Answers to Your Questions About Lyme Disease:
What causes lyme disease?
Lyme disease is caused by a bacteria called Borrelia burgdoferi, which is transmitted by a tick bite. A young tick picks up the bacteria by drinking the blood of a small host, usually a mouse, that is carrying the infection. As the tick matures, it begins to search for a larger host, such as a deer, human or dog. When it bites, the tick regurgitates into the animal’s blood to keep it from clotting. This regurgitation process is what transmits the bacteria to the animal. The tick must be attached for 24 to 48 hours before this transmission process is completed. If the tick is removed before it has been attached for 24 hours, the lyme disease bacteria cannot be transmitted.
How is lyme disease in dogs different from lyme disease in humans?
Lyme disease affects our canine companions in a much different manner than it affects humans. Humans who are infected by the lyme disease bacteria due to a tick bite tend to quickly develop flu-like symptoms, a rash around the tick bite site, and potentially neurological or cardiac abnormalities. Dogs, on the other hand, do not tend to show signs of this disease right away. If they do develop signs of infection, it is weeks to months after exposure and tends to manifest as arthritis or joint pain.
Some dogs never show any clinical signs of the disease at all. However, lack of clinical signs does not mean that lyme disease is not harming your pet. Sub-clinical lyme disease can cause damage to the dog’s cartilage due to chronic low-level inflammation and the kidneys due to chronic stimulation of the immune system.
Do we have lyme disease in this area?
Yes! Lyme disease is unfortunately very common in this area, and this is a disease that our doctors are faced with on a daily basis. Even dogs in our area, that stay inside the majority of the time contract this disease.
How do we treat lyme disease once it is present?
Veterinarians will often prescribe a 28-day course of doxycycline, which is the same antibiotic used in humans. This treatment simply lowers the levels of lyme bacteria so there is no longer an active infection, but some bacteria remain hidden in the body long-term.
We have never been able to completely cure Lyme disease. This is because it has one appearance (OspA) when it enters the body. Then, after entering the body, it changes the proteins on the outside of the bacteria to hide from the immune system (OspC). In the past, lyme vaccines only provided immunity to Osp A. A new vaccine from Zoetis teaches the body to be immune to both appearances of the lyme disease bacteria. It is the veterinary community’s hope that this vaccine will help your dog’s immune system rid itself of the OspA and OspC lyme infection completely. Thereby, curing the dog of lyme disease. Time will tell us if this is truly possible.
Chronic lyme infections require an antibody level test (called a “Quantitative C6 Test”). A dog with a higher C6 antibody level likely has an active infection and should be treated with doxycycline. This is the only way to determine the severity of your dog’s current lyme infection.
How do we protect our dogs from lyme disease?
Regular monthly flea and tick prevention is the absolute best way to prevent lyme disease in dogs. As stated above, the tick needs to be attached to the dogs for 24 to 48 hours to transmit lyme disease. Both oral (Nexgard) and topical (Frontline plus and Frontline Gold) flea/tick preventatives will cause the biting tick to die before this point of transference.
Sometimes we forget to give our dogs their flea/tick prevention on time. In that case, vaccination against lyme provides a second level of defense against the disease. Vaccination will cause the dog’s immune system to be prepared to kill the lyme bacteria.
Traditionally, the lyme vaccine had only worked for dogs that had not already been exposed to the disease. This is because the protein (OspA) that the vaccine created immunity against was the protein the bacteria wore inside the tick. The dog’s antibodies would kill the lyme bacteria before it even entered their bodies. This was great for lyme negative dogs but did not help dogs who were already infected. There is a new Zoetis lyme vaccine that creates immunity against a second protein (OspC) as well, this one that is expressed by the bacteria in the dog’s body. Immunity to this second protein will your dog’s immunity against an infection that is already present in his or her boy. This is why we will recommend vaccination with the Zoetis lyme vaccine after doxycycline treatment to help boost the dog’s ability to fight off the chronic infection.