Table of Contents and Abstracts

Two shih tzu dogs were referred to our clinic because of hematochezia and vomiting. Abdominal ultrasonography revealed a focal, asymmetric, exophytic small intestinal mass with loss of wall layering and muscular layer thickening of the adjacent intestine. Computed tomography (CT) in both dogs revealed a focal, asymmetric, homogenously contrast-enhanced exophytic jejunal and duodenal mass with an intact mucosal layer and generalized lymphadenopathy. Metastasis and ulceration were not detected on CT. The initial imaging diagnosis was lymphoma in both dogs; however, histopathological examination revealed the presence of intestinal mast cell tumors (iMCTs). Despite its similarity to alimentary lymphoma, iMCT should be considered a possible diagnosis, based on imaging characteristics, to ensure that proper treatments are selected. This is the first veterinary report describing detailed ultrasonographic and CT characteristics of iMCTs.

Key clinical message:
This is the first veterinary case report demonstrating sonographic and computed tomographic features of canine iMCT, which can be misdiagnosed as alimentary lymphoma. This report provides another differential diagnosis to consider when determining the appropriate patient treatment direction and histopathological examination.

An 8-year-old spayed female British bulldog was presented with vomiting, hyporexia, and large-bowel diarrhea. Abdominal ultrasound revealed a focal colonic mass with an intussusception located immediately oral to the mass. The intussusception encompassed the ascending and transverse colon and was non-reducible. Colonic resection and anastomosis were completed to include the intussusception and colonic mass. Histopathological examination of the mass demonstrated a spindle cell neoplasm arising within the muscular wall of the intussuscepted segment that obliterated normal architecture. Mild-to-moderate cytoplasmic immunoreactivity of the tumor cell population for CD117 and smooth muscle actin was consistent with a diagnosis of a gastrointestinal stromal tumor. The dog described herein remains alive and free of progressive disease at the time of writing.

Key clinical message:
The entire gastrointestinal tract should be evaluated in any animal with gastrointestinal symptoms. A gastrointestinal stromal tumor remains a plausible differential diagnosis, regardless of the intestinal segment affected, and tumor-associated intussusception is a rare but urgent clinical finding.

A 4.6-year-old spayed female German shepherd dog was admitted to a specialty hospital emergency service upon referral for suspected gastrointestinal foreign body obstruction. Free abdominal fluid was collected, and results of cytologic evaluation were consistent with a septic abdomen. An abdominal barium study revealed free gas and intraperitoneal barium, along with an obstructive gas pattern within the small bowel. Ultrasonography revealed a full-thickness jejunal perforation. On exploratory laparotomy, the perforation was noted to be located mid-jejunum with no associated mass or foreign material. A resection and anastomosis were completed. Histopathologic evaluation of the affected jejunal tissue showed aberrant gastric glandular epithelium consistent with a gastric choristoma, or heterotopic gastric tissue.

Key clinical message:
Clinicians should consider gastric glandular choristoma as a differential diagnosis in cases of seemingly idiopathic small intestinal perforation with no known cause (i.e., foreign body penetration, neoplasia, NSAID use), and histopathologic evaluation should always be done to obtain a definitive diagnosis.

Bilious abdomen is an uncommon but life-threatening condition that has not previously been associated with prophylactic gastropexy. In animals, bilious abdomen is associated with a high mortality rate, due in large part to resulting bile peritonitis. Most bilious abdomen cases in veterinary medicine occur secondary to underlying gallbladder disease or blunt abdominal trauma. This case report describes an instance of atraumatic bilious abdomen with no evidence of primary hepatobiliary disease. Prophylactic incisional gastropexy was performed on a dog within 72 h of its developing bilious abdomen. It is possible that undergoing a gastropexy increased tension on the common bile duct, but no known direct surgical trauma to the duct occurred. The cause of bile leakage in this case is suspected to be secondary to trauma from a distended hollow viscus. Findings at the time of the second surgery support this conclusion.

Key clinical message:
This case suggests a novel mechanism for the development of bilious abdomen in dogs.

