The distribution of pathogens and their antimicrobial susceptibility patterns among canine surgical wound infections in Sweden in relation to different risk factors

Background

Surgical site infection (SSI) is a common nosocomial infection in dogs and a growing concern in veterinary hospitals as an increase in multidrug-resistant pathogens is reported. Despite the need for rational and prudent antimicrobial use, few peer-reviewed and published veterinary studies have investigated the pathogenic growth including susceptibility patterns of the isolated pathogens in canine SSIs.The first objective of the present study was to estimate the distribution of bacterial pathogens in dogs with SSI and to investigate whether this was influenced by type of surgical procedure (clean, clean-contaminated, contaminated or dirty), duration of hospitalization, wound classification and depth of the infection, or antimicrobial treatment. The second objective was to assess susceptibility patterns to clinically relevant antimicrobials.During three years, four animal referral hospitals and three small animal clinics submitted bacterial swabs from canine SSIs for culture and susceptibility, together with a questionnaire completed by the attending clinician.

Results

Approximately two thirds of the in total 194 isolates were staphylococci. Staphylococcus pseudintermedius was the most prevalent finding (46%) followed by beta haemolytic Streptococcus spp. (24%). No associations between distribution of the isolated pathogens and classification of the surgical procedure, duration of hospitalization or depth of the SSI were shown, with the exception of Escherichia coli isolates being significantly more often found in deep wound infections than in superficial skin infections.Overall the possibilities of finding first generations antimicrobials to treat the SSIs included in the study were favorable, as the isolated pathogens were mostly without acquired antimicrobial resistance and multidrug resistance was uncommon. There were only three cases of methicillin-resistant S. pseudintermedius-infections (one percent of all isolates), one case of extended-spectrum beta-lactamase producing E. coli-infection, and no methicillin-resistant Staphylococcus aureus infections.

Conclusions

None of the investigated factors were shown to influence the distribution of bacterial pathogens. The majority of SSIs were caused by staphylococci, and S. pseudintermedius was the most prevalent pathogen. Based on the study results, use of first-line antimicrobials prior to receiving culture and susceptibility results is a rational empirical antimicrobial therapy for the studied dog population.     

Post operative infection, pyrexia and perioperative antimicrobial drug use in surgical colic patients

Reasons for performing study: Infections are common complications in post operative colic patients. It is the impression of some surgeons that pyrexia in the early post operative period is a sign of infection and appropriate timing of perioperative antimicrobials will decrease the incidence of post operative infection. Objective: To determine the association between 1) post operative pyrexia and development of infection and 2) perioperative antimicrobial drug use and infection rate in post operative colic patients. Methods: Medical records of patients undergoing surgical treatment for colic were reviewed. Horses recovering from surgery and surviving >48 h were included. Data relating to case details, duration of surgery, post operative infection, peri‐ and post operative antimicrobial administration, presence, intensity and duration of pyrexia, were recorded. Data were analysed using standard statistical methods for simple comparisons between groups and by logistic regression for more complex comparisons. Results: One‐hundred‐and‐thirteen horses were included in the final analyses, 48 (43%) of which were diagnosed with a post operative infection. Duration of surgery and anaesthesia were associated with post operative infection. Eighty‐five percent of horses (n = 96) exhibited pyrexia (rectal temperature >38.3°C) post operatively. Peak temperature >39.2°C, time post surgery to peak temperature >48 h and duration of pyrexia >48 h were significantly associated with infection. In a combined model, time to first pyrexic >48 h post surgery, peak temperature and time to peak >48 h were equally weighted and the model's positive predictive value for post operative infection was 72%. Timing and dose rate of preoperative antimicrobials were not associated with infection but duration of post operative antimicrobial drug use was. Conclusion and clinical relevance: Slight to mild pyrexia (38–39.4°C) in the early post operative period is not necessarily associated with impending bacterial infection in colic patients and the use of antimicrobials in these patients may be costly and unnecessary.     

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.     

