Comparison of laparoscopic ovariohysterectomy and ovariohysterectomy in dogs

OBJECTIVES: To evaluate technique, complication rates, postoperative pain scores, and clinical outcomes in dogs after laparoscopic ovariohysterectomy (LOVH) or traditional ovariohysterectomy (OVH). STUDY DESIGN: Prospective clinical trial. ANIMALS OR SAMPLE POPULATION: Thirty-four intact female dogs, weighing 2.4-31 kg. METHODS: LOVH (16 dogs) was performed by ligation of the uterus and ovaries with surgical wire, and then removal by an assisted laparoscopic technique. OVH was performed in 18 dogs. Subjective and objective pain scores were assigned at 0, 2, 8, and 24 hours. Surgical time, complications, and pain and incision scores were evaluated. Dogs were followed for up to 6 months. RESULTS: The mean surgical time for LOVH (120 minutes; range, 47-175 minutes) was significantly longer than for OVH (69 minutes; range, 25-140 minutes). Significantly lower pain scores (subjective, in 2 of 10 categories; objective, in 8 of 10 categories) were identified with LOVH at 1 or more time periods. Surgical complications with LOVH were postoperative fever and anorexia (1 dog), minor splenic (3) or pedicle hemorrhage (4), intermittent vaginal hemorrhagic discharge (1), and suture reaction (3). Surgical complications with OVH were hemorrhage from an ovarian pedicle requiring reoperation (1 dog), dehiscence of the abdominal wall (1), and seroma (1). Anesthetic complications included hypotension in 8 OVH dogs and 1 LOVH dog, and hypothermia in 4 OVH and 9 LOVH dogs. The mean incision scores were lower for LOVH at all time periods. CONCLUSION: LOVH was performed successfully in young nonparous dogs >10 kg. Surgical time and complication rates were greater; however, LOVH postoperative pain scores were < or =OVH scores. CLINICAL RELEVANCE: LOVH is a potentially safe surgical alternative to traditional OVH in dogs. Equipment cost and necessity for more than 1 surgeon may limit its usefulness in small animal practice.     

Partial Maxillectomy in the Dog Comparison of Suture Materials and Closure Techniques

This study compares the healing of oronasal defects created by partial maxillectomy when closed using two different suture materials and two different suture patterns. In experiment 1, 24 dogs were divided into four equal groups. Partial maxillectomy was performed on each dog and was closed using either a two-layer simple interrupted suture pattern (12 dogs) or a modified Mayo mattress pattern (12 dogs) with either polyglactin 910 (12 dogs) or polypropylene (12 dogs) sutures. On the seventh postoperative day, the dogs were euthanized, suture line bursting pressures were measured, and wound healing was evaluated grossly and histopathologically. Suture line dehiscence occurred in one dog from each of the four groups. These were the only dogs in which electrocoagulation had been used. The healing of suture lines closed with the two-layer simple interrupted pattern was superior to that of those closed with the modified Mayo mattress pattern based on the degree of gross oral ulceration, suppurative inflammation, fibrosis and oral epithelial covering at the suture line, and the number of necrotic sites in the adjacent tissue. The healing of suture lines closed with polypropylene was superior to that of those closed with polyglactin 910 based on suture line bursting pressures and the degree of suppurative inflammation and tissue necrosis at the suture sites. In Experiment 2, partial maxillectomies were performed on four dogs, and closure was achieved using a two-layer simple interrupted suture pattern with either polyglactin 910 (two dogs) or polypropylene (two dogs). On the 30th postoperative day, the dogs were euthanized, and wound healing was evaluated grossly and histopathologically. All suture lines were well healed. All polyglactin 910 oral sutures were absent, while all polypropylene oral sutures were still present.     

Prolonged anesthesia with desflurane and fentanyl in dogs during conventional and laparoscopic surgery

