Molecular and pathological investigations of the central nervous system inBorrelia burgdorferi–infected dogs

Abstract

Abstract. Although neurological signs have been reported sporadically in dogs with systemic Lyme disease, it is unknown if neuroborreliosis occurs in dogs. The current study systematically evaluates canine brains for evidence of Borrelia burgdorferi infection. Twelve Beagles were experimentally challenged with B. burgdorferi-infected ticks at 18 weeks of age, and 2 unexposed dogs served as controls. One of the uninfected dogs and 6 infected dogs were each given 5 daily immunosuppressive doses of dexamethasone starting at 153 days post-infection. Eleven dogs were confirmed as infected by skin punch biopsy polymerase chain reaction (PCR) and serology. Neurological signs were not seen in any dogs through the end of the 190-day study. Whole blood, serum, cerebrospinal fluid (CSF), and brains from all dogs were collected. DNA was extracted from blood, CSF, and brain and evaluated by PCR for B. burgdorferi. Formalin-fixed brain tissue was examined by histopathology, immunohistochemistry, and PCR. Immunohistochemical staining for B. burgdorferi antigen was negative in all cases. The CSF analysis was normal, and PCR was uniformly negative for B. burgdorferi in all dogs. Six of the 11 (45%) infected dogs had mild to moderate lymphoplasmacytic choroid plexitis, which was more pronounced in the immunosuppressed dogs. The lack of B. burgdorferi DNA and immunohistochemical evidence of organisms, including within the choroid plexus lesions, suggests that B. burgdorferi does not have a direct role in the etiopathogenesis of canine central nervous system pathology.

ACVIM consensus update on Lyme borreliosis in dogs and cats

“…Subclinical histologic evidence of mild‐to‐moderate synovial changes and tick bite site perivasculitis and perineuritis are consistent findings in dogs experimentally infected with Bb after tick exposure; the changes seen are milder in 18‐week old versus 6‐week old exposed puppies . Although neurologic signs were described in a few seropositive dogs in the past, recent field studies showed no association of neurologic signs in seropositive dogs, thus neuroborreliosis as seen in human and equine patients is not well‐documented in dogs . Fatal myocarditis was described in Boxer pups with Bb‐positive immunohistochemistry, for which no other cause was found; there may be a genetic (breed) predisposition for autoimmune myocarditis triggered by a Lyme antigen which mimics cardiac myosin .…”

Tick-borne Diseases (Borreliosis, Anaplasmosis, Babesiosis) in German and Austrian Dogs: Status quo and Review of Distribution, Transmission, Clinical Findings, Diagnostics and Prophylaxis

“…After natural infection, lameness has been described in <5 % of dogs (Levy and Magnarelli 1992;McKenna et al 1995;Hovius et al 2000;Chou et al 2006;Littman et al 2006), less than 1 -2 % show kidney disease (Dambach et al 1997;Chou et al 2006;Littman 2013), and the very rare cases with cardiac (Chou et al 2006;Agudelo et al 2011;Janus et al 2014) and neurological (McKenna et al 1995) involvement are assumed rather than documented. No association was found between exposure to either Borrelia species (or A. phagocytophilum) and neurological signs or inflammatory CNS disease in retrospective and prospective studies (Jäderlund et al 2007(Jäderlund et al , 2009, which have been subsequently confirmed by experimental infection (Krimer et al 2011). The different clinical picture of what is seen in veterinary practice and after experimental infection in dogs is still not well understood.…”

“…Borrelia organisms are rarely detected in body fluids such as blood ( Fig. 6), urine (bladder involvement is also rare), synovial fluid or cerebrospinal fluid (Leschnik et al 2010;Krimer et al 2011;Susta et al 2012). They are more commonly found in connective tissue, fascias, joint capsule (most promising in the affected joint), skin (near the tick bite), lymph nodes, muscle (including the heart), etc.…”

Diversity of Antibody Responses to Borrelia burgdorferi in Experimentally Infected Beagle Dogs

“…Among the minority of dogs with symptoms, recurrent lameness is the most common presenting manifestation (8)(9)(10). With experimental infections through needle inoculation or tick bites, puppies 6 to 12 weeks of age were much more likely to have symptoms than were dogs infected at Ն6 months of age.…”