bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Cephalothin, Cefazolin, and Cefmetazole on the Hemostatic Mechanism in Normal Dogs: Implications for the Surgical Patient
Authors: WILKENS BRENT , SULLIVAN PATRICK , MCDONALD T.P. , KRAHWINKEL D.J.
Published: February 2008

Twenty‐six female beagles were used to evaluate the effects of intravenous and long‐term subcutaneous administration of cephalothin, cefazolin, and cefmetazole on platelet function and the coagulation cascade. Platelet aggregation in response to an adenosine diphosphate (ADP) agonist, bleeding time, platelet count, platelet size, prothrombin time (PT), and activated partial thromboplastin times (aPTT) were evaluated before and 90 minutes after two intravenous doses (22 mg/kg) of cephalothin, cefazolin, and cefmetazole given at 90‐minute intervals. Dogs given saline injections were used as controls. Platelet count, platelet size, PT, and aPTT were evaluated after 7 days of subcutaneous administration of saline, cefazolin, and cefmetazole (22 mg/kg every 8 hours). A significant decrease in platelet aggregation in response to ADP was detected 90 minutes after intravenous administration of cephalothin. Bleeding time was increased significantly 90 minutes after intravenous administration of cefmetazole. Platelet size was decreased significantly 24 hours after onset of the study in all animals, including controls. No significant changes in platelet count, platelet size, PT, or aPTT were detected after 7 days of subcutaneous administration. Cefazolin had no adverse effects on platelet aggregation in response to ADP, bleeding time, platelet count, platelet size, PT, or aPTT. Therefore, cefazolin should be considered as a perioperative antibiotic in dogs with conditions predisposing to hemostatic complications.
Cardiopulmonary and Analgesic Effects of Epidural Lidocaine, Alfentanil, and Xylazine in Pigs Anesthetized With Isoflurane
Authors: TENDILLO F. J. , PERA A. M. , MASCIAS A. , SANTOS M. , SEGURA LA. GÓMEZ DE , ROMÁN F. SAN , CASTILLO‐OLIVARES J.L.
Published: February 2008

To determine cardiopulmonary and analgesic effects of lidocaine, alfentanil, and xylazine in pigs anesthetized with isoflurane, 18 healthy Landrace‐Large White pigs were studied (six for each drug). General anesthesia was induced with isoflurane in O2and maintained with 1% to 1.2% end‐tidal ISO, ensuring presence of a pain response before epidural drug administration. Heart rate (HR), arterial blood pressures (AP), cardiac output (CO), pulmonary arterial pressure, pulmonary capillary wedge pressure (PCWP), central venous pressure, respiratory rate (RR), tidal volume (TV), minute volume (MV), arterial blood gas data, core temperature (CT), and analgesic effects (by pricking the lumbar area and the abdominal wall) were determined at various times (2, 5, 15, 30, 45, 60, and 90 minutes) after epidural administration of lidocaine (5 μg/kg), alfentanil (5 μg/kg), or xylazine (0.2 mg/kg), all diluted in NaCl 0.9% to 0.5 mL/kg. Statistical analysis included two‐way analysis of variance for repeated measures and the least significant difference test for determining differences among means. A probability level ofP<.05 was used. The following results were statistically significant decreases in systolic AP, HR, TV, RR, MV, CT, pH, PaO2, and TCO2and increases in PCWP, PaCO2, and HCO3after LID. After ALF, only CT and HCO3decreased. Core temperature and TV decreased after XYL. Lidocaine provided 45 to 60 minutes of analgesia. Alfentanil had no analgesic effects, and xylazine provided 90 minutes of analgesia. The authors conclude that xylazine, when injected epidurally, provides suitable analgesia in isoflurane‐anesthetized pigs.
Vascular Supply of the Tendon of the Equine Deep Digital Flexor Muscle Within the Digital Sheath
Authors: KRAUS BONNIE L. HAY , KIRKER‐HEAD CARL A. , KRAUS KARL H. , JAKOWSKI RICHARD M. , STECKEL ROBERT R.
Published: February 2008

The vascular and microvascular anatomy of the equine deep digital flexor tendon (DDFT) within the digital sheath was studied by injecting the vasculature with either colored latex or barium sulphate for radiographic, microangiographic, histologic, and computed tomographic (CT) evaluation. Consecutive 4‐mm thick two‐dimensional CT slice data were reconstructed to 3‐dimen‐sional volumetric images to enhance spatial evaluation of the blood supply. Gross dissection and angiographic studies identified three major vascular sources. Above the fetlock, the DDFT was supplied by either a branch of the medial palmar artery (Arteriae digitalis palmaris communis II) or a branch of the medial palmar digital artery (A. digitalis [palmaris propria III] medialis). Below the fetlock, the DDFT was supplied by branches from the lateral and medial palmar branches to the proximal phalanx (Ramus palmaris phalangis proximalis). The most distal aspect of the tendon received small branches from the medial and lateral palmar digital arteries. Using histology and microangiography we observed an extensive and uniform intratendinous vascular network above and below the fetlock, with a relatively avascular region of tendon palmar to the fetlock. The most distal 2.0 to 2.5 cm of the tendon within the sheath was heavily infiltrated with fibrocartilage along its dorsal aspect.
Clinical Effects of Longitudinal Division of the Corpus Callosum in Normal Dogs
Authors: BAGLEY RODNEY S. , BASZLER TIMOTHY V. , HARRINGTON MICHAEL L. , PLUHAR G. ELIZABETH , MOORE MICHAEL P. , KEEGAN ROBERT D. , GREENE STEPHEN A.
Published: February 2008

