Bacterial contamination of suction tips used during surgical procedures performed on dogs and cats

OBJECTIVE: To determine prevalence of bacterial contamination of surgical suction tips. SAMPLE POPULATION: Surgical tips used during 44 surgical procedures performed on 42 dogs and 2 cats. PROCEDURE: Surgical procedures were classified into 1 of 3 categories according to degree of bacterial contamination of the surgical site (clean, clean-contaminated, contaminated). Two sets of suction apparatuses were used for test and control suction tips. Test tips were used normally to suction blood and fluid, whereas control tips were placed on the surgical drapes but not in the surgical wound. Suction tips were collected aseptically and placed into thioglycolate broth tubes for qualitative aerobic and anaerobic bacterial culture at the end of each procedure. RESULTS: Test and control suction tips were contaminated with bacteria during 30 of 44 (68%) procedures. Staphylococcus spp were the predominant bacteria in tips used during clean and clean-contaminated surgeries. When surgery was performed on clean-contaminated or contaminated wounds, prevalence of isolation of other bacteria such as Pseudomonas spp, Streptococcus spp, and Escherichia coli from both test and control suction tips was higher than for clean wounds. Mean time of procedures during which both test and control suction tips became contaminated was not significantly different from time of procedures during which neither tip became contaminated. CONCLUSION AND CLINICAL RELEVANCE: Surgical suction tips often become contaminated during standard veterinary surgical procedures. The risk of wound infection after surgery may be influenced by bacterial contamination of surgical suction tips.     

The Association of Propofol Usage With Postoperative Wound Infection Rate in Clean Wounds: A Retrospective Study

OBJECTIVE: To determine if the use of propofol influences the postoperative infection rate of clean surgical wounds in dogs and cats. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: 863 dogs and cats undergoing clean surgical procedures. METHODS: Medical and anesthetic records of surgical cases used as part of a previously described epidemiologic study on postoperative wound infection rates were reviewed. The records of all animals with clean surgical wounds were reviewed to determine if propofol had been used for anesthetic induction or maintenance during the procedure. To determine the effect of propofol use on wound infection rate, data were analyzed using Fisher's exact test, followed by multiple logistic regression to adjust for various factors, including surgery time, time from clipping to surgery, antibiotic usage, coexisting distant infection, endocrine disease, and the use of immunosuppressive drugs in the perioperative period. RESULTS AND CONCLUSIONS: Of 863 dogs and cats with clean surgical wounds, 46 received propofol as part of the anesthetic protocol. A total of 6 of 46 animals (13%) receiving propofol developed postoperative wound infections, compared with 33 of 817 animals (4%) not receiving propofol (P = .014; % difference = 9%; 95% CI = 0.5% to 24%). Adjusting for all other factors evaluated, animals receiving propofol were 3.8 times more likely to develop postoperative wound infections compared to animals not given propofol (95% CI = 1.5-9.9). CLINICAL IMPLICATIONS: Propofol is a lipid-based emulsion capable of supporting microbial growth. Administration of a potentially contaminated solution may contribute to surgical wound infection or other patient morbidity or mortality. Strict aseptic technique in the preparation of the solution and prompt disposal of unused drug are imperative to curtail the potential for extrinsic contamination.     

Infection rates in clean surgical procedures: a comparison of ampicillin prophylaxis vs a placebo

A total of 122 dogs and 7 cats were included in a prospective, randomized, blind trial to determine the frequency of wound infection after clean surgical procedures and to compare the infection rates in dogs and cats given ampicillin (group 1) with those given a placebo (group 2). The 2 groups were similar in terms of mean age, sex ratio, duration of hospital stay, and types of surgical procedures. A wound infection developed in one of the dogs given ampicillin; there were no wound infections in the animals given the placebo. The infection rates in the 2 groups were not significantly different.     

Comparative Evaluation of Two Surgical Scrub Preparations in Cattle

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.     

