Table of Contents and Abstracts

Equine parvovirus-hepatitis (EqPV-H) was first reported from the serum and liver tissue of a horse diagnosed with Theiler’s disease in the United States in 2018. Theiler’s disease, also known as equine serum hepatitis, is a severe hepatitis with fulminant hepatic necrosis. The disease has most frequently been reported following the administration of equine-origin biological products; however, it has also been reported in in-contact horses with no prior biologic administration. EqPV-H has been detected in clinically healthy horses in North America (USA, Canada), Europe (Germany, Austria, Slovenia), Asia (China, South Korea), and South America (Brazil). Previous prevalence studies conducted worldwide have shown the presence of EqPV-H DNA in serum or plasma ranging from 3.2 to 19.8%. This study investigated the prevalence of EqPV-H DNA in 170 healthy broodmares of various breeds located on 37 farms in southern Ontario, Canada. The occurrence of EqPV-H infection was determined by quantitative PCR for EqPV-H DNA in serum samples. The effects of age, breed, season, pregnancy status, and equine herpesvirus-1 (EHV-1) vaccination history on EqPV-H status were also investigated. There was a prevalence of 15.9% (27/170) with viral loads of EqPV-H ranging from detectable to 2900 copies/mL. Statistical analysis showed that increasing age was a significant factor in the detection of EqPV-H DNA. Neither breed, season, pregnancy status, nor EHV-1 vaccination history was significant in predicting EqPV-H infection status.

Porcine sapelovirus (PSV) is a newly emerging enterovirus that is widely prevalent in China. Since there is no clinical serological testing for PSV, the objective of this study was to develop an indirect enzyme-linked immunosorbent assay (i-ELISA) for detection of PSV immunoglobulin G (IgG) antibody in pigs. A PSV strain, named SHPD202148, was first isolated from the fecal samples of piglets. Its structural protein, VP1, was prokaryotic-expressed in the pET expression system, followed by purification. Using the recombinant protein with reactogenicity as coating antigen, an i-ELISA, characterized by high sensitivity and specificity, had a detection limit at 1:12 800 dilution with a determined cutoff value of 0.352. Finally, field sera collected from different pig herds were tested in parallel by the serum neutralization (SN) test. The result showed that 126 samples were positive and 36 were negative, with an agreement of 97.0% in both cases. This i-ELISA can be used as an alternative serological test for detecting antibodies against PSV in blood serum.

The objective of this study was to assess the application of a urethrostomy technique that utilizes an autologous vascularized intestinal graft as a “neourethra” and to analyze its short- and long-term feasibilities. Six cats with urethral rupture and 8 cats with urethral stricture and a history of urethrostomy were included. The inclusion criteria were the indication for urethroplasty and limited urethral length for perineal urethrostomy. A segment of intestine was prepared as a graft for urethral repair. The diameter of the aboral end was adjusted to facilitate anastomosis with the urethra or neck of the urinary bladder. An ostomy was created in the prepubic region using the oral end. The postoperative follow-up period was at least 1 y. Restoration of urinary flow was successful in all cases immediately after surgery. During postoperative follow-up, minimal complications were observed, with urinary incontinence being one of the most frequent, occurring in 28.5% (4/14) of the cases. Urine culture, carried out at different times during the follow-up period, was positive in 72.7% (8/11) of the cats. The autologous graft from the vascularized intestinal segment was an appropriate urethral substitute and this urethroplasty technique therefore proved to be feasible in cats. The postoperative complications observed were not exclusive to this technique and generally could either be corrected or tolerated. Periodic clinical follow-up examinations are recommended. This procedure allows the reestablishment of urinary flow and should be considered a favorable option, particularly when there is insufficient urethral tissue to allow repair using conventional techniques.

The objective of this study was to evaluate the position of the patella in relation to the proximal femoral axis in the sagittal plane and to assess its reliability as a surgical landmark for femoral component placement in canine hip replacement. The relationship between the patella and the proximal femoral axis was assessed by defining the proximal patellofemoral angle in medio-lateral radiographic projections with 3 different stifle angles (full flexion, 90°, full extension) in medium to large breed skeletally mature dogs (N = 14). Proximal patellofemoral angle measurements were compared between the 3 different groups of stifle position using ANOVA for statistical analysis. The mean proximal patellofemoral angle measurements were −7.4° (± 1.3°) in the flexion group, −1.6° (± 1.5°) in the 90° group, and 2.1° (± 1.8°) in the extension group. Statistically significant differences were seen in the proximal patellofemoral angle between groups (P ≤ 0.001). These results confirm that position of the patella related to the proximal femoral axis differs depending on the degree of stifle flexion. The degree of stifle flexion should be considered in the preoperative planning and intraoperatively when using the patella as a surgical landmark in the sagittal plane for femoral canal broaching in canine total hip replacement.

The objective of this study was to describe patient demographics associated with iliopsoas strains, frequency of common concurrent injuries, and associated strain grades based on musculoskeletal ultrasound.

