Total Ear Canal Ablation Combined with Lateral Bulla Osteotomy for End-Stage Otitis in Dogs Results in Thirty Dogs

Thirty dogs with end-stage otitis were treated by either unilateral or bilateral total ear canal ablation and lateral bulla osteotomy. Otitis was considered end stage when the horizontal ear canal was collapsed, stenotic, or occluded in conjunction with chronic infection of the external and middle ear. The dogs were evaluated clinically and radiographically for 4 to 63 months. The frequency of scratching, head shaking, aural drainage, and para-aural fistulation was significantly decreased. Abnormal ear carriage and head tilt were not changed. The results in 23 dogs were graded as excellent or improved. One dog died of intraoperative hemorrhage. Complications during the period from suture removal to follow-up included para-aural fistulation (3 dogs), facial nerve paralysis (5 dogs), and head tilt (3 dogs).     

Primary ocular sarcomas in the cat

Primary ocular sarcomas were diagnosed following enucleation (12) or necropsy (one) in 13 cats over an eight year period. Twelve of the 13 cats were males; ages of affected animals were seven to 15 years, with a mean of 12. Five of the cats had a history of previous trauma and six others had a history of chronic uveitis. Morphologically the neoplasm was comprised of undifferentiated spindle cells and appeared to arise in the anterior uvea. The cancer was quite aggressive, with extension into adjacent tissues and/or distant metastases commonly encountered. Seven of 12 cats experienced confirmed tumour related deaths within months following enucleation and one was humanely destroyed at the time of original presentation.     

Hiatal Hernia Repair by Restoration and Stabilization of Normal Anatomy An Evaluation in Four Dogs and One Cat

Clinical signs of esophageal hiatal hernia in four dogs and one cat included regurgitation, vomiting, hematemesis, hypersalivation, dysphagia, and dyspnea. Thoracic radiographs, esophagram, and fluoroscopy were used to demonstrate cranial displacement of the esophagogastric junction and part of the stomach through the esophageal hiatus. Other findings included megaesophagus, esophageal hypomotility, gastroesophageal reflux, and pneumonia. Medical therapy failed to resolve the clinical signs. Reduction in size of the esophageal hiatus, fixation of the esophagus to the diaphragmatic crus (esophagopexy), and a left fundic gastropexy were performed. Surgical results were considered good to excellent.     

Gradual Occlusion of Extrahepatic Portosystemic Shunts in Dogs and Cats Using the Ameroid Constrictor

Gradual occlusion of the splenic vein, using a specialized device (ameroid constrictor), was evaluated experimentally in three normal beagle dogs. Splenoportograms were used to verify that total occlusion of the splenic vein had occurred in all dogs within 4 to 5 weeks after application of the device. The ameroid constrictor (AC) was also evaluated as a method of gradual vascular occlusion in 12 dogs and two cats with single, extrahepatic, portosystemic shunts (PSS). Serum bile acid (SBA) concentrations were measured and portal scintigraphy (PS) was performed on all 14 animals preoperatively and 10, 20, 30, and 60 days postoperatively. Two dogs (14%) died from portal hypertension in the early postoperative period. One dog and one cat developed multiple acquired PSS, confirmed by mesenteric portography 90 days after the operation. Portal scintigraphy confirmed total occlusion of the primary shunt in the other 10 animals. Shunt fractions (SF), as measured by PS on postoperative days 30 and 60, declined significantly from preoperative values. Significant decreases were noted between preoperative and postoperative values for preprandial SBA on postoperative day 60 and for postprandial SBA on postoperative day 30. SBA concentrations did not correlate with SF. Based on this study, gradual vascular occlusion using the AC is recommended as a method for treatment of single, extrahepatic, PSS.     

Transdiaphragmatic Approach to Thoracic Duct Ligation in the Cat

An approach combining ventral midline celiotomy with transdiaphragmatic thoracotomy was evaluated in eight healthy cats for ligation of the thoracic duct system. Evans Blue solution was injected into the right colic lymph node to outline the intestinal lymphatic trunk and the thoracic duct system. Three cats (group 1) had mesenteric lymphangiograms and three (group 2) had only lymph node dye injection before thoracic duct ligation. The thoracic duct system was ligated with hemostatic clips just cranial to the aortic hiatus of the diaphragm, through a left transdiaphragmatic thoracotomy. Two cats (group 3) had prethoracotomy mesenteric lymphangiograms and thoracic duct isolation without ligation. Mesenteric lymphangiography was performed immediately after the surgery. In all of the cats, an absence of contrast medium in the thoracic duct system cranial to the surgical site was interpreted as complete obstruction. Four weeks after ligation, there was complete obstruction of the thoracic duct system with alternate lymphaticovenous communications in four of the six cats with ligated thoracic duct systems. Partial obstruction of the thoracic duct system with alternate lymphaticovenous communications was present in the other two cats. Both cats without thoracic duct ligation had patent thoracic duct systems. At necropsy of the six cats with ligated thoracic ducts, there was mild focal lymphadenitis of injected lymph nodes in three cats. The wall of the aorta adjacent to the hemostatic clips was normal in all six cats. The surgical technique was simple and provided excellent exposure. Vital staining with Evans Blue helped visualize the thoracic duct system, but mesenteric lymphangiography did not. Postligation lymphangiography was not of value in identifying incomplete ligation.     

UPTAKE OF 99mTCMDP IN MUSCLE ASSOCIATED WITH A PERIPHERAL NERVE BLOCK

A focal area of increased uptake of radioactivity was observed in muscle during bone imaging with ^99mTcMDP. The area was previously the site of a peripheral nerve block with mepivacaine hydrochloride. Additional experiments were done to document the action of the local anesthetic. The effect on uptake decreased over several days.     

Stress Fractures of the Acetabulum in 26 Racing Greyhounds

Acetabular fractures in 26 racing Greyhounds were reviewed. All fractures occurred during racing or training and were unrelated to any external trauma. All fractures had similar configurations, were minimally displaced, and involved only the acetabulum. Affected dogs were young (16-36 months). Fractures occurred unilaterally (22 dogs) and bilaterally (4 dogs). There was no sex predilection, and both right and left sides were equally represented. Bilateral fractures were associated with retraining between the occurrence of the first and second fractures. Radiographically, a fracture line was consistently visible in the caudal third of the acetabulum. Fractures in gross specimens resembled an inverted "Y." Results of histologic evaluation of two fractured acetabula showed changes characteristic of a nonunion fracture. Microfractures were evident in the grossly normal acetabulum opposite the fractured side. Evidence obtained from this study suggests a common pathogenesis of the fractures related to tremendous repetitive stresses produced during running. Greyhounds with unilateral acetabular fractures may provide a reproducible model for future studies of stress fractures in animals and humans because of the high incidence of bilateral fractures that develop during retraining. Surgical repair of the acetabular stress fracture was more successful than conservative management in returning the dogs to competitive racing.