To determine whether shelter dogs presenting for elective ovariohysterectomy or castration have leukocytosis, whether leukocytes are associated with age and infection, and whether leukocytosis precludes progression to surgery.
138 dogs (from 13 regional shelters) presented for ovariohysterectomy or castration between October 7 and December 6, 2019.
For this prospective study, each dog underwent presurgical physical examination, CBC, and tests for Dirofilaria immitis antigen and Anaplasma phagocytophilum, Borrelia burgdorferi, and Ehrlichia canis antibodies, with additional tests performed as needed. Dogs were aged by dentition as juvenile (< 3 or ≥ 3 to ≤ 6 months) or adult (> 6 months). Leukogram results were compared across age groups with recognized infections and parasitism and with dogs’ progression to surgery.
There were 34 dogs < 3 months old, 22 dogs ≥ 3 to ≤ 6 months old, and 82 > 6 months old. Sixty-three of 138 (45.6%) dogs had leukocytosis (median, 16,500 cells/µL; range, 13,700 to 28,300 cells/µL). Dogs < 3 months of age had higher median leukocyte and lymphocyte counts (14,550 cells/µL and 3,700 cells/µL, respectively) than dogs > 6 months of age (12,500 cells/µL and 2,400 cells/µL, respectively). Only 1 dog had a stress leukogram. Forty-seven dogs had recognized infection, but there was no association with leukocytosis. Surgery proceeded successfully for all dogs with leukocytosis.
Mild to moderate leukocytosis is common before elective surgery in shelter dogs, but surgery can proceed safely. A CBC should be reserved for ill-appearing dogs rather than as a screening test, and age-specific reference intervals should be considered.
Objective—To develop a flow cytometric assay to quantify platelet-derived microparticles (PMPs) in equine whole blood and plasma.
Sample—Citrate-anticoagulated whole blood from 30 healthy adult horses.
Procedures—Platelet-poor plasma (PPP) was prepared from fresh whole blood by sequential low-speed centrifugation (twice at 2,500 × g). Samples of fresh whole blood and PPP were removed and stored at 4° and 24°C for 24 hours. Platelet-derived microparticles were characterized in fresh and stored samples on the basis of the forward scatter threshold (log forward scatter < 101) and labeling with annexin V (indicating externalized phosphatidylserine) and CD61 (a constitutive platelet receptor). A fluorescent bead–calibrated flow cytometric assay was used to determine microparticle counts. Platelet counts, prothrombin time, and activated partial thromboplastin time were measured in fresh samples.
Results—Significantly more PMPs were detected in fresh whole blood (median, 3,062 PMPs/μL; range, 954 to 13,531 PMPs/μL) than in fresh PPP (median, 247 PMPs/μL; range, 104 to 918 PMPs/μL). Storage at either temperature had no significant effect on PMP counts for whole blood or PPP. No significant correlation was observed between PMP counts and platelet counts in fresh whole blood or PPP or between PMP counts and clotting times in fresh PPP.
Conclusions and Clinical Relevance—Results indicated that the described PMP protocol can be readily used to quantify PMPs in equine blood and plasma via flow cytometry. Quantification can be performed in fresh PPP or whole blood or samples stored refrigerated or at room temperature for 24 hours.
To compare hematologic results for juvenile versus adult dogs from shelters that outwardly appeared healthy and were presented for ovariohysterectomy or castration.
138 dogs from 13 regional shelters.
Each dog underwent a physical examination (including use of a flea comb), age estimation by dental eruption characteristics, PCV, CBC, and tests for Dirofilaria immitis antigen and Anaplasma phagocytophilum, Borrelia burgdorferi, and Ehrlichia canis 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.
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.