Longitudinal division of the corpus callosum was performed in six normal beagles to determine surgical morbidity. The corpus callosum was divided sagittally on the midline and the effect on neurological function was determined. Five of six dogs were clinically normal within 14 days or less after surgery. One dog had persistent but improving clinical signs consistent with a forebrain disturbance at 30 days after surgery. Overall, minimal morbidity and no mortality was associated with this surgical procedure. Further study is indicated to determine the efficacy of this surgical treatment for seizure control in dogs with idiopathic epilepsy.
Reverse Saphenous Conduit Flap in Cats: An Anatomic Study
Authors: CORNELL KAREN , SALISBURY KATHLEEN , JAKOVLJEVIC SAMUEL , BAUER MICHAEL , PETRYK DENISE
Published: February 2008

The vascular anatomy of the reverse saphenous conduit flap in cats was denned by contrast radiography of both hindlimbs of 18 feline cadaver specimens. In all 36 flaps, flow of contrast medium from the femoral artery to the distal end of the flap was documented. Direct anastomosis of the superficial branch of the cranial tibial artery with the cranial branch of the saphenous artery and communication of the caudal branch of the saphenous artery with the perforating metatarsal artery, via the medial and lateral plantar arteries, was documented. The cranial branch of the medial saphenous vein was shown to anastomose with the cranial branch of the lateral saphenous vein. The presence of these anastomoses support the feasibility of the reverse saphenous conduit flap as an option for reconstruction of wounds of the metatarsus in cats.
Transplantation of the Canine Distal Ulna as a Free Vascularized Bone Graft
Authors: SZENTIMREY DAVID , FOWLER DAVID , JOHNSTON GEOFFREY , WILKINSON ALEX
Published: February 2008

An autogenous free vascular bone graft of the canine distal ulna was evaluated. The vascularity of the graft was based on a musculoperiosteal sheath supplied solely by the caudal interosseous artery and vein. Four autogenous heterotopic (ulna to tibia) vascular transfers were performed. Two avascular transfers were performed to provide baseline criteria from which the success of vascularized transfers could be assessed. Clinical lameness evaluation, serial radiographs, bone scintigraphy, and sequential fluorochrome bone labeling were performed after surgery in both vascular and avascular transfers. All dogs were free of lameness in the donor limb by the 26th postoperative day. Serial radiographs revealed rapid graft incorporation and hypertrophy in all vascularized grafts and severe bone resorption in nonvascularized grafts. Histology, microangiography, and evaluation of fluorochrome bone labels were performed 90 days after surgery to determine graft viability, incorporation and temporal remodeling patterns. Microangiography and fluorochrome assessment complemented the histological findings. Based on these findings the distal ulnar bone graft was determined to be both viable and structurally adequate for selected cases of long bone reconstruction.
Primary Closure of Equine Laryngotomy Incisions: A Review of 42 Cases
Authors: BOULTON ELIZABETH P. , SEEHERMAN HOWARD J. , KIRKER‐HEAD CARL A. , STECKEL ROBERT R.
Published: February 2008

Laryngotomy incisions for either staphylectomy, ventriculectomy, cordectomy, resection of the palatopharyngeal arch, or subepiglottal cyst removal, were closed primarily in 42 horses. Incisional complications were subcutaneous emphysema (11 horses, 26%), incisional discharge (4 horses, 10%), postoperative fever (4 horses, 10%), incisional abscessation (3 horses, 7%), incisional seroma (2 horses, 5%), and subcutaneous edema (2 horses, 5%). Incisional complications were identified in 22 horses, but only 8 horses (19%) required intervention for incisional healing to occur. Factors such as preoperative and postoperative administration of antibiotics or nonsteroid anti‐inflammatory drugs, use of antibiotic lavage or drains, type of suture material and suture pattern, were not significantly associated with incisional complications. Horses with incisional complications had significantly shorter mean surgical time (P=.011) than horses without incisional complications. Surgical experience was associated with fewer complications (P=.018), but had no significant effect on the frequency of complications requiring intervention. Results of this study indicate that equine laryngotomy incisions can be closed primarily and that most will heal without need for further surgical intervention.
Laparoscopic Anatomy of the Llama Abdomen
Authors: YARBROUGH T. B. , SNYDER J. R. , HARMON F. A.
Published: February 2008

Paralumbar laparoscopy was performed, caudal to the last rib, in seven llamas. All animals were anesthetized, instrumented, and placed in sternal recumbency. Systematic exploration was performed in six donated llamas dividing the abdomen into right and left, cranial and caudal quadrants. The main structures of diagnostic significance that could be observed from the right side were the parietal and visceral surface of the liver, diaphragm, first compartment of the stomach (CI), caudal aspect of the third compartment of the stomach (C3), pancreas, kidney duodenum, jejunum, and ascending colon. From the left side CI, varying lengths of jejunum, ileum, ascending colon, and spiral colon were identified. From both approaches the bladder, and in females the uterus and ovaries could be observed. All animals were necropsied immediately following the procedure. Gross examination of the abdominal viscera in the did not yield any abnormalities that had been missed by laparoscopic evaluation. Using a left paralumbar approach, one clinical case presenting with signs of acute abdominal discomfort was evaluated. A diagnosis was made of diffuse enteritis that was confirmed at necropsy. Because of the distensible nature of the South American camelid (SAC) abdominal wall, the small size of the abdominal viscera, and the freely mobile nature of most portions of the gastrointestinal tract a thorough examination was possible in all animals.
Cardiovascular Effects After Epidural Injection of Xylazine in Isoflurane‐Anesthetized Dogs
Authors: GREENE STEPHEN A. , KEEGAN ROBERT D. , WEIL ANN B.
Published: February 2008

