Tick Exposure

• Generally, the higher the dog's risk of tick exposure, the greater the chance that he's contracted Borrelia burgdorferi bacteria via its bite. "Lifestyle changes have brought Borrelia-carrying ticks closer into our home environments," says Texas veterinarian Ron Hines. He notes urban wildlife bring diseased ticks to human and pet populations. Even so, only a small portion of the United States is endemic. More than 90 percent of borreliosis cases occur in the northeast and northcentral states. Northwestern California and Mississippi also have high numbers of lyme-positive dogs, according to Hines's website, 2nd Chance.
  
  

Symptoms

• Hines refers to lyme disease as the "Great Pretender" because it produces a wide variety of symptoms that can be confused with numerous other dog diseases. "No two cases are alike," he says. Lyme's most common symptoms include fever (between 103 and 105 degrees), lameness--shifting from leg to leg with the front legs most commonly affected, swelling of the joints, swollen lymph nodes, lethargy, depression and appetite loss. Fever and joint pain usually don't present until two to five months after being bitten. Many infected dogs exhibit no symptoms at all.
  
  

Blood Tests

• Although two blood tests help diagnose borreliosis, neither proves infection. The standard blood test detects antibodies made by dogs in response to infection. In endemic areas, as many as 90 percent of dogs test positive but aren't infected, according to Mar Vista Animal Medical Center in Los Angeles. Dogs may have been been exposed but fought off the infection on their own. A second blood test, the "C6 antibody," distinguishes between dogs' antibodies made due to exposure and those made because of vaccination. Like the standard blood test however, the C6 doesn't distinguish between exposure and actual infection.
  
  

Response to Antibiotics

• "If an animal that is suspected of having Lyme disease does not clinically improve within 48 hours of starting antibiotic therapy, it is best to assume that it is not Lyme disease and other diagnostic tests would need to be done to find the source of the problem," according to PetEducation.com. Veterinarians normally prescribe doxycycline, a part of the tetracycline antibiotic family, or amoxicillin, a synthetic improvement on penicillin. Both are inexpensive and have few side effects. Some infected dogs develop severe kidney, heart or nervous system problems; early treatment is critical.
  
  

Expert Insight

• "It appears that many animals may never completely rid themselves of B. burgdorferi despite antibiotic treatment. These animals may never show any further signs of the disease," according to PetEducation.com. Mar Vista Animal Medical Center explains the goal of treatment is to bring dogs into a "premunitive state," the state that 90 percent of infected dogs reach when they become infected but don't get ill.