An alternative pathway electrosurgical unit injury in a dog

Objective: To report esophageal perforation, caused by alternative current pathway from the use of a monopolar electrosurgery unit (ESU), during routine orthopedic surgery in a dog. Study Design: Clinical report. Animals: Two‐year‐old male Labrador retriever. Methods: Medial meniscectomy and lateral suture stabilization were performed on a healthy Labrador retriever with a ruptured cranial cruciate ligament. Monopolar electrosurgery was used during the procedure for hemostasis and tissue dissection. Anesthetic monitoring was augmented with an esophageal electrocardiogram (ECG) probe. The day after surgery, the dog appeared dehydrated. After intravenous fluid therapy, respiratory distress was noted and thoracic radiography and contrast fluoroscopy revealed an esophageal perforation. Results: Exploratory surgery was planned to repair the defect. Cardiac arrest occurred after induction. Gross necropsy findings and histopathologic examination revealed lesions consistent with thermal necrosis of the esophagus and myocardial degeneration. An internal investigation of this medical device accident revealed that multiple factors may have contributed to the injury. Conclusions: An alternative current pathway from the monopolar ESU to the esophageal ECG probe resulted in a full‐thickness esophageal thermal injury and cardiac failure.     

Videofluoroscopy,CT angiography,and ultrasonography of congenital esophageal stenosis in a Labrador retriever

A 7‐week‐old Labrador retriever presented for further investigation into acute onset regurgitation, following weaning from liquid to solid food. A videofluoroscopic swallow study demonstrated a severe, focal esophageal dilation in the mid‐cervical region, with marked luminal narrowing distally. Computed tomography with angiography revealed esophageal stenosis, extending from C4–T2, secondary to circumferential esophageal wall thickening. With the concern for development of secondary aspiration pneumonia, the owners elected to euthanize the dog and consented to postmortem examination. A diagnosis of segmental, cervical esophageal muscular hypertrophy was made on necropsy, consistent with the fibromuscular thickening type of congenital esophageal stenosis reported in humans.     

Esophageal duplication cyst as a cause of choke in the horse

A mare was examined for episodic choking and an abscess in the perilaryngeal region. One month before referral, the mass progressively enlarged, causing esophageal choking. An extraluminal compression of the esophagus 90 cm from the external nares was found on endoscopy and contrast radiography. Serosanguinous fluid aspirated from the mass contained keratinized squamous cells and neutrophils, compatible with an esophageal cyst. Surgical exploration was performed, with incomplete surgical excision. The remaining portion of the cyst was marsupialized and treated locally with a 2% inorganic iodine solution. Further episodes of esophageal choke in this horse have not been reported.     

Pharmacological relaxation of the urethra in male cats: a study of the effects of phenoxybenzamine, diazepam, nifedipine and xylazine.

Urethral pressure profiles (UPPs) were recorded in ten adult healthy male cats before and after administration of either phenoxybenzamine, diazepam, nifedipine or xylazine. A significant decrease (p less than 0.05) in urethral pressure at the level of the prostate was observed following treatment with all drugs. Xylazine produced a significant decrease in urethral pressure 4 to 7 cm from the tip of the penis in healthy male cats. None of the drugs used decreased urethral pressure in the zones of pure striated muscle or pure smooth muscle in these cats, making current recommendations for pharmacological management of urethral spasm suspect. Further studies are necessary to evaluate clinical cases of urethral spasm and to study the effects of these drugs on the urethral pressure of cats suffering from this spasm.     

Megaesophagus in a cat

Megaesophagus in an eight month old Siamese cat is described. Initially, a cause for the vomiting was not discovered and the cat was treated for pyloric spasm. Several months later the same cat, in poor physical condition, was presented with a palpable bulge along its ventral neck. At this time a very dilated and flaccid esophagus was found. An exploratory thoracotomy was done but a cause for the megaesophagus was not discovered.     

Immunohistochemical staining of chlamydial antigen in emerald tree boas (Corallus caninus).

