Evaluation of prognostic factors in the surgical treatment of adrenal gland tumors in dogs: 41 cases (1999-2005).

OBJECTIVE: To identify preoperative predictors of survival and assess intraoperative and postoperative complications and survival rates for dogs undergoing adrenalectomy. DESIGN: Retrospective case series. ANIMALS: 41 dogs that underwent adrenalectomy. PROCEDURES: Records were reviewed to collect data regarding preoperative variables. Intraoperative and postoperative variables were also recorded. Variables were evaluated for association with survival duration via log-rank analysis for categoric variables and by use of Cox proportional hazards. Median survival times were calculated by use of Kaplan-Meier life table analysis. RESULTS: 9 (22.0%) dogs did not survive to discharge. Intraoperative mortality rate was 4.8%. Overall Kaplan-Meier median survival time was 690 days. Variables significantly associated with shorter survival times included preoperative weakness or lethargy, thrombocytopenia, increased BUN concentration, increased partial thromboplastin time (PTT), increased aspartate transaminase (AST) activity, hypokalemia, intraoperative hemorrhage, and concurrent nephrectomy. Postoperative variables significantly associated with shorter survival times included pancreatitis and renal failure. In multivariate analysis, preoperative hypokalemia, preoperative increased BUN concentration, and concurrent nephrectomy were significantly associated with a shorter survival time. CONCLUSIONS AND CLINICAL RELEVANCE: A high mortality rate was associated with adrenalectomy in dogs; however, those that survived until discharge from a hospital had long survival times. Preoperative factors associated with a shorter survival time were weakness or lethargy, thrombocytopenia, increased BUN concentration, increased PTT, increased AST activity, and hypokalemia. Studies are needed to evaluate how treatment for these factors may affect or change outcome after adrenalectomy. Dogs with adrenal masses that require concurrent nephrectomy and cause intraoperative hemorrhage have a guarded prognosis.

Evaluation of a two-centimeter lateral surgical margin for excision of grade I and grade II cutaneous mast cell tumors in dogs.

OBJECTIVE: To evaluate completeness of excision and clinical outcome in dogs with cutaneous mast cell tumors (MCTs) excised with a lateral margin of 2 cm and a deep margin of 1 fascial plane. DESIGN: Prospective study. ANIMALS: 16 client-owned dogs with 1 or more cutaneous MCTs. PROCEDURE: Excision of MCTs was performed with a 2-cm lateral margin and a deep margin of 1 fascial plane. Histologic tumor grading was performed; surgical margins were categorized as complete or incomplete. Follow-up information was obtained via repeat examination of the dogs by veterinarians or client-completed questionnaires. RESULTS: 4 grade I and 19 grade II cutaneous MCTs were evaluated. Overall, 21 (91%) MCTs were completely excised; 2 grade II tumors had foci of mast cells at the 2-cm margin. Two dogs received adjunctive treatments following surgery. Follow-up information was available for all dogs (median follow-up period, 379 days; range, 51 to 538 days); no local recurrence was detected during this time. De novo MCTs were detected in 3 of 16 dogs at 37, 54, and 154 days after surgery. Via Kaplan-Meier analysis, median survival time and disease-free interval were both > 538 days (medians not yet reached). No prognostic variables were identified. CONCLUSIONS AND CLINICAL RELEVANCE: Excision with a 2-cm lateral margin and a deep margin of 1 fascial plane may result in satisfactory excision of grades I and II MCTs in dogs, with recurrence rates similar to those reported previously. Use of these margins may minimize complications associated with larger local tumor resection.

Feline cutaneous hemangiosarcoma: a retrospective study of 18 cases (1998-2003).

Cutaneous hemangiosarcoma (HSA) has been infrequently reported in dogs and cats. Medical records of 18 cats diagnosed with cutaneous HSA were reviewed. Age at the time of diagnosis, breed, sex, tumor location, tumor size, treatment type, survival time, disease-free interval, and cause of death were evaluated. Aggressive surgical excision of the tumor was attempted in 10 cats. A complete surgical excision was achieved in five of the 10 cats. Median survival times were statistically longer in cats that underwent surgery versus cats that did not. Cats with cutaneous HSA treated with aggressive surgical excision of their tumors may have a good long-term prognosis.

Use of thoracoscopy to determine the etiology of pleural effusion in dogs and cats: 18 cases (1998-2001).

OBJECTIVE: To assess use of thoracoscopy to determine causes of pleural effusion in dogs and cats. DESIGN: Retrospective study. ANIMALS: 15 dogs and 3 cats with pleural effusion. PROCEDURE: Medical records were reviewed from 1998 to 2001 for dogs and cats that had exploratory thoracoscopy, biopsy, and histologic analysis to determine the etiology of pleural effusion. Intraoperative and postoperative complications were recorded. Surgical biopsy specimens were evaluated for quantity and quality for providing a histologic diagnosis. RESULTS: Biopsy specimens were deemed adequate in quantity and quality to render a histologic diagnosis in all animals. Etiology of the effusion was neoplasia in 8 animals and non-neoplastic pleuritis in 10 animals. Median survival time of animals with neoplasia was 15 days, whereas those with inflammatory diseases had median survival time of > 785 days. Postoperative pneumothorax was encountered in 2 animals subsequent to pulmonary biopsy. No other major complications were recorded. CONCLUSIONS AND CLINICAL RELEVANCE: Thoracoscopy is a diagnostic option that provides excellent viewing of intrathoracic structures and adequate biopsy specimens with minimal complications. This technique provides a less invasive alternative to thoracotomy for evaluating the etiology of pleural effusion.

