The risk of death: the confidential enquiry into perioperative small animal fatalities

Objective To estimate the risks of anaesthetic and sedation‐related mortality in companion animals in the UK. (The Confidential Enquiry into Perioperative Small Animal Fatalities, CEPSAF). Study design A prospective cohort study with nested case–control study. Animal population All small animals anaesthetized and sedated at participating centres between June 2002 and June 2004. Methods Patient outcomes at 48 hours (alive, dead and killed) were recorded. Anaesthetic and sedation‐related death was defined as death where surgical or pre‐existing medical causes did not solely cause death. Species‐specific risks of anaesthetic‐related death and 95% confidence intervals (95% CI) were calculated. Risks were also estimated in the sub‐sets of dogs, cats and rabbits that were either healthy or sick (ASA 1–2 and 3–5, respectively). Results One hundred and seventeen veterinary practices participated in the study and 98 036 dogs, 79 178 cats and 8209 rabbits were anaesthetized and sedated. Overall risks of anaesthetic and sedation‐related death in dogs were 0.17% (1 in 601, 95% CI 0.14–0.19%), in cats 0.24% (1 in 419, 95% CI 0.20–0.27%) and in rabbits 1.39% (1 in 72, 95% CI 1.14–1.64%) within 48 hours of the procedure. In healthy dogs, cats and rabbits, the risks were estimated to be 0.05% (1 in 1849, 95% CI 0.04–0.07%), 0.11%, (1 in 895, 95% CI 0.09–0.14%) and 0.73% (1 in 137, 95% CI 0.54–0.93%), respectively. In sick dogs, cats and rabbits, the risks were 1.33%, (1 in 75, 95% CI 1.07–1.60%), 1.40% (1 in 71, 95% CI 1.12–1.68%) and 7.37% (1 in 14, 95% CI 5.20–9.54%), respectively. Postoperative deaths accounted for 47% of deaths in dogs, 61% in cats and 64% in rabbits. Most other small animal species had higher mortality risks. Conclusions and clinical relevance Small animal anaesthesia appears to be increasingly safe. Greater patient care in the postoperative period could reduce fatalities.     

Lung lobe torsion in dogs: 22 cases (1981-1999)

OBJECTIVE: To identify breed disposition, postoperative complications, and outcome in dogs with lung lobe torsion. DESIGN: Retrospective study. ANIMALS: 22 client-owned dogs. PROCEDURE: Information on signalment; history; clinical findings; results of clinicopathologic testing, diagnostic imaging, and pleural fluid analysis; surgical treatment; intra- and postoperative complications; histologic findings; and outcome were obtained from medical records. RESULTS: All 22 dogs had pleural effusion; dyspnea was the most common reason for examination. Fifteen dogs were large deep-chested breeds; 5 were toy breeds. Afghan Hounds were overrepresented, compared with the hospital population. One dog was euthanatized without treatment; the remaining dogs underwent exploratory thoracotomy and lung lobectomy. Eleven dogs recovered from surgery without complications, but 3 of these later died of thoracic disease. Four dogs survived to discharge but had clinically important complications within 2 months, including chylothorax, mediastinal mesothelioma, gastric dilatation, and a second lung lobe torsion. Six dogs died or were euthanatized within 2 weeks after surgery because of acute respiratory distress syndrome, pneumonia, septic shock, pneumothorax, or chylothorax. Chylothorax was diagnosed in 8 of the 22 dogs, including 4 Afghan Hounds. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that lung lobe torsion is rare in dogs and develops most frequently in large deep-chested dogs, particularly Afghan Hounds. Other predisposing causes were not identified, but an association with chylothorax was evident, especially in Afghan Hounds. Prognosis for dogs with lung lobe torsion was fair to guarded.     

Intermandibular malignant mesenchymoma in a crossbreed dog

A 12-year-old German shepherd crossbreed dog was presented with a submandibular mass that was initially diagnosed as myxosarcoma on incisional biopsy. Chest radiographs were taken for staging, and magnetic resonance imaging was performed to assess the feasibility of cytoreductive surgery before adjuvant radiotherapy. The dog underwent debulking surgery, and histology permitted reclassification of the tumour as a malignant mesenchymoma (with myxosarcomatous and osteosarcomatous differentiation). The dog was subsequently treated with four fractions of radiotherapy given at seven-day intervals and three doses of carboplatin. The dog remained stable following therapy until its condition acutely deteriorated, and it was euthanased 153 days after surgery. On postmortem examination, there were no signs of local tumour recurrence, but metastases were observed both in the thorax and in the abdomen.     

