Anyone with a parent living for their pet?

Hello to all…I have SO many different things to talk about, but one thing that has been weighing on me since we moved my mom into our home one year ago today is this…we think she is living for her pet. Like most people with pets, it's family. Of course! I have pets of my own and have almost my entire life and can't image life without them. Never would dispute that! Now….I do understand that moving away from what my mom knew for 40+ years to another location of the state knowing ONLY me and my husband would be unbelievably hard for anyone, let alone a mom in her 80s that has Alzheimer's (probably in-between stage 4 and 5 currently), heart disease, chronic kidney disease and high blood pressure…all are managed with meds. She does not drive anymore (and we didn't have to ask her not to…she's happy not to drive in the large city we live in), she uses a walker (also her idea), and the most she walks out of the house on her own is down the street where she can still see the house and back each way. That's all the energy she has to do anyway, so we're lucky there (that she doesn't wander, not that she doesn't have any more energy). She does have a life alert, her phone, and my husband works from home so we know where she is at all times.

So….her pet is almost 17 years old, in the 2nd to last stage of heart disease, she won't stop feeding it extra even though the vet said that's actually worse for it (any meal she has, she gives it bites of hers), and the quality of life for the pet is definitely just existing, sleeping, eating, and that's it. The vet had said about 3 years ago (back in her hometown) that it had maybe 2 years left. It's been 3. So the odds have already been beaten. In any case, there is not much life let in the pet, but my mom, I think, is keeping it alive for her. I truly do. It's not suffering in the way that you might see an animal be in pain or trying to get breath…it's simply old and does have a cough from the congestive heart failure, sometimes sounds like it's gagging, but never throws anything up. During Christmas, it wet near the floor decorations a lot, but that stopped once we had all of them put away, so I guess that was behavioral (didn't like things on the floor, apparently). It definitely has some behavioral issues in general, but it's almost 17 years old…not much is going to change there.

Long rant, but my MAIN question is…has anyone had a parent who seems to be holding onto this life due to a pet still being around? If so, and if the pet passed on first, did the parent lose the will to live and seem to wither away and seem like their purpose was gone (to them, in their own mind)? My mom doesn't seem to want to do anything but watch tv, play on the phone (has pretty much no motivation to do much of anything including putting her dishes away and sometimes not even fixing her own meal), and then anything that has to do with the pet (except feed it in the morning…I end up doing that daily). She doesn't play with it, she just talks to it and asks what it wants, does it need to potty, is it hungry…she does know it's not going to answer her…but this is basically her child in her eyes (I do get it). Sometimes, when she's especially tired or agitated and it's whining at her, she'll say NO! I said NO! Whatever it is you want, NO! and then it usually just lies down. That's when my husband and I really have to pay attention to if it's been able to use the potty or been fed. We are VERY on top of the goings on of my mom and the pet. That's not in question. It's more of what kind of decline might happen should the pet pass away before she does. She's gone back and forth about whether the pet would need to be put to sleep if she passes first.

Hopefully the above makes sense….TIA for your attention :-)