OBJECTIVE: To determine the effects of prolonged anesthesia with desflurane in dogs undergoing laparotomy or abdominal laparoscopy. DESIGN: Randomized prospective study. ANIMALS: 20 adult mixed-breed dogs. PROCEDURE: Dogs were randomly assigned to 1 of 2 groups with 10 dogs/group. Anesthesia was induced with propofol and maintained with desflurane and fentanyl, and pyloroplasty was performed. In 10 dogs, a ventral midline laparotomy was performed; in the other 10, abdominal laparoscopy was performed. Dogs were monitored for cardiovascular and respiratory responses (ECG, oxygen saturation [SpO2], arterial blood pressure, rectal temperature, end-tidal partial pressure of carbon dioxide [PETCO2], and expired desflurane concentration). Recovery times were recorded. RESULTS: Mean +/- SD duration of anesthesia was 201 +/- 25 minutes for dogs undergoing laparotomy and 287 +/- 15 minutes for dogs undergoing laparoscopy. Anesthesia was accompanied by hypotension that was less severe in dogs undergoing laparoscopy. Heart rate did not vary significantly during anesthesia. The SpO2 was > 97% in all dogs at all times, and PETCO2 remained within reference limits. Recovery times for dogs that underwent laparotomy were not significantly different from those for dogs that underwent laparoscopy. Mean +/- SD time to standing was 13.6 +/- 2.4 minutes for dogs that underwent laparotomy and 12.5 +/- 2.9 minutes for dogs that underwent laparoscopy. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that induction of anesthesia with propofol and maintenance with desflurane and fentanyl is safe in dogs undergoing abdominal surgery.     

Effect of changes in ionized calcium concentration in arterial blood and metabolic acidosis on the arterial partial pressure of oxygen in dogs

OBJECTIVE: To evaluate the effects of metabolic acidosis and changes in ionized calcium (Ca2+) concentration on PaO2 in dogs. ANIMALS: 33 anesthetized dogs receiving assisted ventilation. PROCEDURE: Normal acid-base status was maintained in 8 dogs (group I), and metabolic acidosis was induced in 25 dogs. For 60 minutes, normocalcemia was maintained in group I and 10 other dogs (group II), and 10 dogs were allowed to become hypercalcemic (group III); hypocalcemia was then induced in groups I and II. Groups II and IV (5 dogs) were treated identically except that, at 90 minutes, the latter underwent parathyroidectomy. At intervals, variables including PaO2, Ca2+ concentration, arterial blood pH (pHa), and systolic blood pressure were assessed. RESULTS: In group II, PaO2 increased from baseline value (96 +/- 2 mm Hg) within 10 minutes (pHa, 7.33 +/- 0.001); at 60 minutes (pHa, 7.21 +/- 0.02), PaO2 was 108 +/- 2 mm Hg. For the same pHa decrease, the PaO2 increase was less in group III. In group I, hypocalcemia caused PaO2 to progressively increase (from 95 +/- 2 mm Hg to 104 +/- 3 mm Hg), which correlated (r = -0.66) significantly with a decrease in systolic blood pressure (from 156 +/- 9 mm Hg to 118 +/- 10 mm Hg). Parathyroidectomy did not alter PaO2 values. CONCLUSIONS AND CLINICAL RELEVANCE: Induction of hypocalcemia and metabolic acidosis each increased PaO2 in anesthetized dogs, whereas acidosis-induced hypercalcemia attenuated that increase. In anesthetized dogs, development of metabolic acidosis or hypocalcemia is likely to affect ventilatory control.     

Pre-emptive epidural ketamine or S(+)-ketamine in post-incisional pain in dogs: a comparative study

OBJECTIVE: To compare the pre-emptive analgesic effects of epidural ketamine or S(+)-ketamine on post-incisional hyperalgesia. STUDY DESIGN: Prospective randomized study. ANIMALS: Twenty-four mongrel dogs (1-5 years, weighing 11.9+/-1.8 kg). METHODS: Dogs were anesthetized with propofol (5 mg/kg intravenously) and a lumbosacral epidural catheter was placed. Dogs were randomly allocated to 3 groups, each with 8 dogs. The control group (CG) was administered saline solution (0.3 mL/kg); the ketamine group (KG) ketamine (0.6 mg/kg); and the S(+)-ketamine group (SG) S(+)-ketamine (0.6 mg/kg). The final volume was adjusted to 0.3 mL/kg in all groups. Five minutes after the epidural injection a surgical incision was made in the common pad of the right hind limb and was immediately closed with simple interrupted nylon suture. Respiratory (RR) and heart (HR) rates, rectal temperature (T), sedation (S), lameness score, and mechanical nociceptive threshold by von Frey filaments were evaluated before the propofol anesthesia and at 15, 30, 45, 60, 75, and 90 minutes and then at 2, 4, 6, 8, 12, and 24 hours after epidural injection. RESULTS: There were no differences in RR, HR, T, or S between groups. Motor blockade of the hind limbs was observed during 20+/-3.6 minutes in KG and during 30.6+/-7.5 minutes in SG (mean+/-SD). Mechanical force applied to obtain an aversive response was higher from 45 minutes to 12 hours in KG and from 60 to 90 minutes in SG, when compared with CG. CONCLUSIONS: Pre-emptive epidural ketamine induced no alterations in RR and HR, and reduced post-incisional hyperalgesia for a longer time than did S(+) ketamine. CLINICAL RELEVANCE: Although anesthetic and analgesic potency of S(+) ketamine is twice that of ketamine, the racemic form is seemingly better for post-incisional hyperalgesia.     

