Some fluids also "sting" and cause discomfort. When I had to change vets, the new one switched my kidney cat to a slightly more expensive type of fluid because it was more comfortable for cats. And I always warmed the bag of fluids too; cat's body temperature is higher than ours and room temp...
You may want to ask your vet about the possibility of feline infectious anemia which is a bacteria that clings to the red blood cells. It's transmitted by flea bites, cat bites, and close contact with an infected cat (like sharing food bowls). I'm just learning about it now; there seems to be 3...
