For evaluation of the effective preanesthetic medication method, we compared three treatments for 30 cats: intramuscular administration of combination of medetomidine at 500 μg/m² - butorphanol at 0.2 mg/kg (group mid-Med+low-Btr: n=10), medetomidine at 250 μg/m² - butorphanol at 0.4 mg/kg (group low-Med+high-Btr: n=10) and medetomidine alone at 1,500 μg/m² (group high-Med: n=10). All cats were performed ovariohysterectomy or orchidectomy for under the inhalation anesthesia of isoflurane by using an anesthetic mask after the preanesthetic medication described as above. While decreases of heart rate, temperature drops and elongation of arousal time was found for high-Med and mid-Med+low-Btr, those responses were not found under the use of low-Med+high-Btr. As side effects, some cats with high-Med vomited after the premedication, but no cats vomited when they are premedicated with medetomidine - butorphanol combination. In addition, we observed clinically useful sedative effect for all cats in these preanesthetic medication. Some cats with high-Med got excited slightly when and after the recovery from anesthesia, but we rarely found such effects for medetomidine - butorphanol combination groups. We conclude that it is useful for reasons to use the medetomidine-butorphanol intramuscular administration as a preanesthetic medication: obtaining good quality of sedative effect, preventing vomiting induced by medetomidine and smooth recovery from anesthesia.

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Relationship between tumor size and histological invasiveness as prognostic indicators was investigated in 94 canine epithelial mammary tumors. All patients classified into 3 groups according to T category of WHO system (T1; <3 cm, T2; 3-5 cm, T3; >5 cm) or histological staging of tumor cell invasion (S1; no invasion, S2; stromal invasion, S3; vascular or lymph node invasion). Significant differences (p<0.05) of survival time were detected among all 3 groups in each factor. Larger tumors tended to have more advanced histological stages: the rates of S3 in T1, T2, and T3 groups were 12.1, 40.9, and 71.4%, respectively. In 40 cases of invasive tumors (S1 or S2), survival time of T3 cases was significantly shorter than that of T1 (p=0.016) or T2 (p=0.015) cases, suggesting prognostic value of tumor size in the invasive tumor cases. When the patients classified into 4 groups (class1 to 4) according to the mortality rates calculated by combination of T category and histological stage, significant differences (p<0.05) of survival time were detected among the all classes except for between class 3 and 4 (p=0.056). These results suggest that both tumor size and histological stage are important prognostic factors for canine epithelial mammary tumors and that, although larger tumors tend to have more advanced stage, combination of these factors allows more accurate predilection of the patient's prognosis.

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A 9-year-old Labrador retriever dog was presented with a history of cystitis such as hematuria and urinary incontinence. Abdominal radiography revealed a large mass in the abdominal cavity. Ultrasonography revealed fluid retention and echogenic mass within the mass. On intravenous urography, a cystic bladder and both ureters were located caudal and dorsal to the mass respectivly. On laparotomy, the mass was attached to the prostate, ureters and surrounding tissues, which was removed. The mass was diagnosed as a prostatic cyst. Histologically, the wall of the mass was consistent with fibrous tissue and the prostatic tissue with bone metaplasia was confirmed in the mass within the cyst. Because the prostatic tissue was observed in the mass, castration was performed. The patient has been in good health without any recurrence of clinical signs 35 months after surgery.

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A 10-year-old female Shih-Tzu presented with severe ascites and pleural effusion. Exploratory laparotomy revealed a bilateral ovarian mass and ovariohysterectomy was performed. Histopathologically, a diagnosis of ovarian papillary adenocarcinoma with peritoneal metastasis was made. The abdominal and pleural effusions both resolved after surgery but recurred 9 months later. Histopathological examination of the peritoneum and pleura indicated tumor recurrence. Intracavitary cisplatin chemotherapy led to 4-month resolution of the effusion, after which the disease progressed with no favorable response to chemothrapies. The dog died 23 months after the first surgery.

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