FYI, some dogs do not tolerate internal stitches that disolve, apparently their bodies tend to "reject" the cat gut that is used to make the stitches. I found this out the hard way, my Golden Retriever puppy just recently had a reaction. The reaction started after she had the outer layer of stitches removed from her spay incision. Just thought I'd pass this info on to all of you other dog lovers out there