Postoperative complications after surgical management of incomplete ossification of the humeral condyle in dogs

Objective: To describe incidence and type of postoperative complications in the surgical management of incomplete ossification of the humeral condyle (IOHC) and identify any risk factors associated with development of these complications. Study Design: Case series. Methods: Clinical records of dogs (n=57) that had prophylactic transcondylar screw insertion for treatment of IOHC (79 elbows) at 6 UK referral centers were reviewed. Signalment, presentation, surgical management, postoperative care, and complications were recorded. Postoperative complications were divided into seroma, surgical site infections (SSI) and implant complications. Results: Spaniel breeds and entire males were overrepresented. The overall complication rate was 59.5%. Seroma (n=25) and SSI (24) were the most commonly encountered complications. Implant failure occurred in 2 dogs. Labrador retrievers were at greater risk of developing a postoperative complication than other breeds (P=.03). Increasing bodyweight was a significant risk factor for development of a SSI (P=.03). Placement of the transcondylar screw in lag fashion rather than as a positional screw reduced the incidence of postoperative SSI (P=.007). Conclusions: Surgical management of IOHC is associated with a high rate of postoperative complications. Placement of the transcondylar screw in lag fashion may limit postoperative complications and warrants further consideration.     

Risk factors affecting the outcome of surgery for atlantoaxial subluxation in dogs: 46 cases (1978-1998)

OBJECTIVE: To identify risk factors for successful surgical management of dogs with atlantoaxial subluxation (AAS). DESIGN: Retrospective study. ANIMALS: 46 dogs managed surgically for AAS. PROCEDURE: Age at onset of clinical abnormalities, duration of clinical abnormalities prior to surgery, radiographic appearance of the dens, type (dorsal or ventral procedure) and number (1 or 2) of surgeries performed, grade of postoperative atlantoaxial joint reduction, and neurologic status prior to surgery (preoperative), when dogs were discharged from the hospital (postoperative), and during a follow-up evaluation (final) were obtained from the dogs' medical records. Risk factors for surgical success and degree of neurologic improvement were identified and analyzed for predictive potential. RESULTS: Age at onset of clinical abnormalities < or = 24 months was significantly associated with greater odds of a successful first surgery and final outcome and a lower postoperative neurologic grade. Duration of clinical abnormalities < or = 10 months was significantly associated with greater odds of a successful final outcome and a lower final neurologic grade. A preoperative neurologic grade of 1 or 2 was significantly associated with a lower final neurologic grade. Potential risk factors that did not affect odds of a successful outcome included type of surgery performed, grade of atlantoaxial joint reduction, radiographic appearance of the dens, or need for a second surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Age at onset of clinical abnormalities, duration of clinical abnormalities prior to surgery, and preoperative neurologic status are risk factors for success of surgical management of AAS in dogs.     

Retrospective Identification of Bacterial Isolates From Emergency Laparotomy Surgical Site Infections in Horses

Surgical site infection (SSI) with multiresistant bacteria is an important cause of postoperative morbidity after laparotomy in horses. The objective of this study was to identify bacteria isolates and their antibiotic resistance patterns associated with the development of wound infection in horses after laparotomy. This is a retrospective case series. Medical records of horses that underwent ventral midline exploratory laparotomy in a four-year period at one equine hospital were reviewed. Results of microbiologic culture and susceptibility testing are described. The study group consisted of 183 (100%) horses that recovered from anesthesia after laparotomy. The prevalence of infection was 19% (24/124) after first surgery and 83% (19/23) after relaparotomy. The most common microbial isolates were bacteria of the family Enterobacteriaceae followed by Staphylococcus ssp., Enterococcus ssp., Streptococcus ssp., and Bacteroides ssp. Bacteria from the family Enterobacteriaceae showed the lowest resistance to amphenicols, cephalosporins, and quinolones groups of antibiotics. Coagulase-positive Staphylococci were sensitive to amphenicols and only 33% were resistant to trimethoprim/sulfamethoxazole. The most commonly used perioperative and postoperative antibiotics were gentamicin and amoxicillin. Limitations include poor control over exposure factors, covariates, and potential confounders during the surgery, recovery time, or period of hospitalization; relying on others for accurate outcome assessment and recordkeeping; lack of follow-up information once animals were discharged from the hospital. Despite 5 days of antibiotic prophylaxis, the rate of incisional infection is still high. The most common isolates from SSI belong to the family Enterobacteriaceae and the genus Staphylococcus, which showed high resistance to the antibiotics used before the gastrointestinal surgery.     

