Vector-borne disease and its relationship to hematologic abnormalities and microalbuminuria in retired racing and show-bred greyhounds.

Abstract

BACKGROUND: Reference intervals for platelets and white blood cell (WBCs) counts are lower in greyhounds than other breeds. Proteinuria is common. Vector-borne diseases (VBD) cause thrombocytopenia, leukopenia, and proteinuria. Racing greyhounds are commonly exposed to vectors that carry multiple organisms capable of chronically infecting clinically healthy dogs. HYPOTHESIS/OBJECTIVES: Vector-borne disease prevalence is higher in retired racing greyhounds than in show-bred greyhounds. Occult infection contributes to breed-related laboratory abnormalities. ANIMALS: Thirty National Greyhound Association (NGA) retired racing and 28 American Kennel Club (AKC) show-bred greyhounds. METHODS: Peripheral blood was tested for Anaplasma, Babesia, Bartonella, Ehrlichia, hemotropic Mycoplasma, and Rickettsia species using PCR. Antibodies to Anaplasma, Babesia, Bartonella, Ehrlichia, and Rickettsia species and Borrelia burgdorferi were detected using immunofluorescence and ELISA assays. Complete blood counts, semiquantitative platelet estimates, and microalbuminuria concentration were determined. RESULTS: Seven of 30 NGA and 1/28 AKC greyhounds tested positive for &#x2265;1 VBD (P&#xa0;=&#xa0;.05). More positive tests were documented in NGA (10/630) than in AKC dogs (1/588; P&#xa0;=&#xa0;.02). Exposure to Bartonella species (3/30), Babesia vogeli (2/30), Ehrlichia canis (1/30), and infection with Mycoplasma hemocanis (3/30) occurred in NGA dogs. Platelet counts or estimates were&#x2009;>170&#x2009;000/&#x3bc;L. White blood cell counts <4000/&#x3bc;L (4/28 AKC; 5/30 NGA, P&#x2009;>&#x2009;.99; 1/8 VBD positive; 8/51 VBD negative, P&#xa0;=&#xa0;.99) and microalbuminuria (10/21 AKC; 5/26 NGA, P&#xa0;=&#xa0;.06; 1/8 VBD positive; 14/25 VBD negative, P&#xa0;=&#xa0;.41) were not associated with VBD. CONCLUSIONS AND CLINICAL IMPORTANCE: The prevalence of thrombocytopenia and B. vogeli exposure was lower than previously documented. Larger studies investigating the health impact of multiple VBD organisms are warranted.