Comprehensive Review of Blood Collection Techniques in Swine: Practical Guidelines for Veterinary Practice.

Swine veterinary practice involves a range of invasive procedures, including venipuncture and catheterization, for diagnostic, therapeutic, and epidemiological purposes. With the global expansion of pig production and the growing need for effective health monitoring, particularly in the context of infectious disease control programs, such as Aujeszky's disease and swine vesicular disease, the implementation of efficient and welfare-conscious blood collection methods has become a priority. The selection of an appropriate venous access route is particularly critical due to the wide variation in pig size, age, and behavior, as well as the general resistance of adult pigs to human handling, which directly affects operator safety, procedural success, and animal welfare. Commonly employed sites include the jugular and ear veins, while alternative routes-such as the cranial vena cava, orbital venous sinus, tail vessels, cephalic and femoral veins, percutaneous cardiac puncture, subcutaneous abdominal vein, and the mammary vein in lactating sows-may be chosen according to the animal's physiological status and the specific purpose of sampling. Each technique presents distinct advantages and limitations in terms of vein visibility, obtainable blood volume, repeatability, restraint requirements, and potential welfare implications. Forced restraint, required for most methods, can induce substantial stress, alter biological parameters such as serum cortisol, and compromise both sample reliability and animal well-being. While long-term catheterization provides repeated access with minimal handling, its use is typically confined to research settings due to the need for anesthesia, surgical expertise, and individual housing. This review presents a comprehensive anatomical and procedural overview of major blood collection techniques in pigs, critically evaluating their feasibility, invasiveness, and welfare impact. By offering a comparative analysis of each method's suitability across clinical and field scenarios, this work aims to guide swine practitioners in selecting the most appropriate venipuncture or catheterization approach, balancing diagnostic accuracy with ethical responsibility toward animal welfare.