Table of Contents and Abstracts

A 5-year-old spayed female mixed-breed dog was referred to the Atlantic Veterinary College (Charlottetown, Prince Edward Island) because of a 7-month history of intermittent pink, mucoid, vulvar discharge. The dog was imported from the Bahamas at 3.5 y of age and had a history of transmissible venereal tumor (TVT) of the vulva that was successfully treated with a course of vincristine chemotherapy. Complete remission was achieved with a disease-free interval of 6 mo before clinical signs recurred. Abdominal ultrasound and CT scan identified a large caudal abdominal mass thought to arise from the uterine stump. An exploratory laparotomy was performed and the mass grossly excised. Histopathology was consistent with a poorly differentiated round cell tumor, and immunohistochemical analysis confirmed TVT as the most likely diagnosis. No further treatment was carried out. Repeat abdominal ultrasound at 4 mo after surgery showed no evidence of mass recurrence. At 8 mo after surgery, the dog was reported to be doing well clinically.

Key clinical message:
Transmissible venereal tumor should be considered as a differential diagnosis for masses arising from the deep genital tissues of dogs in cases where there is a history of previous TVT. Transmissible venereal tumor should be considered even in dogs that have had complete resolution of a primary mass after chemotherapy.

An 11-year-old neutered male large crossbreed dog was presented for investigation because of a 10-day history of progressive lethargy, hyporexia, and pyrexia. Physical and dermatological examinations were unremarkable. Blood biochemical analysis identified a marked total and ionized hypercalcemia and increased C-reactive protein concentration. Bicavitary computed tomography screening for causes of the dog’s clinical and biochemical abnormalities identified a diffuse panniculitis. Histopathological examination of full-thickness skin biopsies was consistent with pyogranulomatous inflammation. Extensive histochemical staining revealed no infectious etiology. Complete clinical and biochemical remissions were observed after starting immunosuppressive, followed by tapering, doses of prednisolone, supporting an immune-mediated etiology.

Key clinical message:
Sterile, immune-mediated pyogranulomatous inflammation should remain a differential diagnosis for hypercalcemia in dogs. Significant dermatological disease may occur without visible abnormalities.

An 8-year-old castrated male Maltese dog was presented with a urinary bladder mass, urolithiasis, and hematuria. A solitary, pedunculated, intraluminal mass on the caudodorsal wall was identified with extensive irregular bladder wall thickening, and the mass was surgically removed. Postoperative histopathology demonstrated a submucosal lesion comprising spindle cells with marked inflammatory cell infiltration, without malignant changes. Immunohistochemical staining revealed vimentin and desmin positivity in the mass. An inflammatory myofibroblastic tumor (IMT) was definitively diagnosed. No recurrence was observed during a 43-month follow-up period. Although IMTs are rare in dogs, they should be considered a differential diagnosis for mass-like urinary bladder lesions accompanying a chronic inflammatory disease process.

Key clinical message:
Canine IMT should be included in the differential diagnoses of bladder masses, especially when dogs exhibit chronic irritation and inflammation.

A 7-year-old spayed female domestic shorthair cat was presented for evaluation of a large-volume abdominal space-occupying lesion. A computed tomography angiography examination detected a round retroperitoneal mass, in contact with the large abdominal vessels, characterized by an external hyperattenuating capsule and a larger hypoattenuating center. The capsule was soft-tissue attenuating with marked heterogenous contrast enhancement. The center was hypoattenuating pre- and post-contrast administration. The mass displaced both kidneys laterally and the descendent colon ventrally. The mesenteric veins and both phrenicoabdominal veins were markedly increased in diameter. However, the adrenals were not involved. On the excretory phase, no contrast enhancement was observed in either ureter, except for the proximal tract of the right ureter. At laparotomy, both ureters entered the mass that was adherent to the great abdominal vessels. The cytological diagnosis was retroperitoneal extra-adrenal paraganglioma. In cats, retroperitoneal extra-adrenal paragangliomas are very rare. This is the first computed tomography angiography report of a retroperitoneal extra-adrenal paraganglioma in a domestic cat.

