Histopathological confirmation of polyneuropathy in 11 dogs with laryngeal paralysis.

Acquired laryngeal paralysis (LP) is an important cause of upper airway obstruction in dogs. We hypothesize that LP may be part of a generalized polyneuropathy complex. Electro-diagnostic studies were performed in six dogs, and histopathological studies of muscle and nerve biopsies were obtained from 11 dogs diagnosed with acquired LP. Abnormalities in electrodiagnostic procedures were consistent with a generalized polyneuropathy. Loss of large-caliber nerve fibers and axonal degeneration were identified in nerve biopsies, and neurogenic atrophy was observed in muscle specimens. Abnormalities in electrodiagnostic studies and histopathology provide evidence that LP may be part of a generalized polyneuropathy. Establishing a diagnosis of a more involved disease process is relevant for long-term prognosis.

Obstructive lesions and traumatic injuries of the canine and feline tracheas.

Tracheal obstruction and tracheal injury can be life-threatening conditions in dogs and cats. Early identification of associated clinical signs and the use of appropriate diagnostic and therapeutic techniques are important to patient survival. Common causes of tracheal obstruction reported in the veterinary literature include tracheal foreign bodies and tracheal tumors. Tracheal injury has been associated with endotracheal intubation and external trauma. Radiography and tracheoscopy are effective diagnostic modalities, and tracheal repair or resection and anastomosis are the most common treatments.

Topical and systemic medications for wounds.

There are a plethora of topical and systemic medications available to the veterinary practitioner today that aid the wound healing process. Some of these help to maintain a moist environment. Others increase growth factors, provide local energy sources, control infection, provide for debridement, increase wound blood flow and temperature, or reduce wound edema. Modern wound care requires that the proper products(s)be used, depending on the condition of the wound and the phase of wound healing. This article discusses various wound care products and provides guidelines on their use.

Double aortic arch in a dog.

Vascular ring anomalies are developmental anomalies of the thoracic great vessels resulting in complete or partial encircling of the esophagus and the trachea by a vascular ring formation. Persistent right aortic arch with left ligamentum arteriosum accounts for 95% of vascular ring anomalies in dogs. The dog in this report had a double aortic arch, which is a type 4 vascular ring anomaly. Double aortic arch is a rare congenital heart defect resulting from the improper development of the embryonic arches. The prognosis for dogs that have undergone surgery for correction of double aortic arches is generally regarded as poor. The dog in this report underwent surgery for correction of double aortic arches and recovered without dilation or motility disorders of the esophagus. Results indicate that small animals that undergo early surgical correction of double aortic arches with relief of esophageal constriction can have a good prognosis. To the authors' knowledge, there have been no previous reports of dogs that have survived long enough to be discharged from the hospital after surgical correction of double aortic arches.

Radical lateral body-wall resection for fibrosarcoma with reconstruction using polypropylene mesh and a caudal superficial epigastric axial pattern flap: a prospective clinical study of the technique and results in 6 cats.

OBJECTIVE: To describe and evaluate a technique for radical resection of the lateral body wall for treatment of fibrosarcoma with reconstruction using polypropylene mesh and a caudal superficial epigastric axial pattern flap in cats. STUDY DESIGN: Prospective, clinical study. ANIMALS OR SAMPLE POPULATION: Six client-owned cats with fibrosarcoma. METHODS: Six cats with histologically confirmed fibrosarcoma of the lateral body wall were staged using radiography and/or computer tomography scanning. Preoperative radiotherapy was used in 3 cats. All cats had the lateral abdominal wall resected and reconstructed with polypropylene mesh. A caudal superficial epigastric flap was mobilized and rotated to close the skin deficit. The animals were evaluated after surgery for wound complications, tumor recurrence, and metastasis. Outcome was assessed by patient examination and client consultation. RESULTS: Minor dehiscence of the skin flaps occurred in 2 cats, and 1 other cat was successfully resuscitated from respiratory and cardiac arrest after surgery. All tissue specimens were tumor-free at the surgical margins. Follow-up times ranged from 12 to 21 months, with a mean time of 17.2 months. None of the cats had evidence of local tumor recurrence or metastasis; outcome was judged good to excellent in all cats. CONCLUSIONS AND CLINICAL RELEVANCE: Radical lateral body-wall resection and reconstruction is an effective technique for achieving local tumor control with acceptable patient morbidity. Further studies are needed to assess whether the technique will result in improved tumor-free intervals and survival times.