The cardiovascular effects following epidural injection of xylazine or isotonic saline during isoflurane anesthesia were assessed in six healthy dogs. Dogs were anesthetized with isoflurane in O2and maintained at 2.0% end‐tidal concentration. Ventilation was controlled to maintain PaCO2at 35 to 45 mm Hg. The dorsal pedal artery was cannulated for measurement of arterial blood pressure (AP)(systolic AP, mean AP, diastolic AP) and for blood sample collection. Arterial pH and blood gas tensions (PaO2and PaCO2) were determined. Cardiac output was measured by thermodilution. The electrocardiogram (ECG), heart rate (HR), core body temperature, central venous pressure (CVP), mean pulmonary AP, and end‐tidal isoflurane concentration (ETISO) and CO2tension (ETCO2) were monitored. Systemic vascular resistance (SVR), arterial HCO2concentration, base balance, and cardiac index (CI) were calculated. After baseline measurements were taken, either xylazine (0.2 mg/kg) in 5 mL isotonic saline or 5 mL of isotonic saline was injected into the lumbosacral epidural space. Data were then recorded at 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after epidural injection. Data were analyzed by two‐way analysis of variance (ANOVA) for repeated measures. When significant differences were encountered, mean values were compared using Bonferroni's test. The level of significance was set atP<.05. Mean values for diastolic AP decreased at 90 and 120 minutes compared with the mean value at 15 minutes after epidural injection of xylazine. No differences were detected at any time or between treatments for HR, systolic AP, mean AP, CVP, CI, SVR, mean pulmonary AP, temperature, ETCO2, ETISO, arterial pH, PaCO2, PaO2, plasma bicarbonate concentration, or base balance. Results of this study indicate that epidural injection of xylazine (0.2 mg/kg) is associated with minimal cardiovascular side effects during isoflurane anesthesia in mechanically ventilated dogs.
The Effects of Medetomidine on Cardiac Contractility in Autonomically Blocked Dogs
Authors: MORAIS HELIO S. AUTRAN DE , MUIR III WILLIAM W.
Published: February 2008

The effects of medetomidine on load‐dependent and relatively load‐independent indices of left ventricular contractility and hemodynamics were studied in 8 chloralose‐anesthetized, autonomic‐blocked dogs. Left ventricular contractility was assessed by the maximum rate of increase in pressure (dP/dtmax), the slope of the end‐systolic pressure volume relationship (Ees), preload recruitable stroke work (PRSW), and dP/dtmax‐end‐diastolic volume relation (SdPV). Dogs received 5 or 10 μg/kg of medetomidine IV. The dP/dtmaxdecreased significantly 30 minutes after both doses of medetomidine. The Ees did not change. Both SdPV and PRSW increased 5 minutes after both doses of medetomidine. Mean arterial pressure, left‐ventricular end‐diastolic and end‐systolic pressures, peripheral vascular resistance and effective arterial elastance increased 5 minutes after both doses of medetomidine. Stroke volume, cardiac output, and stroke work decreased 5 minutes after medetomidine administration. End‐diastolic volume did not change. End‐systolic volume increased but the difference was not significant. Our study suggests that medetomidine increases inotropy and vascular resistance in autonomic‐blocked dogs and that both ventricular and vascular responses to pharmacological manipulation must be considered for a complete assessment of the inotropic effects of a drug.
Intracapsular Prostatic Omentalization: A New Technique for Management of Prostatic Abscesses in Dogs
Authors: WHITE RICHARD A. S. , WILLIAMS JOHN M.
Published: February 2008

Twenty dogs with abscessation of the prostate gland were treated by celiotomy, drainage, and digital exploration of the gland through bilateral capsulectomy wounds. Omentum was introduced through the capsulectomy wounds and packed into the abscess cavities around the prostatic urethra. Most dogs were discharged from the hospital within 48 hours of the surgery. Long‐term resolution of the problem (no recurrence within 12 months) was achieved in 19 dogs. One dog had recurrent abscessation that was managed by the placement of dependant Penrose drains. Temporary tube cystostomy was performed postoperatively in one dog for the management of transient dysuria. One dog with septic peritonitis resulting from preoperative abscess rupture was managed by concurrent open peritoneal drainage. Intracapsular prostatic omentalization was a simple and effective means of managing prostatic abscessation with minimal requirement for postoperative hospitalization of the patient. The frequency of serious complications, including postoperative urinary incontinence, was low.
Use of Intraoperative Ultrasonography in Six Horses
Authors: ROSE PATRICIA L. , PENNINCK DOMINIQUE
Published: February 2008

Intraoperative ultrasonography was used in six horses to aid localization and removal of bone fragments (3 horses) and foreign bodies (3 horses). The ultrasound transducer was enclosed in a sterile sleeve containing sterile aqueous gel and the examination was performed after aseptic preparation of the surgical site. Using ultrasound guidance a needle was placed in contact with the bone fragment or foreign body and an incision was made along the path of the needle to expose and remove the object. This technique resulted in decreased operative time and minimal tissue dissection.
Effects of Growth Factors and L‐Arginine on Ischemic Skin Flaps in Rats
Authors: WALLS CHARLES M. , GREGORY CLARE R. , BECK L. STEVEN , COOKE JOHN P. , GRIFFEY STEPHEN M. , KASS PHIL H.
Published: February 2008