Prevention and surveillance of surgical infections: A review

Optimal patient care cannot be realized without effectively managing risks related to healthcare‐associated infections (HAI). Among human hospital admissions in the United States in 2002, there were approximately 4.5 HAI per 100 admissions, with surgical site infections (SSI) accounting for an estimated 20%, or approximately 2 SSI per 100 procedures. When considering the occurrence of disease in a population, it is important to remember that disease does not occur randomly in populations. Therefore, when thinking about managing risks associated with the occurrence of SSI, consideration should be given to key factors in disease development (the agent, the host, and the environment), and a multifaceted approach to prevention efforts should be considered, including the identification of high‐risk populations, adherence to aseptic principles, judicious use of antimicrobial drugs, and surveillance targeting SSI to better inform infection control practices within a facility. Although not all HAI are preventable, it is important to focus efforts on the preventable fraction and to take all reasonable precautions to mitigate foreseeable risks.     

Effect of perioperative prophylactic antimicrobial treatment in dogs undergoing elective orthopedic surgery.

OBJECTIVE: To determine whether perioperative antimicrobial prophylaxis would reduce incidence of postoperative infection among dogs undergoing elective orthopedic procedures. DESIGN: Randomized, controlled, blinded, intention clinical trial. ANIMALS: Dogs of any breed, sex, or age undergoing elective orthopedic surgery at a veterinary teaching hospital. PROCEDURES: Dogs were randomly assigned to 1 of 3 groups: treatment with saline solution, treatment with potassium penicillin G, and treatment with cefazolin. Treatments were intended to be administered within 30 minutes prior to surgery; a second dose was administered if surgery lasted > 90 minutes. Dogs were monitored for 10 to 14 days after surgery for evidence of infection. RESULTS: After the first 112 dogs were enrolled in the study, it was found that infection rate for control dogs (5/32 dogs) was significantly higher than the rate for dogs treated with antimicrobials (3/80 dogs). Therefore, no more dogs were enrolled in the study. A total of 126 dogs completed the study. Monte Carlo simulations indicated that compared with dogs that received antimicrobials prophylactically, dogs that received saline solution developed infections significantly more frequently. Difference in efficacy, however, was not observed between the 2 antimicrobial drugs used. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that perioperative antimicrobial prophylaxis decreased postoperative infection rate in dogs undergoing elective orthopedic surgery, compared with infection rate in control dogs. Cefazolin was not more efficacious than potassium penicillin G in these dogs.     

Risk Factors for Incisional Complications after Exploratory Celiotomy in Horses: Do Skin Staples Increase the Risk?

Objective: To assess risk factors for celiotomy incisional infection in horses, especially the use of staples for skin closure. Study Design: Case series. Animals: Horses (n=356) that had 1 exploratory celiotomy for colic and survived >2 weeks after surgery between March 1, 2004 and December 31, 2007. Methods: Incisions were classified as “normal” (no complication, only edema, serous drainage lasting <24 hours) or as “surgical site infection (SSI)” (persistent serosanguinous drainage or purulent drainage with or without positive bacterial culture). All possible risk factors, including method of skin closure (monofilament sutures or staples), were statistically analyzed using univariate and multivariate logistic regression. Results: Of 356 horses, 303 (85%) had normal wound healing and 53 (15%) developed a SSI (purulent: 48 [14%]; persistent serosanguinous: 5 [1%]). Bacterial cultures were positive in 33 of 40 cases. Factors significantly associated with SSI in the multivariate analysis were: use of staples for skin closure (odds ratio [OR] 3.85, P<.001) and surgical site closure by a 1st or 2nd year resident (OR 2.20, P=.016). Lavage of the linea alba with sterile saline solution after closure was a protective factor (OR 0.38, P=.004). Conclusion: Use of staples for skin closure and less experienced surgeons closing the abdomen are risk factors for incisional infection. Incisional lavage after linea alba closure was a protective factor. Clinical Relevance: Despite their ease and speed of application, skin staples can lead to an increase in celiotomy wound complications in horses.     

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.     

