@Teateaandmoretea agreed, but you can question these things and decide whether on balance you want the pet to have them, and say no to treatments that you don’t deem fair and necessary. Vets will offer what they feel is optimal treatment to give owners options, etc. sometimes what science can do isn’t always the best solution for the animal IMHO.
For example, when our dog 13yrs old, became poorly we took him to see the vet, took temp, gave him painkiller, and meds, sent him back home. He seemed a better that afternoon, and managed to get him to eat, but the next day the symptoms had returned, refused to eat, it was a bank holiday weekend (isn’t it just always!) rang emergency vets, went though everything over the phone, he said nothing else I can do, it’s the correct treatment etc. see you vet on Tues, took dog to see her, she could see the deterioration, said can’t leave here like that, we can operate, blood tests etc or pts. DH & I were prepare for this question, we knew he had given up. We sadly agreed to have him pts. She said if you had said operate, I would have tried to talk you out of it. The skeptic in me has always wondered if she would have done that, that we will never know. We didn’t want our very poorly, elderly dog to go through a surgery that we knew would not have changed the outcome.