Ten-day-old chicken embryos were inoculated with isolates of myeloblastosis-associated virus that induced osteopetrosis of slow or rapid onset. Bursa of Fabricius, thymus, spleen, bone marrow, kidney, liver, and lung were examined at 15, 17, and 19 days in ovo and at 7 and 25 days after hatching by histologic and immunoperoxidase techniques. Tissues from 19-day-old in ovo embryos also were examined by electron microscopy. The lymphoid organs of embryos inoculated with all isolates manifested changes suggesting inhibited development. Virus was most often associated with macrophages, heterophils, and non-lymphoid stromal cells in these organs. Viral particles and antigen were abundant in tissues from embryos inoculated with slow-onset isolates, but cell necrosis was infrequent. The kidney and bursa had especially abundant viral particles and antigen. Conversely, viral particles and antigen were minimal in tissues from embryos inoculated with the rapid-onset isolate, yet intravascular cellular thrombi, substantial cell necrosis, and increased heterophils and hemocytoblasts were found.

The cardiopulmonary effects of dorsal recumbency were studied in awake cows restrained for surgical correction of left displaced abomasum. During the recumbent period, Pa(O2), Pa(CO2), arterial pH, and base excess values were significantly decreased. Heart rate, respiratory rate, blood hemoglobin concentrations, and rectal temperature increased significantly.

The fiber type, fiber size, and capillary geometric features were determined from the center of the proximal half of the left and right semitendinosus muscles in 5 mixed-breed dogs, 5 hound-type dogs, and 5 Beagles. There were no significant differences between the left and right muscles of each dog. Comparisons among the 3 groups of dogs revealed that the hound-type dogs had the largest fibers (type I and type II); however, the 3 groups were similar in their fiber-type percentages and their capillary geometric features.

Pituitary function and short-term clinical effects after transsphenoidal hypophysectomy were investigated in clinically normal dogs. In study, I, 8 dogs were given polyionic fluids IV during the first 12 hours after surgery. In study II, 4 dogs were given polyionic fluids IV and glucocorticoid supplementation for 7 days. Pituitary function was assessed by evaluating basal ACTH concentrations and results of a growth hormone stimulation test before and 1 and 12 weeks after hypophysectomy, an ACTH stimulation test, a thyrotropin-releasing hormone-stimulation test, and a modified water deprivation/vasopressin response test before and 1, 4, 8, and 12 weeks after hypophysectomy. Gross and histologic evaluations of the surgery site, thyroid and adrenal glands, and skin were done at 12 weeks after surgery. Four dogs from study I died within 27 hours after hypophysectomy. Postmortem examinations of these dogs revealed liver and lung congestion compatible with circulatory collapse. None of the dogs in study II died. For the surviving dogs in both studies, diabetes insipidus developed immediately after hypophysectomy and resolved within 2 weeks. Hypernatremia also developed immediately after hypophysectomy and resolved by 1 week. Production of ACTH was evident at 1 and 12 weeks after hypophysectomy in all dogs, and results of ACTH stimulation tests after surgery were not notably different from results obtained before surgery. Results of thyrotropin-releasing hormone stimulation and growth hormone-stimulation tests supported the diagnosis of hypothyroidism and hyposomatotropism attributable to hypophysectomy. Histologic examination revealed thyroid atrophy, epidermal and dermal atrophy, and normal adrenal glands in all dogs and remnants of the hypophysis in 2 dogs from study I. Continued ACTH production suggested that complete hypophysectomy was not accomplished in any dog.

Peritoneal lavage was performed on ponies to determine the effect on peritoneal surfaces. Lavage solution (20 L) was introduced into each pony's peritoneal cavity through catheters placed in the paralumbar fossa, and the solution was removed by drainage from the ventral portion of the abdomen. Six ponies each were lavaged with sterile saline (0.9% NaCl) solution, sterile saline solution containing 5 X 10(6) U of potassium penicillin and 3 g of neomycin or povidone-iodine diluted to 3% by volume with sterile saline solution, and 3 ponies were lavaged with povidone-iodine diluted to 10% with sterile saline solution. Peritoneal lavage catheters were inserted in 3 control ponies, but lavage fluids were not administered. Peritoneal fluid specimens were collected at 6, 24, 48, and 96 hours after lavage. Nucleated cell counts, RBC counts, total protein determinations, and cytologic analysis were performed. The ponies were euthanatized at 96 hours, and representative sections of the peritoneum were examined. Lavage with saline solution and saline solution with antibiotics induced a mild, transient inflammatory response in the peritoneal fluid, with minimal or no changes observed at necropsy. Solutions containing povidone-iodine induced chemical peritonitis, which was severe in ponies lavaged with 10% povidone-iodine solutions. Peritoneal lavage with povidone-iodine solutions as dilute as 3% cannot be accomplished without causing inflammation of peritoneal surfaces.

Dissection and injection studies in canine cadavers and in anesthetized dogs were conducted to determine the feasibility of using the latissimus dorsi, gracilis, and rectus abdominus muscles as musculocutaneous free flaps. Lengths of vascular pedicles for the latissimus dorsi (2 +/- 0.8 cm), gracilis (1.8 +/- 0.8 cm), and rectus abdominus (1.9 +/- 0.9-cm cranial deep epigastric, 1.7 +/- 0.5-cm caudal deep epigastric), as well as arterial diameters (1.28 +/- 0.31-mm thoracodorsal for the latissimus dorsi, 1.10 +/- 0.33-mm muscular branch for the gracilis, 1.25 +/- 0.25-mm cranial deep epigastric and 1.26 +/- 0.32-mm caudal deep epigastric for the rectus abdominus) were considered satisfactory for microvascular transfer. Fluorometry demonstrated overlying cutaneous perfusion in all flaps based on their muscle vascular pedicles, with the exception of the rectus abdominus flap based on the caudal deep epigastric artery. In this instance, up to 20% of the cutaneous element had questionable or no perfusion.

