Effects of phosphorus/calcium-restricted and phosphorus/calcium-replete 32% protein diets in dogs with chronic renal failure.

Twenty-four dogs with induced, severe chronic renal failure were allotted to 2 groups of 12 each. Group-A dogs were fed a 0.4% phosphorus (P)/0.6% calcium, 32% protein diet, and group-B dogs were fed a 1.4% P/1.9% calcium, 32% protein diet. Dogs were studied over 24 months to determine clinical status, survival, blood biochemical alterations, glomerular filtration rate (GFR), urinary excretion of P and protein, renal morphologic changes, and renal tissue concentrations of calcium, P, and magnesium. Group-A dogs developed statistically significant differences from group-B dogs in several blood biochemical values (PCV and total solids, calcium, P, potassium, sodium, chloride, total CO2 (TCO2), anion gap, and parathyroid hormone concentrations) and in urinary P excretion. Mean (+/- SEM) GFR values in group-A and group-B dogs were nearly identical when diets were initiated (group A = 0.73 +/- 0.05 ml/min/kg of body weight; group B = 0.72 +/- 0.08 ml/min/kg), but significantly (P = 0.0346) lower GFR developed in group-B than in group-A dogs over time. At 24 months, GFR in survivors was 0.83 +/- 0.08 and 0.63 +/- 0.15 ml/min/kg for dogs of groups A and B, respectively. Other measurements favored the hypothesis that P/calcium restriction was beneficial, but values failed to reach statistical significance. Survival was greater at 24 months in group-A than in group-B (7 vs 5) dogs, and renal tissue concentrations of calcium and P were higher in group-B than in group-A dogs. Differences were not detected between groups in urinary excretion of protein and in the type or severity of renal lesions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chronic frontal sinusitis in dairy cattle: 12 cases (1978-1989).

Chronic frontal sinusitis in 12 dairy cattle most often was associated with a history of dehorning, in which the sinus was entered (67%), or with respiratory tract disease (25%). The most common organisms isolated were Actinomyces pyogenes and Pasteurella multocida. Signs of infection did not develop for months in some cattle and were often intermittent. The most common clinical signs included anorexia, lethargy, fever, frontal bone distortion, exophthalmos, abnormal posture, nasal discharge, and neurologic abnormalities. Treatment consisted of trephination at 2 sites, drainage and lavage of the sinus cavity, and administration of antibiotics and analgesics. Eight cattle responded well to treatment and were discharged, but 4 others had signs of CNS involvement and died or were euthanatized. Trephination of the frontal sinus cavity at carefully chosen sites and antibiotic treatment are indicated when sinusitis is suspected. Drainage of the sinus cavity is imperative to avoid extension of the infection into the CNS.     

Phenolsulfonphthalein pharmacokinetics and renal morphologic changes in adult pony mares with gentamicin-induced nephrotoxicosis

Changes in renal function, determined by pharmacokinetics of phenolsulfonphthalein (PSP), and renal morphologic features were examined in adult pony mares given 20 mg of gentamicin sulfate/kg of body weight, IV, q 8 h (group A) n = 7 or isotonic saline solution, IV, q 8 h, n = 5 (group B) for 14 days. Susceptibility of ponies to gentamicin-induced nephrotoxicosis was varied. Two group-A ponies developed acute renal failure and were euthanatized before treatment day 14, whereas 5 group-A A ponies did not develop physical or behavioral abnormalities after 14 days of gentamicin administration. All group-A ponies but none of group-B ponies developed ultrastructural abnormalities of the proximal tubular epithelium, consistent with gentamicin-induced nephrotoxicosis. Significant (P less than 0.05) differences were not detected in pharmacokinetic values of either group. Clearance of PSP was reduced in 4 group-A ponies that developed the most severe gentamicin-induced nephrotoxicosis. Changes in clearance of PSP were significantly (P less than 0.05) correlated with changes in the serum creatinine concentration.     

