2016 ACVIM Forum Research Abstract Program

A total of 373 cases were evaluated, including 207 dogs predisposed to CCAH and 166 non-predisposed dogs. Independent of breeds groupings and inflammatory activity, mean hepatic copper concentrations in the recent time period were 225 ppm greater than those in the historical time period (P < 0.05). This effect was predominantly due an increase of 386 ppm over time in predisposed breeds (P < 0.001). The mean hepatic copper concentration of 338 ppm in non-predisposed breeds in recent years was greater than the mean hepatic copper concentration of 271 ppm in nonpredisposed breeds in the historical period, but this trend did not reach significance (P = 0.08). In the recent period, the mean hepatic copper concentration of 519 ppm in predisposed breeds with non-inflammatory liver histology was greater than the mean hepatic copper concentration of 297 ppm in non-predisposed breeds with non-inflammatory liver histology (P < 0.001). This difference was not observed in the historical time period. In both periods, dogs with hepatitis had higher hepatic copper concentrations than those without hepatitis, but this difference was magnified in recent years. In the aggregate, these findings confirm that hepatic copper concentrations have changed over time. The etiology of these changes is unknown, but suggestive of changes in environmental copper exposure. Detailed investigations of potential sources of copper exposure, namely drinking water and diet, are needed to further elucidate a potential environmental etiology. Additional investigations also are needed to determine if these changes are important for all breeds of dog. Borrelia burgdorferi (BB) and Anaplasma phagocytophilum (AP) are transmitted by Ixodes spp., and seroprevalence rates in endemic areas can be greater than 15% in dogs. A genetic predisposition to infection (Bernese mountain dogs) or clinical illness associated with BB has been suggested, particularly in people and dogs with Lyme nephritis (Retriever breeds). In vaccine studies, wild caught I. scapularis adults placed in feeding chambers and allowed to feed for seven days usually results in at least a 75% BB infection rate. Recently, an I. scapularis infestation study using a previously reported model and ticks with a similar BB carriage rate from the same collection area previously used, resulted in only a 29.2% infection rate. The purpose of this report is to describe the genetic relatedness of the dogs used in that study.