Evaluation of surgical margins required for complete excision of cutaneous mast cell tumors in dogs.

OBJECTIVE: To determine whether neoplastic mast cells extended into tissue 1, 2, or 3 cm laterally or deeper than 1 fascial plane from the visible edge of cutaneous mast cell tumors (MCTs) in dogs. DESIGN: Prospective study. ANIMALS: 21 client-owned dogs with > or = 1 cutaneous MCT PROCEDURES: After preparation for surgery, each dog's skin was marked 1, 2, and 3 cm from the tumor edge at 0 degrees, 90 degrees, 180 degrees, and 270 degrees. At each 3-cm mark, deep fascia was exposed and sutured to the skin; the tumor was excised in routine fashion and fixed in formalin. Tumors were graded; margins were examined histologically for neoplastic mast cells. RESULTS: 23 cutaneous MCTs in 21 dogs were included in this study. Fifteen (65%) tumors were located on the trunk, 5 (22%) on the hind limbs, and 3 (13%) on the head and neck. There were 3 (13%) grade-I and 20 (87%) grade-II tumors. All grade-I tumors were completely excised at all margins. Seventy-five percent of the grade-II tumors were completely excised at the 1-cm margin, and 100% were completely excised at the 2-cm margin. Two grade-II MCTs located on the hind limbs of dogs were excised with a complete but close (within 1 mm) deep margin. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a 2-cm lateral margin and a deep margin of 1 fascial plane appear to be adequate for complete excision of grade-I and -II MCTs in dogs.

Lactate as a diagnostic test for septic peritoneal effusions in dogs and cats.

Lactate concentration in peritoneal fluid was evaluated and compared to blood lactate concentration in dogs and cats with septic and nonseptic abdominal effusions. All dogs with septic effusions had a peritoneal fluid lactate concentration >2.5 mmol/L and a peritoneal fluid lactate concentration higher than blood lactate, resulting in a negative blood to fluid lactate difference. In dogs, the diagnostic accuracy of the peritoneal fluid lactate concentration and the blood to fluid lactate difference in differentiating septic peritoneal effusion was 95% and 90%, respectively. Peritoneal fluid lactate concentration and blood to fluid lactate difference were not accurate tests for detecting septic peritoneal effusions in cats.

The surgical treatment of cholelithiasis in cats: a study of nine cases.

Nine cats that had surgical treatment for obstructive cholelithiasis were reviewed to evaluate clinical signs, diagnostic test results, and outcome after surgery. Common clinical signs included progressive vomiting (9/9), dehydration (9/9), anorexia (6/9), icterus (5/9), and lethargy (4/9). Five cats had a cholecystectomy performed, one cat had a cholecystotomy, and three cats had a biliary diversion procedure. Four of the cats that had a cholecystectomy had no recurrence of vomiting or anorexia. The majority of cats (7/9) had multiple choleliths, which were radiopaque and most commonly composed of calcium carbonate. Seven cats were diagnosed with cholangiohepatitis, and four of these cats did not need long-term medical therapy. Most cats (7/9) survived long term postsurgery (mean, 21 months; median, 24 months) without additional medical therapy, while the two cats with concurrent hepatic lipidosis died. Cholecystectomy appeared to have low morbidity with good clinical success.

Comparison of peritoneal fluid and peripheral blood pH, bicarbonate, glucose, and lactate concentration as a diagnostic tool for septic peritonitis in dogs and cats.

OBJECTIVE: To establish a reliable diagnostic tool for septic peritonitis in dogs and cats using pH, bicarbonate, lactate, and glucose concentrations in peritoneal fluid and venous blood. STUDY DESIGN: Prospective clinical study. ANIMALS: Eighteen dogs and 12 cats with peritoneal effusion. METHODS: pH, bicarbonate, electrolyte, lactate, and glucose concentrations were measured on 1- to 2-mL samples of venous blood and peritoneal fluid collected at admission. The concentration difference between blood and peritoneal fluid for pH, bicarbonate, glucose, and lactate concentrations were calculated by subtracting the peritoneal fluid concentration from the blood concentration. Peritoneal fluid was submitted for cytologic examination and bacterial culture. Peritonitis was classified as septic or nonseptic based on cytology and bacterial culture results. RESULTS: In dogs, with septic effusion, peritoneal fluid glucose concentration was always lower than the blood glucose concentration. A blood-to-fluid glucose (BFG) difference > 20 mg/dL was 100% sensitive and 100% specific for the diagnosis of septic peritoneal effusion in dogs. In 7 dogs in which it was evaluated, a blood-to-fluid lactate (BFL) difference < -2.0 mmol/L was also 100% sensitive and specific for a diagnosis of septic peritoneal effusion. In cats, the BFG difference was 86% sensitive and 100% specific for a diagnosis of septic peritonitis. In dogs and cats, the BFG difference was more accurate for a diagnosis of septic peritonitis than peritoneal fluid glucose concentration alone. CONCLUSIONS: A concentration difference > 20 mg/dL between blood and peritoneal fluid glucose concentration provides a rapid and reliable means to differentiate a septic peritoneal effusion from a nonseptic peritoneal effusion in dogs and cats. CLINICAL RELEVANCE: The difference between blood and peritoneal fluid glucose concentrations should be used as a more reliable diagnostic indicator of septic peritoneal effusion than peritoneal fluid glucose concentration alone.