The medical records of 72 client-owned agility dogs that had an iliopsoas musculoskeletal ultrasound (MSK-US) between 2009 and 2015 were retrospectively reviewed. Analyses included patient signalment, physical examination, and diagnostic findings.

Twenty-four breeds of canine athletes from 1.5 to 10 y old (median: 5 y, SD: 2.2 y) were included in the study. Of the 72 records reviewed, border collies were the most common breed (27.8%, 20/72) reported. Isolated iliopsoas strains occurred in 26.4% (19/72) of cases. Concurrent pathology was noted in 73.6% (53/72) of cases. Cranial cruciate ligament (CCL) instability was the most common concurrent pathology, representing 27.8% (20/72) of all cases, with hip (8.3%, 6/72), lumbosacral (23.6%, 17/72), other non-CCL hind limb (6.9%, 5/72), and forelimb (6.9%, 5/72) pathologies making up the remainder of cases with concurrent pathology. In patients with a concurrent hind limb injury, 96.7% (30/31) of dogs had their most severe iliopsoas strain grade on the same limb.

MSK-US revealed Grade I strains in 54.2%, Grade II strains in 22.2%, Grade III strains in 5.2%, and chronic changes in 18.1% of cases. There were no statistically significant associations between iliopsoas strain grade and age, body weight, sex, breed, concurrent pathology, anatomic location of concurrent pathology, or sidedness of concurrent pathology.

Iliopsoas strains are one of the most common agility dog injuries; however, patient demographics, prevalence of concurrent injury and correlation with MSK-US findings have not been previously reported. To the authors’ knowledge, this is the first retrospective analysis reporting iliopsoas strain demographics, concurrent injury frequency and correlation with MSK-US evaluation in agility dogs. Although 26.4% of iliopsoas strains occurred as isolated injuries, 73.6% had concurrent injuries, with CCL instability present most commonly, occurring in 27.8% of cases.

Dogs should be thoroughly evaluated for concurrent injuries when presenting with an iliopsoas strain.

The objective of this study was to report long-term clinical and radiographic outcomes following arthroscopic reparative treatment — flap removal, curettage, and osteostixis of subchondral bone — in dogs with humeral trochlea osteochondritis dissecans (OCD). Dogs were included in this retrospective multicenter case series if they had a computed tomography diagnostic of humeral trochlear OCD, with or without medial coronoid disease, that was treated by arthroscopic reparative technique, and a detailed follow-up at least 6 mo postoperatively. The latter included a clinical examination, assessment of lameness, measurement of the brachial circumference and elbow amplitude, International Elbow Working Group (IEWG) radiographic score, owner-completed canine brief pain inventory (CBPI) score, and visual analogue scale (VAS) rating. A generalized linear model and tests for symmetry and marginal homogeneity were used to compare data. Twenty-three dogs (30 affected elbows) were included. Long-term (median: 22 mo; range: 6 to 98 mo) postoperative lameness, CBPI, VAS, joint distension, and pain scores were significantly improved compared with the preoperative values. Long-term postoperative range of motion and brachial circumference did not reveal any significant difference between OCD-affected and unaffected elbows. Long-term IEWG scores were similar to preoperative values in 56% of elbows and had progressed by 1 grade in 44%. Long-term complications included persistent Grade-1 lameness and occurred in 23% of dogs. Long-term outcomes based on lameness and CBPI scores were considered excellent in 67% of dogs, good in 27%, and intermediate in 6%. Arthroscopic treatment is thus a suitable surgical procedure for OCD of the humeral trochlea in dogs and provides good long-term results.

The first objective of this prospective, randomized, crossover experimental trial was to compare the rostral spread of lumbosacral epidural volume calculated by body weight (BW) or vertebral column length (LE) in 6 small, isoflurane-anesthetized female beagle dogs (BW: 7.5 to 10.2 kg; LE measured from the occipital crest to the sacrococcygeal space: 46 to 56 cm). The second objective was to assess the response to a noxious stimulus once the dogs recovered from anesthesia and to determine the effects of the injection on cardiopulmonary variables. While in sternal position, dogs were injected through an epidural catheter with a volume mixture of bupivacaine 0.25% and iopamidol 15% based on BW: 0.2 mL/kg or LE: 0.05 mL/cm (< 50 cm) or 0.07 mL/cm (50 to < 70 cm). Rostral spread was determined by counting the number of vertebrae reached by iopamidol using computed tomography. After anesthesia, cardiopulmonary variables, motor function, and responses to nociceptive stimuli were evaluated. Comparisons were completed with mixed linear models and 2-way analysis of variance (ANOVA) (P < 0.05). The volume of injectate (3.29 ± 0.74 versus 1.81 ± 0.21 mL; mean ± SD) and the number of vertebrae (22 ± 2 versus 19 ± 2 vertebrae) reached by iopamidol were significantly greater for LE than for BW. Response to nociception, time to return of pain sensation, motor function, and cardiopulmonary variables were similar between groups. In conclusion, dosing based on LE resulted in larger rostral spread than when based on BW in dogs of small size.