Circular external skeletal fixation stabilization of antebrachial and crural fractures in 25 dogs

Fracture stabilization using circular external skeletal fixation was evaluated in 14 dogs with antebrachial fractures and 11 dogs with crural fractures. Most dogs were consistently weight bearing on the stabilized limb by 3 days following surgery. Although all dogs developed minor wire/pin tract inflammation and eight dogs developed major wire/pin tract inflammation, postoperative lameness was not consistently associated with wire/pin tract complications. Fractures in 23 dogs achieved radiographic union (mean +/- standard deviation [SD], 61 +/- 21 days; median, 57 days) without additional surgery; two dogs required restabilization of their fractures with linear fixators. Twenty of the 21 owners that could be contacted felt their dog had no (n=15) or only a mild (n=5) intermittent lameness at the time of final, long-term (mean +/- SD, 37 +/- 17 months; median, 42 months) assessment.     

Evaluation of a combined transcutaneous carbon dioxide pressure and pulse oximetry sensor in adult sheep and dogs

OBJECTIVE: To evaluate a combined transcutaneous carbon dioxide pressure (tcPCO(2)) and pulse oximetry sensor in sheep and dogs. ANIMALS: 13 adult sheep and 11 adult dogs. PROCEDURES: During inhalation anesthesia, for the first 10 minutes following sensor placement, arterial blood gas was analyzed and tcPCO(2) was recorded every 2 minutes. Subsequently, the animals were hyper-, normo-, and hypoventilated. The simultaneously obtained tcPCO(2) and PaCO(2) values were analyzed by use of Bland-Altman statistical analysis. RESULTS: Mean +/- SD overall difference between tcPCO(2) and PaCO(2) 10 minutes after sensor application was 13.3 +/- 8.4 mm Hg in sheep and 8.9 +/- 12 mm Hg in dogs. During hyper-, normo-, and hypoventilation, mean difference (bias) and precision (limits of agreement [bias +/- 2 SD]) between tcPCO(2) and PaCO(2) values were 13.2 +/- 10.4 mm Hg (limits of agreement, -7.1 and 33.5 mm Hg) in sheep and 10.6 +/- 10.5 mm Hg (limits of agreement, -9.9 and 31.2 mm Hg) in dogs, respectively. Changes in PaCO(2) induced by different ventilation settings were detected by the tcPCO(2) sensor with a lag (response) time of 4.9 +/- 3.5 minutes for sheep and 6.2 +/- 3.6 minutes for dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The tcPCO(2) sensor overestimated PaCO(2) in sheep and dogs and followed changes in PaCO(2) with a considerable lag time. The tcPCO(2) sensor might be useful for noninvasive monitoring of changes but cannot be used as a surrogate measure for PaCO(2).     

Liver function tests in dogs with portosystemic shunts: measurement of serum bile acid concentration

Sulfobromophthalein excretion and plasma ammonia and serum bile acid concentrations were measured in 11 dogs with portal vascular anomalies. The fasting serum bile acid concentration was increased in all 11 dogs (78.9 +/- 16.1 mumol/L; normal, 2.6 +/- 0.4 mumol/L). For values measured in 8 dogs, the 2-hour postprandial serum bile acid concentration was increased further (177.0 +/- 26.4 mumol/L; normal, 7.6 +/- 2.3 mumol/L). The fasting plasma ammonia concentration was markedly increased in all 11 dogs (246.9 +/- 40.3 micrograms/dl; normal, 27 to 15 micrograms/dl). Thirty minutes after the oral administration of ammonium chloride, the plasma ammonia concentration was increased further in the 7 dogs (510.7 +/- 45.5 micrograms/dl; normal, 57.5 to 20.5 micrograms/dl). Results of the sulfobromophthalein excretion test were abnormal in 10 of 11 dogs (12.3 +/- 1.4%; normal, less than 5% retention after 30 minutes).     

