Evaluation of the addition of adrenaline in a bilateral maxillary nerve block to reduce hemorrhage in dogs undergoing sharp staphylectomy for brachycephalic obstructive airway syndrome. A prospective, randomized study

OBJECTIVE

To assess the use of adrenaline (0.00198%) in a bilateral maxillary nerve block to reduce intraoperative hemorrhage in dogs undergoing staphylectomy for the treatment of brachycephalic obstructive airway syndrome (BOAS).

STUDY DESIGN

Prospective, randomized, double-blinded controlled study.

SAMPLE POPULATION

A total of 32 client owned, clinically affected dogs undergoing a cut and sew sharp staphylectomy for treatment of BOAS. A total of 16 dogs randomly assigned to adrenaline (A) group and 16 to no-adrenaline (NA) group.

METHODS

A bilateral maxillary nerve block was performed in all dogs prior to staphylectomy using lidocaine alone (group NA) or a combination of lidocaine and adrenaline (group A). Total hemorrhage was measured by weighing cotton-tipped applicators and swabs used on precision scales. In addition, a semi-quantitative hemorrhage score (1-5) was determined. Dogs were monitored for intraoperative hemodynamic stability during the procedure.

RESULTS

Total hemorrhage was significantly (p = .013) lower in group A compared with group NA. The median semi-quantitative hemorrhage score was significantly lower for group A (p = .029) compared with group NA. No significant adverse effects were noted due to adrenaline usage.

CONCLUSION

This study demonstrated that the use of adrenaline in a bilateral maxillary nerve block results in significantly lower intraoperative hemorrhage during cut and sew sharp staphylectomy and appeared safe to use.

CLINICAL SIGNIFICANCE

Potential clinical advantages include improved visualization, prevention of unnecessary blood loss and reduction in risk of blood aspiration.

Use of a vessel-sealing device versus conventional hemostatic techniques in dogs undergoing thyroidectomy because of suspected thyroid carcinoma

OBJECTIVE

To compare use of a vessel-sealing device (VSD) versus conventional hemostatic techniques in dogs undergoing thyroidectomy because of suspected thyroid carcinoma.

DESIGN

Retrospective cohort study.

ANIMALS

42 client-owned dogs undergoing thyroidectomy because of suspected thyroid carcinoma.

PROCEDURES

Medical records of dogs treated at 4 referral centers from 2010 through 2016 were reviewed, and information was obtained on patient signalment, surgical technique, tumor-specific factors, and operative duration. Postoperative hospitalization time and complications were compared between dogs grouped on the basis of hemostatic technique.

RESULTS

Thyroidectomy was performed with a VSD in 23 dogs and with conventional hemostatic techniques (ie, ligatures, hemoclips, or electrocautery) in 19 dogs. Hemostatic technique (ie, use of a VSD vs conventional hemostatic techniques) was the only factor significantly associated with operative duration (median time, 28 vs 41 minutes). Postoperative hospitalization times and complication rates did not differ between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that use of a VSD, rather than conventional hemostatic techniques, in dogs undergoing thyroidectomy because of suspected thyroid carcinoma resulted in shorter operative times without significantly affecting complication rates or postoperative hospitalization times.

Electrolyte and acid/base changes in dogs undergoing autologous blood transfusion via a cell salvage device

This study reports electrolyte and acid/base disturbances observed in clinical cases receiving autologous transfusion of blood processed by a cell salvage device. The records of 12 client-owned dogs that received an autologous transfusion via a cell salvage device with pre- and post-autologous transfusion blood work available were reviewed. Blood work from the 12 case dogs was compared to blood work from 12 control dogs with similar diseases. Control dogs received similar surgical treatment and were administered a similar volume per kg of packed red blood cells as case dogs, but did not undergo autologous transfusion. Case dogs that received autologous transfusion via a cell salvage device were significantly more likely to experience a decrease in ionized calcium and magnesium levels post-transfusion than were control dogs. Calcium and magnesium levels should be closely monitored during and after autologous transfusion. Calcium and/or magnesium supplementation may be required.

Efficacy of a half-grip technique using a fine tip LigaSure™, Dolphin Tip Sealer/Divider, on liver dissection in swine model

BACKGROUND

Recently, a lot of energy devices in the surgical field, especially in the liver surgery, have been developed, and a fine tip LigaSure™, Dolphin Tip Sealer/Divider (DT-SD) also has been used frequently to dissect liver parenchyma as well as ultrasonically activated device (USAD). However, the utility of this instrument for liver dissection (LD) is still unknown. Moreover, to reduce bleeding during LD, a half-grip technique (HGT) was contrived. We herein report an experimental study in swine model to evaluate the feasibility and effectiveness of HGT using DT-SD for LD.

