Our 14 yr old lab mix can't take Rimadyl or any other type of NSAID due to liver enzymes. Her tummy also cannot handle the Glucosamine products. I did a ton of homeopathic research and found the Borion Arnica 30c tabs.
I have been using sublingual Arnica 30c tabs 3-4 x daily dissolved in a tiny bit of milk. They can also be added to your dog's water instead, but it makes it more difficult to regulate.
After a few days, I noticed a huge difference in her movement. During the colder months I also give her a couple baby aspirin throughout the day. She has a VERY sensitive tummy and does very well with the above combination.
Look up homeopathic canine arthritis remedies and there is alot of info on the Arnica.
Good luck. Hope your baby feels better soon.