Medial Plating for the Repair of Middle and Distal Diaphyseal Fractures of the Humerus in Dogs

Six middle and distal humeral shaft fractures in dogs were repaired by the application of a bone plate along the medial shaft of the humerus. In all animals, clinical and radiographic evidence of normal bone healing was observed. The bone plate and ancillary implants were removed from five dogs by 10 months. In none of the six dogs were any untoward effects of placing the bone plate along the medial shaft of the humerus detected nor were there any difficulties encountered with the medial humeral soft tissues.     

Pharyngeal Mucoceles in Dogs

Eight cases of pharyngeal mucoceles were diagnosed in 49 dogs with salivary mucoceles over a 7 year period. Five of the eight pharyngeal mucoceles were seen in Miniature Poodles. The presenting complaint in all eight dogs was labored breathing, with or without coughing upon excitement or exercise. Diagnosis was made by aspirating a thick mucoid fluid from the pharyngeal swelling. Treatment consisted of resection of the mandibular and sublingual salivary glands on the affected side and aspiration of the mucocele in all eight dogs, and resection of redundant pharyngeal tissue in five dogs. Time to follow-up ranged from 1.5 to 7.5 years. There were no postsurgical complications or recurrences of the mucocele.     

Placement of Multiple Full Pins for External Fixation Technique and Results in Four Dogs

A technique using a third bar and guide clamp was developed to permit reduction and stabilization of distal limb fractures with full pins and two connecting bars, one on each side of the bone. The system uses only single Kirschner clamps. Four distal limb fractures were stabilized using this technique. Closed reduction was used in three dogs to avoid devitalization of fragments and avoid contamination of a closed fracture. The fracture site stability achieved with this configuration allowed early return to weight bearing and rapid bone healing.     

Scapular Sequestrum in a Horse A Case Report

A 15-year-old Morgan mare presented with a draining tract associated with osteomyelitis and sequestration of the medullary cancellous bone of the right scapula. Moderate lameness and muscle atrophy were present. Partial resection of the lateral cortex allowed exploration and debridement of the medullary cavity of the scapula. The mare returned to soundness, the muscle mass returned, but a small discharging sinus persisted.     

Evaluation of Intestinal Staples for End-to-end Anastomosis of the Small Intestine in the Horse

Segments of jejunum that had been subjected to ischemia 1 month previously were resected en bloc in six horses. Everted end-to-end anastomoses were performed by application of double rows of stainless steel staples. The anastomotic sites were examined at 3 weeks, 3 months, 6 months, and 8 months postoperatively. All but one of the horses experienced colic at some point after the second postoperative week. At 3 weeks, there was extensive adhesion and stricture formation associated with the anastomoses. With increasing time postoperatively, there were progressively less severe adhesions and strictures. At 6 and 8 months, there was separation of the muscularis with noticeable thinning at the anastomotic site.     

Atrial Fibrillation Associated with Anesthesia in a Standardbred Gelding

A Standardbred gelding was anesthetized on three occasions over a 3 year period. Anesthesia was induced with xylazine and thiamylal on the first occasion, with xylazine, guaifenesin, and thiamylal on the second, and with acepromazine, guaifenesin, and ketamine on the third. Anesthesia was maintained with halothane during each episode. The horse had atrial fibrillation (AF) after induction of anesthesia on the first two occasions. Because arterial blood pressure remained within normal limits during AF and anesthesia, conversion to normal sinus rhythm with quinidine was not attempted. Reversion to normal sinus rhythm occurred within 12 hours of recovery after each of the first two anesthetic episodes. The gelding remained in normal sinus rhythm throughout the third anesthetic period and recovered uneventfully. Potential causes for AF in anesthetized horses are discussed.     

Effects of Nylon and Polyglactin 910 Suture Material on Perilimbal Corneal Wound Healing in the Dog

The effects of fine suture materials on corneal wound healing in the dog were studied. In 20 dogs, standardized perforating perilimbal clear corneal wounds were made and closed with either monofilament Polyglactin 910 or nylon. Five dogs each were euthanized 8,12,16, and 21 days postoperatively. Results of gross, biomicroscopic, and histologic examinations at 8,12,16, and 21 days showed nylon and Polyglactin 910 to cause similar inflammatory responses. Epithelialization and suppuration around the suture tracts were observed more frequently when Polyglactin 910 was used. Both materials were associated with a foreign body (granulomatous) response. There was no loss of wound integrity with either material. Strengths of the incised corneal tissues with and without the sutures intact were determined. At day 16 postsurgery, there was a statistically significant difference in tissue strengths between cases in which sutures were and were not intact. This difference was not apparent at 21 days postsurgery, which suggested that the suture dependent phase ends between the 16th and 21st postsurgical days. In addition, at day 16 there was no statistical difference between the tissue strength of wounds sutured with nylon or Polyglactin 910. Corneal suture materials studied should remain in place for at least 16 days, and absorbable material is only appropriate if it retains tensile strength for 16 days.     

Retrobulbar Block in Combination with General Anesthesia for Equine Ophthalmic Surgery

The use of retrobulbar block in conjunction with general anesthesia was evaluated in the horse. A prospective study of 12 cases fulfilling criteria for application of retrobulbar block was compared to a retrospective survey of 25 cases (control group) in which retrobulbar block was not performed. Retrobulbar block was done using a modified Peterson technique and 2% lidocaine HCI without epinephrine. In the control group, four horses exhibited signs compatible with initiation of the oculocardiac reflex; three horses developed bradyarrhythmias and hypotension during global traction related to enucleation, and cardiac arrest occurred in one horse during cataract extraction. In the retrobulbar block group, one horse developed bradyarrhythmia subsequent to retrobulbar block.     

Physical and biological consequences of a climate event in the central North Pacific

Climatic changes over the North Pacific which began in the mid 1970s, peaked in the early 1980s, and ended by the late 1980s, appear to have altered productivity at various trophic levels in the marine ecosystem in the central North Pacific. The climatic change resulted in increased mixed layer depth and the frequency of deep mixing events, particularly during January-March. A number of biological time series for species ranging from primary to apex levels in the North-western Hawaiian Islands, show corresponding declines in productivity of 30–50% from the early 1980s to the present. We hypothesize that during the early 1980s, increased mixing due to the climate event resulted in greater nutrient input into the euphotic zone and ultimately increased ecosystem productivity. Productivity over a range of trophic levels declined when the climate event ended.     

Metal concentrations in the commercially exploited fishes of an endorheic saline lake in the tin-silver province of Bolivia

Abstract. Whole carcass and tissue (skin, muscle, bone, liver) concentrations of twelve metals in two species of fish, the Argentinian pejerrey, Basilichthys bonariensis Cuvier, and the killifish, Orestias luteus Valenciennes, from Lago Poopo, Bolivia were determined using atomic absorption spectrophotometry. Although a similar pattern of metal uptake was apparent in both species, levels of all metals other than antimony were higher in Orestias than in pejerrey. There was no significant difference ( P < 0·05) between large and small fish in the levels of metals in the tissues examined. Concentrations of most metals were highest in bone and skin samples and lowest in muscle. The levels of almost all metals were high when compared with recent North American and European studies. The results are discussed briefly in terms of the geology, mining activities and climate in the area, the unusually high salinities in the lake, and possible differences in feeding niche of the two species. Human health implications are also considered.