Comparison of Two Surgical Site Protocols for Cattle in a Field Setting

Bacterial Contamination of the Surgical Site at the Time of Elective Caesarean Section in Belgian Blue Cows-Part 2: Identified by 16Sr DNA Amplicon Sequencing

This study aimed to describe the bacterial composition of the surgical site during elective caesarean sections (CSs) using the 16Sr DNA amplicon sequencing performed in parallel to bacterial culture. The study involved 13 Belgian blue cows of a previous dataset of 76 animals. Bacteriology was performed on swabs sampled from visceral and parietal peritoneum during the CS. Amplicon sequencing was performed in six samples chosen randomly among the swabs positive for bacteriology and seven among the culture-negative swabs. A total of 2542 bacterial operational taxonomic units belonging to 567 genera were identified. The most often identified genus and species were Mycoplasma (44%) and Mycoplasma wenyonii (36%), respectively. Results showed no difference in microbiota composition between the culture-positive and -negative samples. However, a difference was observed between the bacteriology and amplicon sequencing results. Indeed, seven out of nine cultured strains were not identified by amplicon sequencing in the samples in which they were cultured. In contrast to bacteriology, amplicon sequencing unveiled the presence of bacterial DNA in all elective CSs. The most identified DNA is most likely derived from the haematogenous spread of bacteria to the surgical site. Furthermore, the cultured bacteria were not the dominant species in the sample from which they were cultured.

Clinical characteristics, treatment, and outcome for cattle that developed retroperitoneal abscesses following paralumbar fossa laparotomy: 32 cases (1995-2017)

OBJECTIVE

To describe the clinical and clinicopathologic characteristics, treatment, and outcome for cattle that developed a retroperitoneal abscess (RA) following paralumbar fossa laparotomy (PFL).

ANIMALS

32 Holstein cows with RA.

PROCEDURES

The record database of a veterinary teaching hospital was searched to identify cattle that were treated for an RA between January 1995 and March 2017. Cattle with an RA > 30 cm in diameter located 3.5 cm subjacent to the skin that had undergone a PFL < 3 months before examination for the RA were evaluated. Information extracted from the record of each cow included signalment; physical examination, clinicopathologic, and transabdominal ultrasonographic findings; treatments administered; and outcome. Milk production data were analyzed for the lactations before, during, and after RA treatment.

RESULTS

Common physical examination findings were rumen hypomotility, anorexia, and fever, and common clinicopathologic findings were anemia and neutrophilia. Abdominal palpation per rectum and transabdominal ultrasonography facilitated RA diagnosis and identification of the optimal location for drainage. Thirty of 32 cows underwent surgical drainage of the RA and prolonged administration of systemic antimicrobials. Two cows were euthanized because of concurrent peritonitis, including 1 that underwent surgical RA drainage. Thirty cows were discharged from the hospital alive, and most returned to their previous level of milk production.

CONCLUSIONS AND CLINICAL RELEVANCE

Although uncommon, RA should be suspected in cows that develop anorexia and fever within 3 months after PFL. Cows with RA often returned to their previous level of milk production, but treatment was generally prolonged and costly.

Judicious use of prophylactic antimicrobials to reduce abdominal surgical site infections in periparturient cows: part 1 - a risk factor review

Surgical site infections (SSI) are an uncommon, but significant, consequence of surgical interventions. There are very few studies investigating SSI risk in veterinary medicine, and even fewer in cattle, despite the fact that major surgeries are commonly conducted on livestock. Furthermore, the suboptimal conditions under which such surgeries are frequently performed on livestock could be considered an important risk factor for the development of SSIs. With increasing public concern over the contribution of veterinary-prescribed antimicrobials to the emergence of antimicrobial-resistant bacteria in people, there is widespread scrutiny and criticism of antimicrobial use in livestock production medicine systems. While the causal link between antimicrobial resistance in livestock and people is heavily debated, it is clear that the prevalence of antimicrobial resistance, in any population, is closely correlated with the antimicrobial 'consumption' within that population. As the veterinary profession explores ways of addressing the emergence and selection of antimicrobial-resistant bacteria in food-producing animals, there is a need for veterinarians and producers to carefully consider all areas of antimicrobial use, and employ an evidence-based approach in designing appropriate clinical protocols. This paper aims to review current knowledge regarding the risk factors related to abdominal SSI in periparturient cows, and to encourage practitioners to judiciously evaluate both their standard operating procedures and their use of antimicrobials in these situations. In a second paper, to be published in a subsequent issue of Veterinary Record, these principles will be used to provide specific evidence-based recommendations for antimicrobial use in bovine abdominal surgery.