Objective—To determine the prevalence of circumcaval ureters and other caudal vena cava variations in cats and determine whether circumcaval ureters were associated with macroscopic evidence of ureteral obstruction.
Sample—301 domestic cat cadavers obtained from an animal shelter.
Procedures—All cat cadavers were examined, and anatomic variations of the ureters and caudal vena cava were recorded. In cadavers with a circumcaval ureter, kidney length, width, and height were measured, and the ureters were examined macroscopically to determine whether there was gross evidence of ureteral obstruction in cats with circumcaval ureters.
Results—At least 1 circumcaval ureter was present in 106 of the 301 (35.2%) cats, with a right circumcaval ureter identified in 92 (30.6%) cats, a left circumcaval ureter identified in 4 (1.3%), and bilateral circumcaval ureters identified in 10 (3.3%). Twenty-one (7.0%) cats had a double caudal vena cava, including 2 cats in which the double caudal vena cava was the only anatomic abnormality identified. No sex predilection for anatomic abnormalities was found. Mean right kidney length was significantly greater than mean left kidney length in cats with a right circumcaval ureter.
Conclusions and Clinical Relevance—Circumcaval ureter was present in approximately a third of cats in this study. Variation in the development of the caudal vena cava is the proposed cause. The clinical relevance of this variation is unknown.
Objective—To evaluate the antinociceptive effects of epidurally administered hydromorphone in conscious, healthy cats.
Animals—7 healthy adult cats.
Procedures—An epidural catheter was implanted in each cat. Thermal threshold (TT) was measured by increasing the temperature of a probe placed on the thorax and monitoring the cat's response. Mechanical threshold (MT) was measured by manually inflating a modified blood-pressure bladder affixed to a thoracic limb and monitoring the response. After the baseline TT and MT values were determined, hydromorphone (0.05 mg/kg) or an equal volume of saline (0.9% NaCl) solution was epidurally injected. The TT and MT were again measured at 15, 30, 45, 60, 120, 180, 240, 300, 360, and 480 minutes after injection.
Results—TT and MT did not change significantly from baseline values at any point after saline solution was administered. The MT and TT values were significantly higher than the baseline value at 15 minutes and at 120 and 180 minutes after hydromorphone administration, respectively. The MT and TT values after hydromorphone administration were also significantly different from those obtained at 30 minutes and at 15 minutes and 120 to 300 minutes, respectively, after administration of saline solution. No significant changes in skin temperature were detected after either treatment.
Conclusions and Clinical Relevance—Epidural administration of hydromorphone at a dosage of 0.05 mg/kg yielded thermal and some mechanical antinociceptive effects in cats, and no hyperthermia was detected. Additional studies of the antinociceptive effectiveness and duration of epidurally administered hydromorphone in clinical situations are required.
To radiographically compare patellar ligament length (PLL) in dogs undergoing tibial plateau leveling osteotomy (TPLO) for unilateral cranial cruciate ligament rupture at preoperative, postoperative, and follow-up evaluations.
105 dogs that underwent TPLO for unilateral cranial cruciate ligament rupture at a referral veterinary hospital from October 1, 2008, through November 30, 2017.
Medical records were reviewed to obtain information on dog signalment, surgical procedure, and radiographically measured PLL at preoperative, postoperative, and follow-up evaluations.
Dogs undergoing TPLO had a shorter PLL at the postoperative and follow-up evaluations, compared with the PLL at the preoperative evaluation. Mean ± SD overall unadjusted PLL decreased significantly by 2.3 ± 3.4% between the preoperative and postoperative evaluation and by 2.8 ± 3.9% between the preoperative and follow-up evaluation. The PLL did not differ significantly between the postoperative and follow-up evaluation; mean PLL decreased by 0.4 ± 3.8% between the postoperative and follow-up evaluation.
CONCLUSIONS AND CLINICAL RELEVANCE
The PLL was shorter after TPLO in dogs, which was similar to changes observed for humans after high tibial osteotomy procedures. Further evaluation of clinical assessments, joint mobility, ultrasonographic assessments, and kinematic results are needed to determine the relevance of the PLL and whether a decrease in ligament length results in decreased mobility and persistent lameness in dogs, as has been reported for humans.