The effects of perioperative hypothermia and the duration of anesthesia on postoperative wound infection rate in clean wounds: a retrospective study

OBJECTIVE: To determine the effects of hypothermia and duration of anesthesia on the infection rate in clean wounds in dogs and cats. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Seven hundred seventy-seven dogs and cats undergoing clean surgical procedures. METHODS: Records of animals prospectively evaluated for postoperative wound infection were retrospectively evaluated for the prevalence of perioperative hypothermia. Body temperatures during the perioperative period and the duration of surgery and anesthesia were recorded. Data were analyzed to identify differences between animals with infected and uninfected wounds and multiple logistic regression modeling was used to evaluate the independent contribution of risk factors to the incidence of postoperative wound infection. RESULTS: No statistically significant differences were found in the analysis of temperature data between animals with infected and uninfected wounds. Duration of anesthesia was significantly greater in animals with wound infections (P = .01). Multiple logistic regression modeling identified duration of anesthesia as a risk factor for postoperative wound infection independent of the duration of surgery. CONCLUSIONS: In animals with clean surgical wounds, mild perioperative hypothermia is not a significant risk factor for postoperative wound infection. The duration of anesthesia, however, is a significant risk factor independent of the duration of surgery. CLINICAL RELEVANCE: To decrease the incidence of postoperative wound infection, the duration of anesthesia should be minimized. Surgical time, as well as the time required for ancillary diagnostic tests while under anesthesia should, therefore, be kept to a reasonable minimum.     

Postoperative infection with Actinobacillus spp in horses: 10 cases (1995-2000)

OBJECTIVE: To determine features of postoperative wound infection caused by Actinobacillus spp in horses undergoing clean, elective surgery and to evaluate bacterial susceptibility profiles of bacteria isolated. DESIGN: Retrospective study. ANIMALS: 10 horses. PROCEDURE: Data were retrieved from medical records and the microbiology laboratory database. RESULTS: 1,604 horses underwent clean, elective surgical procedures during the study period. Of these, 23 (1.43%) had postoperative wound infections, and Actinobacillus spp was isolated from 10 of these 23 (43%). Surgical procedures in these 10 horses included laryngoplasty with ventriculocordectomy (n = 3), arthroscopy (3), desmotomy of the accessory ligament of the superficial digital flexor tendon (2), removal of laryngoplasty prostheses (1), and hygroma resection (1). Seven horses survived, and 3 were euthanatized. All 10 Actinobacillus isolates were resistant to penicillin, and 6 were resistant to trimethoprim-sulfamethoxazole. All isolates were susceptible to ceftiofur and gentamicin. During the 5-year period of the study, Actinobacillus organisms were isolated from 35 of 513 (6.8%) samples from the general hospital population submitted for bacterial culture and antimicrobial susceptibility testing. CONCLUSIONS AND CLINICAL RELEVANCE: During the study period, Actinobacillus spp was isolated from a higher than expected percentage of horses that developed postoperative wound infections after clean, elective surgery. Susceptibility profiles for these isolates were different from typical susceptibility profiles for Actinobacillus isolates, suggesting that a pattern of resistance may be emerging.     

Efficacy of Adhesive Incise Drapes in Preventing Bacterial Contamination of Clean Canine Surgical Wounds

Objective— To investigate the efficacy of adhesive incise drapes in reducing bacterial contamination of clean canine surgical wounds.
Study Design— Randomized clinical trial.
Animals— Dogs (n=100) having elective ovariohysterectomy or stifle surgery.
Methods— Dogs were randomly assigned to 1 of 2 groups: drape or no drape. Swabs obtained from the inner edge of the surgical wound at the beginning (swab 1) and end (swab 2) of surgery were submitted for microbial culture. Number of colony forming units was counted for all positive cultures and change in bacterial counts between swabs 1 and 2 was calculated. Percentage adhesive drape adherence at the end of surgery was calculated from a digital photograph of the surgical site. Duration of surgery/anesthesia and the anesthetic induction agent used were recorded.
Results— There was a significant increase in bacterial counts between swabs 1 and 2 ( P =.001). Wound contamination was 14% (6 drape; 8 no drape; P =0.78) with Staphylococcus spp. most commonly isolated. Median percentage drape adherence at the end of surgery was 89.3% (0–100%). Duration of anesthesia was significantly related to wound contamination ( P =.013), but duration of surgery and anesthesia induction agent were not.
Conclusions— Adhesive incise drapes did not reduce wound contamination of clean canine surgical wounds.
Clinical Relevance— Use of adhesive incise drapes in clean surgical procedures is of questionable benefit in dogs.     

