His owner called us and within an hour we had assessed the wound by flushing it and probing for depth and radiographed the area to check for any bone pathology. The location of the wound over the carpal joints and the level of discomfort of the horse meant the vet was highly suspicious of involvement of the joint, therefore making the wound a lot more serious than it outwardly appeared. Joint involvement was assessed in two ways: by taking a sample of the fluid from each of the two carpal joints to be analysed for signs of infection, and instilling sterile saline into the joints to see if any fluid came out of the wound which would confirm communication between the wound and the joint. In this case, the joint fluid collected was more watery and blood contaminated than usual, suggesting a possible infection. No saline was noted coming from the wound when instilled into the joint, however if something has penetrated the joint and then been quickly removed e.g. a thorn, this can seal quickly and the communication is therefore no longer obvious. Antibiotics were instilled into both joints after the joint samples were obtained.
One of the two joints that makes up the carpus had a very high white blood cell count, confirming that an infection was present within the joint. A joint infection is very painful as well as being potentially damaging to all the structures within the joint; if left untreated arthritis can occur secondary to joint damage or infection can extend to the surrounding bones causing an osteomyelitis (bone infection).