Risk factors for human rabies in China

In China, we have witnessed an increasing incidence of rabies in recent years and the number of deaths ranked first among the 39 notifiable infectious diseases. We conducted a case-control study to identify risk factors for human rabies infection and disease to recommend prevention and treatment among people exposed to rabies. Exposure site, pre-exposure prophylaxis and post-exposure prophylaxis were significantly associated with rabies infection. Exposure site at upper limb and trunk or at lower limb were at lower risk as compared with head-exposed patients. The OR was 0.09(95% CI: 0.009-0.93) and 0.01(95% CI: 0.001-0.115) respectively. Pre-exposure prophylaxis (OR = 0.05, 95% CI: 0.03-0.11) and post-exposure prophylaxis (OR = 0.02, 95% CI: 0.01-0.40) were both protective factors as compared with no prophylaxis. For patients who had post-exposure prophylaxis, dose for the first injection and immunity procedure were significantly associated with rabies infection.     

Effects of antibiotic prophylaxis on postoperative complications after rumenotomy in cattle.

A single preoperative dose of antibiotic proved as effective as a preoperative and 7-day postoperative course in reducing complications following rumenotomy in cattle. Exploratory rumenotomy was performed on 29 healthy Angus steers, which were allotted to the following treatment groups: (1) no antibiotic therapy, (2) single-dose, preoperative, antibiotic prophylaxis, using potassium penicillin G, and (3) preoperative potassium penicillin G prophylaxis, followed by a 7-day postoperative course of procaine penicillin G. Steers receiving antibiotics had significantly greater postoperative feed intake, lower rectal temperatures, and fewer abscesses at the surgical site than those receiving no antibiotics. There was no significant difference between animals receiving a single preoperative dose of antibiotic and those treated for an additional 7 days after surgery. In human medicine, it is generally agreed that a single preoperative dose of antibiotic offers effective prophylaxis. There are few published reports on antimicrobial prophylaxis in the veterinary literature, particularly in regard to large animals. Considering USDA requirements for milk withholding times and withdrawal times prior to slaughter for food animals receiving antibiotics, the findings of this study have medical as well as economic value.     

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.     

Surgical Wound Infection Rates in Dogs and Cats Data from a Teaching Hospital

Two thousand sixty-three surgical procedures were performed on 1992 patients (1715 dogs and 277 cats). In a retrospective analysis, the procedures were categorized according to the expected degree of wound contamination, and corresponding wound infection rates were determined. The number of procedures in each category and the percent that became infected were as follows: clean (1100, 2.5%), clean-contaminated (554, 4.5%), contaminated (172, 5.8%), and dirty (237, 18.1%). The administration of antibiotics significantly reduced the frequency of wound infection in clean surgical procedures performed by senior veterinary students (p less than 0.05), but not in clean elective procedures performed by faculty or resident surgeons that required 90 minutes or less to complete. There was a significant correlation between elevation of rectal temperature postoperatively and increased duration of the surgical procedure. However, the rectal temperature measured the day after surgery was not an accurate predictor of wound infection.     

Cortical allograft and endoprosthesis for limb-sparing surgery in dogs with distal radial osteosarcoma: a prospective clinical comparison of two different limb-sparing techniques

OBJECTIVE: To compare surgical and oncologic outcome in dogs with osteosarcoma (OSA) of the distal aspect of the radius treated with limb-sparing surgery, using either a cortical allograft or endoprosthesis, and postoperative chemotherapy; and to evaluate predictive factors for outcome. STUDY DESIGN: Prospective cohort study. ANIMALS: Dogs (n = 20) with spontaneous, non-metastatic OSA of the distal aspect of the radius. METHODS: Dogs were prospectively randomized for limb-sparing surgery with either a cortical allograft (n = 10) or endoprosthesis (10) and full-course adjuvant chemotherapy using single or dual agent protocols of cisplatin, carboplatin, and/or doxorubicin. Surgical (intraoperative findings, postoperative infection, construct failure) and oncologic (local tumor recurrence, metastasis, survival) outcomes were compared. The influence of intraoperative and postoperative variables on surgical and oncologic outcome were evaluated. RESULTS: No clinically significant differences in surgical and oncologic outcome were detected between groups. The percentage of radius replaced by the implant was significantly greater in the endoprosthesis group (60.9% compared with 48.6%, P = .008). Median survival time (MST) for dogs with construct failure, regardless of implant type, was 685 days and significantly greater than MST of dogs without construct failure (322 days, P = .042; hazard ratio [HR] 16.82). Median metastasis-free interval and MST (685 days versus 289 days; P = .034, HR 24.58) were significantly greater in dogs with postoperative infection. Disease-free and overall limb-salvage rates were 70% and 85%, respectively. Overall MST was 430 days. CONCLUSIONS: For dogs with OSA of the distal aspect of the radius, a cortical allograft or endoprosthesis can be used for limb-sparing surgery. Construct failure and postoperative infection significantly improve survival time regardless of implant type. CLINICAL RELEVANCE: An endoprosthesis is an attractive alternative to cortical allografts for limb-salvage of the distal aspect of the radius in dogs because surgical and oncologic outcomes are similar, but the endoprosthesis is an immediately available off-the-shelf implant which is not complicated by the bone harvesting and banking requirements associated with cortical allografts. Mechanisms whereby postoperative infection improves survival time requires further investigation and, if elucidated, may provide the opportunity to improve the outcome of dogs and humans with OSA.     

