Effect of Tamoxifen Citrate on Canine Immobilization (Disuse) Osteoporosis

The effect of tamoxifen citrate on bone mass in immobilization osteoporosis was studied in 11 growing dogs. Immobilization osteoporosis was induced by fiberglass cast immobilization of the right hindlimb for 28 days, while the left hindlimb served as a nonimmobilized control. Six dogs received tamoxifen citrate (1.5 mg/kg per os) once daily for 28 days; five dogs received no treatment. All dogs were euthanatized on day 28 and bone samples were collected. Bone mineral content of the distal tibial metaphysis of casted and uncasted limbs was measured by single photon absorptiometry. Immobilization resulted in a significant reduction in bone mass in the casted limb of untreated and tamoxifen-treated dogs. However, tamoxifen-treated dogs had less severe immobilization osteoporosis than untreated dogs. The calculated bone mass sparing effect of tamoxifen was 24.4%. Because of the complexity of pathologic bone remodeling, use of a single therapeutic agent may not be the optimal means of preventing bone loss associated with immobilization.     

The Use of Prophylactic Penicillin in Orthopedic Surgery: A Clinical Trial

Thirty dogs presented for open surgical repair of fractures were treated with prophylactic penicillin. Thirty other dogs with fractures were not given antibiotics. Each animal was monitored by clinical signs and deep aspiration culture, and followed for 6 months or until the fracture had healed and the implants had been removed.
No statistically significant difference was found in the number of clinical infections or positive bacterial cultures for each group. Differences in results between categories, such as type of injury, implants used, and surgeon, also were not statistically significant.     

Excision of Intralaryngeal Granulation Tissue in 25 Horses Using a Neodymium:YAG Laser (1986 to 1991)

Granulation tissue masses arising from the axial surface of the arytenoid cartilage in 25 horses were excised using a contact neodymium:yttrium aluminum garnet laser. A technique that eliminated the need for general anesthesia or laryngotomy was developed for transen-doscopic removal of the masses in standing horses. Nineteen racehorses made abnormal upper respiratory tract noises or their performance was decreased, whereas six horses not used for racing had a history of stertor (five horses) or epistaxis after nasogastric intubation (one horse). Thoroughbreds were significantly (p = .0126) overrepresented compared with the hospital population. The granulation tissue masses were successfully excised and the defect healed in all 25 horses, although a second excision of granulation tissue regrowth was necessary in four horses. In 21 horses, the underlying chondrosis did not progress appreciably. In four horses with preexisting moderate arytenoid cartilage thickening and concurrent laryn-geal abnormalities, the surgery site healed but the underlying chondrosis progressed substantially. Twelve of 19 (63%) racehorses returned to race at least three times after the surgery. Of the 19 racehorses, five had only slight arytenoid cartilage involvement whereas 14 had moderate cartilage thickening or concurrent laryngeal pathology. All five horses with slight apparent arytenoid cartilage involvement and no concurrent laryngeal pathology returned to racing. Seven of the 14 horses (50%) with moderate underlying cartilage thickening or concurrent laryngeal pathology returned to racing. The six horses not used for racing returned to their previous activity without further respiratory problems.     

Histopathology of experimental brucellosis in rams following vaccination with Brucella ovis

Lesions induced by inoculation of Brucella ovis into the epididymis were compared in rams previously vaccinated with B. ovis bacterin and unvaccinated rams. Inoculation of killed B. ovis did not produce significant lesions in either group whereas prior vaccination exacerbated epididymal lesions following inoculation of live B. ovis. Increased numbers of neutrophils, macrophages and lymphocytes were present in the interstitium and neutrophilic infiltration of the epididymal duct epithelium and intraepithelial cyst formation was more prominent. The inflammatory response surrounding extravasated spermatozoa was more severe in vaccinated rams but it was not determined if the response was directed at spermatozoa or intermixed brucellae, or both.     

Castration of Horses with Primary Closure and Scrotal Ablation

Fourteen horses and one pony, 1 to 16 years of age, were castrated with a technique designed to promote primary healing and ablation of the scrotum following removal of descended testicles. Twenty-six testicles (10 nondescended, 15 normal descended testicles, and 1 neoplastic descended testicle) were removed. Nondescended testicles were removed through a skin incision over the external inguinal ring. Descended testicles were removed, and the scrotum was ablated by excision of the ventral scrotum. All testicles were removed by emasculation. The common vaginal tunic was not opened prior to emasculation of the descended testicles, and transfixation liqation sutures were used in only two horses. All incisions were closed with multiple layers of synthetic absorbable sutures in the subcutaneous and subcuticular tissues. All incisions healed by primary intention, and 14 recovered without complications. As a result of incomplete scrotal ablation, one horse had temporary lameness and swelling of the scrotal area that resembled the presurgical appearance.     

