Insulinoma in a cat.

A 14-year-old domestic shorthair cat was presented with hypoglycaemia and seizures of several weeks duration. Bloodwork revealed hypoglycaemia (1.83 mmol/l; reference range 4.22-8.05 mmol/l) with concurrent normal insulin levels (171 pmol/l; reference range 72-583 pmol/l). An insulinoma was suspected and medical and dietary management were attempted with minimal success. An exploratory laparotomy was performed and a single, well-defined mass was found within the left lobe of the pancreas. The mass was removed and histologically classified as an islet cell carcinoma, consistent with an insulinoma. The cat had an episode of presumed postoperative pancreatitits, but recovered with appropriate treatment. The cat has had no clinical signs of recurrence of greater than 32 months postsurgery. There are only four cases of insulinoma in cats reported in the literature. All prior insulionomas reported were in older cats and were malignant in character, which is similar to the reports in the dog. This case is unique because of the apparent lack of local recurrence and development of metastatic disease, leading to the prolonged survival.

Paraoesophageal hiatal hernia and megaoesophagus in a three-week-old Alaskan malamute.

Paraoesophageal hiatal hernia was diagnosed in a three-week-old Alaskan malamute. Reduction of the hernia was followed by an oesophagopexy and a bilateral gastropexy. During the early postoperative period, the puppy continued to have signs that were thought to be related to a concurrent megaoesophagus. At nine months of age the dog had gained weight and was well except for occasional episodes of regurgitation. These episodes responded well to medical therapy, and at the time of writing the dog had not required further treatment.

Umbilico-biliary fistula in a dog.

This case report describes a previously unreported congenital malformation, an umbilico-billary fistula, in a dog. A one-year-old male bulldog was diagnosed with umbilico-billary fistula using fistulography. Treatment involving surgical removal of the fistula was straightforward and resulted in clinical resolution of the problem.

Hiatal hernia and diaphragmatic eventration in a leopard (Panthera pardus).

A 1-yr-old male leopard (Panthera pardus) presented for intermittent anorexia, emaciation, and generalized muscle wasting. Plain radiographs, ultrasonography, and esophageal endoscopy led to a diagnosis of diaphragmatic eventration with probable concurrent hiatal hernia. An exploratory laparotomy confirmed both diagnoses, and surgical repair and stabilization were performed. After surgery, the leopard was maintained on small liquid meals for 4 days, with a gradual return to normal diet over 2 wk. By 4 wk after surgery, the leopard was eating well and gaining weight, and it showed no recurrence of clinical signs for 2 yr subsequently, becoming mildly obese.

Microvascular transplantation of a free omental graft to the distal extremity in dogs.

OBJECTIVE: To assess the survival of a free omental graft applied to an experimentally created wound on the distal extremity in dogs. STUDY DESIGN: A free omental graft was evaluated as a primary method of treatment for dogs with distal extremity wounds in an experimental model. ANIMALS OR SAMPLE POPULATION: Five adult intact female mixed breed dogs weighing 21.8 kg to 25.0 kg. METHODS: A free omental graft was harvested from the abdomen and transferred to a wound bed overlying the medial aspect of the tibia. A microvascular anastomosis was performed between the graft vessels and vessels at the recipient site. Daily clinical assessment of graft viability was performed. Angiography and 99mTechnetium labeled macroaggregated albumin (99mTc MAA) scintigraphic perfusion scans were performed on either day 4, 5, or 7. Postmortem collection of tissues for histopathologic analysis was performed immediately after imaging. Total operative time and graft ischemia time were evaluated for effects on graft survival. RESULTS: Two of seven grafts survived to the end of the study, three of seven grafts failed because of ischemia, and two of seven grafts failed because of self-trauma. There was no clinically significant morbidity associated with the abdominal portion of the procedure. Because of the small number of surviving grafts, the effects of operative time and graft ischemia time could not be statistically evaluated. CONCLUSIONS: Microvascular transplantation of a free omental graft can result in a viable tissue covering of a distal extremity wound, however, the failure rate is unacceptably high. CLINICAL RELEVANCE: A free omental graft may not have sufficient durability to be an acceptable wound covering by itself. Further studies combining omentum with a skin graft or other tissues may result in a clinically useful technique.

