Introduction

Investigation of canine and feline pancreatic disease remains a real challenge for veterinary practitioners. The diagnostic approach usually requires several investigative tools such as CBC, biochemistry profile, diagnostic imaging, cytology, and histology.

In human medicine, for about 20 years, fine needle aspiration has been considered the standard pancreatic biopsy technique, supported by the accuracy of cytologic diagnosis and the safety of the technique (Smith et al., 1985). In the 1990s, pancreas endoscopic ultrasound-guided biopsy emerged and progressively replaced other sampling modalities, becoming the technique of choice for the detection (allowing the placement of the transducer close to the organ, providing high-quality images) and the cytologic biopsy of pancreatic lesions. Fine needle aspiration of the pancreas guided by endoscopic ultrasound (EUS FNA) is now currently used to obtain cytological and/or histological samples of solid pancreatic lesions with high diagnostic performance and a low rate of complications. Many publications (original articles and reviews) about EUS FNA performance, efficacy, technique, and complications are available, in which pancreatic EUS FNA is particularly described and debated (Siddiqui et al., 2009; Dumonceau et al., 2011; Baghbanian et al., 2012; Eisendrath et al., 2014; Fujii et al., 2014; Iglesias-Garcia et al., 2014; Petrone et al., 2014). A recent study reported EUS FNA sensitivity, specificity, and accuracy of 88%, 100%, and 90%, respectively, for diagnosis of pancreatic adenocarcinoma (Baghbanian et al., 2012). A review article described potential EUS FNA adverse effects; some are related to the endoscopic ultrasound route such as perforation or infections; other complications such as peritonitis, bleeding, or tumor seeding along the needle tract are mainly related to fine needle aspiration (Fujii & Levy, 2014). The complication rate of EUS FNA is approximately 1% (Iglesias-Garcia et al., 2014).

In veterinary medicine, EUS is not yet currently available and only one recent study described the feasibility and safety of EUS FNA of the pancreas in healthy Beagle dogs. It is therefore far too early to draw conclusions on EUS FNA diagnostic yield in veterinary medicine; more studies about EUS FNA in pancreatic disease are necessary. Currently, ultrasound-guided transabdominal fine needle aspiration (US FNA) remains the simplest way to obtain pancreatic cytology. The systematic use of a surgical procedure, including general anesthesia and laparotomy, is not reasonable in daily practice (Watson, 2012). The veterinary literature on canine and feline pancreatic FNA is poor but has grown somewhat in the last decade; obtaining pancreatic cytology is still probably judged as a difficult, unsafe, and irrelevant procedure by many institutions (Cordner et al., 2015; Rudinsky, 2023). However, pancreatic fine needle aspiration has a good diagnostic yield and a low rate of clinical complications according to the most recent study on this topic (Cordner et al., 2015; Rudinsky, 2023).