Testing for protein levels in joint fluid

[Birker2020]

My vet came out today to give my horse his 2nd round of shockwave for his suspensory ligament injury and also to medicate his coffin joint with steroid as x-rays last week showed he had moderate to severe arthritis in the joint.

When the needle went in the joint fluid came out (as its supposed to) so he took a sample away with him and said something about testing it for protein levels. Then he injected the coffin joint with the steroid. I'm usually asking questions but for some reason never thought to ask for the reason behind this.

I'm not unduly worried but just wondered if anyone knows the reason why joint fluid would need testing in this way? I'm guessing it might throw a light on what type of joint disease he has, but surely the xray has already told him that? Not doubting my vets reasoning in anyway, just very curious.

Many thanks if you can advise.

 

[alsiola]

Protein level and white blood cell count in joint fluid give you an impression of the degree of inflammation within the joint, so this may be what he wants to know. We went through a phase of testing joint fluid every time we injected them after one of the vets went on a course, but didn't really feel it helped alter treatment plans to any great degree.