Key clinical message:
This report describes the computed tomography angiography features of a rare case of a retroperitoneal extra-adrenal paraganglioma in a cat. These features could be taken into consideration to direct the diagnosis of a possible neuroendocrine origin for a retroperitoneal mass in a cat.

The clinical presentation, cytologic findings, radiographic findings, and postmortem assessment of a cat with primary pulmonary adenocarcinoma with multiple digital metastasis are described. An unusual shifting, waxing and waning pattern of lameness, suspected to be an early manifestation of digital metastasis before any gross lesions were visible, was documented. Initial cytologic finding of a lung nodule was equivocal for diagnosis of neoplasia despite being strongly suspicious. Palliative management was short-lived, with rapid progression culminating in widespread metastasis to multiple digits, muscles, and other organs. The diagnosis of pulmonary adenocarcinoma was confirmed via necropsy and histopathology.

Key clinical message:
This case report highlights that feline lung-digit syndrome is an important differential diagnosis for an acute, waxing and waning, shifting leg lameness in an older cat. This pattern of lameness should raise the index of suspicion for an underlying primary lung neoplasm, and thoracic imaging (radiographs) should be considered.

A 21-year-old retired polo Argentinian thoroughbred horse from a teaching herd was presented for a routine bronchoalveolar lavage demonstration, during which an incidental finding of a granulomatous mass on the dorsal aspect of the epiglottis was made. Rhinosporidium seeberi was suspected from a histological section obtained from an initial biopsy, and the mass was removed via laser surgery for cytology and PCR. Sequencing of the PCR amplicons confirmed the diagnosis of R. seeberi. A treatment protocol of nebulized voriconazole for 10 d postoperatively was used. Long-term follow-up required 2 more laser surgeries plus oral fluconazole to resolve the remaining fungal spores. However, 2.5 y later, there was no evidence of remaining fungal spores.

Key clinical message:
Horses from endemic regions can potentially be exposed to R. seeberi. Based on its travel history, this horse may have contracted the infection in South America, California, or Alberta. Treatments administered, including diode laser resection, voriconazole antifungal nebulization, and oral fluconazole administration, were successful but required repeated interventions.

Objective
Assessing effectiveness of circular (CM) and linear (LM) scrub methods using 3 different combinations of chlorhexidine in surgical field antisepsis in cats.

Animals and procedure
Surgical field antisepsis was applied with 2 scrub methods (CM and LM) and 3 different chlorhexidine combinations (A1, A2, and A3) in 51 female cats undergoing ovariectomy. Sterile swabs collected from the surgical field pre- and post-antisepsis were inoculated in the laboratory and colony-forming units (CFU/mL) were quantified.

Results
Following the application of antisepsis, the number of positive samples decreased in all groups (P < 0.05) when using both CM and LM, except for CM in the A1 group (P = 0.063). The CFU/mL counts also decreased after antisepsis with both CM and LM in all groups (P < 0.05). A high reduction in CFU/mL counts was observed after antisepsis with both CM and LM in all groups, but no significant differences were observed between the 2 scrub methods (P > 0.05).

Conclusion and clinical relevance
Surgical field antisepsis in cats with CM and LM scrub methods, using 2% chlorhexidine combined with 70% ethyl or 70% isopropyl alcohol, or 1% chlorhexidine combined with 70% ethyl alcohol, can effectively reduce the bacterial load on the skin.

Objective
Thymoma-associated paraneoplastic syndromes in dogs and cats include myasthenia gravis, hypercalcemia, exfoliative dermatitis, erythema multiforme, T-cell lymphocytosis, myocarditis, anemia, and polymyositis. Paraneoplastic myasthenia gravis (MG) is the most commonly reported paraneoplastic syndrome in dogs with thymic epithelial tumors. The objective of this study was to examine cases of canine thymic-associated MG treated surgically, with the specific objective of providing an updated clinical picture of the preoperative management, postoperative complications, and outcomes of these cases.

Animals
Nine dogs with paraneoplastic MG underwent surgical removal of a thymic epithelial tumor.

Procedure
Medical records of dogs with MG that received surgical treatment of a thymic epithelial tumor between January 1, 2012 and October 1, 2022 were obtained from 4 veterinary teaching hospitals. Descriptions of perioperative MG management, complications, and outcomes were reported.