The use of colonic irrigation to control fecal incontinence in dogs with colostomies.

OBJECTIVE: To determine if once-daily colonic irrigation results in fecal continence for a 24-hour period in dogs with colostomies and if colonic volume increased in response to the irrigation. STUDY DESIGN: A prospective controlled experimental study. ANIMALS: Four intact male and one intact female mixed breed dogs. MATERIALS: All dogs received left end-on paralumbar colostomies. Four dogs received once-daily colonic irrigation for 8 weeks, whereas the control dog did not. Daily fecal weights were recorded for the length of the study in all dogs. Barium enema studies and volumetric studies were used to determine colonic volumes. RESULTS: Daily fecal weights were significantly decreased in treatment dogs compared with the control dog. Colonic volume increased in irrigated dogs in response to daily irrigation over the 8 week period of the study. CONCLUSIONS: Colonic irrigation resulted in significantly decreased fecal production over a 24-hour period. Therefore management of dogs with colostomies would be more practical and cost effective. It did not result in complete fecal continence in this study. Further clinical studies are indicated to determine if longer periods of irrigation would result in complete continence.

Long-term outcome of medical and surgical treatment of hiatal hernias in dogs and cats: 27 cases (1978-1996).

OBJECTIVE: To determine long-term outcome of medical and surgical treatment of hiatal hernia (HH) in dogs and cats. DESIGN: Retrospective case series. ANIMALS: 22 dogs and 5 cats. PROCEDURE: Medical records of dogs and cats with HH were reviewed. Outcomes of treatment were obtained from reexamination or owner questionnaires. RESULTS: The most common breeds affected were English Bulldog and domestic shorthair cat. Mean age of all dogs and cats was 4 years. Hiatal hernia was diagnosed by use of contrast radiography of the esophagus (n = 19), fluoroscopy (7), or esophagoscopy (1). Eight of 15 dogs and cats treated medically for 30 days had complete resolution of signs. Of the 7 in this group that did not respond, 1 died on the 10th day of medical treatment and the remaining 6 were treated surgically. Eight of 10 dogs that underwent hiatal plication, esophagopexy, and gastropexy responded favorably. Four of 7 dogs that underwent fundoplication did well. However, 3 of these dogs did not have clinical signs. Fundoplication was successful in only 1 of 4 dogs with clinical signs. CLINICAL IMPLICATIONS: Dogs and cats with clinical signs of reflux esophagitis associated with HH should undergo conservative treatment for 30 days. Most will be managed successfully by use of drugs, dietary alterations, or both. Those that do not respond to conservative treatment will likely require surgery. The best prognosis after, surgery appears to be associated with the esopagopexy technique.

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.

Complications associated with the implantation of polypropylene mesh in dogs and cats: a retrospective study of 21 cases (1984-1996).

Complications associated with implantation of polypropylene mesh in dogs and cats were evaluated retrospectively. Immediate postoperative complications were common (in 10 of 20 cases) but predominantly involved seroma formation which resolved with treatment. The only long-term (i.e., six months or more) complication identified was mass recurrence at the site of tumor resection (in seven of 14 cases). Recurrence was affected by resection size. The average number of ribs resected in cases of thoracic wall neoplasia (with and without mass recurrence) was 1.8 and 3.5, respectively. In this study, implantation of polypropylene mesh facilitated the reconstruction of large tissue defects and was not associated with any serious complications.

Determination of proximal femoral epiphyseal depth for repair of physeal fractures in immature dogs.

