Canine Lyme Disease: Treatment & Prevention
Many dogs that present for annual preventive testing (eg, for heartworm, Lyme, other tick-borne diseases) are Lyme-positive without apparent signs. Infected dogs are at a 5%5 to 10% risk of developing signs of Lyme disease and are unlikely to survive if they develop renal disease.
Vaccinating Lyme-positive dogs has been demonstrated to be safe.6 Treating asymptomatic positive dogs has been demonstrated to reduce antibody titers7; however, there is evidence that Lyme infections are persistent even after antibiotic therapy.8
When a patient is diagnosed with Lyme arthritis, antibiotic therapy is initiated with injectable penicillin, followed by 14 days of oral amoxicillin. For dogs presumed to have Lyme nephritis, discuss with the client further testing (eg, blood chemistry, complete blood count, urinalysis), in-patient care, intensive therapy, and a guarded prognosis.
Vaccination of at-risk dogs before exposure to infected vector ticks is a part of disease prevention. Two types of vaccines with demonstrated safety and efficacy are available: a recombinant vaccine with a single protein from the causative organism, which immunogenicity studies have suggested may provide maximum protection with twice-yearly immunizations, and another vaccine that contains multiple proteins of B burgdorferi, which immunogenicity studies have suggested will maintain effective immunity with annual boosters.9
Successful transmission of the Lyme agent from a tick to a dog requires a minimum of 24 hours of tick attachment and feeding and is most efficient at 48 to 52 hours post-attachment.
- A rapidly acting acaricide will prevent tick feeding by either killing ticks or rendering them moribund before they attach.
- Spot-on products and some collars can achieve “clinical repellence,” essentially shielding dogs from ticks by rapid killing and attachment prevention.
- New oral products are highly effective at killing ticks but often allow some period of feeding, thus providing an opportunity for transmission of B burgdorferi or other tick-borne organisms.