This study determined the effect of the polypeptide growth factors transforming growth factor‐beta (TGF‐β), insulin‐like growth factor‐I (IGF‐I), and growth hormone (GH) alone and in combination with dietary L‐Arginine HCL (ARG) on skin flap survival in rats. Caudally based dorsal skin flaps were created in 110 Sprague‐Dawley rats. The rats were randomly assigned into three treatment groups, based on drinking water supplementation. Group 1 (n = 50) received ARG in their drinking water, group 2 (n = 50) received tap water alone, and group 3 (n = 10) received N‐omega‐nitro‐L‐arginine (L‐NA) and hydralazine. Groups 1 and 2 were divided into subgroups of 10 rats each based on treatment with either: TGF‐β, IGF‐I, GH, or IGF‐I + GH. All subgroups that received GH had significantly greater (P <.0001) median body weight gains when compared with subgroups not receiving GH. L‐arginine HCL when added to IGF‐I negated the positive effects of IGF‐I on both flap survival and weight gain. Although the rats in all subgroups from groups 1 and 2 had an increase in mean percent skin flap survival when compared with the water alone subgroup, only rats receiving IGF‐I, or the combination of ARG with either TGF‐β or GH, had statistically significant enhanced skin flap survival. Rats in group 3 did not show an increase in skin flap survival when compared with the control subgroup.
Ventral Abdominal Approach for Laparoscopic Ovariectomy in Horses
Authors: RAGLE CLAUDE A. , SCHNEIDER ROBERT K.
Published: February 2008

Eleven mares and four mules were ovariectomized by a ventral abdominal laparoscopic technique. This approach required tilting the operative table about 30 degrees elevating the pelvis to allow observation of the ovaries. A triangulation technique with a single laparoscopic portal and four instrument portals was used. The ovarian pedicles were ligated and the ovaries were removed through a single enlarged instrument portal. Females ranged in age from 5 months to 18 years. Mean operative time was 44 minutes (range 20 to 90 minutes); mean operative time of the last seven animals was 26 minutes. Signs of abdominal pain occurred in three mules and one mare in the immediate postoperative period. Peritoneal fluid collected from six animals 48 hours after surgery had a mean leukocyte count of 34,463/μL: (range, 21,000 to 62,800/μL), mean protein concentration of 3.1 g/dL (range, 2.2 to 4.6 g/dL), and mean differential leukocyte count of 74% neutrophils and 26% mononuclear cells. The animals were confined for 2 weeks after surgery. Signs of estrus were observed in two mares within 6 months after ovariectomy. All owners reported satisfaction with the results of laparoscopic ovariectomy. The ventral abdominal laparoscopic approach permitted efficient and safe ovariectomy of foals and adults.
The Effects of Atropine and Glycopyrrolate on Heart Rates in Conscious Mature Goats
Authors: PABLO LUISITO S. , WEBB ALISTAIR I. , McNICHOLAS WALTER T.
Published: February 2008

The effects of intravenously administered atropine (0.2 mg/kg) and glycopyrrolate (0.01 mg/kg) on heart rate were studied in 10 conscious mature goats. In a drug cross‐over fashion, either atropine, glycopyrrolate, or 0.9% saline solution was administered using the same volume (0.05 mL/kg). Atropine and glycopyrrolate caused a significant increase in heart rate (P <.05), whereas saline solution (0.09%) did not. The mean percent changes in heart rate from baseline were similar for atropine and glycopyrrolate up to 14 minutes after administration. Thereafter, glycopyrrolate had a significantly greater mean change in heart rate than atropine, ie, up to 29 minutes (P <.05). Within the atropine group, the mean percentage changes in heart rate became significantly lower compared with the initial increase (1 minute) starting at 11 minutes. For the glycopyrrolate group, the mean percent changes became significantly lower starting at 27 minutes. Glycopyrrolate and atropine had a mean percentage change in heart rate of greater than 1.0%, up to 31 and 22 minutes, respectively. At the doses used, glycopyrrolate had longer duration of action than atropine but the magnitude of increase was similar.
Deep‐Frozen Allogeneic Cancellous Bone Grafts in 10 Dogs: A Case Series
Authors: KERWIN SHARON C. , LEWIS DANIEL D. , ELKINS A. DERRELL , OLIVER JULIAN , PECHMAN ROBERT , MCCARTHY ROBERT J. , HOSGOOD GISELLE
Published: February 2008

Deep‐frozen, aseptically collected and processed allogeneic cancellous bone was implanted in eight dogs during the surgical repair of diaphyseal long bone fractures and in two dogs during arthrodeses. A combined allogeneic and autogeneic cancellous bone graft was used in two fractures with a segmental bone loss of more than 5 cm. Bone union occurred in five fractures and in both arthrodeses. Failure of fixation occurred in two dogs with nonunion fractures and in a third dog with an open, infected fracture. Biopsies from the fracture sites were obtained from these dogs following failure of their fracture fixation. The cancellous bone graft appeared to be in the process of normal incorporation in each case. Failure of fixation was attributed to technical or case management errors or both, in each of the three fractures that failed to achieve bony union. Frozen allogeneic cancellous bone grafts were effectively incorporated when used in the primary repair of fractures and arthrodeses. Combined autogenous and allogeneic cancellous bone grafts may be particularly useful in the repair of fractures with large segmental diaphyseal bone defects. The use of allogeneic cancellous bone grafts in nonunion fractures requires further investigation before it can be recommended.
Cardiopulmonary Effects of Using Carbon Dioxide for Laparoscopic Surgery in Dogs
Authors: DUKE TANYA , STEINACHER SHELLY L. , REMEDIOS AUDREY M.
Published: February 2008