Pulmonary function, ventilator management, and outcome of dogs with thoracic trauma and pulmonary contusions: 10 cases (1994-1998)

OBJECTIVE: To document pulmonary function, ventilator management, and outcome of dogs with thoracic trauma that required mechanical ventilation because of severe pulmonary contusions. DESIGN: Retrospective study. ANIMALS: 10 dogs that required mechanical ventilation because of severe pulmonary contusions caused by blunt thoracic trauma. PROCEDURE: Signalment, historical data, arterial blood gas values, oxygen tension-based indices, ventilator settings, peak inspiratory pressure, positive end-expiratory pressure, tidal volume, and minute ventilation values were retrieved from medical records. RESULTS: All 10 dogs required positive-pressure ventilation because of dyspnea following trauma and had severely abnormal pulmonary function. Survival rate to discharge was 30%. Dogs were categorized into 2 groups; group A included 5 dogs in which pulmonary function improved during ventilation, whereas group B included 5 dogs that were euthanatized because of progressive lung dysfunction (n = 4) or cardiac arrest (1). Mean +/- SD body weight of group-A dogs (30.9 +/- 15.9 kg [68 +/- 35 lb]) was significantly greater than that of group-B dogs (7.6 +/- 1.8 kg [16.7 +/- 4 lb]). Dogs with improved lung function had peak inspiratory pressure that decreased progressively, whereas lung compliance deteriorated in dogs in group B. CONCLUSIONS AND CLINICAL RELEVANCE: Dyspneic dogs with severe pulmonary contusions may require and benefit from positive-pressure ventilation Prognosis is better for dogs that weigh > 25 kg (55 lb).     

Blood pressure response to tourniquet use in anesthetized horses

Blood pressure during anesthesia and surgery was compared for 2 groups of horses. Group A, consisting of 23 horses, had a tourniquet placed on the distal portion of a limb. The other group of 20 horses (group B) had surgery of comparable nature and duration as did group-A horses, but a tourniquet was not used. There was a statistical difference (P less than 0.05) in the peak systolic arterial blood pressure between the groups; group-A horses had a mean (+/- SEM) peak of 151 +/- 6 mm of Hg and group-B horses had a peak of 118 +/- 4 mm of Hg. In addition, group-A horses had immediate decrease in blood pressure, coincident with tourniquet deflation. The blood pressure decrease of 23 +/- 3 mm of Hg represented 16% of immediate predeflation blood pressure. Comparable blood pressure decrease was not observed at the end of surgery in group-B horses. Significant difference was not found when other factors that could affect blood pressure were considered. These factors included preanesthetic medication, anesthetic agents, mode of ventilation, pretourniquet inflation blood pressure, and duration of tourniquet inflation. Significant (P less than 0.05) difference in peak blood pressure was observed when the tourniquet was placed on the dependent, compared with the uppermost, limb, with changes more pronounced when the tourniquet was placed on the dependent limb. Tourniquet placement was associated with hypertension, and tourniquet deflation was associated with blood pressure decrease in these anesthetized horses.     

Pancreatic abscess in dogs: six cases (1978-1986)

Pancreatic abscess was diagnosed by exploratory celiotomy in 6 dogs. The most common clinical signs included acute onset of lethargy (n = 5), anorexia (n = 6), vomiting (n = 5), and diarrhea (n = 2). Physical examination revealed pain response to abdominal palpation (n = 5), depression (n = 5), icterus (n = 3), fever (n = 3), and cranial abdominal mass (n = 2). Consistent preoperative clinicopathologic abnormalities included leukocytosis with left shift, observance of toxic neutrophils on the blood smear, hyperlipasemia, hyperamylasemia, hyperbilirubinemia, and increased serum alkaline phosphatase activity. In 5 of 6 dogs, abdominal radiography revealed increased soft tissue density in the cranial portion of the abdomen. Ultrasonography performed on 4 dogs confirmed pancreatic mass. In all dogs, exploratory celiotomy revealed a cavitary pancreatic mass that contained sterile, mucopurulent material. Histopathologic diagnoses included acute necrotizing or chronic-active pancreatitis and steatitis. Two dogs were euthanatized at the time of diagnosis, and the remaining 4 were treated by use of pancreatic debridement(s), open abdominal drainage, and intensive administration of fluids and antibiotics. One dog was euthanatized 4 days after surgery, because of progressive pancreatic abscessation. Three dogs recovered and were discharged.     

Cutaneous lesion caused by Mycobacterium tuberculosis in a dog

A 5-month-old female mixed-breed dog was examined because of nonhealing wounds in the right submandibular region. Treatment with antibiotics and surgical excision was ineffective. Specimens of the right mandibular lymph node and surrounding tissues were submitted for bacteriologic culturing, and Mycobacterium tuberculosis was isolated. The dog was euthanatized. The risk of infection of human beings who associate with dogs that have cutaneous wounds caused by mycobacteria is unknown.     