A 6-year-old female huacaya alpaca was referred to the clinic for evaluation with a 1-month history of rapid weight loss, inappetence, lethargy, and severe leukocytosis refractory to medical management. Physical examination revealed a body condition score of 1 out of 5 and a large, firm structure palpable in the right caudoventral abdomen. Abdominal ultrasonographic examination revealed 3 masses with hyperechoic, swirling centers. The largest mass measured 15 cm in diameter with a 2-centimeter capsule, and extended from right of midline into the left inguinal region. Transrectal ultrasonography identified a small uterus and clear delineation between the abdominal masses. Complete blood (cell) count findings were consistent with marked systemic inflammation. Based on initial examination and laboratory findings, exploratory laparotomy was elected. Multiple mesenteric masses strongly adhered to the jejunum were observed within the abdomen. Due to the inoperable conditions and the poor long-term prognosis, the alpaca was euthanized under general anesthesia. Bacterial culture of fluid aspirated from the largest mass revealed Yersinia pseudotuberculosis.

Key clinical message:
Clinical progression and attempted treatment of Yersinia pseudotuberculosis in camelids have not been previously described and the bacterium should be considered as a differential diagnosis for abscessation and persistent leukocytosis. Yersinia pseudotuberculosis is also considered a zoonotic agent and proper precautions should be taken when handling cases of abdominal abscessation.

Animal and objective
The objectives of this study were to produce hematological reference intervals for late-pregnancy sows and to assess whether there were associations between sow hematological end points and the number of stillborn pigs.

Procedure
Whole blood was collected from 272 healthy pregnant sows ~1 wk before farrowing, and complete blood (cell) counts and hemoglobin determinations were obtained. Sows were monitored during farrowing, and litter characteristics, including number of stillborn piglets, were recorded.

Results and conclusion
Values for red blood cells, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular concentration, platelets, and white blood cells were significantly higher in Parity 1 sows compared to older sows. The mean (± SD) litter size was 14.5 ± 3.4 pigs, with 1.5 ± 2.0 stillborn pigs per litter. There was no significant association between any hematological end point (except white blood cell counts) and the likelihood of a stillborn piglet in a litter. There was a relationship between parity and stillbirth (P < 0.05), with higher-parity sows being more likely than younger sows to produce a stillborn piglet. Although it had been reported that anemic sows were more likely to have stillbirths, perhaps the relatively high mean hemoglobin concentration of sows in this study resulted in the lack of a relationship.

Objective
Assess trends in access to veterinary care for companion animals in Canada.

Procedure
Analysis and integration of available data, 2007 to 2020.

Results
Cumulative growth in the Canadian veterinary workforce was 38%, and 49% for companion animal veterinarians. Clients per companion animal veterinarian decreased 30% from 2008 to 2020. Absolute client numbers increased 1.3%, compared to pet population growth of 17%. Medicalized pets (those that had received veterinary care in the past year) increased 25%, from 9.02 million in 2007 to 11.24 million in 2020. Non-medicalized pets increased 1.8%, from 4.48 million to 4.56 million. In 2007, 33% of pets were non-medicalized, compared to 29% (15% of dogs and 42% of cats) in 2020. There was a cumulative increase of 31% for total non-medicalized dogs, and a change of −5.6% for cats. Gross and net revenues per client increased by 99 and 112%, respectively, compared to cumulative inflation of 21%.

Conclusion and clinical relevance
The analysis identified a large cohort of pets that had not received veterinary care each year. The trends were fewer clients per veterinarian, each paying higher veterinary costs, and suggested a relative, rather than absolute, veterinary capacity shortage overall. Accessible care-provision models must be encouraged, regulated for, and allowed to flourish alongside traditional models.

Objective
To evaluate the effectiveness of a liposomal-encapsulated bupivacaine suspension (LEBS; Nocita), at a 1:5 dilution with 0.9% NaCl, for the reduction of postoperative pain scores and a related reduction in the need for postoperative opioids in dogs undergoing ventral midline celiotomy.

Hypothesis
When infused at a 1:5 dilution, LEBS results in less postoperative pain (as indicated by pain scale scores), and a reduction in postoperative opioids, in dogs undergoing ventral midline celiotomy. The use of LEBS does not affect wound healing when compared to placebo.

Study design
This was a randomized, blinded, prospective clinical trial.

Animals
We studied 40 client-owned dogs undergoing abdominal surgery via a ventral midline celiotomy.

