Disposition of sulphonamides in food-producing animals: disposition of sulphathiazole in tissues, urine, and plasma of cattle following intravenous administration

Plasma, urine and tissue concentrations of sulphathiazole were determined at various times following intravenous administration to fifteen cattle. The averaged plasma and urine data were consistent with a two-compartment pharmacokinetic model with a half-life of elimination of 1.3 h and a total volume of distribution of 0.41 l/kg body weight. Sulphathiazole was eliminated by excretion of unchanged drug into urine (48%) and by formation of acetylated and polar metabolites. The averaged data obtained from eight selected tissue sites were consistent with the two-compartment pharmacokinetic model presented and confirmed that residues of sulphathiazole in edible tissue can be predicted from serum and urine concentrations of the drug.     

Surgical Treatment of Colic Results in 181 Horses

A retrospective study was performed of 181 horses that underwent an exploratory celiotomy because of acute abdominal disease. Forty-four horses died or were euthanized during surgery. Of the 137 horses that recovered from anesthesia, 72 died of associated diseases or complications, 86 were discharged from the hospital of which 60 survived at least 7 months. Horses with disorders affecting the small intestine had a significantly lower survival rate. Causes of death early in the postoperative period included long bone fracture, shock, ileus, gastric rupture, and peritonitis. After discharge from the hospital, deaths were attributed to colic of unknown cause, malabsorption syndrome, adhesive small bowel obstruction, small and large intestinal volvulus, perforated bowel, and laminitis. Of the 60 horses that were alive at the time of survey, 93.3% had returned to their previous use. A second occurrence of the initial acute abdominal disease was not documented in any horse.     

Suspensory Apparatus Prosthesis in the Horse Part 2: In Vivo Evaluation in a Suspensory Apparatus Disruption Model

The suspensory apparatus of one forelimb was surgically disrupted in six adult horses by transecting the distal sesamoidean ligaments. A double-braided prosthetic ligament made of aramid yarn was installed to support the flexor surface of the metacarpophalangeal joint. The prosthesis was routed through tunnels in the third metacarpal bone and proximal phalanx, and secured to bone with screws. Evaluation by radiography, synovial fluid analysis, cinematography, and dynamography was performed before surgery and at weeks 16 and 30. Supracondylar cortical lysis and periosteal proliferation were observed on postoperative radiographs. Synovitis and fragmentation of the prosthesis were apparent from synovial fluid evaluation. Weight bearing and metacarpophalangeal joint motion were decreased and loading was transferred in part to the opposite forelimb. Clinical lameness improved and weight bearing increased during the second half of the 30-week period. At necropsy, there was abrasion of the prosthesis and the articular surfaces in contact with the prosthesis. Diffuse granulomatous synovitis developed in response to aramid fiber fragments within the synovium.     

Developing group practices: a management challenge

SUMMARY: The advantages and disadvantages of forming larger professional practices are often debated. This paper reports an exploration of the issues through three case studies involving clusters of Sydney general medical practitioners who had expressed a desire to amalgamate their solo or small group practices. Their most frequently stated goals were to reduce financial overheads, to improve the range of services offered to their patients and to improve the opportunities for recreational and study leave. Several barriers to successful amalgamation were identified, and methods of overcoming these were explored. Practices can successfully amalgamate, but only where there is a group of like-minded general practitioners who are willing to invest time to achieve mutually agreed objectives. Amalgamation will not be appropriate in all circumstances. Larger group practices should benefit from the employment of a professional practice manager. These findings may be relevant to veterinary and dental practices.     

Blood Gas Values During Intermittent Positive Pressure Ventilation and Spontaneous Ventilation in 160 Anesthetized Horses Positioned in Lateral or Dorsal Recumbency

One hundred sixty horses were anesthetized with xylazine, guaifenesin, thiamylal, and halothane for elective soft tissue and orthopedic procedures. Horses were randomly assigned to one of four groups. Group 1 (n = 40): Horses positioned in lateral (LR_G1,; n = 20) or dorsal (DR_G1,; n = 20) recumbency breathed spontaneously throughout anesthesia. Group 2 (n = 40): Intermittent positive pressure ventilation (IPPV) was instituted throughout anesthesia in horses positioned in lateral (LR_G2; n = 20) or dorsal (DR_G2; n = 20) recumbency. Group 3 (n = 40): Horses positioned in lateral (LR_G3; n = 20) or dorsal (DR_G3; n = 20) recumbency breathed spontaneously for the first half of anesthesia and intermittent positive pressure ventilation was instituted for the second half of anesthesia. Group 4 (n = 40): Intermittent positive pressure ventilation was instituted for the first half of anesthesia in horses positioned in lateral (LR_G4; n = 20) or dorsal (DR_G4; n = 20) recumbency. Spontaneous ventilation (SV) occured for the second half of anesthesia. The mean time of anesthesia was not significantly different within or between groups. The mean time of SV and IPPV was not significantly different in groups 3 and 4. Variables analyzed included pH, PaCO₂, PaO₂, and P(A-a)O₂ (calculated). Spontaneous ventilation resulted in significantly higher PaCO₂ and P(A-a)O₂ values and significantly lower PaO₂ values in LR_G1, and DR_G1, horses compared with LR_G2 and DR_G2 horses. Intermittent positive pressure ventilation resulted in normocarbia and significantly lower P(A-a)O₂ values in LR_G2 and DR_G2 horses. In LR_G2 the Pao₂ values significantly increased from 20 minutes after induction to the end of anesthesia. The PaO₂ and P(A-a)O₂ values were not significantly different from the beginning of anesthesia after IPPV in DR_G2 or DR_G3. The PaO₂ values significantly decreased and the P(A-a)O₂ values significantly increased after return to SV in horses in LR_G4, and DR_G4. The PaO₂ values were lowest and the P(A-a)O₂ values were highest in all horses positioned in dorsal recumbency compared with lateral recumbency and in SV horses compared with IPPV horses. The pH changes paralleled the changes in PaCO₂. Blood gas values during right versus left lateral recumbency in all groups were also evaluated. The PaO₂ values were significantly lower and the P(A-a)O₂ values were significantly higher during SV in horses positioned in left lateral (LR_LG1) compared with right lateral (LR_RG1) recumbency. No other significant changes were found comparing left and right lateral recumbency. Arterial hypoxemia (PaO₂ < 60 mm Hg) developed in 35% of DR_G1 horses and 20% of DR_G2 horses at the end of anesthesia. Arterial hypercarbia (PaCO₂= 50–60 mm Hg) developed in DRoi horses. Arterial hypoxemia that developed in 20% of DR_G3 horses was not improved with IPPV. Arterial hypoxemia developed in 55% of DR_G4 horses after return to SV. Some DR_G4 horses with hypoxemia also developed hypercarbia, whereas some had PaCO₂ values within normal limits. Arterial hypoxemia developed in one LR_G1, and two LR_G4, horses. Hypercarbia developed in onlv one LR_G4 horse.     