OBJECTIVE: To determine the depth that implants may be safely placed for repair of proximal femoral physeal fractures. STUDY DESIGN: Relationships were determined between the depth of the proximal femoral epiphysis (PFE) and the contralateral PFE, and the PFE and pubic bone width. ANIMALS OR SAMPLE POPULATION: 20 immature dog cadavers. METHODS: Actual PFE depths were determined at the center of the physeal surface and at four other eccentric points. The contralateral intact PFE depth and the width of the cranial aspect of the public bone were measured from radiographs. RESULTS: Mean ratios of actual central PFE depth to radiographically measured (1) contralateral PFE depth and (2) pubic bone width were 1.04:1, and 1.09:1, and ratios of actual eccentric PFE depths were 0.89:1 and 0.93:1. Body weight was not useful in estimating depth of the PFE. CONCLUSIONS: For the central epiphysis, pins may safely be placed a distance equal to 75% to 80% of the contralateral intact PFE depth or pubic bone width, measured from a ventrodorsal radiograph, with minimal risk of penetration through the articular surface. Pins placed eccentrically may be safely driven a depth equal to 65% of the radiographically measured contralateral intact PFE depth or pubic bone width. CLINICAL RELEVANCE: Estimating the safe depth of implant placement into the PFE avoids penetration of the articular surface.

Determination of safe depth of pin penetration for repair of distal femoral physeal fractures in immature dogs: a comparison of normograde and retrograde pin placement.

OBJECTIVE: The purpose of this study was to determine the depth that implants may be safely placed into the distal femoral epiphysis (DFE) for the repair of distal femoral physeal fractures. STUDY DESIGN: The depth of the DFE was related to the radiographic thickness of the patella in this experimental study. ANIMALS OR SAMPLE POPULATION: Twenty immature canine cadavers. METHODS: Patella thicknesses were measured from lateral radiographs. Actual DFE depths were determined for pins driven in normograde fashion and for pins driven retrograde from the central depression between the metaphyseal pegs and from the cranial pegs. The association of DFE depth and patella thickness was evaluated using linear regression analysis. Using 95% confidence intervals, rules for estimating the safe depth of implant placement into the DFE were determined. RESULTS: DFE depth had significant correlation with patella thickness for pins placed in retrograde fashion from the central depression between the metaphyseal pegs (r2 = .83) and from the cranial pegs (r2 = .82) and for pins placed in normograde fashion (r2 = .65). CONCLUSIONS: Based on 95% confidence intervals, pins placed in retrograde fashion from the central depression between the metaphyseal pegs may be safely driven into the DFE a distance equal to 140% of patella thickness. Pins placed from the cranial metaphyseal pegs may be driven to a depth equal to 80% of patella thickness, and pins placed in normograde fashion may be driven to a depth equal to 30% of patella thickness. CLINICAL RELEVANCE: Measurement of patella thickness assists the surgeon in determining the approximate depth that pins may be driven into the DFE without penetrating the articular surface of the stifle joint.

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.

Myoblast gene therapy in canine mucopolysaccharidosis. I: Abrogation by an immune response to alpha-L-iduronidase.

Three dogs with deficiency of the lysosomal enzyme alpha-L-iduronidase were treated by gene replacement therapy targeted at muscle. Direct intramuscular injections of plasmid encoding the alpha-L-iduronidase gene cDNA resulted in no detectable enzyme production, but may have resulted in immunologic sensitization to iduronidase protein, which the dogs lack totally. Myoblasts were grown from skeletal muscle biopsies and transduced with a retroviral vector containing the canine gene under control of the muscle creatine kinase enhancer. Several hundred-fold overexpression of enzyme production occurred in cultured cells; however, following reintroduction of the cultured cells into dogs, enzyme production declined rapidly. Concurrent with the falling enzyme levels, there was production of specific immunoglobulin G (IgG) antibody against iduronidase that was further associated with cellular infiltration of the myoblast injection sites. Most inflammatory cells were lymphocytes and plasma cells, suggesting local humoral and cellular immune responses to the enzyme-producing muscle cells. PCR analysis of tissues collected 2-22 weeks after the final treatment showed the persistence of Neo and canine alpha-L-iduronidase sequences in a progressively decreasing percentage of myoblasts. Results from this study in a canine model of mucopolysaccharidosis I underscore the fact that immunologic reactions to cells producing desirable, normal, but foreign, proteins may be as much an impediment to gene therapy as reactions to the viral vectors used to introduce the foreign gene.

Use of a low-profile gastrostomy device for administering nutrients in two dogs.