METHODS

The swine model experiment was carried out under general anesthesia by veterinarians. LD was performed repeatedly by DT-SD with the HGT (Group A, n = 6), or the conventional clamp-crush technique (CCT) (Group B, n = 6), and by variable mode USAD (Group C, n = 6). The dissection length and depth (cm) as well as bleeding volume (g) were measured carefully, and the dissection area (cm(2)) and speed (cm(2)/min) were calculated precisely. Histological examinations of the dissection surfaces were also executed. Mann-Whitney's U test was used for Statistical analyses with variance at a significance level of 0.05.

RESULTS

Among the three groups, the three averages of dissection lengths were unexpectedly equalized to 8.3 cm. The dissection area (cm(2)) was 9.9 ± 5.1 in Group A, 9.8 ± 4.7 in Group B, and 9.9 ± 4.5 in Group C. The mean blood loss during LD was 10.6 ± 14.8 g in Group A, 41.4 ± 39.2 g in Group B, and 34.3 ± 39.2 g in Group C. For Group A, the bleeding rate was the least, 0.9 ± 1.0 g/cm(2), and the average depth of coagulation was the thickest, 1.47 ± 0.29 mm, among the three groups (p < 0.05). The dissection speed in Group A (1.3 ± 0.3 cm(2)/min) was slower, than that in Group C (p < 0.05).

CONCLUSIONS

This report indicates firstly that the HGT using DT-SD bring the least blood loss when compared with CCT or USAD. Although the HGT is feasible and useful for LD, to popularize the HGT, further clinical studies will be needed.

Intraoperative bleeding in dogs from Grenada seroreactive to Anaplasma platys and Ehrlichia canis

BACKGROUND

Frequent exposure of Grenadian dogs to Rhipicephalus sanguineus results in Anaplasma platys, and Ehrlichia canis seroreactivity. During elective surgeries, substantial intraoperative hemorrhage occurs in some seroreactive dogs.

OBJECTIVES

To assess hemostatic parameters and bleeding tendencies as well as prevalence of PCR positivity in apparently healthy A. platys and E. canis seroreactive and seronegative free-roaming dogs from Grenada.

ANIMALS

Forty-seven elective surgery dogs allocated to 4 groups: Seronegative control (n = 12), A. platys (n = 10), E. canis (n = 14) and A. platys, and E. canis (n = 11) seroreactive.

METHODS

Preoperatively, hemostasis was assessed by platelet count, prothrombin time, activated partial thromboplastin time, and buccal mucosal bleeding time. Intra- and postoperative bleeding scores were subjectively assigned. Blood, spleen, bone marrow, and lymph node aspirates were tested by PCR.

RESULTS

Bleeding scores in dogs coseroreactive for A. platys and E. canis were higher (P = .015) than those of seronegative dogs. A. platys DNA was amplified from 7/21 (33%) A. platys seroreactive dogs and from 1 E. canis seroreactive dog; E. canis DNA was amplified from 21/25 (84%) E. canis seroreactive dogs. E. canis DNA was amplified most often from blood, whereas A. platys DNA was amplified most often from bone marrow.

CONCLUSIONS AND CLINICAL IMPORTANCE

Apparently healthy, free-roaming dogs coseropositive for A. platys and E. canis may have increased intraoperative bleeding tendencies despite normal hemostatic parameters. Future investigations should explore the potential for vascular injury as a cause for bleeding in these dogs. Improved tick control is needed for dogs in Grenada.

[Intraoperative sonography for examination of intervertebral disk extrusion in the dog]

OBJECTIVE

It has been shown that the components of the vertebral canal (dura mater, pia mater, subarachnoid space, spinal cord parenchyma and central canal) can be visualized intraoperatively with the help of ultrasonography. This study was conducted to document the intraoperative sonographical findings of disc extrusion and to determine imaging criteria for the localisation of the extrusion and the consecutive changes of the spinal cord parenchyma.

MATERIAL AND METHODS

43 dogs of different breeds with a diagnosed disc extrusion were sonographically examined immediately after establishing the surgical decompression (hemilaminectomy, laminectomy, ventral slot) (examination 1) and again after removal of disc material (examination 2).