Colopexy of the Left Large Colon to the Right Large Colon in the Horse

Three colopexy techniques were examined in 11 normal horses to determine which would prevent recurrence of targe colon displacement and volvulus. The medial free band of the left ventral colon was sutured to the medial free band of the right ventral colon (technique A). The free band of the left dorsal colon was sutured to the free band of the right dorsal colon (technique B). In technique C, both the ventral and dorsal colon were sutured as in techniques A and B, and the pelvic flexure was sutured to the mesocolon between the right dorsal and right ventral colon. Absorbable (surgical gut) and nonabsorbable (polypropylene) suture material were compared.
One horse from each group was euthanized 2 weeks and 6 months after surgery. The position of the colon and the integrity of the colopexy were examined. At necropsy, attempts were made to produce displacement and volvulus of the colon. In the remaining horses, exploratory celiotomy 1 year after surgery was used to examine the integrity of the colopexy.
Although all horses initially lost weight after surgery, all but one began gaining weight 2 to 4 weeks later and had attained their preoperative weight by 6 months. The horse that continued to lose weight was euthanized 2 months after surgery. Numerous small colon, omental, and large colon adhesions were found at necropsy.
For all colopexy techniques, the colopexy adhesion remained short and intact at polypropylene suture sites. At surgical gut sites, the adhesion had lengthened by 6 months and was absent at 1 year. At necropsy, all colopexies prevented manual displacement of the large colon and volvulus of the colon at the sternal and diaphragmatic flexures. The colopexies did not prevent manual creation of volvulus at the base of the colon. Technique A was the easiest to perform.     

Diversity,endemism and conservation of the freshwater crabs of China (Brachyura: Potamidae and Gecarcinucidae)

China lies at the heart of the global center of freshwater crab diversity in tropical Asia, where the 2 most diverse families occur: Potamidae (505 species, 95 genera) and Gecarcinucidae (344 species, 59 genera). China stands out as the country with the highest species richness of freshwater crabs globally. Its fauna comprises 243 species in 37 genera and in 2 families, and species discovery is still progressing at a rapid pace. The vast majority of the species are distributed in southwest, south central and eastern China in the Oriental zoogeographical region. China also stands out as having a highly endemic freshwater crab fauna at the species level (96%) and at the genus level (78%). Although the recent International Union for the Conservation of Nature (IUCN) red list conservation assessment found only 6 out of 228 species (2%) to be threatened (5 potamids and 1 gecarcinucid), the majority (more than 75%) of Chinese species are regarded as data deficient, so the number of threatened species is likely to be a serious underestimate. Threats from increasing habitat destruction and pollution are a major concern due to the rapidly growing economy and massive developments taking place in China. There is therefore an urgent need for increased species exploration and for the development of a conservation strategy for China's threatened (and potentially threatened) endemic freshwater crab species.     

Billroth II Gastrojejunostomy in Dogs Stapling Technique and Postoperative Complications

Billroth II gastrojejunostomy was performed with surgical staplers in 6 dogs that were not irradiated and in 11 dogs that subsequently received radiation to the pancreas and proximal part of the duodenum. The dogs were monitored clinically for 135 days and then euthanatized and necropsied. Each gastrojejunostomy site was preserved in formalin and the stomal diameter was measured. No mechanical complications were encountered with the use of surgical staplers and no leakage was observed at the staple closure sites before abdominal closure. All dogs vomited approximately 100 ml of coagulated blood 4 to 8 hours after surgery, and 300 to 400 ml of brown fluid after approximately 24 hours. Vomiting was the most common clinical finding after the first 24 hours. Vomiting was subjectively graded from 1 to 3 with grade 1 representing the least severe problem and grade 3 the most severe. Grade 1 vomiting occurred in 12 of 16 dogs that survived 135 days; in the other four dogs, vomiting was classified as grade 2 or 3. All dogs with grade 1 vomiting had stomal diameters of 1.7 to 2.9 cm (mean, 2.2 ± 0.4 cm standard deviation). Dogs with grade 2 or 3 vomiting had stomal diameters of 2.2 to 4.0 cm (mean, 3.2 ± 0.8 cm standard deviation). The difference was statistically significant (p < 0.005). The percentage of weight gained or lost was recorded for each dog. Two nonirradiated dogs gained body weight, whereas the other nonirradiated dogs and all irradiated dogs lost body weight. The overall mean loss of body weight of dogs with grade 1 vomiting was 16.7 ± 12.0% (± standard deviation), compared with 35.5 ± 6.6% (± standard deviation) for dogs with grade 2 or 3 vomiting; the difference was significant (p < 0.01). Routinely scheduled clinical laboratory test results were within normal limits in nonirradiated dogs. Clinical problems other than vomiting and weight loss were anorexia, gastric dilatation, and diarrhea. One nonirradiated dog died on day 56 after rupture at the gastric stump staple line.     

Comparison of Stainless Steel Fascial Staples and Polypropylene Suture Material for Closure of the Linea Alba in Dogs

Five centimeter segments of the linea alba in mature, female, mixed breed dogs were incised and then approximated with either stainless steel fascial staples or size 0 polypropylene suture material. Breaking strength of the linea alba closures was determined at 0 (Phase I, 18 dogs) and at 7,14, and 31 days (Phase II, 18 dogs). Histology and videointeractive planar morphometry were used to evaluate healing of the linea alba. Breaking strength and histologic and morphometric variables were analyzed statistically using analysis of variance in a split plot design. In a clinical trial, 20 cm linea alba incisions were approximated with stainless steel fascial staples after elective ovariohysterectomy in mature, female, mixed breed dogs (Phase III, eight dogs). The dogs were evaluated at 1, 2, 7,14, 31, 90, and 180 days. Linea alba incisions approximated with polypropylene suture material were significantly stronger than linea alba incisions approximated with stainless steel fascial staples on day 0. There was no significant difference between breaking strength values, histologic, and morphometric appearance of linea alba incisions closed with stainless steel fascial staples or polypropylene suture material when compared 7,14, and 31 days after surgery. All of the dogs in the clinical trial appeared to be normal at all evaluation times. Approximation of linea alba incisions with stainless steel fascial staples compares favorably to closure with a simple continuous pattern of polypropylene suture material with regard to breaking strength, clinical, histologic, and morphometric appearance.