Certain diagnostic tests must be performed to confirm the diagnosis of Lyme disease and exclude other diseases that may cause similar symptoms. The following diagnostic tests are often recommended: A complete medical history and physical examination should be obtained by your veterinarian. Special attention should be paid to joints, lameness evaluation and auscultation (stethoscope examination) of the heart.
Diagnosis is based on physical examination, history, clinical signs, rule-outs, positive serology and response to antibiotics.
Blood tests called IFA or ELISA may help to determine disease. The ELISA can detect antibodies to Lyme disease in dogs that have not been vaccinated for Lyme disease. A single positive titer can be an incidental finding in an endemic area and does not indicate disease. Most veterinarians consider a fourfold rise in antibody titer diagnostic of disease.
Western blot is useful to distinguish between antibody levels generated due to infection vs. those due to vaccination.
Joint fluid analysis may be done in arthritic or lame joints. This test can also help determine the cause of the lameness and rule out other infections.
Radiographs (X-rays) may be performed on swollen or lame joints. Swelling in the joint (effusion) is a common finding with Lyme disease but the radiography should otherwise should be normal.
Your veterinarian may recommend additional diagnostic tests to exclude or diagnose other conditions or to better understand the impact of Lyme disease on your pet. These tests ensure optimal medical care and are selected on a case-by-case basis. Tests may include:
A complete blood count (CBC) may be needed to evaluate your dog for other problems such as infections, inflammations or platelet related diseases.
Serum biochemistry tests are usually normal although some muscle enzymes can be elevated during lameness.
Urinalysis may be recommended to evaluate the kidneys and bladder.
ANA or RF tests are done to evaluate for immune system changes that can cause similar clinical signs. These tests are usually negative with Lyme disease.
Ehrlichia titer may be completed. Ehrlichia is an infectious disease that can have signs similar to Lyme disease.
Coagulation (blood-clotting) profile may be completed to evaluate for bleeding abnormalities.
Blood cultures may be done to evaluate for signs of infection. This test is usually negative with Lyme disease.
Treatment of Lyme disease must be individualized based on the severity of the condition and other factors that must be analyzed by your veterinarian. Treatments vary. If your dog has only a positive titer and no clinical signs, no treatment may be recommended. In this situation, regular follow-up visits to your veterinarian are important to ensure the condition does not progress. If the Lyme disease affects other organ systems such as the heart or kidneys, additional treatments are necessary and may include the following:
Antibiotics, which usually provide complete clinical recovery in 24 to 48 hours. This is thought to be due to a decrease in bacterial load, and not elimination of the bacteria because the antibodies stay persistent for long periods. Improvement is usually noted within three days of initiation of antibiotic therapy.
Antibiotics for 14 to 21 days (recommendations vary from two to four weeks) such as tetracycline (often avoided in growing dog), doxycycline, minocycline, cephalexin, amoxicillin or ampicillin.
Steroid therapy. This should be avoided. Dogs that are serology positive and that have no symptoms are not generally treated.