The purpose of this experiment is to characterize the aftereffects of myelography of canine spinal cords using rabbits, since the distal end of the spinal cord of rabbits is more caudal than that of dogs. Twelve healthy New Zealand White rabbits were divided into 4 groups of 3 animals each : a spinal puncture group, a saline injection group, an iodixanol injection group, and an iohexol injection group. The spinal puncture group consisted of rabbits which received a spinal puncture only. The saline injection group consisted of rabbits which received a spinal injection of saline. The iodixanol group consisted of rabbits which received an isotonic, non-ionic iodine contrast agent, iodixanol®, in the same volume as the saline. The iohexol injection group consisted of rabbits which received a low osmolality, non-ionic iodine contrast agent, inhexol®, in the same volume as the saline and at the same concentration of the iodixanol. Under general anesthesia, myelography was performed via the/umbar 5-6 intervertebral space according to the standard method for dogs. Before and 48 hours after the puncture/injection, the animals' behavior was observed, and neurological reflexes were tested. The damaged areas in the spinal cords were inspected histologically 72 hours after the puncture/injection. The rabbits in the three injection groups were neurologically abnormal. There was a marked difference in the ratio of damaged areas between the puncture group and the saline injection group. These findings indicate that neurological disorders might be caused by physical compression of the spinal tissues due to liquid injection. We suggest that it is necessary to confirm the reverse flow of cerebrospinal fluid through a spinal needle during myelography and that if there is any possibility of the contrast agent being injected into the spinal cord accidentally, the procedure should be stopped at once, and an alternative method of examination should be chosen.
A 12-year-old spayed dog of mixed-breed with a 6-month history of progressive dyschezia was surgically treated successfully. Abdominal palpation, radiography, ultrasonography, and rectal endoscopy revealed the presence of a mass expending from the posterodorsal part of the abdomen to the pelvic cavity, which pressed against the rectum toward the abdominal wall. We tried removing the mass through an abdominal median incision, but found the removal difficult since the mass was attached to the posterior part of the pelvic cavity. We changed our approach, and reached the site from the dorsum of the anus. This time, the mass could be detached with the fingers, and we removed it through the abdominal surgical wound. Pathologically, the mass was dianosed as a leiomyoma. At the present time, 12 months after surgery, there is no evidence of recurrence nor any problem with defecation.
The efficiency of long-term medication of trilostane was evaluated in three dogs with pituitary-dependent hyperadrenocorticism (PDH). Trilostane at 6, 2, or 0.2 mg/kg body weight was given orally to the dogs every 24 hours as an efficient but minimum dose to alleviate polyuria and polydipsia. Twenty to thirty days later, these symptoms were lessened in all dogs. In dogs 1 and 2 with alopecia, newly growing hair was seen six months and four months after the medication started. In dog 1, panting disappeared, and lethargy was improved by the therapy. In all cases, there were no side effects observed, although we had feared that this medicine might have side effects when it was given for a long period of time. Complete blood counts and serum biochemical analyses, and ACTH stimulation tests were performed at each visit. As the therapy advanced, the level of serum ALT, ALP, and TCho, and serum cortisol level after stimulation by ACTH decreased gradually in all dogs. These results suggest that trilostane is efficacious in treating canine PDH.
In a one-year-old male rabbit with anorexia, radiography and ultrasonography showed in the caudal part of the stomach a 35.0×29.7 mm mass, which was found to be two tumors after being removed surgically. The mass was adhered too firmly to the distal colon to remove, so the site of the colon was resected with the mass, and an end-to-end anastomosis was created. The tumors were abscessed with a hairball and feces-like material in them. In bacteria culture tests, gram-negative bacilli, Esherichia Coli, were detected in both tumors. These findings suggest the possibility of perforation of the colon.