Serum Biochemistry in Dogs Infected with Ehrlichia canis, Anaplasma platys and Leishmania sp.

Background: Hemoparasitoses have major importance in clinical diseases of small animals for infections are highly prevalent, easily transmitted and difficult to control. Clinical signs are nonspecific, but laboratory abnormalities are frequent, especially changes in serum biochemistry. In veterinary medicine, laboratorial findings may favor the diagnosis of hemoparasitoses and improve the quality of treatment given to these patients. The present study aimed at evaluating changes in serum biochemistry in dogs with molecular diagnosis of hemoparasites (Ehrlichia canis, Anaplasma platys and Leishmania sp.). Materials, Methods & Results: Molecular diagnosis for Ehrlichia canis, Anaplasma platys and Leishmania sp. were obtained in 26 dogs. A complete serum biochemical profile was determined in biochemical analyzer COBAS Mira. Biochemical analyzes, using commercial kits from Synermed, included total and partial protein by colorimetric method, creatinine by the kinetic method, urea, alanine aminotransferase (ALT), aspartate aminotrasnferase (AST), gamma glutamyl transferase (GGT) and alkaline phosphatase by enzymatic method. Considering reference values for canine species, it was observed an increase in the average value for serum urea concentration in dogs with leishmaniasis. These dogs also presented higher globulin concentration, while presenting reduction in serum albumin concentration, also identified in animals infected only by E. canis. Higher values of ALT were observed in the group infected with Leishmania sp. and in co-infections with concurrent increase of AST and alkaline phosphatase. Significant differences were observed between dogs infected by Ehrlichia canis and Anaplasma platys, whereas animals infected by E. canis demonstrated lower values for albumin (P < 0,02), and higher ALT (P < 0,05) and alkaline phosphatase (P < 0,02). Discussion: Renal azotemia, as a result of glomerulonephritis and interstitial nephritis is extensively described in dogs with leishmaniasis, but may also occur in cases of ehrlichiosis, as evidenced in this study. Changes in serum albumin and globulin are frequent in hemoparasitoses, especially in the leishmaniasis and chronic phase of ehrlichiosis, as observed in this study. Changes in biochemical analytes were frequent in animals with hemoparasitoses, highlighting the values of urea and creatinine in dogs with leishmaniasis, that also presented decreased levels of albumin and increased levels of globulins. Although these findings are reported in dogs with anaplasmosis, hipoalbiminemia and hypergammaglobulinemia were not identified in animals infected only by A. platys in this study. The hypoalbuminemia occurs as a consequence of decreased protein intake caused by anorexia, decreased protein production due to liver damage or loss in urine due to the kidney damage (proteinuria) while hyperglobulinaemia is linked to the host's immune response against the parasite, exacerbated in co-infections, as identified in this study. Hepatocellular damage was demonstrated by increased values of alkaline phosphatase and alanine aminotransferase (ALT) in animals infected with Ehrlichia canis. Statistical differences allowed to infer higher pathogenicity of Ehrlichia canis despite Anaplasma platys, especially in relation to oxidative stress and hepatocellular injury, although the differences may be also attributable to the stage of the disease the dogs were in.