Bacterial Culturing for Prediction of Postoperative Complications Following Open Fracture Repair in Small Animals

Swab specimens for bacterial culturing were obtained from 82 consecutive dogs and 13 cats undergoing open reduction and internal fixation of 110 fractures. Bacteria were isolated from 51 wounds. When the data were analyzed by stepwise logistic regression, it was found that bacterial contamination of wounds was associated most often with open fractures and with tibia or radius/ulna fractures. Contaminated wounds were five times more likely to develop complications than those without bacterial contamination. Regardless of results of bacterial culturing, postoperative complications developed significantly more often in animals that were febrile (>39.4° C [103° F]). Postoperative complications did not develop in animals that did not have bacterial contamination of wounds and were not febrile.     

Volvulus of the Distal Part of the Jejunoileum in Four Cows

Four cows were diagnosed as having volvulus of the distal jejunoileum. Affected cattle became acutely depressed, dehydrated, and tachycardic, all developed abdominal distention, and three of four were in severe pain at the time of admission. Feces were scant or absent. The volvulus was corrected by exteriorizing the small intestine and replacing it in correct position. All four cows recovered without complications and were well 6 months or more following surgery.     

Influence of Cholinergic Blockade on the Development of Epinephrine-Induced Ventricular Arrhythmias in Halothane- and Isoflurane-Anesthetized Dogs

The arrhythmogenic effects of anesthetic drugs are assessed using the arrhythmogenic dose of epinephrine (ADE) model. The purpose of this study was to determine the influence of cholinergic blockade (CB) produced by glycopyrrolate (G) on ADE in 1.5 minimum alveolar concentration (MAC) halothane (H)- and isoflurane (I)-anesthetized dogs. Eight dogs (weighing between 12.5 and 21.5 kg) were randomly assigned to four treatment groups (H, HG, I, and IG) and each treatment was replicated three times. Anesthesia was induced and maintained with H (1.31%, end-tidal [ET]) or I (1.95%, ET) in oxygen. Ventilation was controlled (carbon dioxide [PCO₂] 35 to 40 mmHg, ET). G was administered 10 minutes before ADE determination at a dose of 22 μg/kg (11 μg/kg, intravenous [IV] and 11 μg/kg, intramuscular [IM]). The ADE was determined by IV infusion of epinephrine at sequentially increasing rates of 1.0, 2.5, and 5.0 μg/kg/min; and defined as the total dose of epinephrine producing at least four ectopic ventricular contractions (EVCs) within 15 seconds during a 3-minute infusion and up to 1 minute after the end of the infusion. Total dose was calculated as the product of infusion rate and time to arrhythmia. Data were analyzed using a randomized complete block analysis of variance. When significant (P < .05) F values were found a least significant difference test was used to compare group means. Values are reported as means ± standard error. The ADE (μg/kg) for H, HG, I, and IG were 1.53 ± 0.08, 3.37 ± 0.46, 1.61 ± 0.21, and > 15.00, respectively. Heart rates (HRs) (beats/min) and systolic pressures (mmHg) at the time of arrhythmia formation for H, HG, I, and IG were (60.3 ±4.0 and 142.0 ± 7.6), (213.0 ± 13.1 and 239.2 ± 7.1), (62.9 ± 4.5 and 151.9 ± 6.3), and (226.3 ± 6.1 and 323.5 ± 3.4), respectively. The H and I ADE were not different. The HG ADE was significantly less than the IG ADE. The H and I ADE were significantly less than the HG and IG ADE. We conclude the following from the results of this study of epinephrine infusion in halothane- and isoflurane-anesthetized dogs: (1) two distinct mechanisms are responsible for the development of arrhythmias, (2) CB produced by G significantly increases ADE but is associated with higher rate pressure products (RPP) and myocardial work, and (3) ADE methodology could be improved by determining ADE with and without CB.     

Long-Term Follow-up of Partial Limb Amputation in 13 Horses

Thirteen cases of partial limb amputation in horses were reviewed. Nine horses (69%) survived 18 to 111 months (mean, 41 months). Four unsuccessfully treated horses were euthanatized within 21 days of surgery. The horses' ages at amputation were 4 to 13 years (mean, 7.3 years). There was no predilection for the left or right limb nor for fore or hind limb involvement. Osteomyelitis in six horses (46%) was the most common cause for amputation. Severe, open, comminuted fractures of the third metacarpal bone that were impossible to stabilize by any currently available technique in four horses (31%) were the second most common cause for amputation. One gelding was salvaged because of his sentimental value, two horses were used as breeding stallions, and six were broodmares. One stallion lived 30 months, completed two breeding seasons, and started a third. The other stallion began breeding, but became sterile. Three of the mares have produced five foals. One mare died while in foal. One mare aborted near-term twin fetuses and died of uterine hemorrhage. One mare aborted twice before the femoral head ligament on the contralateral limb ruptured, and she was euthanatized.     

Stabilization of Bilateral Sacroiliac Fracture-Luxations in Small Animals with a Single Transsacral Screw

Bilateral sacroiliac fracture-luxations in four dogs and four cats weighing 3.5 kg to 30.9 kg were reduced and stabilized with a single 3.5 mm, 4.5 mm, or 6.5 mm transsacral screw. Alignment of the drill bit was visual in six cases and assisted by the use of an aiming device in two cases. Seven animals were reevaluated at months 3 to 6. No significant screw loosening or loss of reduction had occurred. Although no intraoperative complications were encountered with visual drill bit alignment, use of an aiming device for transsacral drilling is strongly recommended.     

