I am suprised they gave you antibiotics and pain killers, my little furgie was spayed wednesday night (of course she went into heat 2 days before!)... she was very groggy that night, my vet said she is going to be thirsty but don't let her down the water, just some sips here and there, she didn't really eat that night, only peed once,
the next day (yesterday) she was still groggy, I could tell she is sore, she hasn't really been licking her incision at at, I did put some "yuck" spray on her incision (which I got on my hand and even after a million washes still tasted nasty...couldn't eat picky food with my right hand all night!). She ate breakfast and dinner fine, peed a couple times, pooped once, and a little better this morning...she never had to wear the coller or drink from a syringe? I have just been by her side the whole time... good luck with your little love!