Exactly. Someone getting a dog when they're older - like 65+, knowing there is a chance they won't be able to take it out for regular walks, and exercise is unfair on the dog. And as has been said, the dog may outlive the owner. AND it seems unfair on the dog to use it purely for 'emotional support.'
DH and I have one cat left (she is 18 now) and we are nearly 60. Once she is gone - which I suspect will be in the next couple of years - we will not be having any more pets. The ludicrous vet bills are a big reason for this, but our declining health, the fact we are nearly 60, and the fact the pet may outlive us - especially if we got a young cat - are a few other reasons...
It's ludicrous IMO to have a dog that you can't really look after and take for walks and exercise, and they're just sitting in your house with you for 'company.' What's in it for the dog? 
There are a number of dog owners in my village, and ALL the ones who regularly walk their dogs are people under 55. A number of older people 60-65+ have a dog, and they never (or rarely) walk them, as they don't have the energy, and their health is in decline. It's not that someone 60-65+ can't go for a walk, that's possible for plenty of that age. But it's different when you're walking dogs, and looking after them, and trying to exercise them. They are bouncy, active animals, and are rarely suited to people of retirement age IMO.
I know one woman (in my village) who is 73, and she has had 2 different dogs in the past 12 years. (Since her DH died.) One died aged 6 and a half from heart failure. Her current one is a pitbull who she got as a rescue at the age of 2. (5 years ago.) She gets a dog walker to take him for walks 5 times a week... 1.5 hour walks. £25 a time. She said 'I have to get Lucy to walk him as he's so full of energy and I can't cope. He runs me ragged running around my 30ft by 30ft back garden, and runs around tripping me up. And I am forever picking up his shit.'
I am like
and thinking 'why the FUCK have you got this dog?'
She has also had around £3000 of vet bills in the past 6 months for him for various ailments, and he's only about 7 ... Fuck knows how much more money she will be putting out over the next 5 or 6 years for him!
But yeah, as I said - and I stand by it - no-one should be having dogs (IMO) if they are not able to walk them, exercise them, and look after them properly. It's so unfair on the dog. I also don't think anyone should have a dog if they are out at work full time.
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