Risk factors for surgical site infection-inflammation in dogs undergoing surgery for rupture of the cranial cruciate ligament: 902 cases (2005-2006)

Combining a joint health supplement with tibial plateau leveling osteotomy in dogs with cranial cruciate ligament rupture. An exploratory controlled trial

Canine cranial cruciate ligament rupture (CrCLR) is a very common pathology. Surgical stabilization is the first choice treatment, although it does not fully eliminate the increased risk of osteoarthritis. This preliminary study was carried out to explore whether a newly formulated joint health supplement would benefit metabolic, clinical and radiographic changes in dogs with CrCLR surgically treated with tibial plateau leveling osteotomy (TPLO). Besides chondroitin sulfate and glucosamine hydrochloride, the studied supplement contained anti-inflammatory and antioxidant ingredients, the main ones being N-palmitoyl-D-glucosamine (Glupamid®) and quercetin. It was thus intended to target not only chondrodegenerative components of osteoarthritis, but also post-injury inflammatory response and oxidative stress of joint tissues. Thirteen dogs underwent TPLO and were randomly allocated to treatment (n = 6) and control groups (n = 7), the former receiving the joint supplement for 90 days. Lameness and radiographic osteoarthritis changes were scored before (i.e., baseline) and at 30 and 90 days post-surgery. Synovial fluid samples were collected from injured stifles at the same time points. Levels of representative metabolites were measured by proton nuclear magnetic resonance spectroscopy in a blinded fashion. In the metabolomic analysis, special attention was paid to lactate, due to its emerging recognition as a key marker of inflammation. In the last time period (from the 30th to the 90th day), lameness improved by a factor of 2.3 compared to control dogs. No significant difference was observed in the radiographic osteoarthritis score between groups. In the first postoperative month, lactate and creatine levels significantly dropped in treated compared to control dogs. Compared to surgery alone, combining the joint supplement with TPLO resulted in a trend to a better clinical outcome in the later time interval but did not influence osteoarthritis radiographic progression. A significantly better rebalance of joint microenvironment in the early time interval (baseline - 30 days) was shown by metabolomic analysis, thus suggesting that the study supplement could limit ongoing inflammatory responses.

Survey of Intraoperative Bacterial Contamination in Dogs Undergoing Elective Orthopedic Surgery

OBJECTIVE

To investigate the frequency, source, and risk factors of intraoperative (IO) surgeon and patient bacterial contamination during clean orthopedic surgeries, and to investigate the relationship between IO contamination and surgical site infection (SSI) in dogs.

STUDY DESIGN

Prospective clinical study.

SAMPLE POPULATION

Client-owned dogs undergoing stifle surgery (n = 100).

METHODS

IO cultures were taken in each case from surgical foot wrap, peri-incisional skin, surgical gloves, and the surgical team's hands. The environment (operating room [OR] lights, computers, scrub sink faucet, anesthesia gurney, and radiology table) was sampled every 5 months. Bacteria were identified and the contamination of each case was categorized. All gloves from the surgical team were collected and tested for perforations using a water infusion test. Cases were followed for at least 8 weeks to determine the presence or absence of SSI. Perioperative variables were evaluated for association with IO contamination and SSI.

RESULTS

Bacterial isolates were yielded from 81% of procedures from 1 or more sources; 58% had positive hand cultures, 46% had positive glove cultures, 23% had positive patient skin cultures, and 12% had positive foot wrap cultures. Staphylococcus spp. was the most commonly recovered bacteria. There was no apparent association between IO contamination and SSI. The highest level of environmental contamination was associated with the scrub sink faucet, followed by the radiology table, anesthesia gurney, and OR computers. The IO glove perforation rate was 18%.

CONCLUSION

Clean orthopedic procedures commonly had clinically insignificant bacterial contamination. In our study, bacteria responsible for SSI did not appear to colonize the patient in the OR.