Cardiopulmonary effects of laparoscopic surgery were investigated in five crossbred dogs (21 ± 1.9 kg). Premedicated dogs were anesthetized with thiopental and maintained with halothane at 1.5 times minimum alveolar concentration in oxygen. Controlled ventilation maintained partial pressure of end‐tidal co2at 40 ± 2 mm Hg. Vecuronium was used for skeletal muscle relaxation. After instrumentation and stabilization, baseline measurements were made of cardiac output (thermodilution technique), mean systemic, mean pulmonary arterial and pulmonary wedge pressures, heart rate, saphenous vein and central venous pressures, and minute ventilation. Baseline arterial and mixed venous blood samples were drawn for analysis of pH, Pao2, Paco2, Pvo2, Pvco2, and bicarbonate concentrations. Systemic and pulmonary vascular resistances, oxygen delivery and consumption, shunt fraction, and dead space ventilation were calculated using standard formulas. Abdominal insufflation using co2to a pressure of 15 mm Hg for 180 minutes resulted in significant (P<.05) increases in heart rate (15 to 180 minutes), minute ventilation (75 to 135 minutes), and saphenous vein pressure (15 to 180 minutes), and decreases in pH (60 to 180 minutes) and Pao2(60 to 180 minutes). For 30 minutes after desufflation, there was a significant decrease in Pao2, and increases in cardiac output, o2delivery, and heart rate, compared with baseline. There was a significant increase in shunt fraction and decrease in pH at 15 minutes after desufflation only. The changes were within physiologically acceptable limits in these healthy, ventilated dogs.
The Effect of Unilateral Arytenoid Lateralization on Rima Glottidis Area in Canine Cadaver Larynges
Authors: LUSSIER BERTRAND , FLANDERS JAMES A. , ERB HOLLIS N.
Published: February 2008

Five modifications of a cricoarytenoid lateralization and two modifications of a thyroarytenoid lateralization laryngoplasty technique were evaluated for their effect on rima glottidis area. All procedures and evaluations were performed on canine cadaver larynges. Cricoarytenoid lateralization (CAL) techniques provided a greater increase of the size of the glottic opening than did any of the thyroarytenoid lateralization techniques. Cricoarytenoid and interarytenoid disarticulation associated with CAL did not significantly increase glottic size compared with normal. After disarticulation of the cricoarytenoid joint, there was no difference in glottic enlargement whether the suture was placed through the muscular process or through the articular facet of the arytenoid cartilage. Transection of the sesamoid band combined with cricoarytenoid diarticulation distorted the dorsal margin of the rima glottidis.
A Mechanical Evaluation of the Resistance of Various Interfragmentary Wire Configurations to Torsion
Authors: METELMAN LISA A. , SCHWARZ PETER D. , HUTCHISON JENNY M. , ALVIS MARK R. , JAMES SUSAN P.
Published: February 2008

Fourteen interfragmentary orthopedic wire configurations were tested in torsion using a transverse fracture polyvinylchloride pipe model. These models included single and double Kirschner pins with and without orthopedic wire added to the configuration. The orthopedic wire was applied in either an encircling, figure‐of‐eight (skewer pin), or cruciate pattern. Double Kirschner pins were applied in a mono‐ or biplanar fashion. An external fixator model was also tested. Stiffness, yield load, safe load, and energy of absorption were measured and calculated for each model. Orthopedic wire added to any configuration increased stiffness. All single pin configurations with orthopedic wire and the external fixator had the highest stiffness. Two Kirschner pins had a higher torsional yield load and safe load than single pin configurations with or without orthopedic wire. The external fixator model had the highest torsional yield load, safe load and energy of absorption of all configurations tested. However, the external fixator was only significantly different in safe load from the 90° biplanar configurations with wire and the cross pin configuration with encircling wire. The 90° biplanar configurations with wire and the cross pin configuration with encircling wire were equally as effective as the external fixator model in yield load and energy of absorption.
Experiences With Morphine Injected Into the Subarachnoid Space in Sheep
Authors: WAGNER ANN E. , DUNLOP COLIN I. , TURNER A. SIMON
Published: February 2008

The effects of morphine (M), 0.1 mg/kg, administered into the lumbosacral subarachnoid space of sheep used for experimental stifle surgery, were investigated. In a pilot study, preservative‐free morphine was administered to three sheep, morphine containing preservatives to two sheep, and saline (S) to one sheep. After recovery from anesthesia, all five sheep administered M displayed rear limb weakness. One sheep, which had received morphine containing preservatives, also licked and chewed incessantly at its flank and hindquarters during recovery. A group of 24 sheep was used to study the effects of morphine containing preservatives, injected intrathecally, on recovery from general anesthesia and hindlimb orthopedic surgery. Eight sheep received M, eight sheep received S, and eight sheep had a needle placed in the subarachnoid space without any injection (N). Times from end of anesthesia to standing varied greatly and did not differ significantly among groups (P=.73), with M sheep averaging 119 minutes; S sheep, 87 minutes; and N sheep, 83 minutes. One sheep administered M licked and chewed at its hindquarters during recovery. Another group of 24 sheep was used to study the effects of morphine containing preservatives, injected intrathecally, on postoperative lameness. Treatments were as described previously. Sheep were videotaped intermittently for 36 hours after surgery, and each sheep was scored as follows; 0 = not lame; 1 = slightly lame; and 2 = very lame. The average lameness scores, which did not differ significantly among groups (P=.21), were: M sheep, 1.07; S sheep, 0.81; and N sheep, 0.68. One sheep administered M displayed extensor spasms of the hindlimbs, and could not stand until several hours after surgery. We conclude that subarachnoid morphine at the dosage used produces no apparent benefit in sheep which have had stifle surgery, and in fact may cause detrimental side effects, such as hindlimb weakness, and pruritis or irritation of the hindquarters.
Comparative Evaluation of Two Surgical Scrub Preparations in Cattle
Authors: DESROCHERS ANDRÉ , ST‐JEAN GUY , ANDERSON DAVID E. , ROGERS DONNA P. , CHENGAPPA M.M.
Published: February 2008