Percutaneous endoscopic gastrostomy (PEG) tubes are an excellent means of providing nutritional support via the enteral route. Most problems with PEG tubes are associated with their maintenance. A low-profile feeding device has been developed for use in human beings to replace standard PEG tubes in situations in which long-term nutritional support is necessary. We adapted a low-profile feeding device for use in 2 dogs. The device offered the advantage of being easier to maintain than standard PEG tubes. It appeared to have been well tolerated. Its low-profile design is likely to result in few problems resulting from an animal chewing on the device or from accidental dislodgment.

Caecal impaction in a dog.

A seven-year-old, intact male dobermann with a four-week history of anorexia was diagnosed as having impaction of the caecum with inspissated faeces. Radiographic and histopathological findings revealed impaction of the caecum and a mild subacute locally extensive typhlitis. Typhlectomy was curative and no further problems have been reported.

Use of a pedicled rectus abdominis muscle flap for repair of a failed vesicourethral anastomosis in a dog.

A 10-year-old mixed breed dog underwent a prostatectomy for an adenocarcinoma. Within three days the dog had signs of a uroperitoneum. Re-exploration revealed that a portion of the vesicourethral anastomosis had failed. Primary suturing of the tissue along the site of dehiscence following debridement of the devitalised tissue was impossible. A rectus abdominis muscle flap was created and successfully used to repair the site of leakage.

Self-Assembled Metal Colloid Monolayers: An Approach to SERS Substrates.

The self-assembly of monodisperse gold and silver colloid particles into monolayers on polymer-coated substrates yields macroscopic surfaces that are highly active for surface-enhanced Raman scattering (SERS). Particles are bound to the substrate through multiple bonds between the colloidal metal and functional groups on the polymer such as cyanide (CN), amine (NH(2)), and thiol (SH). Surface evolution, which can be followed in real time by ultraviolet-visible spectroscopy and SERS, can be controlled to yield high reproducibility on both the nanometer and the centimeter scales. On conducting substrates, colloid monolayers are electrochemically addressable and behave like a collection of closely spaced microelectrodes. These favorable properties and the ease of monolayer construction suggest a widespread use for metal colloid-based substrates.

Percutaneous endoscopic gastrostomy.

Over the past 5 to 7 years, the veterinary profession has benefitted from our increased ability to provide nutrition to the small animal patient who cannot or will not eat. The adaptation of the percutaneous endoscopic gastrostomy (PEG) for use in the dog and cat deserves a great deal of credit in advancing the level of care we can now give to the chronically ill or critical care patient. The PEG is a relatively simple technique that has proved to be a very cost-efficient way to maintain the nutritional status of the small animal patient. In the author's experience, owner acceptance of using the PEG in the home environment on a chronic basis has been excellent.

Comparison of effects of cimetidine and omeprazole on mechanically created gastric ulceration and on aspirin-induced gastritis in dogs.

A double-blind study was conducted to compare gastric ulcer healing time in nontreated dogs with that in dogs treated with either cimetidine or omeprazole. Single ulcers were created in the gastric antrum by use of a suction biopsy capsule. Each dog was given 25 mg of aspirin/kg of body weight orally for 20 days after ulcer induction. Five control dogs were given aspirin only (no anti-ulcer medication) during the 20-day study. Six dogs were given cimetidine at dosage of 10 mg/kg orally every 8 hours, and 6 dogs were given omeprazole orally at dosage of 2 mumol/kg (0.7 mg/kg) once daily. All dogs were examined endoscopically on days 5, 10, 15, and 20 and were given a score for the size of the mechanically created ulcer and a score for the degree of aspirin-induced gastritis. All dogs were euthanatized on day 21, and gastric lesions were examined histologically. Significant differences were not evident in ulcer healing scores or degree of aspirin-induced gastritis among treated and nontreated dogs on days 5, 10, 15, and 20. However, aspirin-induced gastritis was less severe in dogs of the omeprazole group than in dogs of the cimetidine or control group on each day observations were made. The effect of omeprazole given once daily was comparable with that of cimetidine given every 8 hours in lessening aspirin-induced gastritis.