Chylothorax in a dog with pulmonary lymphangiosarcoma.

Lymphangiosarcoma of the pulmonary pleura was found to be the cause of persistent chylothorax in an eight-year-old, intact male golden retriever. After a two-month course of medical management, a lymphangiogram and thoracic duct ligation were performed with the objective of decreasing further effusion. At surgery, gross lung pathology was biopsied and yielded a histopathological diagnosis of pulmonary pleural lymphangiosarcoma. A relatively rare tumor, lymphangiosarcoma of the pulmonary pleura has not previously been documented as a source of chylothorax in the dog.

Retrospective review of the ultrasonographic features of adrenal lesions in 21 ferrets.

Clinical signs and follow-up information were recorded. Histopathologic diagnoses were obtained for 25 adrenal glands in 21 ferrets. Adrenal lesions included ten adenocarcinomas, nine adenomas, one hyperplasia and one cortical cyst. Four adrenal glands (all right-sided) were diagnosed as unspecified adrenal tumors but lacked a definite histopathologic diagnosis (adenoma vs. adenocarcinoma) due to incomplete surgical resection and consequent small sample sizes. Bilateral adrenal lesions were identified in 4 ferrets (19%). Adrenal shape, size, echogenicity, laterality, and the presence of vascular invasion were evaluated with ultrasound. Size and shape were variable and not specific to lesion type. Both benign and malignant adrenal tumors (adenomas, adenocarcinomas) appeared most often as masses with increased thickness and a normal length (11/23), less frequently as larger masses with increased thickness and length (4/23) or as nodules focally deforming the normal adrenal shape (6/23). The only cortical cyst appeared as a nodule. Three adrenal glands had a normal size and shape and were diagnosed as adenomas (2) or hyperplasia (1). Therefore treatment may be warranted based solely on clinical signs if adrenal glands are ultrasonographically normal. Vascular invasion was not identified ultrasonographically. However, focal absence of periglandular fat resulting in contact of 8 adrenal glands with either caudal vena cava (6), aorta (1) or liver (1) identified ultrasonographically, correlated with incomplete surgical resectability (6/8) and histopathologic diagnoses of carcinoma (4/8) or unspecified tumors (4/8). Therefore, a focal absence of periglandular fat between the adrenal gland and the large vessels or liver, deviation or compression of the large vessels by the adrenal lesion may indicate malignancy. Adrenal tumors (benign and malignant) were often associated with a prominent uterus, uterine stump or prostate with or without prostatic cysts.

Ultrasonographic appearance and clinical findings in 14 dogs with gallbladder mucocele.

Fourteen dogs with enlarged gallbladders and immobile stellate or finely striated bile patterns on ultrasound are described. Smaller breeds and older dogs were overrepresented, with 4/14 Cocker Spaniels. Most dogs presented for nonspecific clinical signs such as vomiting, anorexia and lethargy. Abdominal pain, icterus and hyperthermia were the most common findings on physical examination. All dogs except one had serum elevation of total bilirubin and/or alkaline phosphatase, alanine aminotransferase and gamma glutamyl transferase. All dogs were diagnosed with a gallbladder mucocele upon histologic and/or macroscopic evaluation. Ultrasonographically, mucoceles are characterized by the appearance of the stellate or finely striated bile patterns and differ from biliary sludge by the absence of gravity dependent bile movement. On ultrasound, gallbladder wall thickness and wall appearance were variable and nonspecific. The cystic or common bile duct were normal sized in 5 dogs although all 5 had evidence of biliary obstruction at surgery or necropsy. Loss of gallbladder wall integrity and/or gallbladder rupture were present in 50% of the dogs, all located in the fundus. Gallbladder wall discontinuity on ultrasound indicated rupture whereas neither bile patterns predicted the likelihood of gallbladder rupture. Pericholecystic hyperechoic fat or fluid were suggestive of but not diagnostic for a gallbladder rupture. Cholecystectomy appears to be an appropriate treatment for mucoceles, if not to treat a gallbladder rupture, at least in most dogs to prevent it since gallbladder wall necrosis was identified by histology in 9 of 10 dogs. Mucosal hyperplasia was present in all gallbladders examined histologically. Positive aerobic bacterial culture was obtained from bile in 6 of 9 dogs. Cholecystitis was diagnosed histologically in 5 dogs and 4 dogs had signs of gallbladder infection solely upon bacterial bile culture. Gallbladder infection was not present with all the mucoceles suggesting that biliary stasis and mucosal hyperplasia may be the primary factors involved in mucocele formation. Based on the results of our study, we suggest two alternate courses of action in the presence of a distended gallbladder with an immobile ultrasonographic stellate or finely striated bile pattern: a cholecystectomy when clinical or biochemical signs of hepatobiliary disease are present or a medical treatment (antibiotics and choleretics) and patient monitoring by follow-up ultrasound examinations when the patient does not have clinical or biochemical abnormalities. An aerobic bile culture should be obtained in all patients, by ultrasound-guided fine needle aspirate or at surgery.

