Comparisons of hematologic results for juvenile versus adult shelter dogs presented for ovariohysterectomy or castration.

Objective: To compare hematologic results for juvenile versus adult dogs from shelters that outwardly appeared healthy and were presented for ovariohysterectomy or castration.

Animals: 138 dogs from 13 regional shelters.

Procedures: Each dog underwent a physical examination (including use of a flea comb), age estimation by dental eruption characteristics, PCV, CBC, and tests for antigen and , and antibodies. Additional diagnostic tests were performed as needed. Dogs were grouped by age as < 3, ≥ 3 to ≤ 6, or > 6 months of age, with dogs ≤ 6 months of age considered juveniles and dogs > 6 months of age considered adults. Hematologic results were compared across groups.

Results: There were 138 dogs, of which 56 were juveniles (34 dogs < 3 months old; 22 dogs ≥ 3 to ≤ 6 months old) and 82 were adults. Juvenile (vs adult) dogs had lower mean calculated Hct and mean PCV whether dogs with infectious agents or parasites were included or excluded. The mean PCV and mean cell hemoglobin concentration were lower and the reticulocyte count higher for juvenile dogs < 3 months old (35.8%, 33.1 g/dL, and 135,000 reticulocytes/μL) versus adults (44.9%, 34.7 g/dL, and 68,500 reticulocytes/μL). Most (98.6%) dogs underwent surgery as scheduled; 2 dogs had surgery postponed because of thrombocytopenia or parvovirus infection.

Conclusions And Clinical Relevance: Our findings indicated that outwardly healthy-appearing juvenile shelter dogs often have results for PCV and calculated Hct that are lower than those for adult shelter dogs and adult dog reference intervals but rarely require postponement of ovariohysterectomy or castration.