Objective—To develop a method to experimentally
induce Borrelia burgdorferi infection in young adult
Animals—22 healthy Beagles.
Procedure—All dogs were verified to be free of borreliosis.
Twenty 6-month-old dogs were exposed to
Borrelia burgdorferi-infected adult ticks and treated
with dexamethasone for 5 consecutive days. Two
dogs not exposed to ticks were treated with dexamethasone
and served as negative-control dogs.
Clinical signs, results of microbial culture and polymerase
chain reaction (PCR) testing, immunologic
responses, and gross and histologic lesions were
evaluated 9 months after tick exposure.
Results—Predominant clinical signs were episodic
pyrexia and lameness in 12 of 20 dogs. Infection with
B burgdorferi was detected in microbial cultures of
skin biopsy specimens and various tissues obtained
during necropsy in 19 of 20 dogs and in all 20 dogs by
use of a PCR assay. All 20 exposed dogs seroconverted
and developed chronic nonsuppurative arthritis.
Three dogs also developed mild focal meningitis,
1 dog developed mild focal encephalitis, and 18 dogs
developed perineuritis or rare neuritis. Control dogs
were seronegative, had negative results for microbial
culture and PCR testing, and did not develop lesions.
Conclusions and Clinical Relevance—Use of this
technique successfully induced borreliosis in young
dogs. Dogs with experimentally induced borreliosis
may be useful in evaluating vaccines, chemotherapeutic
agents, and the pathogenesis of borreliosisinduced
arthritis. (Am J Vet Res 2001;62:1104–1112)