Temperature-sensitive strain of Cryptococcus neoformans producing hyphal elements in a feline nasal granuloma.

We report the isolation of a temperature-sensitive, serotype A, mating type alpha strain of Cryptococcus neoformans from a case of nasal cryptococcosis in a cat. The strain grew extremely slowly at 35 degrees C and failed to grow at 37 degrees C in vitro. Histopathological sections of the infected tissue revealed yeast cells producing hyphae up to several hundred micrometers in length, in addition to numerous encapsulated yeast cells typical of C. neoformans. The cultures grown on yeast extract-peptone-glucose agar at 35 degrees C also produced some yeast cells with germ tube-like hyphal elements up to 100 microm in length.

Complications of ileal cannulation in cats.

BACKGROUND AND PURPOSE: The anatomic position of the ileum is such that use of simple, noninvasive sampling techniques is difficult. Sampling of ileal contents by use of a cannula provides information about those contents-digestibility and fermentation patterns; however, complications with use of cannulas in horses and dogs have been reported. Therefore, cats were chosen as a laboratory model in which to study ileal cannulation. METHODS: Simple T-piece cannulas were surgically placed in the ileum of six adult cats. RESULTS: Postsurgical complications included cannula displacement and leakage, with subsequent abscessation and skin inflammation. Owing to these complications, the cannulas were removed from four of the six cats. Similar complications developed after removal of the cannulas. In the only attempt to collect a sample, obtaining a 0.5-ml sample of ileal fluid from one cannula took 3 h. Of the six cats, four died or were euthanized. CONCLUSION: Use of cannulas is not a viable technique of collecting ileal fluid samples in cats.

Short-term hemodynamic evaluation of circumferential mitral annuloplasty for correction of mitral valve regurgitation in dogs.

OBJECTIVE: To determine the short-term hemodynamic effects associated with circumferential mitral annuloplasty (CMA) in dogs with mitral regurgitation. STUDY DESIGN: Prospective experimental study. Animals-Seven healthy adult mongrel dogs. METHODS: Mitral regurgitation was surgically induced, and annular dilation occurred. Echocardiography and cardiac catheterization were used to determine forward ejection fraction (FEF), regurgitant fraction (RF), pulmonary capillary wedge pressure (PCWP), and annular diameter before and immediately after CMA in five dogs. FEF and RF were also evaluated 7 days after annuloplasty. RESULTS: Mean annular diameter and PCWP were significantly reduced immediately after CMA. Significant increases in FEF of 19% and 22% were shown immediately and 7 days after CMA. Significant reductions in RF of 19% and 22% were also shown immediately and 7 days after annuloplasty. CONCLUSIONS: Sustained hemodynamic benefits and a reduction in annular diameter were achieved by CMA in a canine model of mitral regurgitation. CLINICAL IMPLICATIONS: CMA may be a suitable treatment for heart failure because of mitral regurgitation when early signs of cardiovascular decompensation persist despite appropriate medical management.

Pericardiectomy in dogs: 22 cases (1978-1994).

OBJECTIVE: To determine long-term outcome of dogs with neoplastic and nonneoplastic pericardial disease that undergo pericardiectomy. DESIGN: Retrospective study. ANIMALS: 22 dogs. PROCEDURE: Dogs that underwent pericardiectomy and in which the diagnosis had been confirmed histologically were included. Data collected from each record included signalment, history, clinical signs, results of diagnostic evaluations, operative management, postoperative complications, histologic diagnosis, and outcome. Dogs were grouped on the basis of underlying cause of pericardial disease (neoplastic vs nonneoplastic), and survival times were determined by means of Kaplan-Meier analyses. RESULTS: 9 dogs had neoplastic pericardial disease (chemodectoma, 4; hemangiosarcoma, 2; malignant mesothelioma, 2; lymphoblastic lymphoma, 1). Thirteen dogs had nonneoplastic pericardial disease (benign idiopathic pericarditis, 10; lymphocytic plasmacytic pericarditis, 2; osseous metaplasia of unknown cause, 1). Thoracic radiography and echocardiography were the most specific methods for diagnosis of pericardial effusion. Pleural effusion was the most common postoperative complication (8/22 dogs). Prevalence of postoperative complications was not associated with underlying cause of pericardial disease, surgical approach, or surgical procedure (subtotal vs total pericardiectomy). Median survival time of dogs with neoplastic disease (52 days) was significantly shorter than median survival time of dogs with nonneoplastic disease (792 days). Dogs that developed pleural effusion > 30 days after pericardiectomy had a poor prognosis for survival. CLINICAL IMPLICATIONS: Radiography and echocardiography are useful for diagnosis of pericardial effusion in dogs. Dogs with neoplastic pericardial disease have a significantly shorter survival time than do dogs with nonneoplastic pericardial disease.

