History, diagnosis and treatment

Lyme Disease

Following is a brief overview of the pathology of canine Lyme disease. Please click on other categories on this website for more comprehensive information about canine Lyme disease.

Three elements must be present in nature for canine Lyme disease to exist in any area:

1. The Lyme disease bacteria, Borrelia burgdorferi
2. Ticks that can transmit the bacteria
3. Mammals, such as mice, deer, dogs and humans, to provide a blood meal for the various life stages of ticks

In humans, dogs, and many other animals, infection with Borrelia burgdorferi results in the pathology of Lyme disease.

History and evolution of the disease

Human Lyme disease was discovered in 1975 in Old Lyme, Connecticut and was identified in dogs in 1984. Dr. Willy Burgdorfer, an entomologist, discovered the bacteria in 1982, two years before Lyme disease was identified in dogs.

Although there is no national reporting system for capturing incidence of canine Lyme disease, reviewing data for human Lyme disease is important, because it is an indication of the potential exposure for dogs. In fact, the threat of Lyme exposure is thought to be greater in dogs than humans.

Since human Lyme disease was discovered in 1975, the disease has increased dramatically in incidence and geographic spread. The Centers for Disease Control and Prevention (CDC) has been capturing data since 1993 on the incidence of human Lyme disease.

• Human cases have nearly doubled since 1995¹
• Estimates show cases may increase to 40,000 by 2012²
• Human Lyme disease has been found in all 48 contiguous states¹
• Most cases have been identified from Virginia to the Northeast and in the Upper Midwest²
• 28,921 new cases were reported in 2008¹

Diagnosis

Diagnosing canine Lyme disease is a combination of observing clinical signs, diagnostic testing and understanding the dog's risk factors for contracting the disease. Ticks can transmit more than one disease-causing pathogen at the same time and dogs may have multiple infections, making diagnosis difficult in some dogs. Canine Lyme borreliosis and canine anaplasmosis are both transmitted by organisms harbored by the Ixodes tick, and some clinical signs can be similar between the two diseases.

Testing

Testing for disease is the best way to determine if the dog is infected. The IDEXX SNAP® 4Dx® test detects antibodies Borrelia burgdorferi, Anaplasma, canine Ehrlichia and antigens from heartworms. Discuss testing with pet owners if you suspect the dog is infected.

Most common clinical signs

1. Lameness/arthritis
2. One or more painful and/or swollen joints
3. Enlarged regional lymph nodes accompanied by fever
4. Anorexia
5. Lethargy/depression

Risk factors

Determining risk factors is an important part of the diagnosis of any disease, and there is no risk factor greater than an unvaccinated dog in an endemic canine Lyme disease area.

Practitioners can develop a comprehensive protocol to identify the risk factors for canine Lyme disease in their patients. The annual wellness exam is an ideal time to talk to clients about canine Lyme disease risk factors.

• Vaccination history
• Geographic area
• Lifestyle
• Health status

Lyme Disease Risk Factors
A comprehensive discussion.

Treatment

Determining the treatment protocol for dogs that have tested positive for canine Lyme disease is up to the practicing veterinarian and the pet owner. However, it is important that veterinarians make the distinction between the infection and the disease. A dog that tests positive without signs is not necessarily a sick dog. But, a positive dog with signs is a sick dog that generally needs to be treated.

Veterinarians must develop their own treatment protocol in their clinics based on sound information, experience and environmental risk factors.

The best treatment plan is never as effective as preventing canine Lyme disease with a comprehensive tick-borne disease prevention program, including Lyme vaccination.

Lyme Disease Treatment
A comprehensive discussion.

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