RESULTS

In all 34 patients the extruded disc material could be imaged sonographically appearing as inhomogenous, hyperechoic areas of moderate echogenicity. There was a distal shadowing dependent on the grade of calcification in 53% of the patients in examination 1 and in 79% at examination 2. Furthermore, a tendency towards a central localisation of the disc prolapse (67.6% in examination 1 and 57.1% examination 2) was observed. Intraoperative identification of disc extrusion could be accomplished in 79% of the cases. Intraoperative haemorrhage highly significantly impaired the assessment of the spinal cord (p<0.0001).

CONCLUSION

Intraoperative spinal ultrasonography using a linear probe with a frequency from 5 to 10 MHz is a valuable tool for the visualization of spinal structures. It provides information for intraspinal navigation and evaluation of the extent of spinal lesions as well as the state of decompression. Bleeding has a negative influence on the visualization of the spinal canal.

Quantification of Surgical Blood Loss

OBJECTIVE

To compare gravimetric and colorimetric methods of quantifying surgical blood loss, and to determine if there is a correlation between preoperative hemostatic tests (buccal mucosa bleeding time [BMBT] and intraoperative blood loss).

STUDY DESIGN

Prospective clinical study.

ANIMALS

Dogs (n=15) admitted for cutaneous tumor excision, orthopedic procedure, or exploratory laparotomy.

METHODS

Intraoperative blood loss was quantified by measuring irrigation fluid and weighing surgical sponges used for blood and fluid collection during surgery. Results of gravimetric measurements were then correlated to blood loss quantified using spectrophotometric analysis of hemoglobin (Hb) content. Hemostatic variables including BMBT were measured before surgery and compared with the calculated amount of blood loss.

RESULTS

Blood loss quantified by gravimetric measurement showed a significant correlation with colorimetric determination of Hb content in surgical sponges and collected irrigation fluid (r=0.93, P<.0001). BMBT correlated weakly but significantly with intraoperative blood loss (r=0.56, P<.05).

CONCLUSIONS

Quantifying intraoperative blood loss using spectrophotometric Hb analysis accurately assessed the amount of blood loss; however, it is a time-consuming procedure, primarily applicable as a research tool. Gravimetric evaluation of intraoperative blood loss was found to be an accurate method, which can be recommended for use in a clinical setting.

CLINICAL RELEVANCE

Estimation of blood loss using a gravimetric method is accurate and applicable in the clinical setting and provides surgeons with a simple and objective tool to evaluate intraoperative blood loss.

The cardiopulmonary effects of severe blood loss in anesthetized horses

OBJECTIVE

To characterize the acute cardiopulmonary effects of severe hemorrhage in anesthetized horses.

STUDY DESIGN

Prospective experimental study.

ANIMALS

Three geldings and six mares, aged 14.4 +/- 2.7 years, weighing 486 +/- 41 kg (range: 425-550 kg).

METHODS

Horses were anesthetized using xylazine, guaifenesin, ketamine and halothane or isoflurane. Cardiovascular variables, hematocrit, total solids, capillary refill time (CRT) and color of mucous membranes were measured as blood was collected from the carotid artery into sterile plastic bags. Arterial blood gas analysis was also performed.

RESULTS

The average amount of blood collected from these horses was (mean +/- SD) 53 +/- 4.8 mL kg(-1) bodyweight (range: 23-32 kg) over 39 +/- 4 minutes. Hematocrit decreased from 38 +/- 3 to 32 +/- 2% after induction of anesthesia and did not change significantly over the period of blood loss. Total solids decreased significantly after induction of anesthesia, and over the period of blood loss. Systolic, mean, diastolic and pulse pressures decreased as blood was lost. Heart rate did not change significantly. Capillary refill time increased from 1.6 +/- 0.4 seconds to 4.8 +/- 1.3 seconds as blood loss increased. Mucous membrane color deteriorated progressively. Arterial PO2 decreased significantly over the period of blood loss.

CONCLUSIONS

Hematocrit and heart rate do not change significantly during acute severe hemorrhage in the anesthetized horse. Arterial blood pressure, pulse pressure and PaO2 decrease as blood loss increases. Changes in mucous membrane color and CRT also occur as blood loss increases.

CLINICAL RELEVANCE

During severe hemorrhage in the inhalant-anesthetized horse, both heart rate and hematocrit remain unchanged. Blood pressure decreases and changes in arterial PO2 correlate most strongly with volume of blood lost.