Ureterocolonic anastomosis in clinically normal dogs

Ureterocolonic anastomosis was evaluated in 13 clinically normal dogs. Urinary continence was maintained after surgery, and the procedure was completed without technique errors in all but 2 dogs. Three dogs died within 5 weeks (2 of undetermined causes and 1 of aspiration pneumonia and neurologic disease), and 1 dog was euthanatized 4 months after surgery because of neurologic signs. Two healthy dogs were euthanatized 3 months after surgery for light microscopic evaluation of their kidneys. Five dogs were euthanatized 6 months after surgery for light microscopic evaluation of their kidneys. Gastrointestinal and neurologic disturbances developed in 4 dogs at various postoperative intervals. Plasma ammonia concentration measured in 2 dogs with neurologic signs was increased. Plasma ammonia concentration measured in 5 dogs without neurologic signs was within normal limits. All 5 dogs, in which metabolic acidosis was diagnosed, had high normal or above normal serum chloride concentration. Serum urea nitrogen values were increased after surgery because of colonic absorption of urea. Serum creatinine concentration was increased in 1 dog 6 months after surgery. Individual kidney glomerular filtration rate was reduced in 38% (3/8) of the kidneys from 4 other dogs at 6 months after surgery. Of 5 dogs euthanatized at 3 to 4 months after surgery, 4 had bilateral pyelitis, and 1 had unilateral pyelonephritis. Six months after surgery, pyelonephritis was diagnosed in 40% (4/10) of the kidneys from 5 dogs. The ureterocolonic anastomosis procedure is a salvage procedure that should allow complete cystectomy. However, variable degrees of metabolic acidosis, hyperammonemia, and neurologic disease may result.     

Treatment of dogs with osteosarcoma by administration of cisplatin after amputation or limb-sparing surgery: 22 cases (1987-1990).

Twenty-two dogs with appendicular osteosarcoma were treated by amputation (n = 17) or limb-sparing surgery (n = 5). All dogs were given cisplatin (60 mg/m2 of body surface, IV) at 3-week intervals, beginning 1 week after surgery. Number of cisplatin treatments ranged from 1 to 6. Survival data for the 22 dogs were compared with survival data from a historical control group consisting of 162 dogs with appendicular osteosarcoma treated by amputation alone. Median survival time for the 22 dogs given cisplatin was estimated to be 46.4 weeks, and 1- and 2-year survival rates were estimated to be 45.5 and 20.9%, respectively. Survival time was significantly (P less than 0.0001) longer for treated dogs than for control dogs. Statistically significant relation was not found between survival time and number of cisplatin treatments. Three dogs were alive with no evidence of disease at the time of reporting. Of the remaining 19 dogs, 14 (73.4%) were euthanatized for problems documented to be related to metastases. Nine (47.4%) dogs were euthanatized because of bone metastases, and 5 (26.3%) were euthanatized because of pulmonary metastases. The proportion of dogs euthanatized because of bone metastases was significantly (P less than 0.0001) higher for treated than for control dogs. Median survival times for dogs developing bone and lung metastases were estimated to be 51.2 weeks and 21.2 weeks, respectively; however, this difference was not statistically significant. One local tumor recurrence was observed among dogs that had limb-sparing surgery. Significant difference in survival time was not observed between dogs that had limb-sparing surgery and dogs that underwent amputation.     

Vaccination of ewes for prevention of vertical transmission of Neospora caninum

OBJECTIVE: To evaluate the immunologic response of a killed tachyzoite vaccine against Neospora caninum and its effectiveness in preventing vertical transmission of N caninum in sheep. ANIMALS: 40 Dorset ewes seronegative for N caninum. PROCEDURE: Group-A ewes (n = 20) were vaccinated on days 1 and 126 with a killed N caninum tachyzoite preparation in a commercially available adjuvant. Group-B ewes (n = 20) were sham vaccinated. Blood samples were collected from ewes every 2 weeks and a recombinant ELISA (rELISA) was used to determine serum antibody titers against N caninum. During pregnancy, ewes were challenged with live N caninum tachyzoites. Precolostral serum was collected from lambs and tested for antibodies against N caninum by use of an indirect fluorescence antibody test and the rELISA. Tissue specimens from stillborn lambs or lambs that died within 2 weeks of birth were collected and examined for N caninum antigen and DNA by use of immunohistochemistry and polymerase chain reaction assay, respectively. RESULTS: Serum antibody titers against N caninum were significantly higher in group-A ewes, compared with group B ewes, following vaccination. Serum antibodies against N caninum were detected in 100% (33/33) of group-B lambs and 75% (18/24) of group-A lambs. In tissue specimens, N caninum DNA was detected in 9 of 11 group-B lambs and 0 of 10 group-A lambs. Histologically, N caninum tachyzoites were observed in 4 group-A lambs and 3 group-B lambs. CONCLUSIONS AND CLINICAL RELEVANCE: The killed tachyzoite vaccine against N caninum stimulated a humoral immune response in sheep and provided partial protection against vertical transmission.     