Of 120 privately owned captive-bred and wild-collected emerald tree boas (ETBs) (Corallus caninus), 97 died or were euthanatized. Eighteen snakes were necropsied, and tissues were collected from all major organs and processed for light microscopy. Histologic examination demonstrated histiocytic granulomas in the small intestine, heart, and esophageal tonsils of one ETB, small intestine of a second ETB, and in an esophageal tonsil of a third ETB. Within the center of these granulomas, small, basophilic, punctate organisms were demonstrated using hematoxylin and eosin staining. Transmission electron microscopic examination of an intestinal granuloma demonstrated developmental stages of organisms consistent with members of the family Chlamydiaceae. An immunoperoxidase staining technique and 2 different commercially available monoclonal antibodies against chlamydial lipopolysaccharide antigen was used to identify chlamydial antigen in these lesions. Liver of a puff adder (Bitis arietans) with previously reported systemic chlamydiosis served as the positive control. Both monoclonal antibodies stained antigen in these granulomas. Additionally, macrophages within aggregates of lymphoplasmacytic cells in the colon, small intestine, and esophageal tonsils of 3 other ETBs contained antigen. Although both antibodies labeled antigen in serial sections of tissue, a difference in staining intensity was noted.     

Development of a polyclonal-antibody-based immunohistochemical method for the detection of type 2 porcine circovirus in formalin-fixed, paraffin-embedded tissue.

An immunohistochemical method for the detection of type 2 porcine circovirus (PCV2) in paraffin-embedded tissue was developed. Rabbits were inoculated with purified PCV2 to obtain a polyclonal antiserum. Antiserum was applied to sections of porcine tissue that contained lesions consistent with postweaning multisystemic wasting syndrome and in which PCV2 genome had been demonstrated by in situ hybridization. In all cases (18/18), the density and distribution of positive cells detected by in situ hybridization or immunohistochemistry were identical. The immunohistochemical method is more rapid and less expensive than in situ hybridization and is thus more suitable for routine diagnostic use.     

Esophageal achalasia and secondary megaesophagus in a dog

A 5-year-old, castrated male, golden retriever was presented with a history of regurgitation. An esophagram revealed normal peristalsis with failure of the lower esophageal sphincter to open, supporting the diagnosis of esophageal achalasia. Prior to surgery, the dog developed megaesophagus. Heller's esophagomyotomy resolved the clinical signs and the esophageal dilation.     

Paraesophageal hiatal hernia and pyloric obstruction in a dog

Paraesophageal hiatal herniation and pyloric obstruction were diagnosed in a pup with a history of vomiting. Findings of contrast radiography included esophageal reflux, delayed gastric emptying time, and paraesophageal herniation. Exploratory celiotomy revealed increased firmness of the pylorus and a primary defect in the esophageal hiatus, which allowed gastric herniation. Nissen fundoplication was performed following reconstruction of the esophageal hiatus, and pyloroplasty was performed to relieve the gastric outlet obstruction. Pyloric biopsy findings were consistent with a diagnosis of chronic gastritis. Recovery from surgery was initially unremarkable; however, the dog died suddenly 3 weeks after surgery. Necropsy revealed a large diaphragmatic hernia adjacent to the esophageal hiatus; the hernia had resulted in incarceration of the abdominal organs. The hiatal hernia reconstruction remained intact and was not the cause of the diaphragmatic disruption.     

Esophageal disorders in 61 horses. Results of nonsurgical and surgical management

Obstructive esophageal disorders in 61 horses included feed or foreign body impaction (27 horses), strictures (18 horses), perforations (11 horses), and diverticula (5 horses). Horses with feed impaction were treated nonsurgically (25 horses) or by esophagotomy (2 horses). Survival to discharge was 78%, and 37% of these had persistent chronic obstruction at home. Long-term survival was 52%. Long-term survival of nine horses treated nonsurgically for esophageal strictures was 22%; for nine horses treated surgically it was 44%. Long-term survival of horses treated nonsurgically was significantly better in acute than chronic strictures. Surgical repair of esophageal mural strictures was more successful than repair of annular or mucosal strictures. One third of the horses with strictures were foals. Long-term survival for horses with strictures was 33%. Long-term survival was higher for the horses with perforations managed surgically (2 of 4) than nonsurgically (0 of 7). Long-term survival for this group was 18%. One esophageal diverticulum was managed nonsurgically, and four were treated surgically; all horses survived long term. Complications of obstructive esophageal disorders included aspiration pneumonia, chronic obstruction, esophageal mucosal ulceration, postoperative infection, pleuritis, laminitis, laryngeal paralysis, and Horner's syndrome.     