Comparison of caudal and pre-scrotal castration for management of perineal hernia in dogs between 2004 and 2014

AIMS

To compare peri- and post-operative complications associated with caudal scrotal castration (CSC) and perineal hernia repair with pre-scrotal castration (PSC) in conjunction with another surgical procedure.

METHODS

Medical records were reviewed for 51 intact male dogs that were admitted to the Veterinary Emergency and Surgical Center, Levittown, PA, and underwent a CSC and perineal hernia repair using an internal obturator muscle flap (IOMF) between 2004 and 2014. Perioperative, and major and minor post-operative complications noted within the 2 week follow up period were reported and compared to 91 intact male dogs that underwent a PSC in conjunction with a second surgical procedure.

RESULTS

There were no recorded perioperative or major post-operative complications in either group. There were 3/51 (6%) minor post-operative complications in the CSC group compared to 6/91 (7%) in the PSC group. There were 2/51 (4%) and 4/91 (4%) cases that developed heat, erythema and swelling associated with the incision site and 1/51 (2%) and 2/91 (2%) cases that developed scrotal swelling in the CSC and PSC groups, respectively. Overall, there was no difference in the prevalence of minor complications between the two groups (p=0.86).

CONCLUSIONS AND CLINICAL RELEVANCE

Caudal scrotal castration was not associated with more perioperative or postoperative complications relative to PSC. Utilising the CSC approach eliminates the need to aseptically prepare and drape a second site when carrying out perineal hernia repair, as well as the need for patient repositioning. Thus, we recommend that CSC be the preferred surgical technique when performing orchiectomy in dogs concurrent with perineal hernia repair.

Perioperative risk factors for surgical site infection in tibial tuberosity advancement: 224 stifles

OBJECTIVE

To examine perioperative factors affecting surgical site infection (SSI) rate following tibial tuberosity advancement (TTA).

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

224 stifles in 186 dogs.

METHODS

Medical records of dogs that underwent TTA in a single institution were reviewed. Information on signalment, anaesthetic and surgical parameters, as well as occurrence of SSI was recorded. Dogs were followed for a minimum of three months postoperatively. The association between perioperative factors and SSI was assessed using Chi-squared tests and binary logistic regression.

RESULTS

The prevalence of SSI was 5.3% (12/224 TTA). Surgical time (p = 0.02) and anaesthesia time (p = 0.03) were significantly associated with SSI. For every minute increase in surgical time and anaesthesia time, the likelihood of developing SSI increased by seven percent and four percent respectively. The use of postoperative antimicrobial therapy was not significantly associated with lower SSI (p = 0.719). Implants were removed in 1.3% of cases (3/224 TTA).

CONCLUSIONS

The findings of this study suggest that increased surgical and anaesthesia times are significant risk factors for SSI in TTA, and that there is no evidence that postoperative prophylactic antimicrobial therapy is associated with SSI rate.

Efficacy of Postoperative Antimicrobial Use for Clean Orthopedic Implant Surgery in Dogs: A Prospective Randomized Study in 100 Consecutive Cases

OBJECTIVES

To investigate whether administration of postoperative oral antimicrobial drugs has a beneficial effect on preventing surgical site infections (SSI) in clean orthopedic surgery involving stainless steel plating systems.

STUDY DESIGN

Randomized prospective clinical study.

ANIMALS

Dogs (n = 97).

METHODS

One hundred consecutive cases (97 dogs) that had clean orthopedic surgery requiring stainless steel plate fixation were randomly assigned using a random number generator to either YES group (administration of postoperative oral antimicrobials) or NO group (no administration of postoperative oral antimicrobials). Dogs in YES group were administered oral cefalexin or potentiated amoxicillin for 7 days, whereas dogs in NO group were discharged without oral antibiotics. Minimum follow-up was 12 months. Multivariable logistic regression was used to determine risk factors for SSI.