A combination chemotherapy protocol (VELCAP-L) for dogs with lymphoma.

Ninety-eight dogs with lymphoma treated with a 5-drug combination chemotherapy regimen (vincristine, L-asparaginase, cyclophosphamide, doxorubicin, prednisone [VELCAP-L]) were evaluated for pretreatment characteristics predictive for response and remission duration. The complete remission rate was 69%, with a median remission duration of 55 weeks. Dogs with advanced stage of disease, constitutional signs, dogs that were older, and dogs that were dyspneic were less likely to achieve remission. Once in remission, small dogs and dogs without pretreatment thrombocytopenia were likely to have longer remission duration. Toxicoses were frequent, but rarely fatal, and no predictitive factors were found for a dog developing toxicoses. VELCAP-L is an effective treatment for dogs in stage I-III lymphoma, particularly in young, small animals.

Prognosis for dogs with stage I or II splenic hemangiosarcoma treated by splenectomy alone: 32 cases (1991-1993).

A retrospective analysis was performed on the case records of 32 dogs with Stage I or II splenic hemangiosarcoma that were treated by splenectomy alone and that survived the seven-day postoperative period. Median survival time for these 32 cases was 86 days (mean, 116 days; range, 14 to 470 days), and the one-year survival rate was estimated to be 6.25%. Survival was not influenced by signalment, presenting signs, stage of disease, or clinicopathological findings. The data provides a basis from which to evaluate adjuvant chemotherapy for splenic hemangiosarcoma that is confined to the spleen macroscopically.

Ultrasonography of canine gastric epithelial neoplasia.

Signalment, clinical and ultrasonographic findings from 16 dogs with histologically confirmed gastric epithelial neoplasia were reviewed. The most common clinical findings were vomiting, anorexia and weight loss. Hematemesis and melena were uncommon findings. Ten (10/16) dogs were female and there were four Chows. The most common ultrasonographic findings were transmural thickening of the gastric wall associated with altered wall layering. A poorly echogenic lining often was noted on the innermost and/or the outermost portions of the gastric wall, separated by a more echogenic central zone. The distribution of these changes was variable. This ultrasonographic feature, called pseudolayering, was present in 14 dogs. It was believed to most likely correlate to the unevenly layered tumor distribution noted histopathologically. The maximum wall thickening ranged from 1 cm to 2.7 cm. Regional lymphadenopathy was identified ultrasonographically in 15 dogs. Ultrasound-guided fine-needle aspiration biopsy or automated microcore biopsy, endoscopic biopsy, surgical biopsy or necropsy resulted in the diagnosis of carcinoma in 15 dogs and of carcinoid tumor in one dog. The results of this study suggested that ultrasonography was a useful tool for the detection and diagnosis of canine gastric epithelial neoplasia. Furthermore, ultrasonography can assist in obtaining diagnostic samples and in clinical staging of the tumor.

Retrospective ultrasonographic evaluation of adrenal lesions in 26 dogs.