In vitro evaluation of screws and suture anchors in metaphyseal bone of the canine tibia

OBJECTIVE: To compare ease of insertion, load to failure, and mode of failure of cortical and cancellous screws, BoneBiter, IMEX, and TwinFix suture anchors in canine metaphyseal tibial bone. STUDY DESIGN: Experimental biomechanical study. ANIMALS: Canine cadaveric tibias. METHODS: One investigator inserted all anchors and subjectively evaluated ease of placement. Anchor systems were loaded to failure along axis of insertion with audio-video recording to determine failure mode. RESULTS: BoneBiter was the most difficult anchor to insert successfully. Mean+/-SD loads to failure were cancellous screw (711+/-193 N), IMEX 4.7 mm 18 g wire (661+/-163 N), IMEX 4.0 mm 18 g wire (661+/-165 N), cortical screw (635+/-184 N), BoneBiter #5 Kevlar suture (393+/- 109 N), and TwinFix 5.0 mm #2 polyester (267+/-73 N). No significant differences were noted among the cortical screw, cancellous screw, IMEX 4.7 and 4.0 mm, all of which were significantly (P<.001) greater than BoneBiter and TwinFix . Failure modes were pullout of bone, suture-wire breakage, eyelet breakage, or no failure to 1000 N: screws (18,0,0,2), IMEX (18,1,1,0), BoneBiter (2,8,0,0), and TwinFix (0,10,0,0). CONCLUSIONS: Fixation devices were user friendly, with the exception of BoneBiter. Mode of failure is dependent on suture material and anchor design. Cortical and cancellous screws, and IMEX anchors with 18 g wire have significantly greater load to failure compared with BoneBiter and TwinFix suture anchors. CLINICAL RELEVANCE: Based on load to failure, ease of use, design characteristics, and cost, IMEX anchors may have advantages over other comparable soft tissue fixation devices.     

Evaluation of induction characteristics and hypnotic potency of isoflurane and sevoflurane in healthy dogs

OBJECTIVE: To determine induction characteristics and the minimum alveolar concentration (MAC) at which consciousness returned (MACawake) in dogs anesthetized with isoflurane or sevoflurane. ANIMALS: 20 sexually intact male Beagles. PROCEDURES: In experiment 1, 20 dogs were randomly assigned to have anesthesia induced and maintained with isoflurane or sevoflurane. The MAC at which each dog awoke in response to auditory stimulation (MACawake-noise) was determined by decreasing the end-tidal concentration by 0.1 volume (vol %) every 15 minutes and delivering a standard audible stimulus at each concentration until the dog awoke. In experiment 2, 12 dogs received the same anesthetic agent they were administered in experiment 1. After duplicate MAC determination, the end-tidal concentration was continually decreased by 10% every 15 minutes until the dog awoke from anesthesia (MACawake). RESULTS: Mean induction time was significantly greater for isoflurane-anesthetized dogs (212 seconds), compared with the sevoflurane-anesthetized dogs (154 seconds). Mean+/-SD MACawake-noise was 1.1+/-0.1 vol % for isoflurane and 2.0+/-0.2 vol % for sevoflurane. Mean MAC was 1.3+/-0.2 vol % for isoflurane and 2.1+/-0.6 vol % for sevoflurane, and mean MACawake was 1.0+/-0.1 vol % for isoflurane and 1.3+/-0.3 vol % for sevoflurane. CONCLUSIONS AND CLINICAL RELEVANCE: Sevoflurane resulted in a more rapid induction than did isoflurane. The MACawake for dogs was higher than values reported for both agents in humans. Care should be taken to ensure that dogs are at an appropriate anesthetic depth to prevent consciousness, particularly when single-agent inhalant anesthesia is used.     

Evaluation of surgical repair of humeral condylar fractures using self-compressing orthofix pins in 23 dogs