Clinical and Surgical Parameters in Dogs with Perineal Hernia Analysis of Results of Internal Obturator Transposition

The results of treatment of 31 dogs with perineal hernia by internal obturator muscle transposition were evaluated by comparing the clinical signs reported by the owner before surgery with those reported 11 or more months following surgery. The severity and frequency of pre- and postoperative clinical signs were categorized numerically, and composite scores were obtained for each dog. In addition, the dogs were examined 11 or more months following surgery. The presence or absence of an externally obvious perineal swelling was noted, and rectal examination was performed to detect rectal sacculation and the integrity of the pelvic diaphragm dorsal and ventral to a line drawn between the center of the anus and the ischiatic tuberosity. These results were correlated with the postoperative composite scores. Postoperative complications included wound infection (2), wound seroma (2), rectal prolapse (4), urinary incontinence (2), and flatus as a new postoperative problem (11). The postoperative composite score was significantly lower (improved function) following surgery. Dogs with worse signs preoperatively or bilateral perineal hernia benefited less from surgery. More dogs showed improvement when the operation was performed by experienced surgeons. Factors detected at follow-up examination that correlated with more severe postoperative clinical signs were perineal swelling, absence of the ventral portion of the pelvic diaphragm, and rectal sacculation. The presence or absence of reformation of the dorsal aspect of the pelvic diaphragm did not correlate with postoperative clinical signs.     

Chlorhexidine Gluconate Versus Chloroxylenol for Preoperative Skin Preparation in Dogs

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.     

Epidemiologic evaluation of postoperative wound infection in clean-contaminated wounds: A retrospective study of 239 dogs and cats

OBJECTIVE: To evaluate risk factors for development of postoperative wound infections in clean-contaminated wounds. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Two hundred thirty-nine dogs and cats that had clean-contaminated surgical procedures. METHODS: Records of animals that had a clean-contaminated surgical procedure and were prospectively monitored for development of postoperative wound infection were reviewed. Prospective data included signalment, nutritional status, body weight, duration of surgery, surgical procedures, wound classification, surgical site clip time before surgery, hypotension during surgery, the presence of an active distant infection, endocrinopathy, administration of an immunosuppressive agent, administration of antibiotics, and the type of antibiotic used. Additional retrieved data included total anesthesia time, temperature variables, blood loss, and suture material used. RESULTS: Intact males (P =.008) and animals with concurrent endocrinopathy (P =.008) were at a higher risk of development of postoperative wound infection. Total surgery time (P =.02) and total anesthesia time (P =.04) were longer in animals that developed postoperative wound infection. No other factors were statistically significant. CONCLUSIONS: Intact males and animals with a concurrent endocrinopathy were at higher risk of postoperative wound infection after clean-contaminated surgical procedures. CLINICAL RELEVANCE: Time under anesthesia and duration of surgery should be minimized to reduce the risk of wound infection in clean-contaminated surgical procedures.     

Evaluation of Specific Infection Control Practices Used by Companion Animal Veterinarians in Community Veterinary Practices in Southern Ontario

This study evaluated specific infection control practices in community veterinary practices in southern Ontario. Environmental disinfection, management of infectious patients and antimicrobial use in clean surgical procedures were investigated. Community companion animal veterinary practices (n = 101) in Southern Ontario were recruited, and a questionnaire was administered to one veterinarian and one veterinary technician from each practice. The veterinarian questionnaire gathered data on clinic demographics, management of infectious patients, infectious diseases of concern, environmental disinfection and antimicrobial use in surgical procedures. The veterinary technician questionnaire gathered data on environmental disinfection. None of the veterinary practices had a formal infection control programme. Sixty‐five per cent (n = 66) of the veterinary practices did not have an isolation area and 61% (n = 40) of these practices did not employ any specific infection control measures for infectious cases. The products most frequently used for environmental disinfection were hydrogen peroxide based or quaternary ammonium compounds. Bleach was the agent most commonly used for environmental disinfection of infectious body fluids; however 60% of the veterinarians and 40% of the veterinary technicians did not identify a product for environmental disinfection of infectious body fluids. Twenty‐four per cent of the veterinarians reported using antimicrobials in animals undergoing elective sterilization surgeries and 60% reported using antimicrobials in other clean surgical procedures. There is a need for community veterinary practices to develop infection control programmes specific to their individual practice. In addition, veterinarians should discontinue the common use of antimicrobials for clean elective sterilization surgical procedures.     