Canine distemper virus-induced thrombocytopenia

Effects of canine distemper virus (CDV) infection on circulating platelet values were studied in gnotobiotic dogs inoculated with R252-CDV. Thrombocytopenia (less than 200,000 platelets/microliter) was present on postinoculation day (PID) 5 and persisted through PID 15. Peak thrombocytopenia occurred on PID 10 (less than 85,000 platelets/microliter). Thrombocytopenia was accompanied by lymphopenia, neutropenia, and monocytopenia. Platelet membrane-bound CDV antigen and IgG were present from PID 7 onward; neither the third component of complement nor IgM was detected on platelets from CDV-inoculated dogs. The mean number of megakaryocytes per unit of bone marrow surface area was unchanged. Megakaryocyte infection was present in dogs euthanatized on PID 4 (0.33%), increased slightly in dogs euthanatized on PID 8 (3%), and increased sharply in dogs euthanatized on PID 9 and 10 to 17.8% and 8.3%, respectively. Phagocytosis of platelets by stellate reticuloendothelial (Kupffer's) cells in the liver was prominent in dogs euthanatized from PID 5 onward. Seemingly, CDV-induced thrombocytopenia was mediated by virus-antibody immune complexes on platelet membranes. Decreased platelet production after PID 8 resulting from direct viral infection of megakaryocytes was a likely contributing factor and occurred against a background of profound virus-induced dysfunctions of all hematopoietic cellular elements.     

Nonangiogenic and nonlymphomatous sarcomas of the canine spleen: 57 cases (1975-1987)

The case records of and histopathologic findings in 57 dogs with nonangiogenic and nonlymphomatous splenic sarcomas were reviewed. Splenic neoplasms in these dogs included leiomyosarcoma, fibrosarcoma, undifferentiated sarcoma, liposarcoma, osteosarcoma, chondrosarcoma, myxosarcoma, rhabdomyosarcoma, and fibrous histiocytoma. The clinical signs associated with splenic sarcoma included anorexia or decreased appetite, abdominal distention, polydipsia, lethargy, vomiting, weight loss, and weakness. An abdominal mass was detected in 86% of the dogs by use of abdominal palpation (63%), and/or abdominal radiography (74%). The diagnosis was based on histopathologic findings in the spleen. Abdominal exploratory surgery was performed on 43 of the 57 dogs. Twenty-seven dogs were treated by splenectomy, and 16 were euthanatized at the time of surgery because of widespread metastatic lesions. Of the 14 dogs on which surgery was not performed, 11 were euthanatized on the basis of results of preoperative diagnostic tests, and the remaining 3 dogs had splenic neoplasms that were incidental findings at necropsy. Of the 27 surgically treated dogs, 5 died in the immediate postoperative period, 12 died or were euthanatized within 1 year after splenectomy, and only 5 dogs survived greater than or equal to 1 year. Three dogs were lost to follow-up evaluation, and 2 were still alive 6 and 7 months after surgery. The median survival time of the 22 dogs for which survival was known was 2.5 months. The median survival time for 11 dogs with no obvious metastasis at the time of splenectomy was 9 months.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of the impulse oscillometry system for testing pulmonary function during methacholine bronchoprovocation in horses