RESULTS

Overall postoperative infection rate was 12.9%. Infection occurred in 2 cases (4.3%) administered postoperative oral antimicrobials and in 10 cases (21.3%) not administered postoperative antimicrobials. Total anesthetic time and use of oral antimicrobials were the only significant factors associated with SSI. Use of postoperative antimicrobials was associated with a significant reduction in the risk of infection by ~84% and risk of infection was increased by ~2% for each minute increase in anesthesia time.

CONCLUSIONS

Administration of oral postoperative antimicrobials had a protective effect against development of SSI in clean orthopedic implant surgery.

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.

Fighting surgical site infections in small animals: are we getting anywhere?

A diverse array of pathogen-related, patient-related, and caretaker-related issues influence risk and prevention of surgical site infections (SSIs). The entire surgical team involved in health care settings in which surgical procedures are performed play a pivotal role in the prevention of SSIs. In this article, current knowledge of SSI risk factors and prevention methods is reviewed. Although new avenues that can be explored in the prevention of SSIs in veterinary medicine are described, the main conclusion drawn is that the best method for prevention of SSI is to adhere to what we already know.

Prevalence of bacteriuria in dogs without clinical signs of urinary tract infection presenting for elective surgical procedures

OBJECTIVES

To determine the frequency of bacteriuria in dogs presenting for elective surgery, to compare the frequency of bacteriuria in dogs presenting for orthopaedic (non-neurological) procedures to that of dogs presenting for soft tissue procedures and to measure the agreement of microscopic visualisation of bacteria in urine sediment with the occurrence of bacterial growth on culture.

METHODS

Prospective cohort study of 140 client-owned dogs. Urine was collected via prepubic cystocentesis prior to or immediately after induction of anaesthesia. Urine was submitted for quantitative bacteriological culture and urinalysis. The dogs' age, sex, weight and breed were recorded, as well as the surgical procedure performed.

RESULTS

In total, 80 orthopaedic and 60 soft tissue surgical cases were included in the study; 3 dogs (2.1%) returned bacterial growth on culture (positive urine culture) and 19 (13.6%) recorded urine sediment with pyuria and/or bacteriuria on urinalysis (positive urinalysis). All dogs with positive urine culture were female and two of them underwent orthopaedic procedures. Each bitch had growth of Escherichia coli >10(5)  CFU/mL. The agreement between positive urinalysis and positive urine culture was poor (κ = 0.15).

CONCLUSIONS

The prevalence of bacteriuria in dogs without clinical signs of urinary tract infection in this population was low (2.1%). An at-risk population could not be identified because of the small number of positive outcomes. A positive urinalysis showed poor agreement with urine culture results and therefore the decision to treat without performing a urine culture is not advised.

Prospective surgical site infection surveillance in dogs

OBJECTIVE

To 1) describe the incidence of surgical site infections (SSI) in dogs undergoing surgery at the Ontario Veterinary College Health Sciences Centre; 2) describe and compare procedure-specific SSI rates; and 3) identify factors associated with development of SSI.

STUDY DESIGN

Prospective, cohort study

ANIMALS

Dogs (n = 846) undergoing surgery during 45 weeks (September 2010-July 2011).

METHODS

Follow-up telephone conversation with dog owners was performed 30 days postoperatively, with additional 1-year follow-up performed for cases with surgical implants. A standardized questionnaire was administered to detect and characterize SSI.

RESULTS

SSI were identified in 26 (3.0%) dogs; 11 (42%) were classified as superficial SSI, whereas 13 were deep, and 2 were organ/space. Of the confirmed SSI, only 17 (65%) were documented in the medical records. Hypotension (P = .011), class of surgery (P = .029), and use of an implant (P = .001) increased the risk of SSI. Microbial cultures were submitted for 19 cases (73%) and of those, 74% were staphylococci.

CONCLUSIONS

SSI can result in devastating consequences in dogs and understanding risk factors is critical to target prevention practices. Whereas some risk factors such as hypotension are modifiable, others such as class of surgery are not. When possible, active surveillance should be used as part of a hospital infection control program.