One hundred seventeen cattle that had undergone surgery were assigned randomly to two preoperative skin preparation protocols. Group 1 (60 animals) skin preparation was with povidone‐iodine soap and isopropyl alcohol, whereas group 2 (57 animals) had skin preparation with chlorhexidine gluconate and isopropyl alcohol. Quantitative microbial culture plates were used to estimate the number of colony forming units (CFUs) before skin preparation (prescrub), after skin preparation (postscrub), after surgery (postoperative), and in room air (environment). A significant decrease in CFU occurred postscrub for both skin preparations (P <.05). Chlorhexidine and alcohol preparation resulted in significantly fewer CFUs (LSMean ± SE = 2.79 CFU ± 1.74) and a greater percentage reduction in CFUs (98.64%± 2.01) postscrub than povidone and alcohol (LSMean ± SE = 10.27 CFUs ± 1.51, 93.29%± 1.85); (P <.005). Group 2 had a significantly higher frequency of negative cultures postscrub (49.1%) compared with group 1 (18.3%) (P <.001). The number of postoperative CFUs were not significantly different between the two treatment groups. Wound infection frequency for clean surgical procedures was not significantly different between the two skin preparation protocols (group 1 = 9.8%, group 2 = 10.7%), however, infection frequency was significantly higher for surgical procedures with a ventral abdominal approach (5 of 14, 35.7%), compared with a flank approach (1 of 41, 2.4%) or other approaches (orthopedic procedures) (1 of 16, 6.3%) (P <.05). Both skin preparation protocols were effective and safe in decreasing the skin microflora population of cattle before surgery and although preparation with chlorhexidine gluconate and alcohol resulted in less CFUs immediafly postscrub, the frequency of surgical wound infection was similar for both protocols.
Evaluation of an Autologous Tendon Graft Repair Method for Gap Healing of the Deep Digital Flexor Tendon in Horses
Authors: VALDÉS‐VÁZQUEZ MIGUEL A. , McCLURE J. RAYMOND , III JULIAN L. OLIVER , RAMIREZ SANTOS , SEAHORN THOMAS L. , HAYNES PETER F.
Published: February 2008

A sutured tenorrhaphy technique that incorporated an autologous tendon graft was compared mechanically and histologically with a sutured tenorrhaphy at 6, 12, and 24 weeks after repair. Tenorrhaphy was performed in the forelimb tendon of the deep digital flexor muscle and the graft was taken from the hindlimb tendon of the lateral digital extensor muscle; one forelimb site included the graft, whereas the other forelimb site was not grafted. Tenotomies were made immediately proximal to the insertion of the accessory ligament into the tendon of the deep digital flexor muscle. Grafted and nongrafted tenorrhaphies were sutured with 2 polydioxanone in a modified double locking‐loop pattern. Limbs were supported with a bandage and an extended elevated heel shoe that maintained the dorsal hoof wall angle at 70° to 75°; this support was removed at 12 weeks and dorsal hoof wall angle was maintained at 40° to 45° for the remainder of the study. Gap formation (2.5 ±.3 cm) was evident at all tenorrhaphy sites at 3 days on ultrasound examination. In grafted repairs, the breaking stress was increased (P<.001) between 6 weeks (2.56 ±.44 MPa) and 12 weeks (17.69 ± 7.68 MPa), with grafted tendon having a greater breaking stress than nongrafted tendon (8.77 ± 2.5 MPa;P<.05). No differences in breaking stress were evident at 24 weeks. At 12 weeks, repair tissue in grafted tendon was histologically more mature, had less cellularity, better fibroblast orientation and more homogeneous collagen matrix than nongrafted tendon. Polydioxanone suture was still evident histologically at 24 weeks and was associated with minimal cellular reaction. Incorporation of an autologous tendon graft improved the mechanical properties and histological quality of the repair tissue in equine flexor tenorrhaphies at 12 weeks but not at 24 weeks after repair.
Postoperative Analgesic and Cardiopulmonary Effects in Dogs of Oxymorphone Administered Epidurally and Intramuscularly, and Medetomidine Administered Epidurally: A Comparative Clinical Study
Authors: VESAL NASSER , CRIBB PETER H. , FRKETIC MAGDA
Published: February 2008

Thirty dogs undergoing pelvic or hindlimb orthopedic surgery were each administered one of the following postoperative treatments: intramuscular oxymorphone 0.15 mg/kg (OIM) (n = 10); epidural oxymorphone 0.05 mg/kg, (OEP) (n = 10); or epidural medetomidine, 0.015 mg/kg (MEP) (n = 10). Heart rate (HR), respiratory rate (RR), and arterial blood pressure were measured before drug injection and 15, 30, 60, 90, 120, 180, 240, 300, 360, 420, and 480 minutes postinjection (PI). Arterial blood gas analysis was performed before and 15, 30, 60, 90, 120, 180, 360, and 480 minutes PI. The duration of analgesia with OEP, 7.62 + 0.30 hours (mean ± SEM), and MEP, 7.06 + 0.50 hours, was significantly (P<.05) longer than the 4.91 + 0.44 hours obtained with OIM. All treatments resulted in a significant decrease in HR. Four dogs receiving epidural medetomidine each had second degree atrioventricular (AV) block associated with sinus arrhythmia for a brief period during the first 20 minutes after injection. There was no significant difference in arterial blood pressure between OIM and OEP but arterial blood pressure was significantly higher with MEP than with OIM. MEP can provide analgesia comparable with OEP, but bradycardia and second degree AV block will develop in some cases.
Comparison of Three Methods for Relief of Pain After Ear Canal Ablation in Dogs
Authors: BUBACK JANICE L. , BOOTHE HARRY W. , CARROLL GWENDOLYN L. , GREEN RONALD W.
Published: February 2008