Strangulation obstruction was induced in anesthetized ponies for periods of 2 and 3 hours by clamping 45-cm segments of jejunum and associated veins (venous strangulation obstruction) and arteries and veins (arterial and venous strangulation obstruction). Four segments were studied in each of 7 ponies allowed to survive 12 hours, 2 segments in a pony that was allowed to survive 1 hour, and 1 segment in each of 10 ponies allowed to survive 42 days after the strangulation periods ended. Fifteen minutes after the periods of strangulation obstruction ended, the viability of test segments was assessed by clinical judgment (40 segments), fluorescein fluorescence (40 segments), and Doppler ultrasound (32 segments). Because thetest segments were normal at necropsy in long-term survivors, all segments were designated as viable. The overall accuracy of the methods used to predict viability was 88% for Doppler ultrasound and 53% each for clinical judgment and fluorescein fluorescence (P less than 0.005). Failures in the last 2 techniques could be attributed to their tendency to score venous strangulation obstruction segments as nonviable (90% for each). Doppler ultrasound was 94% accurate in these segments.

Healing of cancellous bone graft donor sites in the proximal tibial metaphysis of 12 healthy adult dogs was studied histologically. Cancellous bone was curetted from the metaphysis of the proximal end of the tibia, via a 1-cm diameter circular opening in the medical cortex. A hematoma and fibrovascular tissue filled the bone defect at 2 weeks. At 4 and 8 weeks, endosteal callus, composed initially of cartilage and woven bone and later of lamellar bone, filled the marrow cavity. At 12 weeks, the normal structural arrangement of lamellar bone and hematopoietic marrow was reestablished in the marrow cavity. The medial cortex defect was filled only with lamellar trabecular bone. It was concluded that, in adult dogs, a second cancellous bone graft could be collected from the proximal portion of the tibial metaphysis 12 weeks or more after an initial collection.

Serum antibody titers to canine parvovirus (CPV), canine adenovirus-1 (CAV-1), and canine distemper virus (CDV) were measured in dogs with known immunization status. The dogs represented 3 groups: nonvaccinated dogs less than 12 months old; vaccinated dogs less than 12 months old; and adult dogs greater than 12 months old. For practical reasons, the population from which the specimens were obtained could be considered as free from natural infection with CAV-1 and CDV. In nonvaccinated dogs less than 12 months old, antibodies against all 3 viruses were measured at the time the dogs were given their first vaccination. Altogether, 50.7% of the dogs had titer greater than or equal to 1:10 to CPV, and 26.1 and 46.2% had titer greaterthan or equal to 1:8 to CAV-1 and CDV, respectively. The concentration of maternal antibody seemed to be of major importance for failure of immunization with use of inactivated CPV vaccine, but not with CAV-1 and CDV vaccination. In dogs less than 12 months old and vaccinated against CPV infection with inactivated virus, only 11.5% had titer greater than or equal to 1:80. In dogs vaccinated against infectious canine hepatitis and canine distemper, 63.2 and 78.3%, respectively, had titer greater than or equal to 1:16. In adult dogs greater than 2 months old and vaccinated against CPV infection, less than 50% had titer greater than or equal to 1:80, regardless of time after vaccination. There was no significant difference in titer between vaccinated and nonvaccinated dogs. Approximately 60% of these dogs had titer greater than or equal to CAV-1 at all time intervals after vaccination. There was only a weak correlation between decrease of titers and time; this correlation could be explained by the fact that a proportion of the dogs had been vaccinated with inactivated CAV-1 virus. There was, however, no correlation between titer to CDV and time. The percentage of dogs with titer greater than or equal to 1:16 was at least 60%.

Thirty-four preweaning pigs with induced enteropathogenic Escherichia coli diarrhea were treated with electroacupuncture, traditional acupuncture, or neomycin. In the group treated with electroacupuncture, points GV-1, bilateral ST-36, and Bai-hui were stimulated electrically. In the group treated with traditional acupuncture, points GV-1, bilateral ST-36, BL-20, bulb points, bilateral ear tip, and Shan-gen were used. Acupuncture points CV-12 and bilateral ST-25 also were treated with moxibustion (applying heat generated by a burning herb, Artemisia argyi). Hemoacumpuncture also was applied to Shan-gen, bilateral ear tip, and bulb points. Pigs in the third group were given neomycin orally. Five pigs were inoculated with E coli, but were not treated and served as nontreated controls. At postinoculation day 5, 60% of control pigs and greater than 80% of pigs in treated groups recovered from diarrhea. However, at postinoculation day 3, recovery rates for pigs in the control and group treated with electroacupuncture were only 20 and 27.3%, respectively; whereas pigs treated with acupuncture or neomycin attained 81.8 and 71.4% of recovery rates, respectively. Seemingly, traditional acupuncture, but not electroacupuncture, was effective in controlling induced E coli diarrhea in pigs at its early stage.