Carla Appelgrein

Objective
To establish parameters that describe acidic gastroesophageal reflux (GER) events in nonbrachycephalic, hospitalized dogs without gastrointestinal disease following short total intravenous anesthesia, to establish upper reference limits for parameters that describe GER.

Study design
Clinical prospective study.

Animals
Healthy, client-owned dogs presenting for elective orthopedic surgery.

Methods
Dogs were sedated with IM methadone (0.2 mg/kg) and medetomidine (5 ug/kg), followed by alfaxalone total intravenous anesthesia. The Digitrapper esophageal dual pH monitoring probe was placed transnasally into the esophagus. Dogs were unsedated during the subsequent recording period. A GER event was defined as esophageal pH less than 4.0. Parameters that described GER were: (1) number of GER events per hour, and (2) cumulative esophageal acid exposure (percentage of recording duration) at each sensor. Upper reference limits were calculated for each parameter.

Results
Thirty-five dogs were included (median age 7 years, range 1–12). The median recording duration was 21.1 h (range 13.6–29.3). Productive regurgitation was not noted in any dog. The median number of distal and proximal GER events per hour was 0.3 (range 0–4.3) and 0 (range 0–1), respectively. The median cumulative distal and proximal esophageal acid exposure was 0.2% (range 0.3–9%) and 0% (range 0%–1%), respectively.

Conclusion
Upper reference limits for distal and proximal GER per hour was 2.4 and 0.4, respectively, and, for cumulative distal and proximal esophageal acid exposure, 2.3% and 0%, respectively.

Clinical significance
Dogs undergoing esophageal pH monitoring in a similar hospital setting with parameters above these upper reference limits have excessive GER.

Background

Gastroesophageal reflux and regurgitation occurs in brachycephalic dogs, but objective assessment is lacking.

Objectives

Quantify reflux in brachycephalic dogs using an esophageal pH probe and determine the association with scored clinical observations.

Animals

Fifty-one brachycephalic dogs.

Methods

Case review study. Signs of respiratory and gastrointestinal disease severity were graded based on owner assessment. An esophageal pH probe with 2 pH sensors was placed for 18-24 hours in brachycephalic dogs that presented for upper airway assessment. Proximal and distal reflux were indicated by detection of fluid with a pH ≤4. The median reflux per hour, percentage time pH ≤4, number of refluxes ≥5 minutes and longest reflux event for distal and proximal sensors were recorded. Association of preoperative respiratory and gastrointestinal grade, laryngeal collapse grade, and previous airway surgery with the distal percentage time pH ≤4 was examined using 1-way ANOVA.

Results

A total of 43 of 51 dogs (84%; 95% confidence interval 72-92) displayed abnormal reflux with a median (range) distal percentage time pH ≤4 of 6.4 (2.5-36.1). There was no significant association between the distal percentage time pH ≤4 and respiratory grade, gastrointestinal grade, laryngeal collapse grade, or previous upper airway surgery.

Conclusions and Clinical Importance

The occurrence of reflux is not associated with owner-assessed preoperative respiratory and gastrointestinal grade, laryngeal collapse grade, and previous airway surgery. Esophageal pH measurement provides an objective assessment tool before and after surgery.

OBJECTIVE To describe a technique for circumferential esophageal hiatal rim reconstruction and to report outcomes in brachycephalic dogs with persistent regurgitation treated with the technique. ANIMALS 29 client-owned brachycephalic dogs. PROCEDURES Dogs that had undergone circumferential esophageal hiatal rim reconstruction between January 1, 2016, and December 31, 2019, for treatment of persistent regurgitation were identified through a search of the medical record database of The Animal Hospital at Murdoch University. Circumferential esophageal hiatal rim reconstruction involved apposition of the medial margins of the left and right pars lumbalis dorsal to the esophagus (reconstructing the dorsal margin) and ventral to the esophagus (reducing the ventral hiatal aperture and completing the circumferential reconstruction). Data collection from the medical records included preoperative, intraoperative, and postoperative (short- and long-term outcomes [<= 14 days and >= 6 months, respectively]) data. RESULTS In all dogs, substantial laxity of the left and right pars lumbalis and failure of dorsal coaxial alignment were observed, and circumferential esophageal hiatal rim reconstruction and esophagopexy were performed. Results of short- term follow-up indicated reduced regurgitation frequency; however, 7 of 29 dogs continued to have mild regurgitation, which was attributed to esophagitis and resolved with medical management. Long-term follow-up information was available for 19 dogs: regurgitation had resolved in 16 dogs and occurred once weekly in 3 dogs. No ongoing medication was required for any dog. CONCLUSIONS AND CLINICAL RELEVANCE Circumferential hiatal rim reconstruction combined with esophagopexy substantially reduced regurgitation frequency in dogs of the present study, and we recommend that this procedure be considered for brachycephalic dogs presented with a history of regurgitation unresponsive to medical management.