Penile amputation and sheath ablation in the horse

OBJECTIVE

To report a surgical technique for penile amputation and sheath ablation in horses. Study Design-Retrospective study. Animals or Sample Population-Twenty-five adult geldings of various breeds with conditions requiring penile amputation and sheath ablation.

METHODS

The medical records of horses that had penile amputation and sheath ablation were reviewed. Briefly, the technique involved en bloc resection of the skin and subcutaneous tissues of the inner and outer lamina of the prepuce and penile shaft. Resection of the penile shaft, proximal to diseased segments, and spatulation of the urethral mucosa was followed by fixation of the penis to the ventral abdomen and closure of the peripreputial skin over the ventral aspect of the penis and creation of a new mucocutaneous junction at the urethral orifice.

RESULTS

Mild to moderate postoperative hemorrhage occurred in all horses. Partial dehiscence of the mucocutaneous junction occurred in 8 horses; all healed by second intention. Postoperative pain lasting 24 to 48 hours occurred in 7 horses; 1 required epidural analgesia for pain relief. Long-term follow-up was available for 8 horses; none had any long-term complications.

CLINICAL RELEVANCE

Partial amputation of the penis with pexy to the ventral abdomen and revision of the peripreputial skin can be used as an alternative to en bloc resection and penile retroversion for lesions involving the free part of the penis and the prepuce. It requires smaller incisions and results in less alteration to the normal appearance of the external genitalia than retroversion techniques, while still allowing the surgeon to remove extensive portions of the penis and extirpate the regional lymph nodes.

Surgical technique for intra-abdominal radiotransmitter placement in North American river otters (Lontra canadensis)

Twenty-two free-ranging North American river otters (Lontra canadensis) from northern and eastern New York were captured and surgically implanted with radiotransmitters as part of a relocation project. The surgical technique involved an incision in the paralumbar fossa and transection through the abdominal musculature to introduce a radiotransmitter into the abdominal cavity. Two complications were encountered. Excessive hemorrhage occurred during one procedure. The otter was treated for blood loss with fluids, and it recovered uneventfully. Surgical incision infection occurred in a second animal. The otter was treated with metronidazole and enrofloxacin, and the wound was cleaned daily with chlorhexidine. The otter recovered uneventfully. Otters were released in western New York state. Postrelease monitoring via radiotelemetry revealed that the otters became established in their new ranges. The intra-abdominal implants did not affect their survival or reproductive potential.

Intraoperative hemorrhage during patent ductus arteriosus ligation in dogs

OBJECTIVE

To determine the prevalence of intraoperative hemorrhage in a consecutive series of dogs undergoing patent ductus arteriosus (PDA) ligation at a veterinary teaching hospital, and to describe strategies to reduce the risk of ductus perforation and deal with hemorrhage when it occurs.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Sixty-four dogs.

METHODS

The records of all dogs undergoing PDA ligation at the University Veterinary Center, Sydney between May 1989 and February 1998 were reviewed and the prevalence and nature of complications identified.

RESULTS

Serious hemorrhage occurred in 4 of 64 dogs (6.25%) that underwent PDA ligation. In all cases, hemorrhage resulted from perforation of the craniomedial aspect of the ductus while attempting to expose the tips of the dissecting forceps. Hemorrhage was controlled in 3 dogs by clamping the main pulmonary artery, digital compression of the descending aorta, and completion of ductus ligation during an approximately 5-minute period of circulatory arrest. The remaining dog exsanguinated during an unsuccessful attempt to locate, clamp, and ligate the bleeding point. The mortality rate for PDA ligation was I of 64 dogs (1.6 %).

CONCLUSIONS

The technique described in this report permits simple ligation of a range of different ductus morphologies in dogs of varying breeds, weights, and ages. In the event of serious hemorrhage, prompt ventricular outflow occlusion and ductus ligation followed by rapid whole blood transfusion is life saving in most cases.

The effect of differing rates and injection sites on the amount of protamine delivered before detection of hemodynamic alterations in dogs

OBJECTIVES

To determine the effect of the route and rate of protamine administration on the amount of protamine that could be delivered before a hemodynamic reaction occurred in dogs.

STUDY DESIGN

Prospective randomized experimental study.

ANIMALS

Twenty adult mixed-breed dogs weighing 25.1+/-2.5 kg.