This study compared three methods of pain relief in dogs that had total ear canal ablation with lateral bulla osteotomy. The hypothesis was that systemic opioids with preoperative local nerve blocks would provide superior pain relief. Thirty‐one dogs with chronic otitis externa were included in the study. Dogs were randomly assigned to one of three protocols: systemic opioids alone (10 dogs, group 1), systemic opioids with bupivacaine splash block (11 dogs, group 2), and systemic opioids with preoperative local bupivacaine nerve blocks (10 dogs, group 3). Twenty‐one dogs had bilateral ear ablation and 10 had unilateral ablation. Pain was assessed preoperatively, at extubation, 2 hours postextubation, and 1 day postoperatively by a single observer blinded to the analgesic protocol used. Pain scores were not significantly different within or between groups, nor did unilateral versus bilateral ablation have a significant effect on the score. Mean scores were less than 3 (scale 1 to 5) for all groups at all observation times. Rough recoveries were noted in 30% of group 1 dogs, 0% of group 2, and 20% of group 3 dogs. Ninety‐four percent of dogs were moderately to heavily sedated at extubation. Sixty percent of group 3 dogs remained moderately to heavily sedated 2 hours postextubation. Rectal temperature, pulse rate, respiratory rate, and postoperative change in serum Cortisol levels were not significantly different between groups. Postoperative increase in blood glucose was significantly higher in groups 1 and 3 compared with preoperative levels. Twenty‐three percent of the dogs required additional analgesia or tranquilization after surgery, as determined by the anesthetist; 1 dog in group 1, 2 in group 2, and 4 in group 3. Each of the three analgesic protocols provided similar pain relief in dogs undergoing total ear canal ablation.
Structural Properties of Interlocking Nails, Canine Femora, and Femur‐Interlocking Nail Constructs
Authors: DUELAND R. T. , BERGLUND L. , VANDERBY R. , CHAO E.Y.S.
Published: February 2008

Using standard material testing techniques (bending stiffness, torsional stiffness, and maximum torque to failure or yield torque), the structural properties of interlocking nails (IN), canine femora, and IN/femur constructs were determined. Specimens that were tested included: 6 and 8 mm diameter IN with 5 to 10 screw holes (n = 18), and intact canine femora (n = 10), which also, with an IN inserted, formed the intact construct (IC) group, (n = 10). Specimens in the IC group were first tested with an 8 mm diameter IN with zero screws, followed by one and two screws (4.5 mm diameter) in the proximal and distal femur. A fracture model construct (FMC), (n = 14), consisting of a transverse femoral osteotomy with a 3 mm gap, was used with either 6 mm or 8 mm IN. In the 6 mm FMC, one and two 3.5 mm screws were used sequentially in the proximal and distal femoral segment. In the 8 mm FMC, one and two 3.5 mm screws and one and two 4.5 diameter screws were used similarly. When bending forces were applied parallel to IN screw holes, mean IN stiffness was 20% less than with forces perpendicular to the holes (n = 18), (P<.05). Eight‐millimeter IN were 220% stiffer in torsion and 270% stiffer in bending than 6 mm IN (P<.05). Six‐millimeter IN had approximately 32% of the bending stiffness and torsional stiffness of intact femurs (P<.05). Eight‐millimeter IN had 93% and 79% of the bending stiffness and torsional stiffness, respectively, of intact femurs. Intact femur constructs (8 mm IN with four, 4.5 mm screws) had 147% of the bending stiffness (P<.05), and similar torsional stiffness and maximum torque, as intact femora (P>.05). The mean values of 6 mm FMC with four screws (3.5 mm) were 21% and 33% in torsional stiffness and bending stiffness, respectively, of intact femora values. When tested in torsion, 8 mm FMC failed by bone fracture; 6 mm FMC, in contrast, underwent plastic deformation. In comparing FMC stabilized with an 8 mm IN with two screws (4.5 mm diameter) in each bone segment, to intact femurs, the maximum torque was similar, FMC torsional stiffness was 40% (P<.05), and FMC bending stiffness was 65% (P<.05). These 8 mm FMC percentages are comparable to human IN fracture model construct values, indicating that the 8 mm IN/four screw construct should provide adequate stabilization for many canine diaphyseal femoral fractures.
Early Experience With the Use of an Interlocking Nail for the Repair of Canine Femoral Shaft Fractures
Authors: DURALL I. , DIAZ M.C.
Published: February 2008

Static locked nailing was used to repair fractures of the femoral diaphysis in 15 dogs. The implant consists of a 5, 6, or 7 mm diameter stainless steel rod made up of two parts: the body of the nail, in which there are 13 threaded holes, and a piece without holes that contains a slot for anchoring the jig. Good limb function was obtained after less than 3 weeks in 12 dogs and these dogs remained sound throughout the study. Radiographic examination revealed fracture healing in 11 of the dogs, between 8 and 16 weeks after surgery. One dog was not returned for follow‐up evaluation until 22 weeks after surgery; complete healing was apparent from radiographic examination. The remaining three dogs had to have additional operations, one because of lameness caused by excessive length of the distal screws, one because of a nonunion, and the third because of a sequestrum. Fracture healing in these dogs was observed at 18, 21, and 24 weeks respectively. Loosening of one screw and angulation of the bone occurred in one dog. These complications had no adverse effects on clinical outcome.
Laparoscopic Repair of Scrotal Hernia in Two Foals
Authors: KLOHNEN ANDREAS , WILSON DAVID G.
Published: February 2008