Ultrasonographic assessment of standing laparotomy wound healing in dairy cows

The surgical wounds of 40 cows with a standing clean laparotomy were assessed 10-15 days after surgery. The abdominal wall thickness on the upper (w1), the middle (w2) and the lower (w3) third of the wound (and the contralateral flank n1, n2, and n3), the presence of edema, cavitary lesion, capsulated lesion, or visualization of shadow artifact in the wound were assessed ultrasonographically. On day 30, wound healing status (normal or surgical site infection (SSI)) was determined. Five out of 39 cows (12.8%) had SSI. A significant positive correlation was found between w3 and edema (p<0.01; r=0.44), w3/n3 and edema (p<0.05; r=0.32), w3 and pain on wound palpation (p<0.01; r=0.41); w3/n3 and the presence of pain (p<0.002; r=0.49) and w2/n2 and pain when palpating the wound (p<0.05; r=0.33). No association was found between the ultrasonographic evidence of edema and SSI (p=0.10), cavitary lesion and SSI (p=0.65), encapsulated lesion and SSI (p=1), and shadow artefact and SSI (p=1). The wound ultrasonography 10-15 days after surgery was not predictive of abnormal wound healing.     

Bacterial growth associated with metallic implants in dogs

Tissue and swab specimens for bacteriologic culture were obtained from the operative wound in 40 dogs in which plates and screws were applied and then removed from the sites of healed fractures or arthrodeses. Implants were removed after a mean (+/- SD) application period of 15.7 +/- 9.3 months. Bacteria were isolated from the plate-bone interface in 17 dogs. Of the 17 dogs, 9 had had complications associated with initial management (eg, osteomyelitis, open fractures, or multiple surgical procedures). Control specimens were obtained from 30 dogs that had clean elective orthopedic procedures that did not involve implantation of metallic prostheses. None of the dogs of the control group were given antibiotics. Bacteria were isolated from 2 of 30 specimens obtained from control dogs. The difference between the number of culture-positive specimens from dogs of the implant group and those from dogs of the control group was significant (P less than 0.01).     

Survival and complication rates in 300 horses undergoing surgical treatment of colic. Part 2: Short-term complications

REASONS FOR PERFORMING STUDY: Few studies have assessed short- and long-term complication rates of horses following surgical treatment of colic, a potentially fatal condition. Complications can lead to patient discomfort and increased costs; knowledge of predisposing factors may help to reduce complication rates. OBJECTIVES: To document and analyse short-term complications in 300 horses undergoing colic surgery, and to assess some of the possible predisposing factors. METHODS: History, clinical findings, surgical findings and procedures, and post operative treatments of 300 consecutive surgical colic cases (1994-2001) were reviewed. Comparisons among groups of discrete data were made using chi-squared or Student's t tests as appropriate. RESULTS: Short-term complications in 227 horses following a single laparotomy included colic/pain (28.2%), incisional drainage or infection (26.9%), post operative ileus (13.7%), severe endotoxaemic shock (12.3%), jugular thrombophlebitis (7.5%), septic peritonitis (3.1%) and colitis/diarrhoea (2.2%). Horses with small bowel obstruction had a higher rate of post operative ileus than those with large bowel obstruction. Rates of post operative pain and shock were higher in horses with small colon rather than large colon obstruction, and in those that had an ischaemic rather than a simple obstruction. The rate of wound complications increased with increasing total plasma protein concentration at admission. Horses that had a repeat laparotomy had a higher rate of wound complications compared to those that had a single laparotomy. Application of a stent bandage was associated with a higher rate of wound complications than if no stent was applied; however, application of an incise drape over the wound for recovery was associated with a lower rate of wound complications than for horses that had no protective covering of the wound. CONCLUSIONS: The most common short-term post operative complications following colic surgery were pain, incisional drainage, ileus, endotoxaemiac shock and jugular thrombophlebitis. Some factors that appeared to predispose to these complications were identified. Although many of these factors related to the underlying disease process, a number of factors, including surgical techniques, were identified that might be amenable to modification. POTENTIAL RELEVANCE: Prospective studies to assess the effects of modifying these factors on survival rates should be performed.     