Procedure
Dogs undergoing a ventral midline celiotomy were enrolled and randomly allocated to 1 of 2 groups: those receiving LEBS or a placebo injection protocol into tissue planes during closure. The Glasgow Composite Pain Scale-Short Form (GCPS-SF) was used by an observer blinded to the treatment group to assess patients at 0, 1, 2, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, and 72 h after extubation. Dogs with a score of ≥ 3 in any single category or ≥ 6 total were given a rescue analgesia. Data were analyzed to compare the number of rescue therapy doses administered between the 2 treatment groups.

Results
Forty dogs completed the study. Dogs that received a diluted LEBS protocol were equally likely to require a rescue therapy as those that received the placebo (0.9% NaCl). There were no significant difference in the pain scores or the total number of opioid injections required between the 2 treatment groups.

Conclusion and clinical relevance
In dogs undergoing ventral midline celiotomy, 1:5 diluted LEBS administration alone should not be considered the sole method of pain relief. Liposomal-encapsulated bupivacaine suspension should be used in conjunction with systemic opioids as part of a multimodal analgesic regime. This multimodal approach would allow a reduction in dose or frequency of opioids, therefore lessening the undesired side effects associated with opioids while also decreasing client costs.

Background
Cardiovascular dysfunction associated with acute kidney injury has been recently described in veterinary medicine, but limited information is available for cats with urinary tract obstruction (UTO).

Objective
This retrospective study aimed to describe the type, frequency, timeline, and risk factors for cardiovascular events (CVEs) in cats treated for acute UTO.

Animals and procedures
Medical records of cats admitted to the intensive care unit for either upper (ureteral: UUTO) or lower (urethral: LUTO) UTO from 2016 to 2021 were reviewed. Cardiovascular events were defined as development of arrhythmia, heart murmur or gallop sound, clinical signs consistent with fluid overload (CRFO), or decreased tissue perfusion (DTP).

Results
One hundred and sixty-eight cats with UTO were recruited (56 with UUTO and 112 with LUTO). Cardiovascular events were reported in 61.9% of cases, including arrhythmia (33.6%), gallop rhythm (28.1%), heart murmur (15.3%), CRFO (14.4%), and DTP (8.6%). Potassium concentration, preexisting chronic kidney disease, and renal pelvic dilation at abdominal ultrasonography were associated with CVE occurrence in multivariate analysis.

Conclusions
This study highlighted frequent CVEs in cats treated for UTO, with a potential strong impact on outcome. Therefore, cardiovascular parameters of cats with preexisting chronic kidney disease or those admitted with hyperkalemia or renal pelvic dilation should be closely monitored.

Objective
The objective of this study was to monitor Streptococcus suis fecal shedding in nursery pigs on a farm with a history of S. suis disease involving serotypes 2 and 9.

Animal and procedure
Four cohorts of pigs (n = 480) were monitored from weaning to end of nursery. Rectal swabs from 297 pigs were tested and S. suis serotypes 15 (n = 7), 31 (n = 3), or untypeable (n = 6) isolates were recovered from 16 (5.4%) pigs.

Results
There was no significant association between S. suis fecal shedding and diarrhea. Streptococcus suis isolates recovered from pigs euthanized due to neurological signs or severe lameness were serotypes 9 (meninges) and 31 (tonsil) or untypeable (meninges, tonsil). Serotypes 9 (meninges, tonsil), 15 (spleen, tonsil), 16 (tonsil), 29 and 33 (nasal swabs), and untypeable (meninges, tonsil, and lung) isolates were identified in lame pigs.

Conclusion and clinical relevance
These results suggest that feces may not be a source of infection for the S. suis serotypes producing disease in pigs; however, the association between S. suis fecal shedding and diarrhea needs further investigation. The coincidence of untypeable isolates in feces from healthy pigs and their isolation from meninges of pigs with neurological signs warrants further investigation to determine the molecular characteristics of those isolates.

A 3-year-old spayed female Rottweiler dog was brought to a veterinary clinic because of weakness, lethargy, and hair coat changes. Hematology and clinical chemistry assessments revealed anemia, hypoalbuminemia, hyperglobulinemia, and hypothyroid. After persistent pyuria, an ultrasound-guided cystocentesis was completed, which revealed a large abdominal mass. A presumptive diagnosis of canine lymphoma with renal spread was made. Due to a poor prognosis, the dog was euthanized.