OBJECTIVE: To report short- and long-term clinical and radiographic outcomes in dogs with humeral condylar fractures repaired using self-compressing Orthofix pins. STUDY DESIGN: Retrospective evaluation with solicited long-term clinical and radiographic evaluations. ANIMALS: Twenty-three dogs with humeral condylar fractures. METHODS: Medical records and radiographs were reviewed. Owners were asked to return dogs for long-term clinical and radiographic evaluation. RESULTS: Dogs were aged 1.5-26 months (mean+/-SD, 5.8+/-5.0 months) with 20 dogs weighing <5 kg (mean, 3.6+/-2.8 kg). Of 21 dogs with immediate post-operative radiographs, 10 had anatomic reduction with the rest having either a step and/or gap at the articular surface. Kirschner wire migration and implant loosening were the most common post-operative complications. All fractures with adequate follow-up radiographic evaluations achieved union. Twelve of 13 dogs returned for long-term evaluation (mean, 19.0+/-18.5 months) were either sound (10 dogs) or had subtle, weight-bearing lameness (2). Fourteen dogs had radiographs >/=75 days after surgery (mean, 18.7+/-18.3 months), 8 dogs (57%) had no radiographic evidence of osteoarthritis (OA; mean OA score, 0.8; median 0), and all dogs had good or excellent limb function. CONCLUSIONS: Self-compressing Orthofix pins are suitable implants for the stabilization of humeral condylar fractures in small breed dogs. Implants were convenient and simple to use and complications were easily resolved. Dogs consistently had good long-term clinical and radiographic outcomes with no or minimal lameness and OA. CLINICAL RELEVANCE: Self-compressing Orthofix pins should be considered for the repair of humeral condylar fractures in small breed dogs.     

Changes in pH of peritoneal fluid associated with carbon dioxide insufflation during laparoscopic surgery in dogs

OBJECTIVE: To evaluate changes in pH of peritoneal fluid associated with CO2 insufflation during laparoscopy in dogs. ANIMALS: 13 client-owned dogs and 10 purpose-bred teaching dogs. PROCEDURES: Laparotomy was performed on control dogs; peritoneal fluid pH was measured at time of incision of the abdominal cavity (time 0) and 30 minutes later. Laparoscopic insufflation with CO2 was performed and routine laparoscopic procedures conducted on the teaching dogs. Insufflation pressure was limited to 12 mm Hg. Intraperitoneal fluid pH was measured by use of pH indicator paper at 4 time points. Arterial blood gas analysis was performed at the same time points. RESULTS: Peritoneal fluid pH did not change significantly between 0 and 30 minutes in the control dogs. For dogs with CO2 insufflation, measurements obtained were a mean of 8.5, 24.5, 44.5, and 72.0 minutes after insufflation. The pH of peritoneal fluid decreased significantly between the first (7.825 +/- 0.350) and second (7.672 +/- 0.366) time point. Blood pH decreased significantly between the first (7.343 +/- 0.078), third (7.235 +/- 0.042), and fourth (7.225 +/- 0.038) time points. The PaCO2 increased significantly between the first (39.9 +/- 9.8 mm Hg) and fourth (54.6 +/- 4.4 mm Hg) time points. Base excess decreased significantly between the first and all subsequent time points. CONCLUSIONS AND CLINICAL RELEVANCE: Pneumoperitoneum attributable to CO2 insufflation caused a mild and transient decrease in peritoneal fluid pH in dogs. Changes in peritoneal fluid associated with CO2 insufflation in dogs were similar to those in other animals.     

Cardiopulmonary, anesthetic, and postanesthetic effects of intravenous infusions of propofol in greyhounds and non-greyhounds.

The cardiopulmonary, anesthetic, and postanesthetic effects of an IV infusion of the hypnotic agent propofol were assessed in 6 Greyhounds and 7 non-Greyhounds. After IM injection of acetylpromazine and atropine, a bolus injection of propofol sufficient to allow endotracheal intubation (mean +/- SEM = 4.0 +/- 0.3 mg/kg of body weight in Greyhounds; 3.2 +/- 0.1 mg/kg in non-Greyhounds) was administered, followed by continuous infusion at a rate of 0.4 mg/kg/min for 60 minutes, during which time dogs breathed 100% oxygen. In 23% of all dogs (3 of 13), apnea developed after initial bolus administration of propofol. Arterial blood pressure was well maintained in all dogs, but heart and respiratory rates were decreased significantly (P less than 0.05) during the infusion in Greyhounds. In Greyhounds, mild respiratory acidosis developed after 45 minutes, whereas arterial carbon dioxide tension was increased at all times after propofol administration in non-Greyhounds. In all dogs, PCV and total plasma proteins were unaffected by propofol. Rectal temperature decreased during treatment. Muscle tremors were observed in approximately 50% of dogs (in 3 of 6 Greyhounds and 3 of 7 non-Greyhounds) during and after infusion of propofol. Non-Greyhounds lifted their heads, assumed sternal recumbency, and stood 10 +/- 1, 15 +/- 3, and 28 +/- 5 minutes, respectively, after the end of the infusion; in Greyhounds, the corresponding times were 36 +/- 4, 43 +/- 6, and 63 +/- 7 minutes.     