A review was performed of ultrasonographic findings in 26 dogs with confirmed adrenal lesions. Adrenal shape, size, echogenicity, laterality, and the presence of vascular invasion were evaluated. Histopathologic diagnoses were obtained in all dogs. Adrenal lesions were confirmed as pheochromocytomas (9), adenocarcinomas (6), a poorly differentiated blastoma (1), bilateral adrenal metastases of a carcinoma (1), adenomas--one of which was bilateral--(4) and hyperplasia (6). Size and shape were extremely variable and not specific to lesion type. There was a tendency for pheochromocytomas (7), adenocarcinomas (5) and poorly differentiated blastoma (1) to be rounded masses. Adenomas (4), hyperplasia (7) and adrenal metastases (2) presented predominantly as nodules. No specificity in echogenicity was noted. Mineralization and bilaterality were present in both benign and malignant lesions. Vascular extension or the presence of a thrombus were suggestive but not specific signs of malignancy. Based on our preliminary study, ultrasonography is an effective method for localizing adrenal lesions and is helpful in assessing their extension. However, no definitive differentiation between benign and malignant lesions was possible using ultrasonographic criteria alone.

Radiotherapy of incompletely resected, moderately differentiated mast cell tumors in the dog: 37 cases (1989-1993).

Thirty-seven dogs with moderately differentiated, cutaneous mast cell tumors had incomplete surgical excisions as determined by histopathology, but no gross evidence of tumor. All dogs were irradiated to a total dose of between 46.2 and 48.0 Gy using either an orthovoltage source (n = 20) or a linear accelerator (megavoltage) (n = 17). Radiation was delivered to an area bordered by margins of 3 cm or greater around the surgical scar. The mast cell tumors had not recurred in 97% of dogs by one year after radiation therapy and had not recurred in 93% of dogs by three years after radiation. Both orthovoltage and megavoltage radiation provide excellent local control of moderately differentiated mast cell tumors in dogs.

Helicobacter mustelae-associated gastric adenocarcinoma in ferrets (Mustela putorius furo).

Helicobacter pylori in humans is associated with active, chronic gastritis, peptic ulcer disease, and most recently has been linked epidemiologically to gastric adenocarcinoma. A related organism, Helicobacter mustelae, naturally infects ferrets and also causes a persistent gastritis, a precancerous lesion, and focal glandular atrophy of the proximal antrum. In this report, we document the clinical presentation and histopathologic confirmation of H. mustelae-associated gastric adenocarcinoma in two middle-aged male ferrets. The ferret appears to be well suited to study the pathogenesis of naturally occurring Helicobacter sp.-induced gastric adenocarcinoma.

Evaluation of a multidrug chemotherapy protocol (ACOPA II) in dogs with lymphoma.

A chemotherapeutic protocol using cyclophosphamide, vincristine, prednisone, doxorubicin, and L-asparaginase (ACOPA II) was evaluated in dogs with lymphoma. The response rate for 68 dogs treated with ACOPA II (complete remission [CR] 65%, partial remission [PR] 10%) was lower than that for 41 dogs treated with a related protocol previously evaluated (ACOPA I; CR 76%, PR 12%). Initial treatment with doxorubicin and prednisone did not decrease the prevalence or severity of toxicity during induction. The mortality during induction was 22%. The median duration of CR for dogs treated with ACOPA II was 9 months, with 40% still in remission at 1 year and 21% at 2 years. The rate of CR was lower for dogs with signs of illness at presentation (substage b) and for dogs weighing less than 15 kg. Age was negatively correlated with survival time and duration of remission. Dogs with immunoblastic lymphoma had a more favorable prognosis than did those with lymphoblastic lymphoma. Survival times were also longer for dogs in substage a at presentation. Seven dogs in which treatment was discontinued while in remission had comparable remission duration to that achieved by dogs receiving long-term maintenance chemotherapy.

A light microscopical, ultrastructural and immunohistochemical study of spindle-cell adrenocortical tumours of ferrets.

Twelve adrenocortical tumours with a variable spindle-cell component in ferrets (six spayed females, three intact females, two castrated males, and one intact male) were examined by light microscopy. One tumour with a moderate spindle-cell component was examined ultrastructurally, and three tumours were studied immunohistochemically. Light microscopy revealed a spindle-cell component in the tumours that varied from a few such cells occupying the stroma between packets of adrenocortical cells to cells in such large numbers that they formed almost the entire substance of the tumour. By light microscopy these spindle cells resembled smooth muscle cells, and the ultrastructural findings, particularly the presence of thin contractile filaments, suggested that the spindle cells were of smooth muscle origin. Immunohistochemical staining revealed that the spindle cells were negative for cytokeratins and S-100 protein but positive for smooth muscle actin. Desmin was readily demonstrated in two tumours but not in the other examined. Vimentin was variable, generally producing a small to moderate amount of reaction product.

