The black mark that is showing in this pic doesn't really show up in real live, don'tknow why it looks so obvious here. But you can see what i mean as to why it is so obvious that he wouldn't want to hold that leg on the branch and chose to lean to one side and let it hang down.
Not the femur or leg, that's the pelvis. Not exactly good. A whole bunch of thoughts about it:
First, you did the right thing by taking pix. It helps narrow down causes. Pix are a great tool for keeping chams because our brains are wired to generalize the visual input we take in. The eye of the camera is more objective, even if imperfectly 2D. The discoloration suddenly being more noticeable in an objective photo is a good example. It looks red, not black, on my monitor- and reddening of the interstitial skin can be seen when swelling is this sudden and severe. But my monitor is not great, either!
I once found a pinprick abscess' start in an earlier photo of one of my guys, only after it started swelling on the live animal. I never saw the issue before "in person", but with the earlier photo, things started to make sense. You may want to look at older pix of the area to help determine the progression... even if he's always been off, since arrival.
I have seen a short-term swelling on the pelvis before. Someone has to take a pretty hard fall to have it stick around. Since the swelling is unilateral, I'm guessing it is not related to renal failure (gout is usually bilateral swelling when seen at the pelvis).
The fluid being clear actually raises more questions. If he has fallen recently, I'd say it was inflammation/edema from impact.
Get a Culture & Sensitivity done on the fluid (have the vet draw off fresh), and also have them eyeball it under the microscope. Sometimes, they can tell what kinds of body cells are present in the sample, and it helps direct the next step.
X-ray it, yes, ASAP... The C&S results will take a week, X-rays will tell you something right away (assuming your clinic does its own developing).
If this was on the soft tissue of the upper leg (femur), I'd wonder if an encysted worm (in the muscles, like the quadriceps) was dying and causing the inflammation response. But it is on a boney area of the animal, so I doubt that.
Is it possible that his leg is dislocated from the pelvis? That would certainly account for the lack of use, the leaning, color of the fluid, and swelling. If it has been dislocated the whole time you've had it, the vet may need to surgically put it back in the socket, as there may have been muscle and tendon tightening during that time.
Some animals get viral infections in their synovial fluid (in their joints). The virus can "hide", dormant in the joint of a toe or whatever for a long time, then suddenly pop up- first, as a tenderness/lameness, then swelling. I do not know if this affects reptiles, but it is worth asking your vet.
The part that is not good about it being in the pelvis is, if it was an infection and limited to the leg, and the bone was eaten away, the leg could be amputated, and the cham lives to breed another day. The pelvis is a much more serious area. I really hope it was just dislocated during importation, and a little PT is all it needs to recover.
Hang in there, Debby!