METHODS

Before vascular surgery, the dogs were heparinized to reach an activated clotting time (ACT) of 300 seconds. After completion of the vascular surgery, protamine was administered intravenously until a hemodynamic reaction was recorded. The 4 groups of dogs were given protamine at 5 mg/min (slow) or 10 mg/min (fast) via the cephalic or the jugular veins. Systemic and pulmonary arterial pressures, central venous pressure (CVP), and pulmonary arterial occlusion pressure (PAOP) were recorded before and after protamine administration. The dose of protamine was recorded when a reaction occurred, which was defined as mean arterial pressure (MAP) <60 mm Hg or mean pulmonary arterial pressure (MPAP) >20 mm Hg or more than double the baseline value.

RESULTS

Significant decreases in systolic arterial pressure (SAP), MAP, and diastolic arterial pressure (DAP) and significant increases in systolic (SPAP), mean (MPAP), and diastolic (DPAP) pulmonary arterial pressures were recorded after protamine administration. The cephalic slow group had significantly fewer protamine reactions than other groups (chi-square = 8.57, P = .03, df = 3). Significantly more protamine could be delivered from the cephalic vein (52.5+/-14.5 mg) compared with the jugular vein (37.6+/-16 mg) before a reaction occurred (P = .048).

CONCLUSION

The rate of administration did not have an effect on the amount of protamine delivered. Adverse reactions were minimized when protamine was administered via the cephalic vein at a slow rate.

CLINICAL RELEVANCE

We would recommend delivering protamine after cardiopulmonary bypass or vascular surgery through a peripheral venous route.

Comparison of ketoprofen and carprofen administered prior to orthopedic surgery for control of postoperative pain in dogs

OBJECTIVE

To compare analgesic and adverse effects of ketoprofen and carprofen when used to control pain associated with elective orthopedic surgeries in dogs.

DESIGN

Prospective randomized clinical trial.

ANIMALS

93 client-owned dogs: 46 undergoing reconstruction of the cranial cruciate ligament, 47 undergoing femoral head and neck excision, and 15 control dogs anesthetized for radiographic procedures.

PROCEDURE

Dogs undergoing surgery were randomly given ketoprofen, carprofen, or saline (0.9% NaCl) solution, SC, prior to surgery. Pain score and serum cortisol concentration were recorded for 12 hours after surgery for all dogs. When pain score was > or = 7, oxymorphone was administered i.m. Bleeding time was measured prior to and during surgery.

RESULTS

The proportion of dogs that required oxymorphone was significantly higher for the carprofen and placebo groups than for the ketoprofen group. Pain score for the placebo group was significantly higher than for the ketoprofen and carprofen groups, 2, 8, and 9 hours after surgery. Cortisol concentration was significantly higher for the placebo group than for the carprofen group at 4 and 6 hours after surgery. Significant differences were not detected between ketoprofen and carprofen groups with respect to pain score and cortisol concentration. Bleeding time was significantly longer for the ketoprofen group than for the other groups during surgery. One dog treated with ketoprofen developed a hematoma at the surgical site.

CONCLUSIONS AND CLINICAL RELEVANCE

Ketoprofen and carprofen given prior to surgery were effective for postoperative pain relief in dogs. However, ketoprofen should not be used when noncompressible bleeding may be a problem.

Complications and mortality associated with anesthesia in dogs and cats

The complications and mortality associated with anesthesia of dogs and cats in a university teaching hospital were determined. During one year, 2,556 dogs and 683 cats were anesthetized by the anesthesia service. Hypotension occurred in 179 (7%) dogs and 58 (8.5%) cats. Cardiac dysrhythmias occurred in 64 (2.5%) dogs and 12 (1.8%) cats. Transfusions were required in 31 (1.2%) dogs. Hypercapnea occurred in 33 (1.3%) dogs and one (less than 1%) cat. Hypoxemia occurred in 14 (0.5%) dogs. Anesthetic complications, as defined, occurred in 12.0% of dogs and 10.5% of cats, while deaths associated with the perianesthetic period occurred in 0.43% of dogs and 0.43% of cats.

Splenocaval shunting for alleviation of portal hypertension in a dog: a case report

OBJECTIVE

To describe the construction and use of a splenocaval shunt to prevent portal hypertension in a dog with iatrogenic rupture and subsequent complete occlusion of an intrahepatic portosystemic shunt (IPSS).

STUDY DESIGN

Case report describing a single, client-owned animal.

RESULTS

During dissection, the back wall of an IPSS was torn. Complete shunt occlusion was required to control the hemorrhage. This resulted in the development of life-threatening portal hypertension. Emergency splenocaval shunt construction reduced the portal pressure from 47 to 20 cm H2O. The dog experienced minimal postoperative complications. A second surgical procedure was performed a month later to completely ligate the splenocaval shunt.

