How to prevent Lyme disease

April is Canine Lyme Disease Prevention Month. Each year veterinarians in this area are seeing more and more cases of this illness. Prevalence screening studies estimate that 15-30 percent of dogs in this area have been exposed to Borellia burgdorferi, the bacteria that causes Lyme disease. Veterinarians are now commonly diagnosing Lyme disease in dogs. Severity of illness ranges from a chronic subclinical condition to Lyme nephritis, the universally fatal form of the disease that causes sudden, severe kidney failure.

The bacteria that causes this debilitating disease was discovered more than 30 years ago near Old Lyme, Conn. Since then, the disease has been spreading throughout the country. The bacteria is transmitted by Ixodes ticks, commonly referred to as deer ticks. Dogs are up to 10 times more susceptible than people to infection with Borellia. They can also serve as a means for ticks to gain easier access to the indoor human population. (Cats do not seem susceptible to the bacteria.) Most canine patients who become infected with the bacteria will never be completely cleared of infection, regardless of treatment. In battling Lyme disease, prevention is the key. Unfortunately, several common misunderstandings interfere with veterinarians’ ability to prevent this serious illness.

First, many pet owners do not understand the timing of the deer tick life cycle. These ticks generally spend the summer months as tiny, immature stages. In late summer, they actually enter a pupation stage when they are not feeding at all. The adult stage generally peaks in February and March, when it feeds vigorously before laying eggs. Most pet owners use tick control during the summer months because they are able to see the larger summertime ticks. Unfortunately, they stop the tick control just when the adult deer ticks are emerging – late fall and early winter.

Second, many pet owners mistakenly believe that since they do not see any ticks, their dogs are not being exposed. In humans, 40 percent of patients diagnosed with Lyme disease do not realize they EVER had a tick on their own body! These ticks are so tiny, that the vast majority of pet owners will never see them. Believe me when I tell you that they are biting your dog. I commonly see fluffy little house dogs that test positive for Borellia.

Third, many pet owners use the wrong type of tick control. Some veterinary-quality tick control products have shown 90 percent or higher effectiveness in preventing the transmission of Borellia when used regularly and properly. Despite similar packaging, the over the counter products at the grocery store are not the same. In addition, more and more pet owners are getting the products through Internet or mail order sources. The manufacturers have been warning veterinarians for years about the potential for significantly decreased efficacy from poor storage and shipping conditions. The safest, most effective tick control really does come from your veterinarian.

Finally, many pet owners and veterinarians avoid vaccinating against Lyme disease. There is a lot of misinformation and outdated information regarding vaccination against Lyme disease. It is true that bacterial vaccines are less effective and shorter acting than their viral counterparts. However, vaccine technology has improved greatly in recent years leading to safe, effective vaccines that could drastically reduce the number of dogs who suffer or die from Lyme disease.

Recombinant DNA vaccines against Borellia burgdorferi are genetically engineered wonders of modern science. They contain only a single protein, almost eliminating adverse reactions. The protein, called OspA, is the vehicle that the bacteria uses to transport itself from the tick into the dog’s blood stream. When the tick begins to feed, the dog’s antibodies against OspA lock the bacteria inside the tick, preventing transmission. In other words, we now have a safe, effective Lyme vaccine that works inside the tick, not the dog!

In fact, the OspA protein is not present on the surface of the Borellia bacteria once it enters a dog’s body. This means that in the unlikely case of a vaccine failure, the antibodies in the dog’s blood would not react with the bacteria inside the patient. This may be important since the symptoms of Lyme disease are actually caused by a complex interaction between the bacteria and the immune system.

The overwhelming majority of dogs in this area would benefit from routine inoculation with a modern Lyme vaccine in addition to year round use of veterinary-quality tick control products. If all dog owners followed this advice, we could nearly eliminate Lyme disease as a cause of death and disease in our patients.

Dr. Watts is a companion animal general practitioner and owner of Clevengers Corner Veterinary Care. He can be reached through ClevengersCorner.com or by calling 428-1000.