Use of wound soaker catheters for the administration of local anesthetic for post-operative analgesia: 56 cases

Objective  To describe the administration of local anesthetic through wound soaker catheters for post-operative veterinary patients and to characterize complications.
Study design  Retrospective study of hospital records.
Animals  Records of patients in which a wound soaker catheter was placed post-operatively between November 1, 2004 and July 1, 2006 at a veterinary teaching hospital. Records in which a limb amputation was performed between January 1, 2002 and August 1, 2007 and in which a wound soaker catheter was not placed were reviewed for historic control.
Results  A total of 56 cases were identified in which a wound soaker catheter was placed post-operatively including 52 dogs, 2 cats, and 2 goats. Twenty canine cases were identified in which limb amputation was performed and no wound soaker catheter was placed. The majority of surgical procedures for which a wound soaker catheter was placed included thoracic limb amputation (46.4%) and pelvic limb amputation (35.7%). Wound soaker catheters remained in place for an average of 1.6 ± 0.5 days. Feline and caprine patients received intermittent bupivacaine boluses every 6 hours. Canine patients received continuous lidocaine infusions. Complications included disconnection of the catheter from the infusion (7.7%), one seroma, and one suspected lidocaine neurotoxicity. Incisional infections were noted in 3/56 (5.3%) limb amputations with wound soaker catheters placed which was not higher than the incisional infection rate found in the historic control cases 3/20 (15%).
Conclusion and clinical relevance  Use of the wound soaker catheter was a viable means of providing local analgesia in post-operative veterinary patients. Studies are needed to evaluate efficacy of pain management, and to further investigate techniques for catheter placement and maintenance which may help to optimize the analgesia achieved using this technique.     

Wound infection rates in dogs and cats after use of cotton muslin or disposable impermeable fabric as barrier material: 720 cases (1983-1989)

A retrospective study involving 720 dogs and cats that underwent a variety of elective surgical procedures was done to compare the effectiveness of reusable cotton barrier materials with that of a commercially available disposable barrier system for prevention of wound infection. The overall wound infection rate, using cotton barrier materials, was 3.1% and for disposable materials, was 4.4%. The difference between groups was not significant.     

Surgical management of small intestinal incarceration through the gastrosplenic ligament: 14 cases (1994-2006)

OBJECTIVE: To determine prevalence, clinical findings, and long-term survival rate after surgery associated with incarceration of the small intestine through the gastrosplenic ligament (ISIGL) in horses. DESIGN: Retrospective case series. ANIMALS: 14 horses with ISIGL. PROCEDURES: Medical records of horses with ISIGL examined between January 1994 and December 2006 were reviewed. Signalment, initial physical examination findings, results of abdominal fluid analysis, and clinical laboratory values were recorded, along with surgical findings, including segment of incarcerated intestine and surgical procedures performed. Long-term survival data were obtained through client interviews. RESULTS: Clinical findings included small intestinal distention identified via rectal palpation (10/14 horses) or transabdominal ultrasonography (8/11), nasogastric reflux (4/14), and abnormal abdominal fluid (9/9). All horses required intestinal resection and anastomosis. Postoperative complications included adynamic ileus (5/14 horses), incisional infection (4/14), diarrhea (3/14), and laminitis (1/14). No breed or age predilection was detected, although geldings were at increased risk for ISIGL. Long-term survival rate was 79% (11/14 horses). CONCLUSIONS AND CLINICAL RELEVANCE: ISIGL was an uncommon cause of colicin this hospital population. With appropriate surgical intervention and postoperative management, the long-term prognosis for surgically treated horses was fair to good.     

Clinical assessment of epidural analgesia induced by xylazine-lidocaine combination accompanied by xylazine sedation in calves

: The aim of the present study was to investigate whether epidural administration of a xylazine-lidocaine combination accompanied by xylazine sedation would provide satisfactory analgesia for some surgical procedures on 10 calves admitted to the Department of Veterinary Surgery, University of Kafkas with perineal urolithiasis (n:2), rectovaginal fistula (n:1), atresia ani (n:2), omphalophlebitis (n:2), omphaloarteritis (n:1) and umbilical hernia (n:2).Following intramuscular injection of xylazine at a dose of 0.05 mg/kg for sedation, xylazine-lidocaine combination (0.2 mg/kg lidocaine + 0.02 mg/kg xylazine + 5 ml 0.9% NaCl) was administrated into the lumbosacral (L6-S1), sacrococcygeal (S5-Co1) or intercoccygeal (Co1-Co2) space. Heart rate, respiratory rate and rectal temperature were recorded prior to and during analgesia at 5, 10, 15, 30 and 60 minutes. Furthermore, depth and duration of analgesia were evaluated during surgical intervention.The study revealed that the combination of epidural xylazine-lidocaine with xylazine sedation was highly satisfactory for surgery of the lower urinary tract and the perineal region, but it was less so for surgery of the umbilical area.     