Esophageal Disorders in 61 Horses: Results of Nonsurgical and Surgical Management

Obstructive esophageal disorders in 61 horses included feed or foreign body impaction (27 horses), strictures (18 horses), perforations (11 horses), and diverticula (5 horses). Horses with feed impaction were treated nonsurgically (25 horses) or by esophagotomy (2 horses). Survival to discharge was 78%, and 37% of these had persistent chronic obstruction at home. Long-term survival was 52%. Long-term survival of nine horses treated nonsurgically for esophageal strictures was 22%; for nine horses treated surgically it was 44%. Long-term survival of horses treated nonsurgically was significantly better in acute than chronic strictures. Surgical repair of esophageal mural strictures was more successful than repair of annular or mucosal strictures. One third of the horses with strictures were foals. Long-term survival for horses with strictures was 33%. Long-term survival was higher for the horses with perforations managed surgically (2 of 4) than nonsurgically (0 of 7). Long-term survival for this group was 18%. One esophageal diverticulum was managed nonsurgically, and four were treated surgically; all horses survived long term. Complications of obstructive esophageal disorders included aspiration pneumonia, chronic obstruction, esophageal mucosal ulceration, postoperative infection, pleuritis, laminitis, laryngeal paralysis, and Horner's syndrome.     

Cerebellar vermian hypoplasia in a Cocker Spaniel

An eight-week-old female Cocker Spaniel was presented with ataxia, dysmetria and intention tremor. At 16 weeks, the clinical signs did not progress. Investigation including imaging studies of the skull and cerebrospinal fluid analysis were performed. The computed tomography revealed a cyst-like dilation at the level of the fourth ventricle associated with vermal defect in the cerebellum. After euthanasia, a cerebellar hypoplasia with vermal defect was identified on necropsy. A polymerase chain reaction amplification of cerebellar tissue revealed the absence of an in utero parvoviral infection. Therefore, the cerebellar hypoplasia in this puppy was consistent with diagnosis of primary cerebellar malformation comparable to Dandy-Walker syndrome in humans.     

Locked jaw syndrome in dogs and cats: 37 cases (1998-2005)

A consecutive series of cases of dogs and cats with locked jaw syndrome (inability to open or close the mouth) are reported in this study. Dogs were significantly overrepresented (84.0%) and adult dogs were more frequently affected (81.0%). Temporomandibular joint ankylosis due to fracture was the most common cause (54.0%) of locked jaw syndrome. Additional potential causes of locked jaw syndrome are masticatory muscle myositis, neoplasia, trigeminal nerve paralysis and central neurological lesions, temporomandibular joint luxation and dysplasia, osteoarthritis, retrobulbar abscess, tetanus, and severe ear disease. Treatment of locked jaw is directed towards the primary cause. It is important to treat the tonic spasm in order to minimize periarticular fibrosis. Surgical intervention is recommended for temporomandibular joint ankylosis. Masticatory muscle myositis treatment is initiated by gradually opening the mouth, with medical treatment based on immunosuppressive therapy. Fracture and masticatory muscle myositis are associated with a relatively good prognosis in regard to short-term outcome as compared to animals with central neurologic lesions or osteosarcoma which have a poor prognosis.     

Pre-operative fibrous osteodystrophy and severe,refractory, post-operative hypocalcemia following parathyroidectomy in a dog

A 13-year-old dog exhibited dramatic, radiographic osteopenia consistent with fibrous osteodystrophy secondary to primary hyperparathyroidism. Following parathyroidectomy, the dog developed severe, prolonged hypocalcemia, but was successfully treated and discharged 32 d after surgery. A variety of factors may have contributed to this dog’s hypocalcemia including hypoparathyroidism and hungry bone syndrome.     

