Q&A

Q: How common is Lyme Disease?

A: Lyme Disease is the most commonly diagnosed vector-borne disease in people throughout the world. It has been documented in dogs, cats, humans, rodents, and small mammals, birds and other animals.

On the West Coast, the highest prevalence is in Northern California (4% of all cases in the U.S.), Oregon and southern Washington. Although there are reported cases in Southern California, especially in Malibu and the Pacific Palisades, the incidence is low.

Q: How do humans catch Lyme Disease?

A: Lyme Disease is caused by a spirochete called Borrelia burgdorferi, which is spread from mammal to mammal by an infected tick. This tick, which also spreads another disease called Ehrlichia, abounds in the Southern California area.

In a study done more than 9 years ago, 10-50% of these ticks in Northern California were infected, while in Southern California, fewer than 1% were infected. Tick-laden migratory birds can easily disseminate these ticks to new locations.

Transmission requires 48 hours of tick attachment.

Q: What are the signs of Lyme Disease?

A: In high risk areas 75% of dogs may be exposed, but based on blood tests, only 5-10% develop clinical signs.
Clinical signs are usually related to host reaction to the organism rather than damage caused by the spirochete directly.

In dogs, clinical signs develop 2-5 months after tick exposure, especially in young or immuno-compromised patients. Initially, one may see fever, shifting leg lameness, swollen joints, enlarged lymph nodes, loss of appetite and general malaise. Later, arthritis develops in multiple joints. Kidney failure may develop due to irreversible damage to the kidney filters, causing loss of appetite, vomiting, lethargy, weight loss, swollen legs, fluid accumulating in the body cavities, and death. Other reported symptoms include rheumatoid arthritis, neurological dysfunction, and inflammation of the heart muscle.

In cats, arthritis and meningitis are the most frequently seen symptoms.
 
In humans, the joints, brain and heart are target organs for the disease.

Q: Can people catch Lyme Disease from pets?

A: No, only from infected ticks. Dogs and cats appear to be sentinel hosts but are not reservoir hosts for human infections.

Q: How can I protect my pets and family from becoming infected?

A: Tick control is at the heart of prevention. A good topical tick control product should be applied monthly throughout the year to all dogs and cats that go outside.

Currently, we recommend Frontline Plus. Since there needs to be about 48 hours of attachment before this disease is transmitted, we recommend that you examine the skin for ticks daily. Immediately after hikes through wooded or natural areas, check your pet's and your skin (especially your scalp) for ticks.
 
Although vaccines are available, they create diagnosing complications, and in some cases may accentuate or create disease. We do not recommend vaccination as a replacement for tick control measures.

Dogs should be selected for vaccination based on where they reside geographically, or travel, and by their habits. For example, outdoor hunting or field trial dogs that frequent known tick-infested areas would be a high priority. Currently, we are not recommending or providing Lyme Disease vaccines here in Southern California.

Reduce the presence of rodents and deer near your house as much as possible.

Q: If my pet becomes infected what is the treatment?

A: Currently, treatment consists of long-term antibiotic therapy. One of the most popular is Doxycycline because it is reported to protect joint cartilage as well. Other antibiotics are used in later stages or with neurological or cardiac symptoms.

We recommend an annual "4DX" blood test to check for Lyme, Ehrlichia, Babesia and Heartworm, which are four diseases transmitted by insects.

Information in this article was obtained from Infectious Diseases of the Dogs and Cats, 2^nd edition, by Craig E. Greene DVM , MS , Diplomate ACVIM.

Dr. Sandy’s Home Veterinary Care staff is committed to providing you with the best medical care possible for the well-being of your pets and your family.