Lyme Disease (Canine)

Canine Lyme Disease is a multi-symptom disease that is transmitted to dogs by ticks. Ticks can also transmit Lyme disease to people, but infected dogs cannot directly transmit disease to people or any other animal. Many dogs that are exposed to Lyme disease do not show any signs of illness, but may test positive on screening tests. Vaccines are available for prevention. Antibiotics are used for treatment of dog Lyme Disease although recurrence is possible.

Common name: Lyme Disease
Scientific name: Borrelliosis

Canine Lyme Disease Diagnosis

Signalment
All dogs that are exposed to ticks are susceptible to Lyme Disease.

Incidence/prevalence
In endemic areas (areas where the disease is most common) it is reported that up to 75% of dogs will test positive for exposure to Lyme disease. It is believed that only 5-10% of these positive dogs will ever show clinical signs of the disease.

Geographic distribution
Lyme Disease is present in all 48 of the mainland United States, however 85% of cases in humans and dogs are found in the Eastern Coastal states, from Massachusetts to Virginia. Ten percent of cases are seen in the Upper Midwest states and 4% in Northern California. All other states combined account for only 1% of cases.

Clinical signs (primary, most to least frequent, scientific term, synonyms)
Lameness (different limbs are affected at different times), swollen, painful joints, general malaise/lethargy, anorexia (not eating), enlarged lymph nodes, fever.

Clinical signs (secondary, most to least frequent, scientific term, synonyms)
Kidney disease, neurologic disease.

Cause (scientific, common term)
Borrelia burgdorferi.

Organ system affected (most to least affected)
Joints, renal (kidneys), central nervous system.

Diagnostic tests
IDEXX SNAP 3DX or SNAP 4DX (C6 Peptide Antibody test) is an accurate test for antibodies indicating exposure to the organism which can also be used in vaccinated dogs. Quantitative C6 Peptide Antibody Test determines the level of antibody present and can be used to monitor response to treatment. Western Blot tests for antibodies but is not usually done in routine practice.

Differential Diagnosis
Injury, arthritis of other origin, renal disease of other origin, nervous system disease of other origin.

Overview

Canine Lyme Disease is caused by Borrelia burgdorferi and transmitted by deer ticks (or related ticks). In areas where the disease is common up to 75% of dogs will test positive for exposure. It is believed that only 5-10% of these positive dogs will ever show clinical signs of disease. Lyme disease is present in all 48 of the mainland United States, however 85% of cases in humans and dogs are found in the eastern coastal states, from Massachusetts to Virginia, 10% of cases are seen in the Upper Midwest states and 4% are in Northern California. All other states combined make up the last 1%. The causative organism cannot survive in the environment alone. Transmission of the organism occurs from an attached tick typically over several hours. Lyme disease cannot be transmitted from a dog directly to any other animal or person. In areas where the disease is common, most dogs will test positive for exposure as evidenced by antibodies in the blood to the organism, however, they may not show any signs of illness or disease may develop after several months. Dogs that become sick from an infection with Lyme disease may show a number of different clinical signs, including lameness, joint pain, fever, or general malaise. In rare cases, dogs can get severe, even fatal kidney disease.

Dog Lyme Disease Treatment

Home Care
Canine Lyme Disease prevention through tick control is the most important aspect of home care. Routine examination of pets for ticks is especially important after visits to grassy or wooded areas. Veterinarians can provide advice on tick control products.

Professional Care
Lyme Disease vaccination is available which is 75-80% protective against disease. Although, controversy exists as to its safety and efficacy. Use of the vaccine depends on the risk of exposure and disease. Some suspect the vaccine may occasionally cause kidney disease in so similar to what is caused by Lyme Disease, however it has not been proven. A positive Lyme disease test indicates exposure but not necessarily disease. The IDEXX SNAP 3DX or SNAP 4DX (C6 Peptide Antibody test) is an accurate test for antibodies indicating exposure to the organism which can also be used in vaccinated dogs An examination will be conducted and full blood work and urinalysis may also be run to determine if there are any other causes for illness.

Action
If a veterinarian determines that a dog has clinical signs consistent with a diagnosis of Canine Lyme Disease, treatment with antibiotics, most commonly doxycycline, for at least 30 days is often initiated. Doxycycline will not clear the infection but can reduce or eliminate clinical signs of disease. Relapses may occur. Other blood and urine tests and a reduction in clinical signs suggest response to treatment. The attending veterinarian can recommend ongoing tick control and vaccination programs.

Outcome
Most cases of dog Lyme Disease resolve with appropriate antibiotic treatment, although recurrence or reinfection is possible.

References/Additional Readings

Greene, C E. (2006) “Borreliosis.” Infectious Diseases of the Dog and Cat. 3rd edition. 417-424. Elsevier. St. Louis, MO.

Author

Cara Lane, MA, VMD

Editor

Steven Hansen, DVM, MS, MBA

DABVT, DABT