Effects of preoperative administration of ketoprofen on whole blood platelet aggregation,buccal mucosal bleeding time,and hematologic indices in dogs undergoing elective ovariohysterectomy

OBJECTIVE: To determine effects of preoperative administration of ketoprofen on whole blood platelet aggregation, buccal mucosal bleeding time, and hematologic indices in dogs after elective ovariohysterectomy. DESIGN: Randomized, masked clinical trial. ANIMALS: 22 healthy dogs. PROCEDURE: 60 minutes before induction of anesthesia, 11 dogs were given 0.9% NaCl solution (control), and 11 dogs were given ketoprofen (2 mg/kg [0.9 mg/lb], IM). Thirty minutes before induction of anesthesia, glycopyrrolate (0.01mg/kg [0.005 mg/lb]), acepromazine (0.05 mg/kg [0.02 mg/lb]), and butorphanol (0.2 mg/kg 10.09 mg/lb]) were given IM to all dogs. Anesthesia was induced with thiopental (5 to 10 mg/kg [2.3 to 4.5 mg/lb], IV) and maintained with isoflurane (1 to 3%). Ovariohysterectomy was performed and butorphanol (0.1 mg/kg [0.05 mg/lb], IV) was given 15 minutes before completion of surgery. Blood samples for measurement of variables were collected at intervals before and after surgery. RESULTS: In dogs given ketoprofen, platelet aggregation was decreased 95 +/- 10% and 80 +/- 35% (mean +/- SD) immediately after surgery and 24 hours after surgery, respectively, compared with preoperative values. At both times, mean values in dogs given ketoprofen differed significantly from those in control dogs. Significant differences between groups were not observed for mucosal bleeding time or hematologic indices. CONCLUSIONS AND CLINICAL RELEVANCE: Preoperative administration of ketoprofen inhibited platelet aggre gation but did not alter bleeding time. Ketoprofen can be given before surgery to healthy dogs undergoing elective ovariohysterectomy, provided that dogs are screened for potential bleeding problems before surgery and monitored closely after surgery.     

Extra-articular absorbable suture stabilization of coxofemoral luxation in dogs

OBJECTIVE: To evaluate the effectiveness of an extra-articular surgical technique using absorbable suture material for the stabilization of traumatic coxofemoral luxation in dogs. STUDY DESIGN: Prospective, clinical study. ANIMALS: Fourteen client-owned dogs with recent and long-standing traumatic coxofemoral luxation (13 craniodorsal and 1 ventral). METHODS: Coxofemoral luxations were surgically reduced and maintained in place with an extra-articular iliofemoral multifilamentous absorbable suture (3 to 6 strands of 2 USP Polyglactin 910). No external support was employed, and all the dogs were encouraged to use the affected limb postoperatively. The average time of clinical and radiographic follow-up was 11.6 +/- 6.3 months (from 2 to 22 months). RESULTS: During the follow-up period, no reluxations occurred and no complications associated with the surgical technique were identified. The dogs started bearing weight from 1 to 10 days after the surgery (mean, 4.3 +/- 2.9 days) and the period of lameness ranged from 7 to 30 days (20 +/- 8.6 days). At the final clinical examination, the dogs did not demonstrate any lameness or pain during passive flexo-extension movements, and there was no significant limitation of the range of motion. CONCLUSION: Extra-articular stabilization with multifilamentous absorbable sutures is a simple, effective method of treatment for acute and chronic coxofemoral luxation. The absorbable material used is strong enough to maintain articular stability during the period of scar tissue formation even in large-breed dogs. CLINICAL RELEVANCE: Absorbable sutures avoid the possible complications related to the use of nonabsorbable material and seem to be sufficient to maintain articular stability during the capsular healing process.     

