.
A disadvantage for some clients is the frequency of administration. Allergy injections are usually given every one to three weeks, but sublingual immunotherapy requires twice-daily administration. However, some pet owners prefer the routine of giving medication every day and find themselves forgetting to give an injection every few weeks, so that isn’t an obstacle for them.
If the cost of allergy testing and immunotherapy worries you, consider dogs like Scratchie. Each time he visits, there is a professional fee plus the cost of oral and topical medications, and occasionally lab fees for cytology or culture. Such a visit can range from $50-$275. The cost of serum-testing a dog is around $140, and it’s a one-time expense. A vial of sublingual serum, which lasts five months, costs $105. I realize that isn’t an inconsequential amount, but if the therapy prevents multiple visits to the animal hospital, you will have come out ahead. Not only that, but you’ll get a better night’s sleep when your allergic dog stops licking, head-shaking, and thumping his leg against the floor while scratching all night!