Table of Contents and Abstracts

Background
Equine herpesvirus type 1 (EHV-1) is an important viral pathogen in horses, associated with diverse clinical manifestations including fever, upper and lower respiratory disease, neurological signs, ocular disease, and abortion. Currently, EHV-1 variants (genotypes) are classified based on a single nucleotide polymorphism mutation of the open reading frame 30 (ORF30).

Objective, animals, and procedure
The aim of this retrospective study was to evaluate the EHV-1 genotypes present in horses with various clinical presentations, including respiratory disease, abortion, and neurological disease, at a referral center in the province of Ontario.

Results
Equine herpesvirus type 1 was detected in 11.7% of the tested horses, with clinical presentations including abortion (21%), myeloencephalopathy (64%), fever (11%), pneumonia (3.5%), and asymptomatic cases (3.5%). The neuropathogenic strain was more commonly present in horses with abortions and fevers. Equine herpesvirus myeloencephalopathy was associated with the non-neuropathogenic strain in 50% of the cases and the neuropathogenic strain in 44% of the cases. However, in 6% of the cases, the viral genotype was unknown.

Conclusion and clinical relevance
These findings highlighted that this is a multifactorial problem and clinical disease may not be solely attributed to viral genome. This variability reinforced the need for continued research into the behavior and epidemiology of EHV-1.

An 8-month-old intact male Labrador retriever dog from New Brunswick was referred to the Atlantic Veterinary College Small Animal Internal Medicine service (Prince Edward Island) for evaluation of marked hypercalcemia, polyuria-polydipsia, and urinary incontinence. Thoracic radiographs revealed a nonspecific, patchy-to-diffuse, interstitial-to-alveolar lung pattern, despite the absence of respiratory signs or abnormal lung auscultation. Fecal examination by Baermann analysis identified 1st-stage larvae of Angiostrongylus vasorum. Although A. vasorum has been documented in wild canid populations in parts of eastern Canada, this was the first confirmed case of an autochthonous infection in a companion animal in mainland Canada. The findings provide further evidence for the geographic expansion of A. vasorum within the Canadian Maritimes and contribute to a growing body of reports describing its emergence in North America. The dog’s clinical presentation was atypical for angiostrongylosis, with no respiratory signs despite radiographic abnormalities, and hypercalcemia as a prominent clinical feature. These findings highlighted the variable and sometimes nonspecific nature of A. vasorum infection in dogs. Veterinarians practicing in eastern Canada should consider A. vasorum as a differential diagnosis in dogs with compatible clinical or imaging findings, even in the absence of respiratory signs or known endemicity. Routine Baermann fecal screening and prophylaxis with effective anthelmintics are recommended for dogs with increased risk of exposure to gastropod intermediate hosts.

Key clinical message:
Angiostrongylus vasorum is an emerging parasite in North America and can induce a variety of clinical signs in dogs. Veterinarians, specifically in the Canadian Maritimes, need to consider A. vasorum as a potential cause of respiratory signs, neurological signs, bleeding, and other clinical signs, and should recommend appropriate parasite prophylaxis in newly endemic areas.

Intranasal inflammatory polyps are commonly reported in cats but are rarely described in dogs. A pug dog was presented with chronic upper airway obstruction consistent with brachycephalic obstructive airway syndrome (BOAS). Computed tomographic examination of the skull revealed intranasal soft-tissue masses causing marked airflow obstruction. Surgical correction of BOAS was completed, including removal of the intranasal obstructive tissue. Histopathologic examination confirmed inflammatory polyps. Clinical signs improved markedly following surgery. This case highlights intranasal inflammatory polyps as an uncommon and potentially underrecognized comorbidity in dogs with BOAS and emphasizes the importance of considering this diagnosis in brachycephalic dogs with persistent or atypical respiratory signs.

Key clinical message:
Intranasal inflammatory polyps may represent an uncommon and underrecognized comorbidity in dogs with BOAS. Recognition of concurrent intranasal pathology is important, as surgical management may result in significant clinical improvement.

A 17-month-old neutered male Bedlington terrier weighing 5.4 kg was presented because of vomiting, lethargy, and oliguria. Serum chemistry analysis revealed severe azotemia and ultrasonography revealed hyperechoic renal cortices. Acorn-induced acute kidney injury was suspected based on the animal’s history of eating dried acorns over the previous 8 d. The dog did not respond to conventional intravenous fluid therapy, but his condition improved with intermittent hemodialysis. Although acorn intoxication is well documented in grazing animals, including cattle, it has rarely been reported in dogs. Acorns can cause acute kidney or liver injury, with high mortality rates. To the best of our knowledge, this is the first reported canine case of acorn toxicosis successfully treated with hemodialysis. The case findings indicate the importance of raising awareness among pet owners about the potential life-threatening effects of consuming acorns, particularly in regions where animals’ exposure to acorns is likely.

Key clinical message:
Acorn ingestion can cause life-threatening acute kidney injury in dogs. Early recognition and timely intervention with hemodialysis can result in successful outcomes.