Role of carboplatin in multi-modality treatment of canine tonsillar squamous cell carcinoma--a case series of five dogs

Canine tonsillar squamous cell carcinoma is an aggressive disease with a poor prognosis. A retrospective study was undertaken of all dogs that were presented between January 1999 and January 2004 to the Animal Health Trust for the treatment of tonsillar squamous cell carcinoma. Five cases were identified, and their median survival time was 211 days (95 per cent confidence interval 80 to 352) with two of the five dogs remaining alive at the end of the study, 826 and 1628 days from diagnosis with no clinical signs of disease. The protocol was well tolerated with only one of the five dogs showing toxicity associated with carboplatin and all dogs that started radiotherapy completing it. Compared with results of previous studies, these cases suggest that surgical cytoreduction followed by coarse fractionated radiotherapy together with carboplatin may be a useful way to treat this tumour. Carboplatin alone caused partial remission in the two cases where it was used as neo-adjunctive therapy.     

Eosinophilic fibrosing gastritis and toxoplasmosis in a cat

A 3-year-old, neutered male Tiffany cat was presented to the Animal Health Trust for investigation of pyrexia and a gastric lesion. Radiography and ultrasound showed severe thickening of the gastric wall and regional lymphadenopathy. There was altered gastric wall layering, predominately due to muscularis thickening. Histopathology confirmed eosinophilic fibrosing gastritis. The cat also had evidence of generalised Toxoplasma gondii infection, which may have been responsible for the gastric changes.     

The hemodynamic effects of intrathecal oxytocin in normal dogs

OBJECTIVE: To evaluate the hemodynamic effects produced by intrathecal administration of oxytocin in healthy isoflurane-anesthetized dogs. STUDY DESIGN: Prospective single-dose trial. ANIMAL POPULATION: Six healthy purpose-bred adult dogs weighing between 7.3 and 14.5 kg. METHODS: Dogs were anesthetized with isoflurane and instrumented. Oxytocin at a dosage of 1.6 microg/kg was administered intrathecally at the cisternal space at time 0. Hemodynamic data were recorded immediately before and at 1, 5, 15, 30, and 60 minutes after oxytocin administration. Statistical analysis included an analysis of variance (ANOVA) for repeated measures over time. A P < .05 was considered significant. RESULTS: Baseline values +/- standard error of the mean for heart rate, mean arterial pressure, central venous pressure, cardiac output, systemic vascular resistance, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, and pulmonary vascular resistance were 101 +/- 11 beats/minute, 76 +/- 7 mm Hg, 4 +/- 4 mm Hg, 1.9 +/- 0.7 L/min, 3834 +/- 2556 dynes x sec/cm5, 14 +/- 3 mm Hg, 4 +/- 2 mm Hg, and 430 +/- 201 dynes x sec/cm5, respectively. Variations from the baseline values were seen in all parameters after intrathecal oxytocin administration, but no statistically significant differences were found. CONCLUSION: The intrathecal injection of 1.6 microg/kg of oxytocin is associated with minimal hemodynamic effects during isoflurane anesthesia. CLINICAL RELEVANCE: This study revealed no clinically significant deleterious effects from the intrathecal administration of oxytocin, and investigations into its use as a perioperative analgesic are therefore warranted.     

Urinary Bladder Herniation through a Vaginal Tear in a Rottweiller with Dystocia

A four-year old female Rottweiler presented with a 34-hour history of dystocia. Physical examination revealed a purple-black, fluid-filled sac protruding from vulva and suspended by a similar colored stalk. Digital vaginal examination indicated that the stalk of tissue extended up into the cervix and beyond. Due to the grossly necrotic appearance, the stalk of tissue was ligated, and the sac was removed. Three puppies were delivered vaginally, but a subsequent caesarian section was required due to uterine inertia likely secondary to exhaustion. Three more live puppies were delivered via the c-section. Further abdominal exploration revealed a tear in the left vaginal wall, one ligated ureter, and the second ureter free at its distal end and leaking urine into the abdomen. The surgical findings indicated that the bladder, ureters, and urethra had herniated through the vaginal tear and prolapsed through the vulva.     

B-MODE AND DOPPLER ULTRASOUND IMAGING OF THE SPLEEN WITH CANINE SPLENIC TORSION: A RETROSPECTIVE EVALUATION

The ultrasonographic appearance of splenic torsion has been described; the splenic parenchyma can be normal, hypoechoic or anechoic with interspersed linear echoes (coarse/"lacy" appearance). The ultrasonographic parenchymal appearance of 15 dogs in this report with splenic torsion varied: mottled hypoechoic regions (n=2), diffusely hypoechoic (n=11) and normal (n=2). Because splenic torsion causes vascular congestion due to splenic vein compression and eventual thrombosis, visible splenic vein intraluminal echogenicities compatible with thrombi were seen in 13 dogs using B-mode. Using spectral Doppler and color Doppler imaging of the splenic veins, no measurable flow velocities were detected in any of the 15 dogs. The varied B-mode ultrasonographic appearance of the splenic veins for intraluminal echoes and spectral or color Doppler evaluation for absent velocity flow.