Objectives

To report the surgical technique of seed skin grafting and clinical application for reconstruction of wounds on the distal limb of client‐owned dogs.
Materials and Methods

Medical records from The Animal Hospital at Murdoch University were retrospectively reviewed for dogs requiring reconstruction using seed grafting for distal limb skin defects between January 2009 and May 2020.

Results

Fifteen dogs were included. Grafting was performed on distal limb wounds at or below the carpus or tarsus, following trauma (n = 12) or neoplasia excision (n = 3). Complete epithelialisation with minimal contracture was recorded at a median of 4 weeks (range 3 to 8 weeks) after implantation. Median follow‐up was 37 months (range 3 to 55 months) after grafting. Postoperative complications included epidermal inclusion cyst in two dogs. Good functional outcome with acceptable cosmesis despite sparse hair growth was achieved in all cases.

Clinical Significance

Seed grafting is a simple technique that can be used reliably to reconstruct wounds on the distal limb in dogs where other reconstructive techniques are not suitable. Complete epithelialisation with sparse hair growth, good long‐term functional outcome and minimal complications can be expected.

Objective: Document the highest extension angle of the carpus and quantify the ground reaction forces observed during entrance of the A‐frame at three incline angles. Methods: Kinematic gait analysis measuring carpal extension was performed on 40 dogs entering the A‐frame at 40°, 35° and 30° incline. The average of the highest carpal extension angle from each of three trials at each incline was examined for a significant effect of incline, including covariates of dog height, body weight and velocity. Kinetic gait analysis was performed on 8 dogs of similar body morphology entering the A‐frame at 40°, 35° and 30° incline. Vertical and cranio-caudal ground reaction forces were normalized and averaged from three trials at each incline and examined for a significant effect of incline, including covariates height and velocity. Results: The highest carpal joint extension angle did not differ statistically between the three A‐frame angles of incline for the first or second limb. The covariate-adjusted mean carpal extension angle for the first limb at 40° was 64° (95% CI 60‐68). Regarding the cranio-caudal forces, the peak propulsive force and the proportion of time spent in propulsion (%) were significantly higher at 40° incline compared to 30°. There was no significant effect of incline on the vertical ground reaction forces. Conclusion: Decreasing the A-frame incline from 40° to 30° did not reduce carpal extension angles. The failure to find a difference with narrow confidence intervals may indicate the physiologic limit of carpal extension was reached. Ascent up the A-frame at 40° requires a higher propulsive force combined with extended time spent in propulsion to maintain forward movement. Future research should examine the effect of repetitive loading with A‐frame contact on the limits of physiologic carpal extension.

Objective: The main purpose of this study was to investigate the effect of a decrease in the A-frame angle of incline on the vertical and cranio-caudal ground reaction forces observed in a homogeneous cohort of agility dogs during entrance and contact with the A-frame. Materials and Methods: A crossover study design was applied to eight large breed dogs to compare the vertical and cranio-caudal ground reaction forces entering the A-frame at three angles of incline: 40° (standard), 35° and 30°. The peak vertical force, passive impact peak, peak propulsive force, peak braking force, the time point (percentile) in the stance phase at which these events occurred and the proportion of time for limb contact spent in braking (% braking) and propulsion (% propulsion) were examined. The variables measured from three trials at each incline were evaluated for a significant effect of A-frame angle with height and velocity included as covariates. Results: The peak propulsive force and the % propulsion were significantly higher at the 40° angle of incline compared with 30° (p = 0.013, p = 0.0165 respectively) and the % braking was significantly lower at the 40° angle of incline compared with 30° (p = 0.0165). There was no significant effect of A-frame angle on the vertical ground reaction forces measured. Clinical Significance: Compared with 30° incline, ascent up the A-frame at a 40° incline requires a higher propulsive force and extended time in propulsion to maintain forward movement and convert potential energy into forward kinetic energy.

