…I would rather give Grendel five different medications than have to give one to any of the other kids.

Kako is just a bitch.  She draws blood constantly just to prove she won’t take your shit.  Trying to give her medication is an exercise in survival skills — namely mine.  As the vet so correctly noted during Kako’s first illness, she can be very unpleasant.

Kazon is the baby of the house, but he’s such a baby that it’s equivalent to giving unpalatable cough medicine to a toddler.  He squirms and whines and tries to spit it out, and then afterward acts like he’s just been beaten profusely; he’s a master of the guilt trip.  It’ll take him hours to forgive me.

Loki is the cat who killed Satan and took his place.  There exists no soul which he will not take should the mood strike him.  Add to that his unnatural athletic abilities and medicating him becomes a test of physical stamina, mental fortitude, and whether or not he can be controlled long enough — something that doesn’t come without its own price later (he will get his revenge).

Grendel, on the other hand, may not like being medicated, but he’s fully aware that there’s a significant trade off to follow: if he’s a good boy and takes his medication, he get lots of loving afterward.