Agmatine Administration Effects on Equine Gastric Ulceration and Lameness

Abstract

Osteoarthritis (OA) accounts for up to 60% of equine lameness. Agmatine, a decarboxylated arginine, may be a viable option for OA management, based on reports of its analgesic properties. Six adult thoroughbred horses, with lameness attributable to thoracic limb OA, received either daily oral phenylbutazone (6.6 mg/kg), agmatine sulfate (25 mg/kg) or a control for 30 days, with 21-day washout periods between treatments. Subjective lameness, thoracic limb ground reaction forces (GRF), plasma agmatine and agmatine metabolite levels were evaluated using an established rubric, a force platform, and mass spectrometry, respectively, before, during and after each treatment period. Gastric ulceration and plasma chemistries were evaluated before and after treatments. Braking GRFs were greater after 14 and 29 days of agmatine compared to phenylbutazone administration. After 14 days of phenylbutazone administration, vertical GRFs were greater than for agmatine or the control. Glandular mucosal ulcer scores were lower after agmatine than phenylbutazone administration. Agmatine plasma levels peaked between 30 and 60 min and were largely undetectable by 24 h after oral administration. In contrast, plasma citric acid levels increased throughout agmatine administration, representing a shift in the metabolomic profile. Agmatine may be a viable option to improve thoracic limb GRFs while reducing the risk of glandular gastric ulceration in horses with OA.

A Preliminary Protocol of Radiographic Image Processing for Quantifying the Severity of Equine Osteoarthritis in the Field: A Model of Bone Spavin

“…Considering that taking X-rays in healthy horses is not justified, the horses were pre-examined during a routine screening examination for hind limb lameness. The horses underwent a basic clinical examination and a detailed orthopedic examination following the protocol outlined by Taguchi et al [57]. Lameness was scored according to the guidelines and scale of the American Association of Equine Practitioners (AAEP) [58], the description of which is summarized here in Table 1.…”