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.

Effects of cephalothin, cefazolin, and cefmetazole on the hemostatic mechanism in normal dogs: implications for the surgical patient.

Twenty-six female beagles were used to evaluate the effects of intravenous and long-term subcutaneous administration of cephalothin, cefazolin, and cefmetazole on platelet function and the coagulation cascade. Platelet aggregation in response to an adenosine diphosphate (ADP) agonist, bleeding time, platelet count, platelet size, prothrombin time (PT), and activated partial thromboplastin times (aPTT) were evaluated before and 90 minutes after two intravenous doses (22 mg/kg) of cephalothin, cefazolin, and cefmetazole given at 90-minute intervals. Dogs given saline injections were used as controls. Platelet count, platelet size, PT, and aPTT were evaluated after 7 days of subcutaneous administration of saline, cefazolin, and cefmetazole (22 mg/kg every 8 hours). A significant decrease in platelet aggregation in response to ADP was detected 90 minutes after intravenous administration of cephalothin. Bleeding time was increased significantly 90 minutes after intravenous administration of cefmetazole. Platelet size was decreased significantly 24 hours after onset of the study in all animals, including controls. No significant changes in platelet count, platelet size, PT, or aPTT were detected after 7 days of subcutaneous administration. Cefazolin had no adverse effects on platelet aggregation in response to ADP, bleeding time, platelet count, platelet size, PT, or aPTT. Therefore, cefazolin should be considered as a perioperative antibiotic in dogs with conditions predisposing to hemostatic complications.

Surgical management of atypical lateral tracheal collapse in a dog.

Tracheal collapse is often diagnosed in small-breed dogs through use of conventional radiography or fluoroscopy, by which the dorsoventral orientation of the collapse can be seen. In the dog of this report, an unusual lateral form of tracheal collapse was diagnosed by means of bronchoscopy after multiple radiographic procedures had failed to define a cause for cough and dyspnea. Surgical reinforcement of the abnormal region of the trachea resulted in resolution of clinical signs and in reduction in dynamic airway collapse, which was documented on follow-up bronchoscopy.

Effect of total ablation of the external acoustic meatus and bulla osteotomy on auditory function in dogs.

Seven dogs with end-stage bilateral otitis externa were evaluated for auditory function before and after bilateral total ear canal ablation and lateral bulla osteotomy. Evaluations were performed by owner questionnaire and by recording brainstem auditory-evoked responses. Prior to surgery, all dogs could hear a loud voice or noise, however, only 3 dogs responded to a voice spoken at a normal level. Of the 14 ears tested electrodiagnostically, only 1 did not have a response, using air-conducted or bone-conducted stimuli. After surgery, 2 dogs responded to a normal voice, but all 7 responded to loud voices or noise. Three ears that had recordable brainstem auditory-evoked responses to air-conducted stimulation prior to surgery, failed to respond after surgery. Ears that responded to bone-conducted stimulation prior to surgery also responded after surgery.

Treatment of dogs in hemorrhagic shock by intraosseous infusion of hypertonic saline and dextran.

Under isoflurane anesthesia, 50% of the calculated blood volume was removed from 11 dogs. After 30 minutes, five dogs were treated with hypertonic saline and dextran (HSD) (5 mL/kg) followed by isotonic saline solution (2 mL/kg) intraosseously. Six dogs (controls) received isotonic saline (7 mL/kg) intraosseously. All treatments were administered through the medullary cavity of the tibia over a 30-minute period. Cardiac output, mean arterial pressure, central venous pressure, packed cell volume, total protein, and blood gases were monitored for 4 hours. Cardiac output, mean arterial pressure, and circulating volume (indicated by packed cell volume and total protein) were significantly improved after administration of HSD. We conclude that intraosseous infusion of HSD is efficacious in treating hemorrhagic shock and believe the technique may prove to be useful in clinical situations when intravenous lines cannot be established rapidly.

