Pet au Carla reacting to an owner who has given him a good quality life and takes especially good care of him when his illness flares up?

Admin Mawile: (^・ω・^ )

-For a very long time, he believes it’s only because of his value. A First Blood, even an ill one, is worth enough to make an effort in keeping it alive, and he assumes his inherent value as a rare species is the only factor in their kindness. Of course, once the costs of keeping him alive exceed even that worth, the good treatment will also come to an end, and it’s only after this doesn’t happen that he actually starts to believe you care. 

-Rest and low activity are what help his illness most, and it eventually recedes to the point where only exertion leaves him agonized and unable to breathe. Flare ups still happen, but the longer he spends able to rest and recover from years of strain, the more the Endzeit recedes. He hates feeling useless, though, and you’ll have to find some ways of keeping his sharp mind busy.