He got neutered yesterday and starting last night he had diarrhea. He woke me up about 5 times during the night and is using his puppy pad again as I type this. [

] He's obviously not feeling well at all. The vet opens in 10 minutes and I'll be on the phone with them asap.
I'm worried about a couple of different things.... when I took him to be neutered about 5 months ago (when he was 7 months old), the bloodwork before surgery showed that his electrolyte levels were off and he had a heart arrythmia. The vet held off on doing the surgery and we retested his blood a few days later. The electrolytes were still slighty off, but the vet thought it should be okay to go ahead with surgery.
I was just recently able to bring myself to schedule that surgery (he just turned 1 year old).... so yesterday his heart and electrolytes were fine, but his liver values were a little off. The vet went ahead and did the surgery, but said we should monitor it every 6 months or so. Well that brings me to his current situation; he was given injectable Rimadyl after the surgery yesterday and I think that might be related to the diarrhea. I hope nothing is seriously wrong. [

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I'm planning to start adding milk thistle to his diet asap, rather than take a "wait and see" approach with any liver problems.
So basically, I'm just worried about my little guy. He's my whole world and I'm terrified of losing him. This is just like deja vu with my Persian cat, Blitzen, who was a very, very special pet to me and I lost him at 2 years of age due to multiple genetic defects (including liver and heart issues). Please send prayers and/or good thoughts our way!!