SOME EFFECTS OF SARCOPTIC MANGE ON DOGS

Sequential changes in pathology were examined for scabies-infested dog s to determine the effects of infestation with Sarcoptes scabiei var. canis. During 8 wk of infestation with S. scabiei, the progression of the disease was evaluated weekly by skin scrape, clinical examination, and blood analyses. At 8 wk, selected organs were microscopically exa mined for histopathology. All infested dogs developed an advanced leve l of scabies infestation by 8 wk. Of the 36 blood parameters evaluated , only values for erythrocyte sedimentation rate (ESR) deviated signif icantly from the normal ranges for dogs. However, infested dogs had si gnificantly (P < 0.01) lower average hemoglobin and hematocrit concent rations after 8 wk of infestation compared to their values prior to in festation or to the values for the control dogs. Red blood cell levels for infested dogs dropped significantly (P < 0.01) from preinfestatio n concentrations by week 8. Conversely, by 8 wk total white blood cell and neutrophil concentrations were significantly (P < 0.01) greater t han uninfested controls. Also, whereas average eosinophil concentratio ns were not statistically different for infested dogs compared to cont rols, some individual infested dogs exhibited eosinophilia at 4-8 wk o f infestation. The ESRs for infested dogs were significantly (P < 0.01 ) greater at week 6 and 8 than for experimental dogs prior to infestat ion or control dogs. All parameters except neutrophils had returned to preinfestation levels by 2 wk after treatment for scabies. Neutrophil concentrations were no longer significantly different by 4 wk posttre atment. There were no significant differences in serum enzyme, biochem ical and electrolyte concentrations between infested and control dogs. Organ histopathology was essentially normal with none of the findings attributable to scabies infestation.