OBJECTIVE: To compare sensitivity of the impulse oscillometry system (IOS) with that of the conventional reference technique (CRT; ie, esophageal balloon method) for pulmonary function testing in horses. ANIMALS: 10 horses (4 healthy; 6 with recurrent airway obstruction [heaves] in remission). PROCEDURE: Healthy horses (group-A horses) and heaves-affected horses (group-B horses) were housed in a controlled environment. At each step of a methacholine bronchoprovocation test, threshold concentration (TC(2SD); results in a 2-fold increase in SD of a value) and sensitivity index (SI) were determined for respiratory tract system resistance (R(rs)) and respiratory tract system reactance (X(rs)) at 5 to 20 Hz by use of IOS and for total pulmonary resistance (RL) and dynamic lung compliance (C(dyn)), by use of CRT. RESULTS: Bronchoconstriction resulted in an increase in R(rs) at 5 Hz (R(5Hz)) and a decrease in X(rs) at all frequencies. Most sensitive parameters were X(rs) at 5 Hz (X(5Hz)), R(5Hz), and R(5Hz):R(10Hz) ratio; RL and the provocation concentration of methacholine resulting in a 35% decrease in dynamic compliance (PC(35)C(dyn)) were significantly less sensitive than these IOS parameters. The TC(2SD) for X(rs) at 5 and 10 Hz was significantly lower in group-B horses, compared with group-A horses. The lowest TC(2SD) was obtained for X(5Hz) in group-B horses and R(5Hz) in group-A horses. CONCLUSIONS AND CLINICAL RELEVANCE: In contrast to CRT parameters, IOS parameters were significantly more sensitive for testing pulmonary function.The IOS provides a practical and noninvasive pulmonary function test that may be useful in assessing subclinical changes in horses.     

Methicillin-resistant Staphylococcus aureus infections in 11 dogs

Methicillin-resistant Staphylococcus aureus infection was identified in 11 dogs. The infection was associated with surgical treatment especially orthopaedic surgery. Infection after traumatic wounding, and recurrent pyoderma was also seen. Oral antibiotic treatment improved or resolved the infection in nine of the 11 dogs, although the methicillin-resistant isolates were susceptible to relatively few antibiotics.     

Carotid Body Tumors in the Dog Eleven Cases (1978–1988)

Case records of 11 dogs with histologically confirmed carotid body tumors were reviewed. Surgical excision had been attempted in ten dogs with carotid body tumors, and one dog had been euthanatized at diagnosis. There were no intraoperative deaths but perioperative mortality was 40%. Horner's syndrome and laryngeal paralysis were the most common postoperative morbidities. The median survival time after surgery alone in the four dogs that survived the perioperative period was 25.5 months (range, 12-45 months). Two dogs treated with postoperative radiation therapy had survival times of 6 and 27 months. Of the six dogs surviving the perioperative period, two dogs are still alive at 19 and 32 months postoperatively. Of the four dogs that died, one was euthanatized 12 months postoperatively for nontumor-related causes. The remaining three dogs died of distant metastases. The carotid body tumors studied were characterized by local tissue invasion, neurovascular complications after therapy, and a propensity to metastasize to multiple sites in the body.     

Clinical signs associated with pseudorabies in dogs

Clinical signs in dogs with pseudorabies (Aujeszky's disease) were tabulated from 25 confirmed cases. The duration of disease was short, ranging from 6 to 96 hours. Eight dogs were euthanatized. Of those not euthanatized, 12 (71%) died within 24 hours of onset, 16 (94%) died within 48 hours, and only 1 (6%) lived longer than 48 hours (96 hours) after the onset of clinical signs. All of the dogs had ptyalism, 84% were restless, 84% were anorectic, 76% were atactic, and 64% wandered aimlessly. Sixty-four percent of the dogs had tachypnea, 60% had dyspnea, 56% vocalized, 52% were pruritic, 48% held their necks rigidly, 36% vomited, 36% had muscle spasms, 36% were aggressive, 28% had trismus, and 24% had dysphagia. Five of 25 dogs (20%) had abnormal pupillary light responses. Two of the 25 dogs circled and 2 walked backwards. Each of the following were detected once: blindness, ptosis, facial paresis, excessive lacrimation, head-tilt, head-pressing, signs of abdominal pain, and photophobia. All dogs had been exposed to swine, although in some instances the farmer was unaware pseudorabies existed in the herd or believed it was not in the herd on the basis of negative results on serologic testing.     