Objective To describe a modified rib pivot thoracotomy and its clinical application in client-owned dogs and cats. Study design Case series of 24 dogs and 1 cat requiring a thoracotomy. Methods A lateral thoracic incision over the required thoracic segment was made. The latissimus dorsi muscle was reflected dorsally. The predetermined rib was identified and the periosteum overlying the rib was elevated circumferentially, avoiding the intercostal neurovascular structures. Holes were pre-placed above and below the proposed osteotomy site. The rib was osteotomised and pivoted cranially. The pleura was incised and the required intrathoracic procedure was then performed. The thoracic cavity was closed by pre-placement of a suture through the pre-placed holes within the osteotomised rib. The pleura and intercostal musculature were closed, avoiding the intercostal neurovascular structures. The rib was re-apposed and the lateral approach was closed. The cases included were reviewed for both the rib pivoted as per the procedure required and postoperative complications. Results The study group comprised 8 Staffordshire Bull Terriers, 2 Poodles, 2 German Shepherd Dogs, 1 each of Basset Hound, Rhodesian Ridgeback, Golden Retriever, Australian Shepherd, Vizsla, Bull Mastiff, Schnauzer, Jack Russell Terrier, Bulldog, Deerhound, Labrador Retriever and Australian Terrier, and 1 cat. A modified rib pivot thoracotomy was performed for lung lobectomy (n = 11), oesophagectomy (7), subtotal pericardectomy (5), patent ductus arteriosus ligation (1) and thoracic duct ligation (1). Follow-up ranged from 2 to 40 weeks postoperatively. Postoperative complications included seroma formation in two dogs. Conclusion A modified rib pivot thoracotomy should be considered as an alternative lateral thoracic approach with good exposure, minimal complications and low morbidity.

Objective This article aims to investigate the effect of a decrease in the A-frame angle of incline on the highest carpal extension angle in agility dogs. Methods Kinematic gait analysis (two-dimensional) measuring carpal extension was performed on 40 dogs entering the A-frame at 3 angles of incline: 40° (standard), 35° and 30°. The highest carpal extension angle from three trials at each incline was examined for a significant effect of A-frame angle with height, body weight and velocity included as covariates. Results There was no significant effect of A-frame angle on the highest carpal joint extension angle for the first or second limb. The adjusted mean carpal extension angle for the first limb at 40° was 64° [95% confidence interval (CI), 60–68), at 35° was 61° (95% CI, 57–65) and at 30° was 62° (95% CI, 59–65). The raw mean carpal extension angle for all dogs across all A-frame angles for the first limb was 62° (95% CI, 60–64) and the second limb was 61° (95% CI, 59–63). Clinical Significance Decreasing the A-frame angle of incline from 40° to 30° did not result in reduced carpal extension angles. The failure to find a difference and the narrow CI of the carpal angles may indicate that the physiologic limits of carpal extension were reached at all A-frame angles.

Objective: This case series describes the computed tomography (CT) and surgical findings of nine dogs with dermoid sinuses. Methods: Medical records were reviewed and summarised. Results: CT with intravenous contrast showed a superficial, peripherally contrast-enhancing, fluid-filled structure with a contrast-enhancing, soft tissue-attenuating tract that extended from the skin through the dorsal midline soft tissues, often to the level of the nuchal ligament. The tract often extended in an oblique direction to the nuchal ligament, but the tract ventral to the nuchal ligament, found at surgery, was not always discernible on CT. The dermoid sinuses were excised from all dogs. At surgery, the tract often extended ventral to the nuchal ligament, terminating on the vertebra. The most ventral aspect of the tracts involved a fibrous strand extension of the sinus, which was not discernible on CT. Conclusion: Preoperative CT facilitated the diagnosis of a dermoid sinus and directed surgical planning; however, careful dissection beyond the nuchal ligament is imperative for complete excision.