The objective of this study was to compare the rostral spread of lumbosacral epidural volumes of a mixture of dye and contrast medium, calculated using body weight (BW) or vertebral column length (LE), in 22 dog cadavers. The dogs weighed 4.6 to 52.0 kg. Dogs were paired within a < 10% difference for BW and LE and with the same body condition score (BCS). Pairs of dogs were injected while in sternal recumbency through an epidural catheter with a volume mixture of iopamidol and dye, calculated based on BW: 0.2 mL/kg in one of the cadavers and based on LE: 0.05 mL/cm (< 50 cm), 0.07 mL/cm (50 to < 70 cm), 0.08 mL/cm (70 to < 80 cm), and 0.11 mL/cm (≥ 80 cm) in the other cadaver. The extent of rostral spread was determined using computed tomography for iopamidol and anatomical dissection for dye. Comparisons for dye and iopamidol within each dog, and for BW and LE within matched pairs, were completed with mixed linear models (P < 0.05). The number of vertebrae reached by dye was greater than the number reached by iopamidol in both BW and LE, but the rostral spread was not significantly different between BW and LE for all pairs. In conclusion, dye tends to spread further than iopamidol and therefore, these two methods should not be considered interchangeable when used in research studies.

The objective of this study was to evaluate and compare 2 different xylazine:ketamine combination anesthetic protocols in free-ranging beavers (Castor canadensis). Twenty-two beavers (weighing 2.5 to 18.5 kg) were equally assigned to one of the following protocols: 1:10 xylazine:ketamine ratio and 3:10 xylazine:ketamine ratio. Using standard metabolic scaling, the following ranges of dosages were calculated and used:

• for the 1:10 xylazine:ketamine group 1.08 to 2.25 mg/kg (median = 1.2 mg/kg) of xylazine + 10.8 to 22.5 mg/kg (median = 12 mg/kg) of ketamine IM; and
• for the 3:10 xylazine:ketamine group 2.04 to 3.67 mg/kg (median = 2.7 mg/kg) of xylazine + 6.81 to 12.25 mg/kg (median = 8.8 mg/kg) ketamine IM.

Measured cardiorespiratory parameters and anesthetic event intervals were compared between protocols. Both protocols rapidly induced levels of anesthesia adequate for minimally invasive procedures of short duration. Durations of immobility ranged from 15 to 35 min and were not significantly different between the protocols (P = 0.64). Recovery phases, following the IM administration of 0.2 mg/kg of atipamezole 30 to 65 min post-induction, were usually faster with the 3:10 xylazine:ketamine protocol, but this was not statistically significant (P = 0.40). Heart rates were significantly lower with the 3:10 xylazine:ketamine protocol (P = 0.0002). P_ETCO₂ values, measured with a nasal cannula, were similar between protocols and suggestive of hypoventilation. Despite the fact that the 3:10 xylazine:ketamine protocol was associated with a greater cardiac depression, the apparent, even if not statistically significant, faster recovery time with that protocol is definitively an asset for projects occurring in remote locations relying on helicopter transportation.

This study investigated the mRNA of immune factors expressed by milk somatic cells from 72 healthy lactating Holstein cows on 1 farm. Milk samples were collected aseptically from the right front mammary gland before milking. The milk samples that had a negative reaction to the California mastitis test were used to analyze the mRNA of immune factors. Cows were divided into 2 groups based on the detection of bacteria in milk samples: positive group (n = 22 cows), which showed bacteria in cultures, and negative group (n = 50 cows), which did not show bacteria in cultures. There were significant positive correlations among the relative mRNA levels of interleukin (IL)-6, IL-8, arginase 1, chemokine (C-C motif) ligand (CCL) 1, and chemokine (C-X-C motif) ligand (CXCL) 13, as well as among the relative mRNA levels of IL-10, pentraxin 3, CCL5, and CCL14. Significantly high levels of IL-1β, IL-6, IL-8, arginase 1, Batf, CCL1, CXCL14, and toll-like receptor 4 in the positive group were discovered compared to the negative group. These results suggest that the presence of bacteria in lactating healthy dairy cows may affect mRNA levels of inflammatory mediators expressed by somatic cells.

Saccharomyces boulardii group (SB group) calves were fed 2.0 × 10¹⁰ CFU/day of S. boulardii in milk replacer after 2 wk of age. All calves received inactivated vaccine for Histophilus somni, Pasteurella multocida, and Mannheimia haemolytica at 3 wk of age and 3 wk later. After vaccination, the SB group calves showed significantly higher (mean difference: 1.56-fold) antibody titer against H. somni than the control group. The number of calves with the antibody titer above the cut-off value for M. haemolytica of the SB group was significantly higher than that of the control, and the percentage was twice as high. In addition, the mRNA transcription of IL4 and IL10 in peripheral blood mononuclear cells at the booster of the SB group was significantly higher than those of the control. In conclusion, S. boulardii may have positively affected immune responses to the inactivated multi-bacterial vaccine in young calves in the field.