Microalbuminuria and comparison of serologic testing for exposure to Borrelia burgdorferi in nonclinical Labrador and Golden Retrievers.

Canine Lyme disease is caused by the spirochete Borrelia burgdorferi after transmission by an Ixodes tick, typically resulting in joint pain, fever and lethargy. Lyme nephritis is a poorly characterized syndrome associated with severe glomerular and tubular renal injury and poor clinical outcome in young to middle-aged dogs positive for exposure to B. burgdorferi. The aims of this study were to identify associations between natural exposure to B. burgdorferi and the presence of microalbuminuria in nonclinical young Labrador and Golden Retrievers and to compare two commonly used serologic tests available to document B. burgdorferi exposure: the Western blot and the commercial point-of-care C6 peptide enzyme-linked immunosorbent assay (ELISA) tests. Microalbuminuria was assessed using a commercial point-of-care ELISA specific for canine albumin. Blood and urine samples from 268 asymptomatic Labrador and Golden Retrievers were included. Of these, 18.7% were positive for B. burgdorferi exposure according to the C6 ELISA; 21.2% were positive for natural exposure to B. burgdorferi and 11.5% for vaccinal antibodies according to the Western blot. The agreement rate was 93% between the two tests (kappa = 0.78, P < 0.0001) for natural exposure. Urine from 6.1% of the dogs was positive for microalbuminuria. There was no association between microalbuminuria and exposure to B. burgdorferi based on results of a Western blot (P = 0.57) or C6 ELISA (P = 0.53). Microalbuminuria is likely not a consequence of B. burgdorferi exposure in young nonclinical Labrador and Golden Retrievers.