A 4-year-old neutered male cat was presented with a perineal mass extending over the penis. The mass was surgically excised via perineal urethrostomy. Histopathology confirmed a high-grade B-cell lymphoma confined to the penis and extending microscopically to the prepuce. The cat remained disease free for 6 mo before dying of an unknown cause. To the authors’ knowledge, this case may represent the first reported instance of a feline lymphoma clinically confined to the penis.

Key clinical message:
Penile lymphoma, though rare in cats, should be considered in the differential diagnosis for perineal or penile masses. Surgical excision can achieve local control, but prognosis and the role of adjuvant therapy remain uncertain.

Objective
The objective of this study was to describe a novel method of femoral torsion correction in dogs and partially validate the technique by applying it to femoral bone models.

Models and procedure
We conducted an in vitro study using 12 femoral bone models. Twelve bone models, consisting of 6 replicas of each of 2 right femurs (Bone Model 1 and Bone Model 2), were reconstructed, using stereolithography, from femoral computed tomographic scans of 2 chondrodystrophic dogs. An intramedullary pin-assisted distal femoral osteotomy (IPA-DFO) was done on all bone models to correct 30° of torsion (CTA2). Preoperative and postoperative femoral anteversion angle (FAA) and anatomical lateral distal femoral angle (aLDFA) were measured. The magnitude of torsional correction was defined as the T angle, calculated as the difference between postoperative and preoperative FAA.

Results
Mean T angle was 31.7 ± 1.7° for Bone Model 1 and 30.8 ± 0.9° for Bone Model 2. No significant differences were detected between CTA2 and T angles in either bone model. No significant differences were observed between preoperative and postoperative aLDFA values.

Conclusion and clinical relevance
The IPA-DFO consistently reproduced the planned femoral torsion correction in the bone models studied without inducing unintended frontal plane alignment change.

Objective
The study objective was to compare right and left heart morphology and function in dogs with compensated chronic right ventricular (RV) pressure overload secondary to pulmonic stenosis (PS) and chronic precapillary pulmonary hypertension (cPCPH).

Animals and procedure
This cross-sectional observational retrospective study included 64 client-owned dogs, including healthy controls (n = 15) and groups with PS (n = 31) and cPCPH (n = 18). The RV pressure gradient (RVPG) was determined by peak pulmonic or peak tricuspid regurgitation velocity and needed to be > 55 mmHg. Echocardiographic parameters assessing RV size [indexed diameter (RVIDd/Ao), area (N-RVAd) in diastole], hypertrophy [(RVFWd/LVFWd), (RVFWd/RVIDd)], and systolic function [fractional area change (RVFAC), indexed area in systole (N-RVAs)] were documented. Interventricular septal flattening was assessed using left ventricular (LV) eccentricity index (EI).

Results
The RVPG was lower in cPCPH compared to PS [91 mmHg (55 to 158 mmHg) vs 108 mmHg (56 to 219 mmHg); P = 0.022]. The cPCPH group displayed more dilated [RVID/Ao: 0.13 (0.09 to 0.25) vs 0.10 (0.07 to 0.19), P = 0.004; N-RVAd: 1.17 (0.65 to 1.66) vs 0.83 (0.45 to 1.45), P = 0.010] and less hypertrophied RV [RVFWd/LVFWd: 0.9 (0.44 to 1.4) vs 1.0 (0.75 to 2.0), P < 0.020; RVFWd/RVIDd: 0.30 (0.19 to 0.55) vs 0.44 (0.24 to 0.67), P < 0.001], RV with poorer systolic function [N-RVAs: 0.69 (0.27 to 1.23) vs 0.35 (0.16 to 0.92), P = 0.001; RVFAC: 0.37 (0.14 to 0.66) vs 0.57 (0.29 to 0.71), P = 0.004], and more interventricular septal flattening [EIs:1.5 (1.09 to 5.71) vs 1.22 (0.88 to 2.1), P = 0.013] compared to PS. The RVID/Ao, N-RVAd, N-RVAs, RVFAC, RVFWd/RVIDd, and EIs were influenced by RVPG and the cause of RV pressure overload (independent of RVPG). Tricuspid regurgitation was more commonly observed in dogs with cPCPH.

Conclusion and clinical relevance
After adjusting for RVPG, dogs with PS had less RV dilation, better RV function, and less left heart compromise compared to dogs with cPCPH.

Objective
Medial shoulder instability (MSI) is a frequent cause of thoracic limb lameness in dogs, yet its diagnosis remains challenging, with arthroscopic examination considered the gold standard. The objective of this study was to assess the diagnostic sensitivity of preoperative shoulder abduction angle measurements and MRI findings for detecting MSI in dogs with arthroscopically confirmed diagnoses.

Animals and procedure
Medical records from AniCura Jeløy Dyresykehus (Moss, Norway) (2017 to 2024) were retrospectively reviewed for dogs with unilateral MSI diagnosed via arthroscopy. Inclusion criteria included signalment and clinical history and clinical, orthopedic, and neurological examinations, followed by bilateral shoulder abduction angle measurements using the contralateral “healthy” limb as reference. Preoperative imaging included neutral lateral shoulder radiography and MRI examinations. Shoulder abduction angles and MRI findings were compared with arthroscopic diagnoses to assess sensitivity.

