How to perform abdominocentesis and interpret abdominal fluid in equine patients.

The research article details the procedure for performing abdominocentesis and interpreting abdominal fluid in horses as a diagnostic tool for examining equine abdominal conditions.

Research Objective and Method

The research aimed to provide a concise description and practical demonstration of the abdominocentesis procedure in equine patients. For the purpose of the demonstration, one healthy university-owned animal was used. This method involves collecting abdominal fluid from a horse in a standing sedated state, and the procedure’s efficacy was validated through images from various clinical cases documented at the University of Illinois Veterinary Teaching Hospital.

• A 10x10cm area on the most dependent portion of the abdomen next to the midline is clipped and prepared aseptically.
• For numbing the area, 1 to 2 mL of 2% lidocaine is instilled both subcutaneously and into the abdominal musculature at the abdominocentesis site.
• An incision is made through the skin and the external rectus sheath with a No. 15 blade, which is then rotated 180°.
• By placing a teat cannula into the incision and applying pressure to penetrate the peritoneum, fluid collection is achieved. The teat cannula is rotated as necessary. Alternatively, an 18-gauge, 1.5-inch needle can also be inserted through the skin in the ventral abdomen’s centre in the aseptically prepared area.

Collection and Analysis of Abdominal Fluid

The collected abdominal fluid is stored in a red top tube for stall side analysis (lactate and total protein) or culture and a purple top tube for cytological evaluation.

• The normal abdominal fluid is straw-colored and clear, with a total protein less than 2 g/dL, and L-lactate less than 2 mmol/L (or similar to peripheral L-lactate).
• The fluid is considered normal if it has a nucleated cell count less than 500 cells/µL.

Research Conclusion

Abdominocentesis contributes significantly to investigating equine abdominal conditions, proving its value as a diagnostic tool. This method becomes particularly effective, providing guidance for treatment and referral decisions, when used in conjunction with other diagnostic procedures in cases of colic in horses.