Influence of three anesthetic protocols on glomerular filtration rate in dogs

OBJECTIVE: To investigate renal function in clinically normal dogs when awake and during anesthesia with medetomidine; xylazine, ketamine, and halothane (XKH) combination; or propofol. ANIMALS: 10 adult female Beagles. PROCEDURES: At intervals of 15 days, dogs were administered medetomidine (0.05 mg/kg, IV); XKH combination (xylazine [1 mg/kg, IV], ketamine [5 mg/kg, IV], and halothane [1% end-tidal concentration]); or propofol (6 mg/kg, IV) to induce anesthesia or no treatment. Glomerular filtration rate was assessed on the basis of renal uptake (RU; determined via renal scintigraphy) and plasma clearance (CL) of technetium 99m-labeled diethylenetriamine pentaacetic acid ((99m)Tc-DTPA). RESULTS: In awake dogs, mean +/- SEM RU was 9.7 +/- 0.4% and CL was 3.86 +/- 0.23 mL/min/ kg. Renal uptake and CL of (99m)Tc-DTPA were not significantly modified by administration of XKH (RU, 11.4 +/- 0.9%; CL, 4.6 +/- 0.32 mL/min/kg) or propofol (RU, 9.7 +/- 0.3%; CL, 3.78 +/- 0.37 mL/min/kg). Half-life elimination time of plasma (99m)Tc-DTPA decreased significantly in XKH-anesthetized dogs, compared with the value in awake dogs (14.4 minutes and 28.9 minutes, respectively). However, glomerular filtration rate was significantly decreased by administration of medetomidine (RU, 3.9 +/- 0.1%), and the time to maximum kidney activity was significantly increased (867 +/- 56 seconds vs 181 +/- 11 seconds without anesthesia). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that anesthesia with propofol or an XKH combination did not alter renal function in healthy Beagles, but anesthesia with medetomidine decreased early RU of (99m)Tc-DTPA.     

Eructation of gas through the gastroesophageal sphincter before and after gastric fundectomy in dogs

The gas eructation function of the gastroesophageal sphincter (GES) was investigated in 6 conscious, fed dogs before and after gastric fundectomy. Using a perfused 4-lumen catheter with a Dent sleeve, gastric and GES pressures were measured. To induce eructation, nitrogen gas was insufflated (440 ml/min) into the stomach through one channel of the catheter. After base-line studies were completed on each dog, fundectomy, to remove 30% of the stomach, was performed. Mean (+/- SEM) GES pressure was 45.3 +/- 3.3 mm of Hg before fundectomy and 41.4 +/- 1.9 mm of Hg after fundectomy (P greater than 0.05). Before fundectomy, treatment with metoclopramide or cisapride increased GES pressure to 62.2 +/- 4.1 mm of Hg (P less than 0.001) and 61.1 +/- 5.0 mm of Hg (P less than 0.05), respectively. Gastric contraction rates were the same, 4.92 +/- 0.24/min and 4.80 +/- 0.16/min before and after fundectomy, respectively. During insufflation, gastric pressures before eructation increased to 12.2 +/- 1.3 mm of Hg before fundectomy and to 13.6 +/- 0.9 mm of Hg after fundectomy (P greater than 0.05). Eructation occurred at intervals of 1.44 +/- 0.20 minutes before fundectomy and 1.56 +/- 0.13 minutes after fundectomy (P greater than 0.05). Before fundectomy, administration of metoclopramide or cisapride resulted in eructation intervals of 1.72 +/- 0.21 minutes and 1.39 +/- 0.02 minutes, respectively; these intervals were not significantly different from those measured in dogs not given drugs. After fundectomy, the GES pressure in 5 dogs decreased and remained low during insufflation. After a series of normal eructation intervals, multiple eructations were observed in 4 of these dogs. Fundectomy did not impair ability to eructate gas from the stomach.     

Evaluation of a portocaval venograft and ameroid ring for the occlusion of intrahepatic portocaval shunts in dogs

OBJECTIVE:To evaluate the use of a portocaval venograft and ameroid constrictor in the surgical management of intrahepatic portosystemic shunts (PSS). STUDY DESIGN: Prospective, clinical study. Animal Population: Ten client-owned dogs with intrahepatic PSS. METHODS: Portal pressure was measured after temporary suture occlusion of the intrahepatic PSS. In dogs with an increase in portal pressure greater than 8 mm Hg, a single extrahepatic portocaval shunt was created using a jugular vein. An ameroid ring was placed around the venograft and the intrahepatic PSS was attenuated. Transcolonic pertechnetate scintigraphy was performed before surgery, 5 days after surgery, and 8 to 10 weeks after surgery. Dogs with continued portosystemic shunting were evaluated further by laparotomy or portography. Clinical outcome and complications were recorded. RESULTS: Mean (+/- SD) portal pressure increased from 6 +/- 3 to 19 +/- 6 mm Hg with PSS occlusion; in all 10 dogs, the increase in portal pressure was greater than 8 mm Hg. There were no intraoperative complications, and, after creation of the portocaval shunt, the intrahepatic PSS could be completely ligated in 8 of 10 dogs. The final portal pressure was 9 +/- 4 mm Hg. Postoperative complications included coagulopathy and death (1 dog), ascites (3 dogs), and incisional discharge (3 dogs). Five of 8 dogs had continued portosystemic shunting at 8 to 10 weeks after surgery. Multiple extrahepatic PSS were demonstrated in 4 of these dogs. Clinical outcome was excellent in all 9 surviving dogs. CONCLUSIONS AND CLINICAL SIGNIFICANCE: The surgical technique resulted in a high incidence of multiple extrahepatic PSS. Short-term clinical results were promising, but long-term outcome must be evaluated further.     

