As premedication, we administered medotomidine and medazolam (MM) to 48 dogs classified as grade I or II according to the Classification of the American Society of Anesthesiologists. Following endotracheal intubation, anesthesia was maintained by administration of isoflurane. We measured the arterial blood gases of all dogs during spontaneous ventilation (pre-stage). After that, the ventilation of 35 dogs was changed to artificial ventilation (Group 1), and the remaining 13 dogs were left unchanged (Group 2). After 15 to 30 minutes, arterial blood gases in the dogs of Groups 1 and 2 were measured again (post-stage). The measured values were compared and analyzed. In Group 1, post-stage values of pH, PaCO2, PaO2/FIO2 (P/F ratio) and alveolar-arterial oxygen difference (P (A-a) O2) had been significantly improved compared with pre-stage values. In Group 2, there were no significant differences in pH, PaCO2, P/F ratio, or P (A-a) O2 between pre-and post stages. In both groups, there were no significant differences in saturated base excess, lactate, or electrolytes. Consequently, it was concluded that inhalation during spontaneous ventilation after preanesthetic medication with MM may cause an increase in PaCO2 and a lowering of oxygenation of the lung, and that artificial ventilation can improve these symptoms. In conclusion, during the inhalation anesthesia of a dog with isoflurane and preanesthetic MM, artificial ventilation should be the procedure of choice.
The purpose of this study was to estimate the effective dose of radiation to which veterinary staff were exposed during general radiographic procedures. The Ordinance for Enforcement of Veterinary Practice Act has published dose limits of occupational exposure in accordance with the International Commission on Radiological Protection. According to the recommendation, exposure of any radiation worker must be maintained beneath a certain dose limit, that is, the dose must not exceed 20 mSv per year for 5 consecutive years. But there is danger that single dosimetry under a lead apron might lead to underestimation of the dose that a radiation worker actually received. Calculation by single dosimetry is done as if the whole body was radiated uniformly, although protective shielding such as a lead apron covers the body widely. The Act requires double dosimetry to estimate the effective dose of radiation more exactly, and requires that a radiation worker should wear an additional dosimeter at the location at which he or she receives the highest deep-dose equivalent. Experimentally, using a double dosimitry model, we tested and calculated the effective dose for veterinary staff: it was 2.4 micro Sv per one radiograph. By extrapolation, it is estimated that the limit of 20 mSv per year will be exceeded when, for example, one veterinary nurse is engaged in holding an animal down on the stand to take one radiograph, more than 160 times per week, excluding exposure of the hands.
A diagnosis of granulomatous pneumonia was made in two cats. Case 1 was an 8-year-old castrated mixed-breed cat which was referred to our clinic for a check-up. Thoracic radiography showed a mass, which was removed surgically. The cat has been well without recurrence after surgery. Case 2 was a 7-year-old castrated mixed-breed cat with a history of respiratory distress when excited. Radiography showed multiple masses in the lung, and further examinations such as computed tomography and fine-needle aspiration/clonal expansion were done. Based on these, we diagnosed the disease tentatively as well-differentiated lymphoma, and started chemotherapy, but it was ineffective. By biopsy, the disease was diagnosed as granulomatous pneumonia. After that, we could only treat the cat with prednisolone and cyclosporine.
In feline hypertrophic cardiomyopathy (HCM), we hypothesized that a decrease in local release of prostacyclin (PGI2) and/or an unbalanced ratio of thromboxane A2 to PGI2 in the myocardium may induce microcirculatory disturbance, and aggravate the disease, we performed long-term treatment with beraprost sodium (BPS), a PGI2 derivative, on two cats with HCM, and made an echocardiographic examination of its effect morphologically and functionally. The left ventricular posterior wall and interventricular septum became thinner; The left ventricular end-systolic and end-diastolic diameters, left ventricular end-systolic and end-diastolic volumes, left ventricular fractional shortening, and left ventricular ejection fraction were remarkably improved, leading to an increase in cardiac output. Consequently, BPS might be an effective agent for feline HCM.
A female Shiba dog, ten years and eight months old, was referred to our hospital for further examinations and treatment. Erythrocytosis and the presence of a liver mass had been diagnosed at a previous clinic. Hematology showed erythrocytosis at our hospital as well. As the single mass in the right lateral lobe was confirmed by ultrasonography and computed tomography, the relevant lobe was removed completely. Histopathologically the mass was diagnosed as a hemangiosarcoma. Beginning ten days after surgery, the dog was given 30 mg/m2 of doxorubicin every three weeks, six times in total. Until now the dog has been in good condition without medication for four years. Erythrocytosis disappeared after surgery.