Comparison of radiographic scoring systems for assessment of bone healing after tibial plateau leveling osteotomy in dogs.

Introduction: Accurate radiographic assessment of bone healing is vital in determining both clinical treatment and for assessing interventions aimed at the promotion of bone healing. Several scoring systems have been used to evaluate osteotomy changes following tibial plateau leveling osteotomy (TPLO). The goal of this study was to compare the ability of five radiographic scoring systems to identify changes in bone healing following TPLO over time (Aim I), and to evaluate the influence of limb positioning on TPLO osteotomy scoring (Aim II). Materials and methods: Phase I-A randomized, blinded, prospective study was conducted using similarly positioned postoperative TPLO radiographs from seven dogs taken immediately postoperatively, 6-weeks, and 8-weeks postoperatively. Ten reviewers assessed the radiographs, and five different scoring systems were tested for each set including three previously published ones, a Visual Analog Score (VAS), and a subjective 11-point scale. For each system, responses for 6-week postoperative were compared to 8-week postoperative. Scores were judged as correct (=showing an increase in score), incorrect (=decrease in score), or unchanged (=same score). Phase II-An international group of 39 reviewers was asked to score radiographs from three dogs, taken in different positions, using the VAS grading system. Scores were averaged and comparisons were made for each set. Results: Phase I-The VAS system identified the greatest number of sets correctly (76%), with the least unchanged scores (15%), and 9% incorrect scores. Phase II-All three patients had an increase in the average difference between VAS-scores for differently positioned radiographs compared to similarly positioned radiographs. The magnitude of change between different positions far exceeded the magnitude of comparison of the similarly positioned radiographs from the 6- and 8-week time point. Discussion/Conclusion: The VAS system appears to be the most appropriate of the tested systems to identify small changes in bone healing. In addition, the positioning of postoperative TPLO radiographs makes a substantial difference in the healing score that is assigned. Care must be undertaken when performing postoperative radiographs in both the clinical and research setting to ensure accurate assessment of bone healing.

Seed skin grafts for reconstruction of distal limb defects in 15 dogs.

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.

Computed tomographic findings, surgical management and postoperative outcomes of large intermuscular lipomas in the hindlimb of 11 dogs.

OBJECTIVE: Lipomas are benign adipose tissue tumours of mesenchymal origin and can originate in various locations. Intermuscular lipomas in the thigh can cause substantial hindlimb expansion in the dog. We describe the computed tomography findings, surgical management and the outcomes of 11 dogs with large intermuscular lipomas of the hindlimb. DESIGN: Retrospective case series. METHODS: Medical records between 2009 and 2019 of dogs presenting to The Animal Hospital at Murdoch University were reviewed. Inclusion criteria included dogs with a histologically confirmed, large hindlimb lipoma that was surgically excised following preoperative computed tomography (CT) imaging. RESULTS: CT with intravenous contrast revealed a well-defined, smoothly marginated, fat attenuating mass with minimal vascularity, separating the muscle bellies of the caudal hindlimb. The mass was often in close proximity to the femoral artery and vein. All lipomas were marginally excised. At surgery, some lipomas were intimately associated with the sciatic nerve and some showed infiltration of, or attachment to, neighbouring muscle that could be excised en bloc with the lipoma. Postoperative closed-suction wound drainage was used in 6 of 11 dogs. One dog required revision surgery due to partial wound dehiscence. Long-term follow-up with owners reported good postoperative function of the affected hindlimb in all dogs. One dog developed an infiltrative lipoma in the same location 22 months post-excision. CONCLUSION: Preoperative CT allowed a presumptive diagnosis of intermuscular lipoma and facilitated surgical planning for marginal excision. Large intermuscular lipomas of the hindlimb can be safely excised with minimal short-term complications, good long-term functional outcome and low likelihood of recurrence.

Hypoventilation, cardiac dysrhythmia, and cardiac arrest following acute Brunfelsia species (Yesterday, today, tomorrow) intoxication in a dog.

BACKGROUND: Intoxication following ingestion of the popular garden shrub 'Yesterday, today, tomorrow' (Brunfelsia sp.) is known to result in gastrointestinal and central nervous system clinical signs in dogs. CASE REPORT: A 2-year-old dog developed acute-onset vomiting, profuse diarrhoea and ptyalism after unsupervised access to an enclosed backyard that contained a Brunfelsia sp. shrub. During initial assessment the watery diarrhoea contained plant material and the dog appeared painful on abdominal palpation. Soon after admission, severe neurological abnormalities developed. Decontamination was undertaken by gastric and colonic lavage under general anaesthesia, but on recovery the patient had generalised seizures that were unresponsive to benzodiazepines. Following treatment with multiple antiepileptic medications and endotracheal intubation for loss of gag reflex, the patient developed respiratory failure requiring mechanical ventilation. Four days after initial presentation, the patient developed cardiac dysrhythmia leading to fatal cardiac arrest. Plant material recovered from the shrub and the patient's gastrointestinal tract were identified as Brunfelsia spp. CONCLUSION: This is the first report of hypoventilation, severe cardiac dysrhythmia and cardiac arrest associated with Brunfelsia sp. intoxication in a dog. Previous reports described clinical signs of gastrointestinal disease and mild cardiac dysrhythmia progressing to seizure activity and opisthotonus. Electrocardiography should form part of patient monitoring and mechanical ventilation considered for patients that develop respiratory failure, especially if massive ingestion is suspected.

Laparoscopic and computed tomography-guided percutaneous radiofrequency ablation of renal tissue: acute and chronic effects in an animal model.

OBJECTIVES: To evaluate the laparoscopic and percutaneous delivery of impedance-based radiofrequency ablation (RFA) of the kidney by studying the acute and chronic clinical, radiographic, and histopathologic effects in the porcine model. METHODS: Eight kidneys from 4 pigs underwent laparoscopic RFA. Six kidneys from 3 additional pigs received computed tomography (CT)-guided, percutaneous RFA. CT scans were performed immediately after RFA and before harvest at 2 hours, 24 hours, 3 weeks, and 13 weeks. The gross, radiographic, and histopathologic changes were recorded for each period. RESULTS: Grossly, the RFA lesions were sharply demarcated, measuring 3 to 5 cm. Two major complications (14%) occurred (one urinoma, one psoas muscle injury) in 14 ablations. No deaths or significant blood loss occurred as a result of RFA. Radiographically, the immediate CT scanning demonstrated small perinephric hematomas and wedge-shaped defects. Delayed CT showed nonenhancing defects up to 5 cm. Color-flow and power Doppler were unable to distinguish significant tissue changes during RFA. The histopathologic evaluation revealed marked inflammation surrounding the necrotic regions in the early lesions; chronic lesions were characterized by dense fibrosis. The tissue temperatures ranged from 62 degrees to 118 degrees C in the area of ablation. CONCLUSIONS: RFA is readily delivered laparoscopically or percutaneously with minimal morbidity. Impedance-based application of radiofrequency energy allows monitoring and control of ablation. Using a multi-antenna probe, areas of tissue up to 5 cm can be completely destroyed. The RFA lesion can be monitored as a nonenhancing cortical defect on CT.