Results
Seventeen dogs (9 males, 8 females) with a median age of 72.0 mo and a median weight of 25.0 kg were included. Median lameness grade was 2 (mild to moderate). Median shoulder abduction angles were 42° in affected shoulder and 28° in contralateral shoulder, with a median difference of 14°, ranging from 11 to 26°. The shoulder abduction angle test (threshold > 40°) showed 100% sensitivity (95% CI: 80.5 to 100%) for MSI detection, whereas the sensitivity of MRI examination (medial compartment pathology) was 23.5% (95% CI: 6.8 to 49.9%).

Conclusion and clinical relevance
Bilateral shoulder abduction angle measurement is a practical, noninvasive, and apparently effective diagnostic tool for MSI that outperformed MRI with regard to diagnostic sensitivity in the study sample. Given the cost of MRI and need for anesthesia, shoulder abduction angle measurement may be preferable in clinical settings. Moreover, in cases of unilateral shoulder lameness, a difference > 10° in the abduction angles between the affected and contralateral “healthy” shoulders might be a simple, accessible indicator of MSI.

Background
Ethylene glycol (EG), the toxic ingredient in some antifreeze products, is a potent animal poison.

Objective and animals
Our objective was to characterize EG poisoning in cats and dogs hospitalized at a Canadian veterinary teaching hospital.

Procedure
We conducted a medical record review.

Results
Twenty-one cases were included from the 17-year study period (dogs n = 15, cats n = 6). Common signalments were young male intact dogs (n = 5) and adult spayed female cats (n = 4). More cases were presented in summer (n = 10) than other seasons. Cases were often presented > 8 h after onset of signs (n = 12). Diagnostic tests included venous blood gas (n = 17), serum chemistry (n = 14), urinalysis (n = 14), AFAST/TFAST (n = 6), and full abdominal ultrasonography (n = 2). The most common treatments were IV fluids (n = 17) and 4-methylpyrazole (n = 8). The survival-to-discharge rates were 33% and 0% for dogs and cats, respectively.

Conclusion
Poisoning with EG had a high fatality rate in dogs and cats presented to the emergency clinic. Animals were often presented late in the course of poisoning, making antidotal therapy unsuccessful.

Clinical relevance
Regardless of time of year, EG should be considered a differential diagnosis for animals with CNS depression, gastrointestinal signs, and evidence of acute kidney injury. In clinics that do not have commercial diagnostic tests available, the authors recommend combining findings from venous blood gas, urinalysis, ultrasonography, and a Wood’s lamp screen to establish a diagnosis.

Objective
Hyperkalemia in dogs and cats can cause rapid cardiac and neuromuscular compromise. Fast recognition, ECG-guided stabilization, and cause-directed therapy improve survival.

Animals and procedure
Part 2 of this 2-part review gives a patient-side approach for recognition, confirmation, and emergency treatment of hyperkalemia. It integrates current veterinary evidence and core physiology into step-by-step guidance for ECG interpretation, point-of-care testing, drug selection, and monitoring. It also maps 1st-hour priorities to common etiologies such as urethral obstruction and hypoadrenocorticism.

Results
Immediate cardioprotection with intravenous calcium treats cardiotoxicity. Potassium decreases rapidly with regular insulin plus dextrose, β₂ agonists serve as adjuncts, and bicarbonate is reserved for severe acidemia. Potassium elimination follows with balanced crystalloids and, when needed, renal replacement therapy. After initial stabilization, durable correction depends on identifying and treating the underlying cause and removing excess potassium from the body. Close glucose surveillance prevents late hypoglycemia after insulin. For urethral obstruction, prompt unblocking and fluids often normalize potassium with little need for repeat shifting drugs. For Addisonian crisis, fluids and glucocorticoids correct the driver while potassium decreases.

Conclusion and clinical relevance
Use a consistent sequence: Verify true hyperkalemia, protect the heart, shift potassium, remove potassium, and fix the cause. Pair ECG findings with serum potassium concentrations to guide action, since ECG stages do not always match absolute potassium concentrations. This approach helps emergency clinicians stabilize patients quickly and avoid relapse. Part 1 of this review covered homeostasis and causes, whereas Part 2 delivers diagnostic and treatment approaches.

A 3-year-old neutered male domestic shorthair cat was evaluated for hematuria. Ultrasonography and CT scanning identified moderate right-side hydronephrosis associated with right proximal and distal ureteral strictures, as well as partial stenosis of the left distal ureter. Medical management, including fluid therapy, ureteral muscle relaxants, and corticosteroids, was initiated but failed to improve progressive renal pelvic dilation as assessed on serial ultrasound scans. This case highlights the limited efficacy of conservative therapy and contributes to the growing body of evidence on the management of feline ureteral strictures.