CONCLUSIONS

A splenocaval shunt can be used to divert blood from the portal to the systemic circulation to control portal hypertension. In this dog, it resulted in a successful outcome with few complications.

CLINICAL RELEVANCE

The splenocaval shunt could be constructed before the dissection of a difficult IPSS if problems arise as occurred in the dog described in this report. Complete IPSS occlusion can be performed without development of portal hypertension.

Circumferential suture of the mitral annulus for correction of mitral regurgitation in dogs

OBJECTIVE

To develop a method for reducing mitral regurgitation in dogs by positioning and tightening a circumferential suture around the mitral valve annulus.

STUDY DESIGN

Description of clinical cases.

ANIMALS

15 dogs with spontaneous mitral valve disease, annular dilation, and refractory congestive heart failure treated between 1962 and 1994.

METHODS

A composite suture material was constructed using braided Teflon-impregnated polyester sternotomy suture, barium sulfate thread, and Silastic tubing. Through a left lateral thoracotomy, the suture was positioned around the mitral annulus by passing it through the coronary sinus, right atrium, and underneath the left coronary arteries before tightening it.

RESULTS

Six dogs died during surgery because of hemorrhage from the left atrium, coronary sinus, or left coronary artery. Three dogs died postoperatively because of coronary artery compression by the suture. Satisfactory suture placement was achieved in six dogs, three of which were long-term survivors (6 to 26 months) before they were euthanatized for noncardiac reasons.

CONCLUSIONS

Reduction of mitral annulus diameter with a circumferential purse-string suture does not require cardiopulmonary bypass. The surgery is technically difficult, and detailed knowledge of coronary artery anatomy is required. The current suture design is inexpensive, radiopaque, and biocompatible; no special instruments are required for placement.

CLINICAL RELEVANCE

Mitral regurgitation is the most common cardiovascular disorder in dogs and the most common cause of congestive heart failure. Annular dilation occurs as a consequence of mitral regurgitation. Placement and tightening of a circumferential suture around the mitral annulus reduces the degree of mitral regurgitation.

Clinical evaluation of cimetidine, sucralfate, and misoprostol for prevention of gastrointestinal tract bleeding in dogs undergoing spinal surgery

OBJECTIVE

To determine the incidence of gastrointestinal (GI) tract bleeding in dogs undergoing spinal surgery with adjunct corticosteroid treatment, and to determine the protective efficacy of cimetidine, sucralfate, and misoprostol against such bleeding in these dogs.

ANIMALS

40 dogs that underwent spinal surgery.

PROCEDURES

Myelography and surgery were performed on the first or second day of hospitalization. Methylprednisolone sodium succinate was given at a dosage of 30 mg/kg of body weight prior to myelography, followed by a second full or half dose 2 to 4 hours later at clinician discretion. Spinal surgery was performed in conventional manner, postoperative administration of analgesics was done, and dogs were fed a diet lacking red meat. Dogs were assigned at random to 1 of the 3 treatment groups or to the control group. Dogs of the treatment groups received cimetidine, sucralfate, or misoprostol. Physical examination and determination of PCV and serum total protein values were performed daily. A fecal sample was examined daily for gross and occult blood.

RESULTS

36 of 40 dogs had GI tract bleeding during a hospitalization period of 3 to 6 days. There was no significant difference in development of bleeding between the control group and any of the treatment groups.

CONCLUSIONS

Gastrointestinal tract bleeding occurred in 90% of dogs undergoing spinal surgery combined with administration of methylprednisilone sodium succinate, a higher rate than that found in previous studies. This bleeding was not life-threatening. Prophylactic benefit from any of the GI protectants tested was not found.

The effect of carotid artery occlusion on lingual arterial blood pressure in dogs

Although temporary occlusion of the carotid arteries is commonly done to reduce blood loss during nasal surgery in the dog, data supporting its use are mostly anecdotal and subjective. Twelve dogs were placed under general inhalation anesthesia and mechanically ventilated to maintain normocapnea and an end-tidal halothane concentration equivalent to 1.3 times the minimum alveolar concentration. Tourniquets were placed around both carotid arteries of each dog. Both lingual arteries were cannulated in each dog and their heart rate and blood pressure were measured bilaterally. During unilateral carotid artery occlusion, the blood pressures in the ipsilateral lingual artery were significantly (P < 0.05) lower than the preocclusion control pressures and pressures recorded in the contralateral vessel. Bilateral carotid artery occlusion resulted in a further significant (P < 0.05) fall in all lingual arterial pressures. The recorded heart rates only varied significantly from preocclusion control values when they increased during bilateral carotid occlusion (P < 0.05). The results of this study confirm that carotid artery occlusion has the potential to reduce intraoperative blood loss during oronasal surgery in the dog.