Results
Six of the 9 dogs received medical therapy for MG, with either a cholinesterase inhibitor (4 dogs) or a cholinesterase inhibitor and immunosuppressive agent (2 dogs), before surgery. The median duration of medical therapy for MG before surgery was 7.5 d (range: 2 to 60 d). Three of 9 dogs experienced immediate postoperative complications and were euthanized. Six of 9 dogs (66.6%) survived to discharge and 3 of 6 dogs that survived to discharge were alive at the time of writing. At the time of writing, 3 of 6 dogs had complete resolution of clinical signs attributable to MG and 2 of 6 had partial resolution. The median time from surgery to resolution of clinical signs of MG in these dogs was 63 d (range: 2 to 515 d).

Conclusion
Dogs with thymic epithelial tumors and paraneoplastic MG are at a high risk for perioperative complications.

Clinical relevance
The findings of this study corroborate previous literature stating that paraneoplastic MG is a poor prognostic indicator for dogs with thymic epithelial tumors, while also highlighting the variation in approaches to clinical management of thymic-associated MG in veterinary medicine and the lack of established protocols guiding perioperative management.

Objective
To determine if short-duration peripherally inserted central catheters (PICCs) cause a hypercoagulable state in healthy dogs, based on point-of-care viscoelastic coagulation monitor (VCM).

Animals
Ten beagle dogs were randomly and equally allocated into control and PICC groups.

Procedure
Control dogs had VCM analysis on whole blood following direct venipuncture before sedation (T0) and 2 h after sedation (T2). In the experimental group, a PICC was placed (medial saphenous or femoral vein) under sedation and removed after 4 h, with measurements before placement (T0) and 2 and 6 h after placement (T2 and T6, respectively). Parametric data were analyzed using 1-way ANOVA with Holm-Šídák test for multiple comparisons and paired or unpaired Student’s t-test. Nonparametric data were analyzed using Friedman test with Dunn multiple comparison test for Wilcoxon matched-pairs signed-rank test, and Mann-Whitney U test for PICC group, control group, and to compare PICC versus control groups, respectively.

Results
Clot formation time was longer at T2 versus T6 (P = 0.0342, but not clinically relevant) in the PICC group, with no significant differences between the PICC and control groups.

Conclusion and clinical relevance
Short-term placement of a PICC line did not alter viscoelastic endpoints in healthy beagles.

Objective
The present study reports the first isolation and whole-genome sequencing of a Trueperella abortisuis bacterium from a goat.

Animals and sample
The T. abortisuis was isolated from the uterus of a goat following an abortion.

Procedure
The T. abortisuis was identified by pure culture phenotype and MALDI-TOF analysis and further characterized by whole-genome sequencing.

Results
This isolate was reliably identified as T. abortisuis and showed similar properties to type strain T. abortisuis DSM 19515^T, which was recovered from a sow following an abortion. The assembled genome of this isolate was 2 564 866 bp long with a GC content of 63.9%. A total of 30 virulence-related genes were determined, suggesting the pathogenic potential of this organism.

Conclusion and clinical relevance
This study details the first isolation of T. abortisuis from goats. The genotypic findings of this isolate will serve as a baseline description for any similar future studies.

Testicular tumors are rarely reported in rabbits. In this case study, a 4-year-old Holland lop rabbit, previously diagnosed with unilateral cryptorchidism, was presented because of enlargement of the descended testis. The rabbit was clinically normal. Following unilateral orchiectomy and scrotal ablation, histopathological analysis revealed 2 distinct types of testicular tumor in the descended testis: a granular cell tumor and a seminoma. To the best of the author’s knowledge, this is the first documented report of simultaneous testicular tumors in the testis of a rabbit with unilateral cryptorchidism.

A swine production system had 3 sections located a few kilometers apart. Sections A and C contained several thousand sows and nursery and finishing pigs. Section B, located between the other 2 sections, was the smallest and had 6 finishing sites and 2 sow sites. The entire system was infected with porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, and Actinobacillus pleuropneumoniae. Section B was depopulated, cleaned, disinfected, and repopulated with negative gilts. Despite extreme measures, recontamination occurred for each pathogen, with aerosol considered the most plausible contamination source.