Analgesia in Dogs After Intercostal Thoracotomy: A Clinical Trial Comparing Intravenous Buprenorphine and Interpleural Bupivacaine

We prospectively studied 26 dogs that presented for intercostal thoracotomy. Dogs were pre-medicated with oxymorphone, induced with diazepam and etomidate, and anesthesia was maintained with isoflurane in oxygen. Preoperatively, animal patients were randomly assigned to one of two groups. Group 1 (n = 13) received buprenorphine (10 μg/kg intravenously [IV]) every 6 hours for 24 hours starting 10 minutes before tracheal extubation. Group 2 (n = 13) received 0.5% bupivacaine (1.5 mg/kg) administered interpleural (IP) by slow injection through a pediatric feeding tube fixed to the most dorsal aspect of the thoracotomy incision. Interpleural injections were administered with each dog placed in lateral recumbency with the incision positioned ventrally; IP injections were administered every 4 hours for 24 hours starting 10 minutes before tracheal extubation. All cases were monitored in the intensive care unit for 24 hours postoper-atively. The analgesic efficacy of each regimen was evaluated using a pain scoring system that included a subjective pain score, heart rate, and respiratory rate. Arterial blood pressure, arterial blood gases, oxygen saturation, body temperature, and changes in the electrocardiogram or neurological status were also noted. Significant increases in mean heart rate, respiratory rate, and total pain score occurred after surgery in dogs in the buprenorphine group. In contrast, dogs in the bupivacaine group had no significant changes when compared with their preoperative values. Dogs in the bupivacaine group had significantly decreased total pain scores and better PaO₂ and oxygen saturation values when compared with the dogs receiving buprenorphine. Hypoventilation did not occur in either group.     

Modified Lateral Orbitotomy for Removal of Orbital Neoplasms in Two Dogs

A simplified lateral orbitotomy is described that decreases surgical time and lessens tissue dissection, yet maintains the exposure to the orbit provided by other orbitotomy techniques. The approach involves cutting the orbital ligament, incising the temporalis aponeurosis from the dorsal zygomatic arch, making parallel zygomatic arch osteotomies, and reflecting the zygomatic arch ventrally. Closure of the wound involves wiring the zygomatic arch back into place. This orbitotomy procedure provides excellent exposure for removal or biopsy of orbital masses. The use of this technique for surgical excision of orbital masses in two dogs, one with an adenoma of the third eyelid gland and one with an orbital fibrosarcoma, and their subsequent management is described.     

Number of Heterobasidion annosum vegetative compatibility groups in roots of basidiospore-infected stumps

Heterobasidion annosum was isolated from colonized parts of Sitka spruce stumps in Dundeugh Forest, Scotland and amabilis fir stumps in River Jordan, Vancouver Island, British Columbia. Isolates from each stump were paired in all combinations on malt extract agar and their interactions were scored according to established criteria. As many as ten vegetative compatibility (VC) groups were detected among isolates from the roots of a single stump. In four stumps that were intensively studied, about one-half of the VC groups in the roots were not detected in the upper part of the stump. Transfer of VC groups of H. annosum from stump roots to tree roots was observed.     

A Modified Cloward''s Technique for Arthrodesis of the Normal Metacarpophalangeal Joint in the Horse

A modified Cloward's technique was performed for arthrodesis of one metacarpophalangeal (MCP) joint in eight horses. Dorsal arthrotomies were performed medial and lateral to the common digital extensor tendon and two 16 mm holes were drilled through the joint. A perforated cylindrical stainless steel basket filled with cancellous bone was impacted into each hole. The limbs were supported in casts for 8 weeks. The joints were examined and radiographed at 4 weeks, 8 weeks, 6 months, and 10 months. One horse was euthanatized at week 14 to assess the progress of the arthrodesis. In the other seven horses, there was clinical fusion at month 6. Dynamographic evaluations were performed 11 months after surgery at the walk and trot. The maximum vertical forces exerted during weight bearing by treated and control limbs were compared. No difference was detected at the walk; however, a significant difference was present at the trot (p less than 0.05). It was calculated that at the trot the horses placed 90% as much force on the treated limb as on the control limb. Eleven months after surgery, the baskets contained compact and cancellous bone. Ingrowth of bone occurred through all openings, completely filling the baskets and fusing the joints.     

Depletion and movement of water beneath cereal crops grown on a shallow soil overlying chalk

Changes in water storage and gradients of water potential were measured beneath cereal crops grown on Andover soil series for three seasons. The measurements showed that depletion of water from the soil (0-0.3 m) was 20–29% of the total profile depletion and that from the chalk/soil and chalk layers was 71–80%. Rain showers rewet the soil so that depletion from the non-soil layers contributed about 35% of the total water use despite containing only 12% of the roots.
Water in the chalk/soil and chalk layers was held at matric potentials between – 200 and – 800 kPa and gradients of hydraulic potential indicated upward movement from depths of almost 3 m. Comparisons of measured water depletion beneath the root zone with estimates of upward movement to the rooting zone indicate that substantial upward movement is possible, although the estimates were generally larger than the measured depletion.
The estimated contribution of the water moved to the root zone for shoot dry matter production was 8% and 22% for winter and spring cereals respectively.