Results of Partial Mandibulectomy for the Treatment of Oral Tumors in 142 Dogs

Partial mandibulectomy was performed for the treatment of benign or malignant oral tumors in 142 dogs. Forty-two dogs with a benign tumor (ameloblastoma) had a 22.5 month (range, 6 to 74 months) median disease-free interval, with a 97% 1-year survival rate; there was local recurrence in one dog. Twenty-four dogs with squamous cell carcinoma had a disease-free interval of 26 months (range, 6 to 84 months), with a 91% 1-year survival rate; recurrence and metastasis developed in two dogs and metastatic disease in one dog. Based on survival curves, 37 dogs with a melanoma had a median survival time of 9.9 months (range, 1 to 36 months), with a 21% 1-year survival rate; 20 dogs died or were euthanatized for recurrent or metastatic disease. Twenty dogs with osteosarcoma had a median survival time of 13.6 months (range, 3 to 28 months), with a 35% 1-year survival rate; nine dogs died or were euthanatized for recurrent or metastatic disease. Nineteen dogs with fibrosarcoma had median survival time of 10.6 months (range, 3 to 32 months), with a 50% 1-year survival rate; 12 dogs died or were euthanatized for recurrent or metastatic disease. Results of this and previous studies demonstrated that partial mandibulectomy was effective in prolonging survival and decreasing recurrence for squamous cell carcinoma and ameloblastoma. Progressive disease and corresponding low survival times were common in dogs with melanoma, osteosarcoma, and fibrosarcoma. There were no differences in survival times or the progression of disease among five partial hemimandibulectomy procedures. The high rates of recurrence and metastasis in dogs with these tumors suggest a need for evaluation of ancillary chemotherapy and local radiation therapy to decrease the prevalence of progressive disease.     

Partial Gastrectomy with an Automatic Stapling Instrument for Treatment of Gastric Necrosis Secondary to Gastric Dilatation-Volvulus

A gastrointestinal anastomosis stapling instrument was used to perform partial gastrectomy in nine dogs undergoing emergency surgery for gastric dilatation-volvulus. The amount of necrotic stomach resected was 20% to 50%. Permanent gastropexy was performed, and six dogs also required partial or total splenectomy. Six dogs (67%) were normal after surgery, with follow-up periods of 6 to 16 months for five dogs. One dog died and two dogs were euthanatized because of postoperative complications unrelated to the surgical technique. There were no complications involving the partial gastrectomy staple line.     

Cardiovascular device infections in dogs: report of 8 cases and review of the literature

BACKGROUND: Infection is an infrequent but major complication of cardiovascular device implantation. HYPOTHESIS: Treatment of patients with cardiovascular implant infection with antibiotic therapy and removal of the device is superior to antibiotic therapy alone. METHODS: Medical records were reviewed for dogs that received a cardiovascular device from June 2001 to August 2006 at the University of Minnesota Veterinary Medical Center and the University of Missouri Veterinary Medical Teaching Hospital. RESULTS: Six of 63 (9.5%) pacemaker systems and 2 of 47 (4.3%) patent ductus arteriosus (PDA) occlusion devices became infected. Median time from procedure to diagnosis of implant infection was 62 days (range, 5 to 419). Median age of dogs with pacemaker infections was 8.5 years (range, 6.2 to 11.9). Pseudomonas aeruginosa and Staphylococcus spp were the most commonly cultured isolates. Four dogs were treated with antibiotics and pacemaker replacement. All 4 recovered completely from their infections. One was alive at the end of the study period, and 3 had been euthanized. However, the reasons for euthanasia were unrelated to pacemaker infection. In contrast, both dogs with infected pacemakers that were treated with antibiotics alone were euthanized because of complications attributable to infection. Infection of PDA occlusion devices occurred in puppies < 16 weeks of age, and Pasteurella spp were isolated from both. One was successfully treated with a combination of antibiotics and surgery, and the other was euthanized without treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Antibiotic therapy alone is associated with chronic complications in patients with cardiovascular implants and is unlikely to effect a cure.     

Leiomyosarcoma in dogs: 44 cases (1983-1988).

During a 5-year period, leiomyosarcoma was diagnosed in 57 dogs. Forty-four dogs were included in the study on the basis of completeness of medical records. All dogs underwent exploratory laparotomy, and dogs were allotted to 4 groups according to primary site of tumor: spleen (16 dogs, median age 10.3 years), stomach/small intestine (13 dogs, median age 10.3 years), cecum (10 dogs, median age 11.8 years), and liver (5 dogs, median age 9 years). All dogs with leiomyosarcoma of the liver had visible metastasis and were euthanatized at surgery. In the other 3 groups, 79% of the dogs had no gross evidence of metastasis at surgery, and 64% survived greater than 2 weeks. Median survival in these 3 groups was 10 months (range, 1 month to 7 years); 48% died of metastasis, 32% died of unrelated causes, and 16% died of unknown causes. The prognosis in dogs with leiomyosarcoma of the spleen, stomach, small intestine, and especially the cecum is good to excellent if surgery is performed. In dogs with leiomyosarcoma of the liver, the prognosis is poor.