- I dissent.
.3mg (dose) x .9 kg (weight) = 0.27, divided by .5 mg/ml = a dose of .54cc's. You are essentially giving him that, now, divided into 2 doses 12 hours apart. You could see if a single, 24hr dose at .5cc's knocks the pain better.
Oxbow Joint Support might also be worth a shot. I frankly haven't had much luck with any of the Oxbow supplements, but it can't hurt and there's a small chance that it could actually help a little.
The other product I was trying to think of is Myristol. I did some digging into it a while back for one of my own guys, and found that some rabbit societies recommend it for buns with arthritis. I didn't end up pursuing it further, and don't know of anyone else who has tried it with their guinea pig. It is an alfalfa-based pellet, unfortunately, which might be problematic since he's already prone to sludge. I had contacted the company to ask if they might consider a timothy-based product, but never heard back. You might ask your vet about it. Again, I can't vouch for its safety or effectiveness, but have seen it mentioned on several rabbit sites such as this one:
- I dissent.
We lost a guinea pig to a blocked urethra a few years ago. It's devastating. Sending you my deepest sympathy.