Perioperative administration of antimicrobials associated with elective surgery for cranial cruciate ligament rupture in dogs: 83 cases (2003-2005)

OBJECTIVE: To evaluate perioperative antimicrobial use associated with elective surgery for cranial cruciate ligament rupture in dogs. DESIGN: Retrospective case series. ANIMALS: 83 dogs. PROCEDURES: Medical records were reviewed and antimicrobial use practices were evaluated for dogs with no other problems that would affect antimicrobial use decisions. RESULTS: Antimicrobials were administered before or during surgery to 75 of 83 (90%) dogs. Timing of administration with respect to first incision, intraoperative administration, and duration of administration were variable. Antimicrobial administration began after surgery in 3 (3.6%) dogs. Fifty-five of 65 (85%) dogs treated before surgery received the first dose within 60 minutes of the first incision. Time from first antimicrobial administration to closure of the incision ranged from 15 to 285 minutes (mean +/- SD, 141 +/- 53 minutes). If a guideline of repeated administration every 2 hours after first administration until closure of the surgical site was used, 22 of 43 (51%) dogs received the required intraoperative dose, whereas 6 of 32 (19%) dogs that did not require intraoperative treatment were treated. Twenty-four (29%) dogs received antimicrobials after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Certain discrepancies between antimicrobial use practices in this study and standard guidelines used in human medicine were evident.     

Surgical stress and postoperative complications related to regional and radical mastectomy in dogs

Background

Surgery is the treatment of choice for regional control of mammary neoplasms in female dogs. Various surgical techniques may be used, as long as mammary gland anatomy, lymphatic drainage, and known prognostic factors are respected. The purpose of this study was to compare surgical stress—including duration of surgery, nociception and hematological changes—and postoperative complications in dogs undergoing regional and unilateral radical mastectomy. Eighteen dogs were selected for each technique. Postoperative pain (nociception), hematological changes, and postoperative complications were compared between the two groups.

Results

The group treated with radical mastectomy had a longer surgical duration, showed more intense physiological changes, achieved higher scores on nociception scales, and experienced more postoperative complications.

Conclusion

Compared to regional mastectomy, radical mastectomy was associated with longer surgical duration, greater nociceptive stimulus, greater surgical stress, and higher incidence of postoperative complications in dogs. Although evaluation of long-term results was not a goal of this study, it is suggested that postoperative recovery and patient quality of life should be considered when choosing a surgical approach for treating mammary tumors in dogs.     

Multidrug-resistant E. coli and enterobacter extraintestinal infection in 37 dogs

BACKGROUND: Extraintestinal infections caused by multidrug-resistant (MDR) Escherichia coli and Enterobacter are becoming more common in veterinary medicine. OBJECTIVE: To generate hypotheses for risk factors for dogs acquiring extraintestinal infection caused by MDR E. coli and Enterobacter, describe antimicrobial resistance profiles and analyze treatment and clinical outcomes. ANIMALS: Thirty-seven dogs diagnosed with extraintestinal infection caused by MDR E. coli and Enterobacter spp. between October 1999 and June 2006. METHODS: Retrospective case series assembled from hospital records data, including clinical history before 1st MDR isolation and treatment outcome. Identity and antimicrobial susceptibility profiles were confirmed by standard microbiological techniques for 57 isolates. RESULTS: Most dogs had an underlying disease condition (97%), received prior antimicrobial treatment (87%), were hospitalized for >or =3 days (82%), and had a surgical intervention (57%). The urinary tract was the most common infection site (62%), and urinary catheterization, bladder stasis, or both were common among dogs (24%). Some dogs were treated with high doses of co-amoxyclavulanate (n = 14) and subsequently recovered even though the isolates showed in vitro resistance to this antimicrobial. Other dogs were successfully treated with chloramphenicol (n = 11) and imipenem (n = 2). CONCLUSION AND CLINICAL IMPORTANCE: Predisposing disease condition, any prior antimicrobial use rather than a specific class of antimicrobial, duration of hospitalization, and type of surgical procedure might be risk factors for acquiring MDR extraintestinal infections. Whereas culture and sensitivity results can indicate use of last-resort antimicrobials such as imipenem for MDR infections, some affected dogs can recover after administration of high doses of co-amoxyclavulanate.     

