Lyme Disease Testing in Dogs

Lyme disease, or borreliosis, was first recognized in dogs in 1985. The common deer tick is usually the culprit, transmitting Borrelia burgdorferi bacteria with its bite. The disease is difficult to diagnose because there is no simple test. Diagnosis requires collaboration of dog owner and veterinarian in determining the dog's history of exposure and existing symptoms. Reliable diagnosis also includes blood tests and observation of the dog's reaction to antibiotics. Lyme disease is put into a sort of remission but cannot be cured.

  1. Risk Of Exposure

    • Risk of exposure is the first factor in determining the likelihood of Lyme disease. Only a relatively small portion of the U.S. is endemic, that is only a relatively small area of the States has the disease constantly present. More than 90 percent of cases occur in the Northeast and North Central states. Northwestern California and Mississippi also see a large number of lyme-positive dogs. All of the areas where lyme disease is present are areas with high pet populations, increasing the total number of animals potentially exposed.

    Symptoms

    • "Lyme disease is a perplexing condition because it can present itself in so many different ways. No two cases are alike and the wide variety of symptoms that Lyme can produce can be confused with many other dog diseases," says Texas veterinarian Ron Hines. He notes that many infected dogs show no symptoms at all. When exhibited, symptoms are usually fever (between 103 and 105 degrees), lameness, swelling in the joints, swollen lymph nodes, lethargy and depression, and loss of appetite. Lameness, Hines specifies, often shifts from leg to leg with the front legs most commonly affected.

    Blood Tests

    • Two blood tests are required to help diagnose the disease but neither proves certainty of infection. Most dogs test positive in the standard blood test but aren't actually infected. This test detects antibodies made by the dog in response to infection, but in actuality 90 percent of these dogs have been exposed and fought off the infection on their own. The "C6 antibody test" distinguishes between antibodies made due to exposure and those produced as a result of vaccination. But again, this test does not distinguish between exposure and actual infection.

    Antibiotics

    • Antibiotic treatment for lyme is also part of the diagnostic process. If a dog doesn't clinically improve within 48 hours of starting antibiotic therapy then it's best to assume it's not lyme disease and prudent to begin looking elsewhere for answers. Vets usually prescribe two to four weeks of doxycycline which is part of the tetracycline antibiotic family. Amoxicillin, an effective alternative, is a synthetic improvement upon penicillin. Both medications are inexpensive and have few side effects. Early treatment is critical since some infected dogs develop severe kidney, heart or nervous system problems.

    No Cure

    • "Eradication of the lyme spirochete [bacteria] is not a reasonable expectation with treatment," according to the Mar Vista Animal Medical Center in Los Angeles. "The organism is simply too good at hiding. The goal instead is to bring the patient into what is called a 'premunitive state.' This is the state that 90 percent of infected dogs achieve when they get infected but never get ill: the organism is in their bodies latently but is not causing active infection."