Urodynamic evaluation of lower urinary tract function in cats after perineal urethrostomy with minimal and extensive dissection.

Perineal urethrostomy was performed in five male cats with minimal, sharp intrapelvic transection of the ischiocavernous and ischiourethralis muscles and ventral penile ligaments, and in five male cats with extensive blunt intrapelvic dissection and sharp muscle transection. Urethral pressure profiles and cystometrograms with simultaneous fine wire electrode sphincter electromyography were performed in sedated cats before surgery and on days 14 and 28. Premicturition pressure, urethral opening pressure, maximum detrusor pressure, total volume infused, and residual volume were measured during cystometry, and maximal urethral closure pressure was measured during profilometry. A grading of (+), (++), or ( ) was used to represent the intensity of electromyographic activity. There was no difference between minimal and extensive dissection for any cystometrogram or profile variable at days 14 or 28. Urethral opening pressure and maximal detrusor pressure during cystometrography were higher in preoperative studies than after minimal or extensive dissection. Sphincter electromyography after surgery was not significantly different from preoperative results in either surgical group. The results of this study indicate that neither sharp nor blunt intrapelvic dissection significantly alters the postoperative urodynamic status in male cats.

Familial allergic rhinitis in cattle.

A group of Angus X Holstein cattle were determined to have allergic rhinitis. Clinical signs included nasal discharge, tearing, sneezing, and nasal pruritus. The diagnosis was made on the basis of intradermal skin testing of affected and clinically normal cattle. The affected cattle had positive test results to various tree, grass, weed, and mold allergens. The clinical signs and seasonal occurrence were similar to those features for allergic rhinitis in man. Breeding data indicated an inherited mode of transmission, although only females were affected.

Cardiopulmonary effects of the pneumatic anti-shock garment on swine with diaphragmatic hernia.

The pneumatic anti-shock garment is a widely used prehospital treatment modality for injured patients in shock. Laceration of the hemidiaphragm is a post-traumatic condition that usually is unrecognized during the prehospital phase of trauma care. In order to study the effects of inflation of the pneumatic anti-shock garment on experimental swine with diaphragmatic injury, a premeasured custom-fitted external counter pressure device was applied to the swine both before and after surgically induced laceration to the left hemidiaphragm. At each inflation pressure, several measurements were recorded: blood pressure, heart rate, respiratory rate, tidal volume, pulmonary artery pressures, pulmonary capillary wedge pressure, cardiac output and arterial blood gas determinations. Roentgenograms of the chest were obtained both before and after diaphragmatic laceration and at each inflation pressure after injury. Herniation of abdominal viscera was induced in all swine at 60 millimeters of mercury and was accompanied by statistically significant aberrations in tidal volume, pH, pO2, pCO2, pulmonary capillary wedge pressure and pulmonary artery pressures. Blood pressure increased, in both the injured and noninjured swine, and remained at normal or above normal levels throughout the inflation period in both groups. Extrapolating this phenomenon to the clinical setting when the use of or further inflation of the pneumatic anti-shock garment, or both, is generally determined by blood pressure response alone, patients with blunt trauma and lacerated diaphragms in whom external counter pressure is used may sustain irreversible cerebral hypoxia before any problem is suspected.

Evaluation of anastomoses of small intestine in dogs: crushing versus noncrushing suturing techniques.

Fifteen dogs were used to compare simple interrupted crushing and noncrushing single-layer small intestinal anastomoses. Groups of 5 dogs each were used to evaluate both techniques at 3 postsurgical times--days 4, 21, and 42. There were no significant differences between the 2 techniques at the evaluations. Grossly, there were marked adhesion formations at the 3 evaluation times. Luminal diameters at the anastomotic site indicated there may have been only slightly more stenosis with the noncrushing technique. Bursting pressure studies determined that the anastomotic strengths of the 2 techniques were not measurably different statistically. However, their bursting strengths had greatly increased from day 4 to day 21. There were also significant increases in bursting strengths of jejunal segments caudal to the anastomotic sites from day 4 to day 42. Subjective histopathologic evaluations of anastomotic sites revealed that the types and amounts of inflammation, collagen content, continuity of layers, and severity of peritonitis were not different within each time. It was concluded that both techniques for small intestinal anastomoses in the dog have equal value.