Assessment of 3 audible monitors during hypotension in anesthetized dogs

Severe hypotension was produced in 8 dogs during halothane anesthesia. Three monitors detecting respiratory rate, Doppler signal and pulse rate were compared to direct blood pressure measurements. Deep anesthesia was most consistently detected using the respiratory monitor. The signal fade of the Doppler device was best at detecting hypotension from blood loss. Changes in heart rate were not useful.

A wire loop technique for ligation of patent ductus arteriosus

A novel, yet simple and inexpensive, technique is described for the safe passage of suture material for closure of patent ductus arteriosus in small animals. The risk of haemorrhage is reduced by minimising dissection with forceps and by preventing inadvertent grasping of perivascular connective tissue.

General principles of small animal blood component administration

Administration of blood components instead of whole blood has become the most important means of transfusion support in dogs and in some settings in cats as well. Component administration entails the transfer of biological material and carries an inherent risk of disease transmission and adverse reactions. This article reviews the indications, pretransfusion considerations, and follow up in small animal patients receiving blood component therapy.

Flexible external fixation for craniodorsal coxofemoral luxations in dogs

An external fixator consisting of two Ellis pins connected by a flexible band was developed and evaluated as a treatment for craniodorsal coxofemoral luxations in dogs. The technique for closed application of the fixator without injury to the coxofemoral joint or sciatic nerve was developed in six dog cadavers. The coxofemoral joints were then surgically destabilized and the limbs were manipulated through a full range of motion to assess the efficacy of the fixator in maintaining joint reduction. The fixator maintained joint reduction and stability after a surgically created craniodorsal luxation except when the femur was externally rotated 90 degrees. A flexible external fixator was then applied unilaterally in four healthy dogs. The dogs tolerated the fixator well and were bearing weight on the limb within 2 days after surgery; the range of motion was not limited by the fixator. The efficacy of a flexible external fixator in maintaining joint reduction after craniodorsal coxofemoral luxation was then evaluated in eight large dogs. The right coxofemoral joint in each dog was luxated surgically by removal of the dorsal joint capsule and transection of the ligament of the head of the femur and deep gluteal muscle. The joint was reduced and the fixator pins were applied in a closed fashion. In four dogs, a flexible external band was applied to the pins. Luxation did not reccur in these four dogs. The bands were not applied initially in four control dogs. Luxation occurred in three of the four control dogs within 24 hours of surgery. The joints that luxated were reduced and the flexible bands applied. Luxation did not recur after the bands were in place. The dogs tolerated the external fixators well, were bearing weight within 2 days of surgery, and walking with only minimal lameness 5 days after surgery. Luxation of the coxofemoral joints did not occur during the 2-week period in which the fixators were in place. The joints remained stable 1 week after removal of the fixators, at which time the dogs were euthanatized. Necropsy evaluation identified inflammation surrounding the pins and fibrous thickening of the dorsal joint capsule. The flexible external fixators were applied closed, maintained reduction of the coxofemoral joint after replacement of a craniodorsal luxation, and allowed weight bearing and limb usage soon after surgery. The flexible external fixator has several advantages over other methods of treating craniodorsal coxofemoral luxations. Complications noted in this study included pin tract drainage, pin loosening, and disruption of the flexible bands.

En bloc ovariohysterectomy as a treatment for dystocia in dogs and cats

En bloc ovariohysterectomy, a technique that involves ovariohysterectomy before hysterotomy and removal of the neonates, was performed on 63 animals (37 dogs and 26 cats). Intraoperative complications were limited to 1 cat that bled excessively during surgery and was later found to have a clotting disorder. Postoperative complications included anemia that required blood transfusion in 3 cats, uroperitoneum in 1 dog, and death in 1 cat. The rate of neonatal survival (75% for dogs and 42% for cats) was similar to that documented by previous studies of medical and surgical management of dystocia. We concluded that en bloc ovariohysterectomy is a safe and effective alternative to cesarean section for surgical treatment of dystocia in dogs and cats.

