Risk factors and long-term prognosis of catheter-associated thrombophlebitis in neonatal foals

Thrombophlebitis is a possible complication of the use of indwelling catheters in hospitalized neonatal foals. Limited data are available concerning associated risk factors, and long-term prognosis regarding vein patency is currently unknown.

Identify risk factors for catheter-associated thrombophlebitis in neonatal foals and assess long-term prognosis in a small subset.

Two hundred twenty-three foals < 31 days of age, hospitalized in Utrecht University Equine Hospital between 2019 and 2024.

Retrospective review of medical records. Foals that received an indwelling intravenous catheter and lived for at least two subsequent days were included. Odds ratios were determined, using logistic regression, for factors potentially associated with thrombophlebitis. Owners of affected horses were contacted, and horses available for follow-up were visited for clinical evaluation.

Twenty-one foals (9.4%) developed catheter-associated thrombophlebitis. In a multivariable model, hospitalization in the neonatal intensive care unit (NICU, OR 5.2, 95%CI 1.5-19.7), diarrhea (OR 4.6, 95%CI 1.4-17.3), Friesian breed (OR 4.1, 95%CI 1.1-13.9) and dwell time over four days (OR 3.9, 95%CI 1.3-14.8) were significantly associated with thrombophlebitis development. Seventeen affected foals survived to discharge. Eight horses, aged five months to five years, were available for follow-up by clinical evaluation and demonstrated appropriate blood flow.

Risk factors for developing catheter-associated thrombophlebitis in hospitalized neonatal foals were identified. This knowledge can aid in implementation of preventive measures.