Comparative study of the pharmacokinetics of alfentanil in rabbits, sheep, and dogs

The central arterial pharmacokinetics of alfentanil, a short-acting opioid agonist, were studied in rabbits, sheep, and dogs after short-duration infusion of the drug. Alfentanil was infused until a set end point (high-amplitude, slow-wave activity on the EEG) was reached. This required a larger alfentanil dose and a higher alfentanil arterial concentration in sheep, compared with rabbits and dogs. The plasma concentration-time data for each animal were fitted, using nonlinear regression, and in all animals, were best described by use of a triexponential function. In this study, differences in the disposition kinetics of alfentanil among the 3 species were found for only distribution clearance and initial distribution half-life. In dogs, compared with rabbits and sheep, the first distribution half-life was longer, probably because of pronounced drug-induced bradycardia (mean +/- SD, 48 +/- 21 beats/min). Distribution clearance was faster in sheep, compared with dogs, also probably because of better blood flow in sheep. Elimination half-life was similar in all species (rabbits, 62.4 +/- 11.3 minutes; sheep, 65.1 +/- 27.1 minutes; dogs, 58.3 +/- 10.3 minutes). This rapid half-life resulted from a small steady-state volume of distribution (rabbits, 908.3 +/- 269.0 ml/kg; sheep, 720.0 +/- 306.7 ml/kg; dogs, 597.7 +/- 290.2 ml/kg) and rapid systemic clearance (rabbits, 19.4 +/- 5.3 ml/min/kg; sheep, 13.3 +/- 3.0 ml/min/kg; dogs, 18.7 +/- 7.5 ml/min/kg). On the basis of these pharmacokinetic variables, alfentanil should have short duration of action in rabbits, sheep, and dogs. This may be beneficial in veterinary practice where rapid recovery would be expected after bolus administration for short procedures or after infusion for longer procedures.     

Long-term outcome of distal femoral osteotomy for treatment of combined distal femoral varus and medial patellar luxation: 12 cases (1999-2004)

OBJECTIVE: To determine long-term outcome of distal femoral osteotomy as a component of treatment for distal femoral varus and medial patellar luxation in large-breed dogs. DESIGN:Retrospective case series. ANIMALS: 12 dogs (16 stifle joints). PROCEDURES: Medical records and radiographs were reviewed to identify large-breed dogs with medial patellar luxation (grade > or = 2) and femoral varus angle > or = 12 degrees treated with distal femoral osteotomy, with a minimum follow-up (by a veterinarian) of 18 months. Signalment, weight, medial patellar luxation and lameness grade, pre- and postoperative femoral varus angle, surgical technique, time to radiographic bone union, and complications were recorded. Follow-up with owners via questionnaire was performed > 18 months after surgery. RESULTS: 16 corrective distal femoral osteotomies were performed with ancillary medial patellar luxation procedures in 12 dogs; 4 dogs had staged bilateral procedures. Mean +/- SD preoperative and postoperative femoral varus angles were 16.3 +/- 4.3 degrees and 3.9 +/- 2.5 degrees , respectively. Mean +/- SD time to radiographic union of the distal femoral osteotomy was 52.6 +/- 13 days. One dog had Kirschner wire migration from the tibial tuberosity. Patellar luxation was not detected after surgery in any dog. Mean +/- SD follow-up by a veterinarian was 1,335 +/- 410 days and by use of an owner questionnaire was 1,497 +/- 464 days. All 10 variables of owner-observed patient comfort and function were significantly improved. CONCLUSIONS AND CLINICAL RELEVANCE: Distal femoral osteotomy in combination with traditional treatment provided predictable osteotomy healing, patellar stabilization, and long-term improvement in patient comfort and function when used to treat combined distal femoral varus and medial patellar luxation in large-breed dogs.