Re: Cat with oedema and muscle rigidity

Noweia — Thu, 15 Nov 2012 20:28:50 GMT

Thanks Kate for your reply.

As an update we biopsied Tinker the other day - took a chunk from one of the 3cm swellings above the elbows, and a sliver of muscle from the Sartorius on the left side. The swelling has come back as fibrous tissue - no evidence of neoplasia - and the muscle as more fibrous tissue (!) - so we are now wondering about some sort of fibroproliferative muscle disorder.

Repeated blood samples this day did clot so we are no longer too concerned about that issue. I would dearly love to repeat the muscle biopsy and do further tests but funds are limited.

Tinker is a little better in himself today after a few days on steroids - so we are increasing the dose to full immunosuppressive levels and reassessing him after that.

Here is a video of the cat walking about on surgery day: http://www.youtube.com/watch?v=kwMge_oPF5o

And a photo pre-op - I was attempting to pull the hind limb caudally and the contracted muscles stood out for the photo:

Re: Cat with oedema and muscle rigidity

Kate Richardson — Sat, 10 Nov 2012 17:38:49 GMT

Interesting one! I would be suspicious of either muscle, joint or skeletal pain.

Muscle- measure CK and AST on bloods to assess for muscle damage. Differentials would be inflammation (eg immune mediated myositis, toxoplasmosis), hypokalaemic myopathy (what was the potassium out of interest- you said electrolytes were normal, Ca and phos are normal on your bloods) or degenerative myopathy

Joint pain- consider multiple joint taps for cytology/culture- again inflammation (immune mediated), infection (bacterial, FCV, mycoplasma), DJD, bleeding into joints- you have a mild-moderate anaemia and you mentioned the blood did not clot in the syringe, so I would repeat and monitor haematology including a smear exam, your platelet count looks ok, but would want to check smear, and consider clotting times if you are concerned about a coag problem. Not a common problem though, and I would suspect there is a simple explanation for the apparent lack of clotting in the syringe.

Skeletal pain, seems less likely if your xrays were normal- did you do general xrays ie catogram type rads? did bone look normal density? Less likely than muscle or joint pain I think in your case, but consider nutritional disease such as vit D deficiency, or hypervitaminosis A (liver rich diets), parathyroid disease which is unlikely as Ca/Phos were normal and nutritional disease unlikely if on a balanced cat food, but worth asking owner re diet as it sometimes can surprise you!

So muscle or joint would be my main differentials, so CK/AST as mentioned above on bloods, do a urine sample as well as you may find myoglobin in the urine (which may appear to be haemoglobin initially on dipstick, so you may need to get lab to check it further if you suspect myoglobin, and then if normal muscle enz/urine, joint taps may be next step.

Pain relief in mean time, if cat is eating and drinking ok, then meloxicam should be fine but could add buprenorphine via oral mucosa if nec. Hope that helps to start with

Edit- one other thought to consider given the murmur (which can often be transient in sick cats as well as innocent), and the oedema, and depends on how much you think there may be associated cardiac pathology, would be endocarditis, but I guess I would expect a sicker cat eg pyrexic, neutrophilia