Iodoacetate and allogenous cartilage particles as models for arthritis induction in equine

Experimental models of osteoarthritis (OA) have been widely developed in different animal species, because of the high incidence of osteoarthritis diseases in humans and animals. To date, no ideal OA animal model has been reported. The present study compare different osteoarthritis models to determine which one is suitable for inducing experimental equine OA. Fifteen donkeys were divided into three equal groups (n = 5). The radio carpal joints of the right forelimb of 15 donkeys were injected with 25 mg monoiodoacetate (MIA) (group A), 50 mg allogenous cartilage particles (ACP) (group B), or vehicle solution (group C) over a period of 70 days. Osteoarthritis induction was evaluated weekly through lameness score, carpal circumference, joint flexion angel, synovial fluid analysis (total protein and WBC count), and radiology. Animal were euthanized and joints histopathology were performed at 70 days. Lameness score and joint circumference was increased in both group A and B however joint flexion angel was decreased compared to group C (p < 0.05). Osteophytes were observed in MIA injected joints only accompanied with subchondral bone sclerosis. Cartilage damage was observed grossly and histologically in Group A together with synovial membrane fibrosis. Group B had on cartilage damage grossly however histological examination revealed some cartilage surface discontinuity with synovial membrane edema. Injection of monoiodoacetate in the donkey is a successful model to create the acute clinical signs of joint disease as well as cartilage damage. However, allogenous cartilage particles injection need more investigation to be applied.