Esophageal manometry in horses, cows, and sheep during deglutition

Esophageal pressure events during deglutition were evaluated in healthy adult animals (6 horses, 6 cattle, and 5 sheep), using a 3-side hole catheter assembly perfused with water by use of a hydraulic-capillary infusion system. The peak postdeglutition pressure, contraction time, and contraction length were determined for the cranial and caudal esophageal sphincter regions and for each functionally different region within the body of the esophagus. The percentage of deglutitions in which relaxation developed at the sphincter regions and the propagation speed (velocity at which pressure waves traversed the esophagus) for the regions within the body of the esophagus also were determined. Mean (+/- SEM) resting pressures within the cranial and caudal esophageal sphincter regions in the horse were 84.8 +/- 4.39 and 12.7 +/- 0.61 mm of Hg, respectively, with postdeglutition peaks of 208.0 +/- 4.78 and 100.0 +/- 1.06 mm of Hg, respectively. Peak postdeglutition pressure was 92.3 +/- 1.59 mm of Hg in the cranial two thirds of the esophageal body and 100.9 +/- 1.31 mm of Hg in the caudal third. Mean resting pressure of the cranial esophageal sphincter region in the cow was 82.0 +/- 7.81 mm of Hg, whereas that of the caudal esophageal sphincter region was 20.5 +/- 0.36 mm of Hg. The peak postdeglutition pressures for the cranial esophageal sphincter region, proximal portion of the esophageal body, caudal portion of the esophageal body, and caudal esophageal sphincter region in the bovine esophagus were 238.1 +/- 2.93, 105.4 +/- 1.97, 114.5 +/- 1.49, and 112.0 +/- 1.20 mm of Hg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Esophageal duplication cyst in a dog

A cranial cervical mass was surgically removed from a dog. On histologic examination, the mass was consistent with an esophageal duplication cyst, a condition rare in humans and not reported in the dog.     

Myotonia in related Chow Chow dogs

A myopathy associated with myotonia was observed in three related Chow Chow dogs. The clinical signs were first noticed at 2 to 3 months of age. They included muscle spasm and stiffness of gait which decreased in severity with exercise. Electromyographic findings and the demonstration of a muscle percussion dimple confirmed the presence of myotonia. Dystrophic changes were observed in muscle biopsies but histochemical techniques did not demonstrate fibre type changes. An inherited aetiology was suspected but not confirmed.     

Acute hemorrhagic and necrotizing pneumonia, splenitis, and dermatitis in a pet rabbit caused by a novel herpesvirus (leporid herpesvirus-4)

A 1.5-year-old female rabbit (doe) was presented with a 3-day history of lethargy, anorexia, and mild facial swelling. The animal died shortly after examination and severe, acute hemorrhagic pneumonia was noted grossly. An alphaherpesvirus consistent with leporid herpesvirus-4 was isolated and characterized from this animal. This is the first confirmed report of the disease in Canada.     

Intrathoracic esophageal perforation of unknown cause in four horses

Three horses (age 17 - 23 years) were referred to the equine clinic of the University of Berne due to colic, fever, tachycardia and tachypnea. All horses showed pleural effusion. Clinical findings in 2 of the horses were highly suggestive of an intra-thoracic esophageal perforation. Severe septic pleuropneumonia without suspicion of an esophageal lesion was diagnosed in the 3rd horse. In addition, an 11 year old stallion was referred to the equine clinic for treatment of a presumptive large colon impaction. The horse was given laxatives after nasogastric intubation. Subsequent dramatic clinical deterioration and signs consistent with severe pleuropneumonia suggest that esophageal perforation had occurred when passing the nasogastric tube. All 4?horses were euthanized due to a poor prognosis. Esophageal perforation was diagnosed or confirmed post mortem in all cases. A hypertrophy of the tunica muscularis of the intra-thoracic esophagus was found in 3 of 4?horses.     

Citrinin as a possible cause of the pruritis, pyrexia, haemorrhagic syndrome in cattle

An outbreak of the pruritis, pyrexia, haemorrhagic syndrome affected eight of a herd of 175 cows which was divided into two groups of 115 and 60 according to yield. There was no difference in management between them but citrus pulp pellets were fed only to the larger group in which the eight cows were affected. Silage, which had been made without the use of additives, was also fed to both groups. The citrus pulp was visibly mouldy and contained 30 to 40 parts per billion of citrinin. Signs of the syndrome occurred within three days of the cows starting to ingest the citrus pulp, which was fed for 21 days, and the last case occurred six days after the feeding of citrus pulp ceased. Five calves whose dams had been fed citrus pulp were subsequently born with superior prognathism. In contrast to the eight cows that developed the syndrome only one out of 68 heifers which were fed larger quantities of citrus pulp for 10 days developed mild signs of the syndrome and then recovered, suggesting that older animals may be more susceptible. The clinical signs, gross pathology and histopathology are described and compared with those of previous outbreaks. Mycotoxins, particularly citrinin, were strongly implicated as the cause of this outbreak.