There is one topic that is near and not dear to my heart — Lyme disease. Not only are more and more dogs affected, but more and more people are as well. Lyme disease causes joint issues, kidney failure, heart disease and neurologic disease in dogs. I’ll go over the main things to know about the disease and how to prevent it. I feel like I am always talking about ticks or Lyme disease, but unfortunately, I am always seeing it.
Lyme disease is caused by an organism spread by ticks. Once an infected tick bites, they feed on blood. As they regurgitate this blood, the Borrelia organism is spread into the bloodstream. The good thing is that it does take at least 12-24 hours according to studies for the organism to spread. The bad news is that many ticks in our area are infected. The tick must bite and be alive to spread it. You cannot get it from a dead tick, touching a tick but not getting bit, eating a tick (please don’t do this anyway) or eating a deer that has been a host to Lyme-carrying ticks.
Borrelia is carried by the black-legged or deer tick, which are two different names for the same tick. These are the most common tick in Vermont and the Northeast. Though they can be different sizes based on their life stage, they look relatively similar. The female has a black shield on top of a brownish red body and is the most commonly seen, as they are the sex that feeds in order to reproduce. The nymph and adult stage both transmit Lyme disease. Ticks live in fields and woods, but are essentially found everywhere these days.
Many animals can be a host for the Borrelia organism, but not all of them get Lyme disease. For instance, deer are a dead-end host. That means that deer do not get Lyme disease and do not transmit the Borrelia organism. They simply help keep the ticks alive and fed so that they can transmit it to other species. The baby stage of the tick, larvae, are not infected. They then feed on mice and other small animals which transmit the Borrelia organism to them. White-footed mice are the most common carriers which infect ticks.
Larvae then mature into nymphs, at which point they are often infected from their previous feed. Nymphs become adults which lay eggs and begin the cycle over again. Adults and nymphs can both spread Lyme disease to humans and dogs.
In dogs, we draw a blood sample which tests positive or negative for antibodies to the Lyme organism. This simply means that a dog was exposed and the body reacted to develop some immunity. This is not predictive of whether a dog will become clinical for Lyme disease. There is a second test which gives us a number instead of yes or no. This number has more value in predicting if a dog will become sick and if we should treat them.
Lyme is treated with an antibiotic. At this point, we are still unsure if a treated animal can experience issues from Lyme in the future. It can be hard to determine if dogs become clinical with issues from the same exposure, or if they were exposed again. Without keeping them inside and alone this is hard to study or predict.
At this point, our biggest weapon against Lyme disease in dogs is tick prevention. This comes in collars, pills and liquids. Since these products don’t exist for humans, an important step in stopping ticks from spreading to you is making sure that they die when they bite your dog. I recommend prevention during all 12 months, since ticks are often active even in winter months. We also have a vaccine in dogs that decreases the severity. Like the flu vaccine, it does not prevent Lyme disease. However, it decreases the symptoms. Studies show that vaccinated dogs are highly protected against the spread to the kidneys, which is often fatal.