Lyme Disease Update
Over the past year there has been a dramatic rise in the incidence of Lyme disease in dogs in this area. This serious disease is not known to infect cats and is transmitted by the small deer tick. At the Ashland Animal Hospital we have observed at least a 4 – 5 fold increase in Lyme disease this past year. We have found that approximately 50% of dogs in our area are positive on an antibody test for Lyme disease. Although most symptomatic dogs respond well to a course of antibiotic therapy, a small number of dogs can develop a more serious for of the disease.
The disease is caused by the bacteria (Borrelia bugdorferei) that is spread by the bite of a small deer tick. Deer ticks can be very hard to see on a dog because of their small size and brown color that helps camouflage them. We currently use a varienty of topical preventatives against ticks (Revolution, Preventic collar, Frontline) but unfortunately these are not 100% effective in preventing Lyme disease.
While the initial symptoms of Lyme disease are somewhat variable, most dogs will display fever, lethargy, and joint pain. In some cases the joints of the carpus (wrist) or tarsus (ankle) may be warm and swollen. Many dogs are suddenly very stiff and unwilling to walk. At this stage, nearly all dogs show immediate improvement and subsequent resolution of their symptoms once started on antibiotics. It is uncertain if the Lyme bacteria can ever be completely removed from the dog’s system, similar to the disease in humans. Future recurrences of joint pain or disease involving other organs such as the kidney are possible. It should be stressed that only about 5 % of dogs who test positive will ever develop any clinical signs. Most dogs will remain asymptomatic and our current understanding of treating this disease strongly suggests that treating an asymtomatic dog is not recommended and will have no effect on preventing any future clinical disease. Furthermore, although we are seeing a significant increase in the number of dogs suffering from glomerular nephritis, a serious kidney disease linked to Lyme disease, a direct link has not been demonstrated in these new cases we are seeing. Several studies of Lyme disease have demonstrated that treatment of asymptomatic Lyme positive dogs does not prevent the future development of this serious disease.
In the past we have not recommended vaccinating for Lyme disease because of the previous low incidence of the disease. However, we are now recommending that you consider vaccinating your dog if he/she has tick exposure. We are now offering a recombinant Lyme vaccine for your dog. This vaccine uses a new technology to create what we believe to be safer and more effective vaccine. While there is still no vaccine that offers 100% protection from Lyme disease, the vaccine we are using has an excellent safety record and appears to be very effective in stopping Lyme disease in the tick before it can be transmitted to your dog. We recommend that all dogs be tested Lyme negative before receiving the vaccine. Good tick prevention should be used in conjunction with the vaccine.