Comparison of Three Skin Preparation Techniques Part 2: Clinical Trial in 100 Dogs

The skin of 100 dogs undergoing clean or clean-contaminated surgical procedures was prepared with povidone-iodine (PI) or 4% chlorhexidine gluconate (CG) with saline or 70% isopropyl alcohol rinse. Skin bacteria at the incision site were quantified with Replication Organism Detection and Counting (RODAC) plates immediately before and after skin preparation in the preparation room, in the operating room, and postoperatively. The percentage of bacterial reduction, negative cultures, cultures with more than five colony-forming units, and skin reactions for each technique were calculated for each sample period and analyzed with the analysis of variance and Fischer tests. The percentage of bacterial reduction for all techniques was significant and comparable with results of a previous experimental study. There were no significant differences in percentages of bacterial reduction between PI and the CG techniques for surgical times up to 8 hours. There were fewer negative cultures and more cultures with high bacterial counts with PI than with CG and saline after the cleansing scrub. There were fewer negative cultures after surgery with CG and alcohol than with the other two techniques. Duration of the surgical procedure did not significantly affect the culture results. Significantly more skin reactions occurred with PI. The authors conclude that PI and 4% CG with a saline rinse are equally effective in antimicrobial efficacy under clinical conditions. However, 4% CG with a 70% isopropyl alcohol rinse may be inferior in residual antimicrobial activity.     

A Comparison of Epidural Saline, Morphine, and Bupivacaine for Pain Relief After Abdominal Surgery in Goats

The purpose of this study was to determine the analgesic efficacy of bupivacaine, morphine, or saline (control) when injected epidurally into the lumbosacral epidural space in goats after abdominal surgery. Goats received either bupivacaine (0.5%; 1.5 mg/kg in 0.9% sodium chloride solution), 0.9% sodium chloride solution (0.2 mL/kg), or preservative-free morphine (0.1 mg/kg). Total volume injected into the epidural space was 0.2 mL/kg for all groups. The variables evaluated were times to extubation, sternal recumbency, standing, and eating; heart and respiratory rates; and pain score. Only two of the goats in the bupivacaine group were able to stand on their hindlimbs before 6 hours. Time to eating was shorter for the saline group when compared with the bupivacaine group. Heart rate over all time in the saline group (137 ± 4 beats/min, mean ± SEM) was higher than the morphine (125 ± 3 beats/min) and bupivacaine groups (121 ± 3 beats/min). Respiratory rate over all time was increased in the saline group (26 ± 1 breaths/min) compared with the bupivacaine (24 ± 1 breaths/min) or morphine (24 ± 1 breaths/min) groups. At 50 minutes, the pain score for the saline group was higher than the morphine group. Pain score over all time in the saline group (1.5 ± 0.10) was higher than the morphine (1.2 ± 0.07) and bupivacaine (1.2 ± 0.04) groups. One goat in the saline group required two intravenous injections of flunixin meglumine for pain.     

Gunshot Fractures of Extremities: Classification, Management, and Complications

Fifteen clinical cases of gunshot fractures were studied. A radiographic classification of the fractures was developed to aid in fracture evaluation. Type I fractures involved a simple transverse or oblique fracture with minimal soft tissue damage. Type II fractures were severely comminuted with no cortical bone defect and minimal soft tissue damage. Type III fractures were "shatter" fractures, characterized by severe comminution, cortical bone defects, and extensive soft tissue damage. Type I and Type II fractures (combined 26.7%) healed in 8 weeks or less. Eleven of the 15 cases evaluated (73.3%) were found to be Type III fractures, requiring more than 14 weeks for complete cortical healing. Osteomyelitis was associated with 3 cases of Type III tibial fractures, 2 of which developed after a second surgical intervention. Management, complications, and prognosis of gunshot fractures are discussed.