There is a difference. I found the tilt table test uncomfortable, but it didn’t hurt or harm me. I find that most IVs hurt, but usually don’t harm me. But what about when you’re the one giving the care? How do you know the difference between when you’ve done something that your patient finds uncomfortable, painful, or harmful? Does your patient know? I’m guessing that if you’re lucky, you have a very aware and articulate patient who can distinguish between unpleasant sensations vs. painful sensations and that you know enough as a clinician to be able to discern whether any of those sensations (or signs, like their blood pressure plummeting) means that you are now actually harming someone.
You don’t get all of those potential channels with an animal, and when you’re a pet owner who is trying to take care of your pet, you really are just left guessing based on how your pet is reacting.
I’ve been thinking about this a lot lately. A good friend of mine has two sick, elderly kitties that she’s caring for at home. Both get oral meds and special diets, but one also gets subcutaneous fluids which my friend has to administer at home. Her cat grumbles throughout, but towards the end, according to my friend, the cat kicks it up a notch and my friend is horrified, worrying that what she’s doing to the cat has crossed from uncomfortable to painful or harmful. And so starts the freaking out.
We’ve both been looking on line for information on how to do this procedure on a “difficult” cat. Not unholy hell beast, not like my cat for example, but on a cat that is not as sedate and chill as all the cats that you find in majority (entirety?) of “how to” videos. So many of the videos focus on things like how to deal with the infusion set or how to place the needle. Admittedly, those are important factors but there are also the not trivial issues of “how to calm the cat”, “how to get the cat to sit still”, “how to gauge if your cat is just ‘grousing’ vs. telling you that something is wrong”.
I’m guessing that there aren’t videos on this because the people who make the videos choose the calm cats to (a) show how “easy” it can be and (b) to allow them to focus on the stuff like infusion set and needle placement. I do wish someone would make some on the other issues though. Anyone who has had to deliver medicine or care to a feline at home knows that response to your cat’s apparent distress will make a big difference in how successfully you can administer treatment. My own cat, for example, acts like any constraint is killing her. She will fight you wildly if you try to hold her down for more than a few seconds. E.g., this morning we had a nice combing and catnip session, after which I forgot to clean the fuzz out of her comb. I went back to my desk only to notice a few minute later that she was doing something with the comb…oh crap, she was eating the hairball. I immediately start trying to startle her away from the comb by making sounds at her, only to realize that it’s too late for this approach when she looks up at me with wide, freaked out eyes and a huge hairball hanging out of her mouth.
I go to her, grab her, and hold her with my forearms while I try to pluck the hairball out of her mouth with my hands. Not working because she’s writhing and bucking, windmilling her paws at my arms, and snapping her head up and away from my fingers. “Need some help!” I call to Mr. Patient and present the wriggling cat, still wedged between my elbows to him as he comes over. The cat greets him with more writhing, bucking, and snapping. But she’s out of luck. Mr. Patient grabs her face and picks the hairball off her lip. I release the cat and she bolts from the room.

Try grabbing me now!
She comes back a few minutes later, and this is how I know we have made some progress with this cat. When we first got her, anything that startled her was sufficiently traumatic that she would hide for hours after. Now, she recovers faster. Although note the pose in the picture to the left. She’s back, but she’s barricaded herself under the coffeetable.
Admittedly, I would not have approached her like that to give her a medication. Had I not made the alarming noises at the cat to start with, I might have had an extra second or two between grabbing her and her turning into the hellbeast. But those extra seconds wouldn’t have been worth much if the medication were anything that requires time to administer, like fluids.
For your amusement and edification, I’m sharing this gem I came across in researching how to give fluids to a difficult cat.
I also thought I’d share the following tip, although I haven’t heard back from my friend on whether it worked or not. I started out by noting that it’s tough to know how to interpret your cat’s “feedback”, so toward that end, I recommended my friend try a “sham” infusion with her cat. That is, set everything up as if she were going to inject and infuse, but don’t actually place the needle. Just poke the cat, then keep her still for the time she’d usually have to stay still for the infusion. If the cat’s grumbling pattern is low and grousy then kicking it up a notch toward the end, we have reasonable evidence to conclude that the escalation in vocalization is not pain or harm but the “discomfort” of running out of patience.