Cutaneous amyloidosis in a horse with lymphoma.

A horse with malignant lymphoma (histiolymphocytic) and cutaneous amyloidosis is described. The lymphoma involved the dura mater of the spinal cord and some of the peripheral lymph nodes. Multifocal amyloid deposits were present in the skin and subcutis of the ventral abdomen but not within the lymphoma cell infiltrates or in the viscera.

Comparison of fibrosarcomas that developed at vaccination sites and at nonvaccination sites in cats: 239 cases (1991-1992).

Questionnaires were sent to veterinarians who had submitted a fibrosarcoma from a cat to the surgical pathology services of the veterinary schools of the University of Pennsylvania and Tufts University between Jan 1, 1991 and June 30, 1992. Questionnaire items included signalment, FeLV and feline immunodeficiency virus status, site of sarcoma, vaccination site, vaccines used, treatment, biologic behavior of the tumor, and final outcome. Data were analyzed, using Student's t-test for continuous data, chi 2 test for categoric data, and log-rank test for survival estimates. Comparing results for cats with vaccination-site (VS) tumors and nonvaccination-site (NVS) tumors, we determined that VS tumors developed in younger cats and were larger than NVS tumors. Although VS sarcomas were biologically aggressive and redeveloped more often than NVS sarcomas, metastasis was not detected, and cats with VS tumors survived longer than cats with NVS tumors. Vaccination-site sarcomas developed in cats after injection of many types of vaccines, administered singularly or in combination. Of the cats in the VS group administered a single vaccine, 37% were given rabies, 33% were given feline viral rhinotracheitis/calicivirus/panleukopenia virus, and 30% were given FeLV vaccines. Cats with VS tumors were more likely to have received FeLV vaccine and less likely to have received rabies vaccine than those with NVS tumors. Although vaccines produced by certain manufacturers were used most often in cats with VS and NVS sarcomas, it was believed that this probably represented marketing practices and brand popularity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytosine arabinoside as a single agent for the induction of remission in canine lymphoma.

Cytosine arabinoside (AraC) was administered as a continuous IV infusion to 15 dogs with malignant lymphoma at a dose of 300 mg/m2/d for 2 consecutive days. Dogs were re-examined 7 d after treatment for response to therapy and for hematologic toxicity. Regardless of response, all dogs were started on combination chemotherapy at this time. Other toxicities were reported by owners. No dog responded objectively to Ara-C treatment, although 1 dog with circulating lymphoblasts had partial regression of lymphadenopathy but persistent blastemia. Thrombocytopenia (platelet count < 200,000/microL) 7 days posttreatment was the most commonly encountered hematologic toxicity, occurring in 10 of 14 dogs. Three of these 10 dogs were also mildly neutropenic (neutrophil counts of 2000 to 3000 cell/microL). Nonhematologic toxicity occurred in 8 of 15 dogs and was principally gastrointestinal in nature and mild in severity. Cytosine arabinoside at a dose of 300 mg/m2/day was not considered an active drug for the induction of remission in dogs with lymphoma.

Tail chasing in a bull terrier.

A Bull Terrier that was continuously chasing its tail was examined clinically, electroencephalographically, and by computed tomography of the head. The dog was also given test treatments with an anticonvulsant (diazepam) and a pure opioid antagonist (naloxone). The dog appeared to be hysterical and dissociated from its surroundings. Electroencephalography revealed a seizure pattern that was most marked over the temporal lobe, and computed tomography revealed mild hydrocephalus. Diazepam effectively controlled tail chasing, whereas naloxone did not. The dog was discharged on anticonvulsant therapy but subsequently had to be euthanatized when aggression developed. Results of examination and treatment have led the investigators to propose a hereditary mechanism for tail chasing, perhaps related to zinc malabsorption.