# A Systematic Review of Bacterial Sampling Collection for Veterinary Microbiology in Companion Animals

## TL;DR

This paper reviews how samples for bacterial testing are collected in dogs and cats, finding significant variability and a need for standardized guidelines to improve diagnostic accuracy and antibiotic use.

## Contribution

The study identifies gaps in standardized bacterial sampling practices in veterinary microbiology and advocates for evidence-based guidelines to improve diagnostic reliability.

## Key findings

- Swabs are commonly used but less reliable compared to tissue and fluid samples.
- Pre-laboratory factors like antibiotic use and transport conditions are often poorly documented.
- Sampling methods and culture recommendations vary by anatomical site and suspected bacteria.

## Abstract

Accurate diagnosis of bacterial infections in dogs and cats depends on proper collection, handling, storage, and transport of samples. This review examined current practices for taking and processing samples for bacterial testing, based on seventeen studies published over the last ten years. The results showed that sampling methods vary widely across body sites. Swabs were most commonly used, but tissue and fluid samples generally provide more reliable results. Key information, such as prior antibiotic use and storage or transport conditions, was often missing, which can affect test accuracy. The choice of culture method and storage depends on the suspected bacteria and the body site sampled. Overall, there are significant gaps in standardisation. Developing clear, evidence-based guidelines could improve test reliability, support responsible antibiotic use, and ultimately enhance the health of companion animals and the wider community.

Accurate microbiological diagnosis in companion animals relies heavily on appropriate sample collection, handling, storage, and transport. This systematic review, conducted according to the PRISMA 2020 guidelines, aimed to assess current microbiological sampling procedures used in dogs and cats, from specimen collection to laboratory submission. Seventeen studies published in English over the past decade met the inclusion criteria. Considerable variability in sampling practices was observed across different anatomical systems. Although swabs were the most frequently employed sampling method, their use is limited by reduced representativeness and an increased risk of contamination, whereas tissue biopsies and aspirates provide more reliable diagnostic results. Sampling practices were generally more consistent for urine samples; however, pre-laboratory factors, such as prior antimicrobial exposure, as well as transport and storage conditions, were inconsistently reported, hindering reproducibility and standardisation. The anatomical site sampled and the suspected pathogen determined whether aerobic or combined aerobic–anaerobic cultures were recommended. Overall, the findings reveal considerable methodological gaps and underscore the need for harmonised, evidence-based guidelines to support accurate and clinically relevant bacterial culture in veterinary diagnostics. Standardised protocols, developed collaboratively by clinicians and diagnostic laboratories, have the potential to improve diagnostic consistency, strengthen antimicrobial stewardship, enhance surveillance, and ultimately benefit clinical outcomes within One Health initiatives.