Reference values for activated coagulation time in cats

Objective-To establish reference values for activated coagulation time (ACT ) in cats by use of jugular venipuncture and direct collection of blood int o ACT vacuum tubes. Animals-100 clinically normal cats that were to have elective surgery perfo rmed at a private practice. Procedure-Collection of 3 blood samples for ACI measurement was attempted f or each cat at the time of elective surgery: sample 1, obtained before seda tion; sample 2, tube 1 of 2 consecutive samples obtained from a single veni puncture of the contralateral jugular vein after sedation with acepromazine and ketamine hydrochloride; and sample 3, tube 2 collected immediately fol lowing collection of sample 2 without removing the needle from the vein. Ve nipuncture quality was rated subjectively on a 3-point scale. Results-Median ACT were 95 seconds for each sample group. The middle 95% of values ranged inclusively from 55 to 185 seconds (sample 1), 65 to 135 sec onds (sample 2), 45 to 145 seconds (sample 3), and 55 to 165 seconds overal l (samples 1, 2, and 3). Significant differences in ACT values were not det ected between sample groups. Significant relationships between ACT and veni puncture quality or sex of cat were not detected. Conclusions and Clinical Relevance-With the ACT protocols used, clinically normal cats had ACT of < 165 seconds. The ACT in cats does not appear to be significantly affected by sex, sedation with acepromazine and ketamine, or by moderately traumatic venipunctures. These results refute widespread sta tements that ACT should be < 65 seconds in healthy cats. Cats with ACT repe atedly > 165 seconds should be further evaluated for hemostatic disorders.