Published descriptions of expected findings for laboratory analysis of peritoneal fluid (PTF) from companion pigs are lacking.
To describe routine PTF analysis results from clinically healthy and ill companion pigs.
Intraoperative PTF was collected prospectively from 32 healthy, sexually mature companion sows during ovariohysterectomy, and PTF analyses from 10 clinically ill companion pigs, with fluid collected transabdominally, were identified retrospectively. Clinically ill pigs had peritonitis ( n = 4), uterine neoplasia ( n = 4), end stage renal disease ( n = 1) or disseminated intravascular coagulation (DIC, n = 1). Analysis included total nucleated cell concentration (TNCC), total protein by refractometry (TP‐ref), and differentials of nucleated cells.
In PTF from healthy pigs, TNCC was commonly < 10 000/μL (range 190–14 670/μL) and TP‐ref was < 6.0 g/dL, with percentage differentials predominated by mononuclear cells (macrophages, lymphocytes, and individualized mesothelial cells) with < 15% neutrophils and < 10% eosinophils. Pigs with peritonitis or uterine neoplasia had TNCC similar to that of healthy pigs, but with higher percentages of neutrophils, often > 50%, and lower percentages of large mononuclear cells, often < 25%. Most pigs with neoplasia had tumor‐associated inflammation, likely contributing to higher neutrophil percentages. Two patients with peritonitis and one with DIC had higher TP‐ref than the healthy pigs.
PTF fluid from companion pigs with peritonitis or uterine neoplasia, particularly with concurrent inflammation, may have similar TNCC but increased proportions of neutrophils compared to healthy sows. Therefore, in contrast to some other large animal species, high percentages of neutrophils in PTF may warrant evaluation for peritonitis or abdominal neoplasia in pigs, regardless of the TNCC.