CVJ - April 2022, Vol. 63, No. 4



Packed cell volume and heart rate to predict medical and surgical cases and their short-term survival in horses with gastrointestinal-induced colic

Vesna Kadunc Kos, Petra Kramaric, Maja Brloznik (page 365)

The objective of this prospective case-control study of 125 horses with gastrointestinal tract-induced colic was to determine whether heart rate (HR) and packed cell volume (PCV) can predict surgical versus medical treatment and its short-term survival (time of discharge of the patient). Sixty-four horses were treated medically and 61 surgically (29 small intestinal and 32 large intestinal cases). At admission, both PCV and HR were higher in horses treated surgically than in horses treated medically; however, with longer duration of colic before presentation, the PCV was higher in the small intestinal surgical group only. In addition, both PCV and HR were higher, and the duration of colic was longer in non-survivors compared to survivors. Binary logistic regression demonstrated a significant association between HR and type of treatment, and both HR and PCV were predictive of survival. Simple parameters such as HR and PCV provide useful information for management of colic cases.

Ultrasonographic characteristics of the portal venous system of 37 healthy, unsedated, student-owned cats: A prospective study

Maxime Derré, Catherine Layssol-Lamour (page 373)

The aim of this study was to determine portal vein and divisional branch diameters and portal vein velocities in healthy, unsedated cats, using B-mode and Doppler ultrasound.

Thirty-seven healthy, adult cats, all owned by students.

Enrollment of cats in the study was done prospectively. Ultrasonographic imaging in both the longitudinal and transverse planes was assessed, with all examinations and measurements done by the same person. The assessment included the following 3 sites: extra-hepatic portion of the portal vein, intra-hepatic branches of the portal vein, and the aorta at the level of the porta hepatis. The Shapiro-Wilk test was used for normality and P < 0.05 was used to define statistical significance.

Both the extra-hepatic portion of the portal vein and the porta hepatis were identified in all 37 cats (100%), whereas the aorta was recorded in 31 (84%), and the left and right intra-hepatic branches of the portal vein were seen in 29 (78%). Pulsed-wave Doppler ultrasound of the portal vein was obtained in 32 cats (86%). In longitudinal view, average maximal diameter of the extra-hepatic portal vein was 3.6 mm (± 0.7 mm), and the mean portal flow velocity was 14.6 cm/s (± 4.3 cm/s). In transverse view, average maximal diameter was 4.8 mm (± 0.8 mm) for the extra-hepatic portal vein, and 3.1 mm (± 0.8 mm) and 2.6 mm (± 0.7 mm) for the left and right intra-hepatic branches, respectively. The portal-vein-to-aorta ratio averaged 1.2 (± 0.2).

This study produced sonographic data of the portal venous system in healthy, conscious adult cats, which may be useful during investigation of liver diseases, including congenital and acquired liver diseases.

Analysis of antimicrobial sales data of the main distributor in Quebec from 2016 to 2019: An estimate of usage in dairy cattle, horses, and small animals

Jasmin Laroche, Cécile Ferrouillet, Luc DesCôteaux (page 379)

Because antimicrobial usage (AMU) data are crucial in understanding and dealing with the threat that antimicrobial resistance (AMR) poses to global health, data of the sale of antimicrobials from 2016 to 2019 of CDMV Inc. — a major distributor of veterinary products in Canada — were collected and analyzed for the province of Quebec. The primary objective was to describe the evolution of AMU sales data for dairy cattle, small animals, and horses; a secondary objective was to determine effects of a new provincial regulation on antimicrobials of very high importance (in Quebec) on sales for dairy cattle. Results are described in milligrams of antimicrobials per kilogram of animal biomass (mg/PCU) for dairy cattle, small animals, and horses; intramammary products were analyzed for number of treatments per 100 cow-years; and results for dairy cattle were compared in Canadian-defined course doses for cattle (DCDbovCA) per 100 cow-years to a recent study for this species in Quebec. Between 2016 and 2019, there were decreased sales of Category 1 antimicrobials for all species included in the study (Category 1-VI for small animals). This reduction was even more apparent for dairy cattle, for which a 76% decrease occurred from 2018 to 2019 (1.7 to 0.4 mg/PCU). This marked reduction was attributed to the new regulation implemented in February 2019. Since a farm- and clinic-level AMU monitoring system has not yet been implemented in Quebec, analysis of CDMV Inc. sales enabled observations of temporal trends in AMU for dairy cattle, horses, and small animals. These temporal trends based on CDMV Inc. sales will be useful for making comparisons and validating trends derived from farm- and clinic-level data generated by a monitoring system.