Nonstrangulating indirect scrotal hernias were corrected in two 4‐week‐old Percheron foals by a laparoscopic technique. After laparoscopic reduction of herniated nonstrangulated small intestine each testes was retracted through the vaginal ring. The ligament of the tail of the epididymis was transected by electrocautery. The testicular vessels and nerves were isolated by cautery of the mesenteric portion of the mesorchium and then ligated. Staples were used to close the opening of the inguinal canal by apposing the peritoneal edges of the vaginal ring. Resection of umbilical stalk remnants via celiotomy performed in one foal after laparoscopic observation of enlargement of the right umbilical artery and urachus. No complications or recurrence of herniation had occurred 16 weeks after surgery.
Chlorhexidine Gluconate Versus Chloroxylenol for Preoperative Skin Preparation in Dogs
Authors: STUBBS W. PRESTON , BELLAH JAMIE R. , VERMAAS‐HEKMAN DONNA , PURICH BARBARA , KUBILIS PAUL S.
Published: February 2008

The efficacy of 3% chloroxylenol (PCMX) or 4% chlorhexidine gluconate (CG) for preoperative skin preparation was assessed in 100 dogs undergoing clean or clean‐contaminated surgical procedures. Replication Organism Detection and Counting (RODAC) plates were used to quantify skin bacteria colony forming units (CFU) at the operative site before and after skin preparation and immediately postoperatively. Reduction of CFU after skin preparation and immediately postoperatively was significant for each agent. However, CFU levels were significantly lower in the CG group than in the PCMX group after surgical preparation, regardless of initial CFU numbers. No significant difference in CFU counts was observed between antiseptic groups postoperatively. Within‐group comparisons showed PCMX to be significantly less efficacious when the prescrub CFU number was greater than 1,000. Bacterial reduction was similar in the CG group regardless of prescrub CFU levels. The number of negative cultures after skin preparation was significantly greater with CG than with PCMX. Chlorhexidine gluconate also had fewer cultures with heavy bacterial growth (>5 CFUs) after surgical preparation. There was no significant difference between antiseptics in the number of negative cultures or cultures with more than 5 CFUs immediately after surgery. The number of skin reactions and postoperative wound infections that occurred with each technique were similar. Three percent PCMX, as used in this study, was less effective than 4% CG in its immediate antimicrobial activity, however, this difference was not associated with an increased wound infection rate.
Gradual Occlusion of Extrahepatic Portosystemic Shunts in Dogs and Cats Using the Ameroid Constrictor
Authors: VOGT JAMES C. , KRAHWINKEL D.J. , BRIGHT RONALD M. , DANIEL GREGORY B. , TOAL ROBERT L. , ROHRBACH BARTON
Published: February 2008

Gradual occlusion of the splenic vein, using a specialized device (ameroid constrictor), was evaluated experimentally in three normal beagle dogs. Splenoportograms were used to verify that total occlusion of the splenic vein had occurred in all dogs within 4 to 5 weeks after application of the device. The ameroid constrictor (AC) was also evaluated as a method of gradual vascular occlusion in 12 dogs and two cats with single, extrahepatic, portosystemic shunts (PSS). Serum bile acid (SBA) concentrations were measured and portal scintigraphy (PS) was performed on all 14 animals preoperatively and 10, 20, 30, and 60 days postoperatively. Two dogs (14%) died from portal hypertension in the early postoperative period. One dog and one cat developed multiple acquired PSS, confirmed by mesenteric portography 90 days after the operation. Portal scintigraphy confirmed total occlusion of the primary shunt in the other 10 animals. Shunt fractions (SF), as measured by PS on postoperative days 30 and 60, declined significantly from preoperative values. Significant decreases were noted between preoperative and postoperative values for preprandial SBA on postoperative day 60 and for postprandial SBA on postoperative day 30. SBA concentrations did not correlate with SF. Based on this study, gradual vascular occlusion using the AC is recommended as a method for treatment of single, extrahepatic, PSS.
Reduction in Plate Strain by Addition of an Intramedullary Pin
Authors: HULSE DON , HYMAN WILLIAM , NORI MEERA , SLATER MARGARET
Published: February 2008

Objective—The purpose of this study was to determine the strain sparing effect of a bone plate and rod system compared with a bone plate alone.

Study Design—Mathematical analysis and in vitro modeling of implant‐bone constructs. Implants were instrumented with uniaxial strain gauges.

Animals or Sample Preparation—Five pairs of canine femurs.

Methods—Bone plates were instrumented with two 350‐ohm strain gauges. The bone plates were used to bridge a simulated fracture gap in five pairs of canine femurs. In one femur of each pair, a bone plate alone was used to bridge the gap; in the opposite femur, a bone plate and intramedullary rod combination was used. Each specimen was mounted on a custom jig and loaded in an axial servohydraulic testing machine. A constantly increasing compressive load was applied at the rate of 0.7 cm/sec. Strains at 400.5 N were recorded and analyzed using Wilcoxon's signed rank test. Mathematical modeling was done using parallel beam theory.

Results—Stress reduction in the plate and rod system was twofold compared with the plate alone (P= .059). As important, based on stress reduction in the plate, the fatigue life of the plate/rod system increased 10‐fold over the plate system alone and was greater than 10‐fold at higher absolute stress values. Mathematical analysis of the plate/rod system was similar to that seen with the in vitro analysis.

Conclusions—The combination of a bone plate and intramedullary pin was superior in reducing plate stress when compared with the plate alone and functioned as two beams acting in concert.

Clinical Relevance—Stabilization of comminuted fractures by bridging the zone of fragmentation with a bone plate without anatomic reduction of each fragment is a useful method of managing this type of injury. Addition of an intramedullary pin reduces the stress applied to the plate and thereby extends the fatigue life of the bone plate.