Disease features in horses with induced equine monocytic ehrlichiosis (Potomac horse fever)

Fifty-five horses were inoculated IV and/or SC with materials containing Ehrlichia risticii, ie, infected whole blood, buffy coat cells, or cell culture, to study clinical and hematologic features of equine monocytic ehrlichiosis (Potomac horse fever). Major clinical and hematologic features of induced E risticii infection were biphasic increase in rectal temperature with peak increases of 38.9 C and 39.3 C on postinoculation days (PID) 5 and 12, respectively; depression; anorexia; decreased WBC count (maximal decrease of 47% on PID 12); and diarrhea from PID 14 to PID 18. Increased WBC count was an inconsistent feature, with a maximal increase of 51.5% on PID 20. During times of decreased and increased WBC counts, lymphocyte/neutrophil ratios remained fairly constant. However, not all horses had all clinical and hematologic features, and these features were present in different degrees among horses. Increased rectal temperature, depression, anorexia, and decreased WBC count were more consistent features, whereas diarrhea developed in 73% of the horses. Of 55 horses, 39 (71%) had all clinical and hematologic features of the disease (classic disease), whereas 16 (29%) horses did not have greater than or equal to 1 of these features (nonclassic disease). The E risticii titer in the blood (ehrlichemia) was maximum during the peak increase in rectal temperature. In 55 horses, mortality was 9%. Significant differences (P greater than 0.5) in clinical and hematologic features were not detected between horses that survived and those that died of E risticii infection.     

Evaluation of four warming procedures to minimise heat loss induced by anaesthesia and surgery in dogs

OBJECTIVE: To evaluate the efficiency of four warming procedures, introduced after anaesthetic induction and continued during surgery, in minimising heat loss in anaesthetised dogs. DESIGN: Dogs were paired. One of each pair was a control; the other was subjected to one of four warming procedures. METHODS: Ninety-six dogs were involved in total. Pairs of dogs were matched for breed, hair length, and type of surgical procedure and placed adjacent to each other in a large temperature-controlled surgical theatre. One dog within each pair was assigned to one of four warming procedures that commenced immediately after anaesthetic induction. Group 1 (11 pairs) were placed on a purpose-designed prewarmed (41 degrees C) electrically heated pad. Group 2 (18 pairs) were placed on a prewarmed electric heat pad (41 degrees C), cocooned by four wrapped water bottles (initially 41 degrees C) and subjected to radiant heat (150 watt lamp placed 50 cm away from the head of the dog). Group 3 (11 pairs) were surrounded by a forced air warming mattress (set at 43 degrees C). Group 4 (8 pairs) were connected via the anaesthetic breathing circuit to a heater/humidifier (set at 41 degrees C). Rectal temperature measurements were recorded every 15 min for the first 3 h of anaesthesia. The fall in rectal temperature of the control dog was subtracted from the fall in temperature of the treatment dog and this measurement was used to assess the efficacy of the various warming procedures. RESULTS: The mean rectal temperature of unheated 'control' dogs decreased 1.9 +/- 0.6, 1.4 +/- 0.4 and 1.1 +/- 0.4 degrees C over the first, second and third hour respectively. After 3 h the temperature fall differential for all groups were 0.7 +/- 0.7 (Group 1), 3.1 +/- 1.1 (Group 2), 2.4 +/- 1.1 (Group 3) and 1.0 +/- 1.1 degrees C (Group 4). Thus the group 2 procedure was the most successful in preventing a drop of temperature followed by groups 3, 4 and 1. CONCLUSION: Large dogs undergo significant reduction in core body temperature especially during the first 2 h of anaesthesia and surgery. Supplementary warming substantially reduces this fall in body temperature, although certain warming procedures were found to be more effective than others.