Outcome and complication rate of nasal planectomy reconstructed with direct mucocutaneous apposition

Madeline J. Edgar, Mariana T. Quina, Cheryl A. Tano, Christopher P. Bloch (page 386)

Nasal planectomy is recommended in cases of squamous cell carcinoma of the nasal planum in dogs and can be curative if excision is complete. Due to the noticeable alteration in appearance inherent in nasal planectomy, several techniques are described for reconstruction. The goal of this study is to report the complication rate and owner satisfaction following nasal planectomy with repair by direct mucocutaneous apposition compared to other reported reconstruction techniques meant to be more cosmetic. Eleven dogs were identified that underwent nasal planectomy with reconstruction via mucocutaneous apposition. Complications were noted in 8/11 dogs: all minor. All dogs underwent CT preoperatively for surgical planning. Complete excision was noted in 10/11 cases. Results suggest that direct mucocutaneous apposition is a viable surgical option for reconstruction following nasal planectomy with favorable major complication rates and owner satisfaction. In addition, direct mucocutaneous apposition for closure following nasal planectomy should be considered, especially in cases in which bone is not resected, because of low complication rates and reasonable cosmetic outcome.

Case Reports

Ultrasonography and digital radiography findings in sheep with clinical disease associated with small ruminant lentivirus infection

Ryan M. Breuer, Elizabeth A. Riedesel, Jennifer Fowler, Michael J. Yaeger, Joe S. Smith, Amanda J. Kreuder (page 391)

Digital radiography and ultrasonographic images were used in this case series to evaluate 4 ewes from a single flock for chronic weight loss and ill-thrift. On examination, all displayed tachypnea, dyspnea, coughing, and normothermia with abnormal thoracic auscultations. Three of the 4 animals were diagnosed with chronic respiratory disease associated with Maedi-visna (MV) infection confirmed via serologic testing. Diagnostic thoracic imaging identified characteristics consistent with pathological lesions associated with interstitial pneumonia in the 3 MV affected animals; these findings were absent in the animal that tested negative for MV.

Key clinical message: Diagnostic imaging may be useful to clinicians looking to obtain further visualization of lung pathologies and as a reliable means of detecting thoracic lesions indicative of interstitial pneumonia on-farm. These results can be used to aid the practitioner in determining appropriate further diagnostic testing and treatment strategies while awaiting confirmatory test results for diagnosis of MV.

Surgical treatment of middle ear cholesteatoma using an oral approach in 2 dogs

Kae Shigihara, Naoko Yayoshi, Harumi Sawada, Yutaka Momota, Yasushi Hara (page 400)

Middle ear cholesteatoma is caused by the formation of epidermoid cysts that result in distention and enlargement of the tympanic bulla with subsequent destruction of surrounding tissues. We report treatment of middle ear cholesteatoma in 2 dogs, via an oral surgical approach. Abnormal tympanic bulla contents and the wall compressing the pharynx were successfully removed in both cases. Computed tomography imaging, surgical findings, and histopathology results were consistent with middle ear cholesteatoma in both cases. The outcomes in both cases suggest that an oral surgical approach may be an alternative treatment for middle ear cholesteatoma in dogs.

Key clinical message: Despite the limited number of cases described herein, our report indicates that the direct oral approach for canine cholesteatoma may be and alternative approach.

Ultrasonographic and computed tomographic features of a true gastro-gastric intussusception with concurrent foreign bodies in a dog

Aurélie Bruwier, Aurore Fouhety, Jean-François Boursier, Dimitri Leperlier, Anne-Sophie Bedu (page 407)

A 2-year-old intact male Cane Corso dog was presented for acute weakness, vomiting, and diarrhea. Abdominal ultrasound revealed the stomach had severe wall edema and a target appearance. Computed tomography was consistent with a gastro-gastric intussusception and concurrent mineral-like gastric foreign bodies. After reduction of the intussusception, bilateral incisional gastropexy was performed to prevent recurrence. True gastro-gastric intussusception is a rare condition and should be considered if the stomach has severe wall edema with a target sign on abdominal ultrasound. Computed tomography was useful to confirm this rare diagnosis and screen the entire abdomen for concurrent lesions.