Subtotal colectomy with surgical stapling instruments via a trans-cecal approach for treatment of acquired megacolon in cats

Surgical stapling equipment was used to perform an end-to-end colonic anastomosis in 15 cats for the treatment of acquired megacolon. An end-to-end stapling device was passed to the anastomotic site by a trans-cecal approach. Subsequent closure of the cecal incision was accomplished with a thoracoabdominal stapling device. Two cats had hemorrhagic episodes immediately after surgery that required blood transfusions. All 15 cats have had good to excellent health after subtotal colectomy and colocolostomy performed using this stapling technique. Results of this study have demonstrated that "single surgical field" placement of the end-to-end stapling device has the primary advantage of simplicity and a lower chance of contamination compared with (dual field) rectal passage of similar devices. Closure of the cecal access incision is easily performed without reducing the diameter of the large intestinal lumen. The stapling technique provided an efficient and consistent method for anastomosis of the large bowel in cats.

Clinical and histological comparison of tissue damage and healing following incisions with the CO2-laser and stainless steel surgical blade in dogs

The tissue damage and subsequent healing of skin, linea alba and intestinal wall incisions made with a CO2-laser and a stainless steel surgical blade were evaluated clinically and histologically in dogs (n = 10). The amount of blood lost in each type of skin incision was measured by taking the pre- and postoperative mass of surgical swabs. The tissues were sutured and the skin incisions examined every day. The animals were subsequently euthanased (Day 12) and all incisions examined histologically. A delay in the healing process was observed in the laser incisions of the skin during the first 4 d, but there was no difference in the healing rate of the intestinal wounds or of the linea alba. The blood loss due to the laser incisions was significantly less than that caused by the surgical blade. It was concluded that the CO2-laser can be used with confidence when incising the skin and intestine and that, due to its precision, the surgical blade is by far a more accurate method to incise the linea alba.

Adrenalectomy of sheep: a novel technique

A rapid technique for adrenalectomy of sheep was developed. Bilateral adrenalectomy was performed in a single stage operation by inducing ischaemia with latex rings of the type used commonly for the castration of lambs and calves. The success of the technique was demonstrated by failure of exogenous ACTH to increase circulating cortisol concentrations. Adrenal steroid replacement was used to maintain the sheep during the post-operative period (cortisol 0.25 mg.kg-1, deoxycorticosterone acetate 0.05 mg.kg-1). Adrenalectomised sheep were maintained for up to 20 days without glucocorticoid, provided a lowered dose of mineralocorticoid was administered (0.04 mg.kg-1 x day-1). Adrenalectomised sheep had significantly (P < 0.007) lower packed cell volume (23.75%) than normal sheep (31.24%), across a broad range of cortisol concentrations (0 to 734 ng/mL), indicating that plasma cortisol may not reflect true blood concentrations when drawing comparisons between adrenalectomised and normal sheep.

Rhabdomyosarcoma of the tongue in a horse

A 5-year-old Quarter Horse mare was examined because of a 6-month history of quidding and nasal discharge that contained feed material. Physical examination revealed weight loss and dorsal displacement of the soft palate, caused by a soft tissue mass located at the dorsal aspect of the base of the tongue. Surgical resection of the mass was successfully performed through an oral approach. The histopathologic diagnosis was rhabdomyosarcoma.

Prekallikrein deficiency in a family of Belgian horses

A 7-year-old Belgian stallion hemorrhaged excessively after castration; the hemostatic mechanism was investigated. The horse had normal one-stage prothrombin time and markedly prolonged activated partial thromboplastin time (APTT). Results of intrinsic coagulation factor assays were all normal with the exception of prekallikrein activity, which was markedly reduced (less than 1% activity; value for control population, 63 to 150%). Two of this horse's full siblings, a brother and sister, had markedly prolonged APTT and low prekallikrein values (2.5% and less than 1%, respectively). The addition of plasma from a normal equine plasma pool corrected the prolonged APTT in the 3 Belgian sibling with low prekallikrein activity. Prekallikrein activity in 10 other closely related Belgian horses ranged between 12.5 and 64% (mean, 29.3%), compared with 63 to 150% (mean, 91%) in 10 mixed-breed horses. In the 3 Belgian siblings with low prekallikrein activity, the APTT approached normal after prolonged incubation (15 minutes) with the contact activator and in response to addition of an ellagic acid activator. The 3 Belgian siblings with low prekallikrein activity may be homozygous for prekallikrein deficiency, whereas the other close relatives may be heterozygous for the genetic defect.