Table of Contents and Abstracts

Long-term assessment of nephrosplenic space (NSS) closure and comparisons with ultrasonography and rectal palpation are lacking. The objective was to evaluate NSS closure in 12 research horses 5 y following laparoscopic ablation, using a novel adhesion scoring system, and to assess whether rectal examination and ultrasonographic findings could predict adhesion adequacy. The NSS was examined via rectal palpation and ultrasonography prior to surgery, and at 30 d and 5 y after surgery. Ultrasonographic measurements of the distances between the renal fascia and spleen were recorded. The NSS adhesions were scored laparoscopically at 5 y and compared with ultrasound and rectal findings. Logistic regression was used for statistical analysis (P < 0.05). Three of 11 horses had adhesions considered inadequate for preventing colon entrapment. The remaining horses had strong adhesions in greater than 50% of the NSS. Ultrasonographic measurements of the caudal NSS decreased significantly over time (P < 0.05) but these changes were not predictive of adhesion adequacy. Surgery time, number of suture bites, or bleeding did not predict an adequate adhesion. Overall, laparoscopic NSS closure resulted in adequate adhesions in 8 out of 11 horses, persisting for at least 5 y. Rectal palpation was a reliable method for assessing NSS closure, whereas ultrasonography showed limited utility due to bowel interference and lack of predictive value. These findings support the long-term effectiveness of NSS closure and may help increase client confidence and adherence to this preventative surgical intervention.

Equine herpesvirus-1 (EHV-1) is ubiquitous in the horse population, but prevalence estimates have ranged from 3 to 88% depending on the population and method of sampling. No prevalence studies have been carried out in Ontario, Canada. The objective of this study was to measure the prevalence of EHV-1 shedding in healthy broodmares in Ontario. A total of 381 mares from 42 farms in Ontario were sampled, including pregnant and barren broodmares. Samples were collected from the nose, vagina, and blood of each mare up to 6 times from December 2016 through October 2017 using a cross-sectional study design. The EHV-1 glycoprotein B (gB) copy number was measured using droplet digital polymerase chain reaction (ddPCR). A survey was completed at time of sampling regarding signalment, pregnancy status, and vaccination. Overall, 85% of the mares sampled were positive for EHV-1 from at least one site, on at least one occasion. Samples were positive 8.1%, 15.8%, and 17.2% of the time from the nose, vagina, and white blood cells, respectively. Pregnant mares had increased odds of shedding virus from the nose [odds ratio (OR) = 1.50, 95% confidence interval (CI): 1.03 to 2.18, P = 0.037]. Vaccination only reduced the odds of virus presence in blood (OR = 0.70, 95% CI: 0.49 to 0.99, P = 0.043). Advanced gestation appeared to also have a sparing effect on virus presence in blood (OR = 0.89, 95% CI: 0.85 to 0.93, P < 0.001). Most mares in Ontario were positive for EHV-1 despite being healthy and vaccinated, although the amount of viral DNA detected was extremely low. In addition, the vagina was identified as a source of viral shedding.

The objective of this study was to determine the effect of either oral supplementation of sodium selenite and alpha-tocopherol or intramuscular administration of a commercial preparation of selenium (Se) and vitamin E to Standardbred broodmares with low (21.0 ± 18.1 IU/g Hb) whole blood glutathione peroxidase (GPx) activity. Ten mares received 3 weekly intramuscular (IM) doses, whereas 9 mares were orally supplemented daily for 10 wk. Blood samples were collected via jugular venipuncture and the whole blood GPx activity was measured at each sampling time for the 32-week period. Both oral and intramuscular administration resulted in a marked increase in whole blood GPx activity in both groups of mares.

When persistent or severe, intra-abdominal hypertension can evolve into abdominal compartment syndrome if timely therapeutic intervention is not rendered. Such interventions rely heavily on dependable, accurate monitoring of intra-abdominal pressure. The most reliable way to monitor intra-abdominal pressure in small animals is by indirectly measuring intravesicular pressure. The objective of this study was to compare the water manometry, external pressure transducer (ExtT), and pressure tip catheter techniques for their accuracy in measuring intravesicular pressure against a known intra-abdominal pressure. We hypothesized that the water manometry technique would be more accurate than the external pressure transducer (ExtT) technique in a canine cadaveric model and that pressure tip catheter would be the most accurate of the 3. Each technique was carried out on 22 small-breed canine cadavers in a randomized order, with incremental increases in insufflation pressure via a supraumbilical Veress needle. Induced abdominal pressure ranged from normal (4 mmHg) up to levels consistent with severe intra-abdominal hypertension (30 mmHg). Tukey’s multiple comparison test was used to assess and isolate differences, after the fixed-effects test was applied. There was a statistically significant difference in accuracy with the ExtT technique when compared to insufflation pressure, with a ± 2.63 mmHg overestimation observed (P-value = 0.0041). No statistical difference in accuracy was noted between the water manometry and pressure tip catheter techniques. Study limitations included the cadaveric nature that does not account for direct clinical translation of these findings. In conclusion, of the 2 commonly used techniques, water manometry appears to be more accurate than ExtT. The pressure tip catheter technique appears to be just as accurate as water manometry in this cadaveric model.

The objective of this study was to evaluate the accuracy of Board-certified specialist veterinary surgeons in assessing reduction of lateral humeral condylar fractures (HCFs) using orthogonal radiographs and to determine how often immediate surgical revision is recommended in order to correct a perceived malreduction. This was an ex-vivo study of 21 elbows from 11 skeletally mature canine cadavers. Lateral HCFs were surgically created and repaired with either anatomical or malreduced fixation (1-, 2-, or 3-mm step-offs in both distal and caudal directions). Fourteen Board-certified surgeons assessed postoperative radiographs to determine reduction quality and the need for immediate revision surgery. It was determined that surgeons frequently misclassified malreduced fractures, particularly those with caudal malreduction. Overall, 1-mm defects were misclassified at a rate of 24%, 2-mm defects at 34%, and 3-mm defects at 28%. Distal malreductions, especially those ≥ 2 mm, were more likely to be identified and recommended for immediate revision. Overall, 25% of 1-mm step-offs, 54% of 2-mm step-offs, and 45% of 3-mm step-offs were recommended for immediate revision. There was limited intraobserver consistency, with perfect accuracy and consistent reoperation advice achieved in 51% and 26% of distal and caudal malreductions, respectively. It was concluded that standard radiographs may not allow reliable detection of HCF malreductions, especially in the caudal direction. The reported outcome of HCF surgical repair might therefore be influenced by reduction misclassification.