Key clinical message: This case highlights the usefulness of a CT examination to confirm this rare diagnosis, to determine the position of gastric compartments, and to detect potential concurrent lesions prior to surgery.

Mineralized, obstructive cardiac myxoma with chondroid differentiation in a cocker spaniel

Cassandra Mellish, Étienne Côté, Enrique Aburto, Jonathan Lichtenberger (page 411)

A 12-year-old castrated male cocker spaniel dog was referred for evaluation of signs consistent with right-sided heart failure. Thoracic radiography revealed mineralization in the region of the right atrium. Echocardiography identified a mass partially filling the right atrium and right ventricle and obstructing flow through the right heart. These findings were confirmed at necropsy and histopathologic features were consistent with myxoma with chondroid differentiation.

Review Articles

The effect of laparoscopy on intracranial pressure as measured by optic nerve sheath diameter: A review

Kevin G. Mitchell, Ryan B. Appleby, Melissa D. Sinclair, Ameet Singh (page 416)

Laparoscopic surgery has many benefits over open surgery including lower complication rates, and shorter duration and lower cost of hospitalization. However, recent human literature suggests laparoscopy and carbon dioxide insufflation can result in intracranial hypertension. Invasive monitoring of intracranial pressure is not routinely performed in veterinary medicine, and ultrasonographic evaluation of the optic nerve sheath has been employed as an indirect measure of intracranial pressure in many species. The optic nerve sheath is continuous with the meninges of the brain and becomes distended with intracranial hypertension. Optic nerve sheath diameter is a reliable and consistent measure of intracranial pressure and has been utilized in humans to evaluate patients for intracranial hypertension secondary to laparoscopy and capnoperitoneum. No thorough evaluation of the effects of laparoscopy on intracranial pressure has been performed in dogs. Ultrasonographic evaluation of the optic nerve sheath is a safe, non-invasive, and inexpensive procedure that may allow for the evaluation of intracranial pressure without the need for invasive monitoring systems. As laparoscopic procedures are performed increasingly often, this review aims to inform the reader on the effects of capnoperitoneum and to facilitate appropriate patient selection, anesthetic considerations, and surgical planning.

Brief Communications

Effects of cannabidiol without delta-9-tetrahydrocannabinol on canine atopic dermatitis: A retrospective assessment of 8 cases

Chie Mogi, Masanori Yoshida, Koji Kawano, Takaaki Fukuyama, Toshiro Arai (page 423)

We aimed to examine the effects of cannabidiol (CBD)-containing hemp oil without delta-9-tetrahydrocannabinol (THC) as a supplemental treatment for canine atopic dermatitis (CAD), as well as its adverse effects, and effects on concurrent drug use in dogs.

In this retrospective case series, 8 dogs with CAD were diagnosed by veterinary dermatologists certified by the Japanese Society of Veterinary Dermatology.

The medical records of dogs supplemented with CBD-containing hemp oil were evaluated with respect to signalment, physical examination, plasma C-reactive protein concentrations, pharmacologic management, the CAD Extent and Severity Index (4th iteration), and the Pruritus Visual Analog Scale.

Overall, CBD, used as a supplement in combination with other drugs, was well-tolerated over a wide dose range and decreased the occurrence of pruritus in dogs with CAD when ingested twice a day.

This study provides the first report of supplementation with CBD without THC that was effective in controlling pruritic behavior in dogs with CAD.

Clinical relevance
Further controlled studies are required to investigate the dose range, efficacy, and safety.

Student Paper

Bilateral anterior segment dysgenesis in a 7-week-old domestic shorthaired cat

Erin Douglas (page 435)

A 7-week-old, intact, female domestic shorthaired cat was presented to the Atlantic Veterinary College (AVC) Ophthalmology service for a 1-week history of buphthalmia in the left eye and bilateral elevated intraocular pressures. Ocular examination revealed bilateral non-visual glaucomatous eyes. Bilateral enucleations were performed without complications and histopathology revealed anterior segment dysgenesis of varying degrees in both eyes.

Key clinical message: Anterior segment dysgenesis is a developmental condition that can result in primary congenital glaucoma for which the best course of treatment is enucleation.