Endoscopic surgery in the treatment of contaminated and infected synovial cavities

REASONS FOR PERFORMING STUDY: Contamination and infection of synovial cavities are a common occurrence in clinical practice and, if inadequately treated, may have career or life threatening consequences for affected horses. HYPOTHESIS: The objectives in treating contamination and infection of joints, tendon sheaths and bursae are most effectively met by endoscopic surgery. METHODS: Over a 6 year period, cases of synovial contamination and infection admitted to a referral clinic were evaluated and treated endoscopically. The horses received local and systemic antimicrobial drugs with minimal nonsteroidal anti-inflammatory medication but no other medical or surgical treatment. All arthroscope and instrument portals and, whenever possible, all traumatic wounds were closed. Diagnostic information, endoscopic observations and results of treatment were evaluated retrospectively. RESULTS: A total of 140 affected animals were referred and 121 cases were treated endoscopically. These involved 70 joints, 29 tendon sheaths, 10 bursae and in 12 cases a combination of synovial cavities. The most common aetiologies were open wounds (n = 54) and self-sealing punctures (n = 41). Foreign material was identified endoscopically in 41 but predicted prior to surgery in only 6 cases. Osteochondral lesions were evident at surgery in 51 and recognised before surgery in 25 cases; 32 horses had intrathecal tendon or ligament defects. Follow-up information was obtained for 118 animals; 106 (90%) survived and 96 (81%) returned to their preoperative level of performance. The presence of osteitis/osteomyelitis, other osteochondral lesions and marked deposits of pannus were associated with nonsurvival. For those animals which survived, non-Thoroughbred horses, a combination of synovial structure involvement and regional i.v. antimicrobial administration were associated with reduced post operative performance. Marked pannus, regional i.v. antimicrobial administration and duration of systemic antimicrobial administration were associated with a group combining nonsurviving animals and those with reduced post operative performance. CONCLUSIONS: Endoscopic surgery makes a valuable contribution to the management of synovial contamination and infection. POTENTIAL RELEVANCE: The information obtained from and therapeutic options offered by endoscopy justify its early use in cases of synovial contamination and infection.     

Open versus closed bilateral anal sacculectomy for treatment of non-neoplastic anal sac disease in dogs: 95 cases (1969-1994)

OBJECTIVE: To determine complications associated with anal sacculectomy in dogs with non-neoplastic anal sac disease and compare complication rates for open versus closed techniques. DESIGN: Retrospective study. ANIMALS: 95 dogs. PROCEDURE: Medical records were reviewed for information on signalment, history, physical examination findings, type of anal sac disease, surgical technique (closed, standard open [surgery performed prior to 19801, or modified open [surgery performed after 19801), and postoperative complications. RESULTS: In 57 dogs, a closed technique was used, and in 38, an open technique was used. Only 3 dogs developed short-term complications (excessive drainage, scooting and inflammation, and seroma formation), and 14 developed long-term complications (continued licking of the surgery site, fecal incontinence, fistulation, and stricture formation). Development of postoperative complications was significantly associated with surgical technique. Dogs that underwent standard open sacculectomy prior to 1980 were 13.67 times as likely to have a long-term complication as were dogs that underwent closed sacculectomy. Weight of the dog, type of anal sac disease, age at the time of surgery, and whether the wound was closed surgically were not significantly associated with whether dogs developed postoperative complications. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that anal sacculectomy is a safe and effective treatment for non-neoplastic anal sac disease in dogs and is associated with a low rate of complications. The standard open technique was associated with the greatest number of complications, whereas complication rates for the closed and modified open techniques were similar to each other.