I'm a veterinarian. Dogs are omnivorous, but cats are true carnivores. Don't project your shit onto your animals.

Cats and dogs, have evolved as carnivores, so to try and make them into vegetarians in quite futile, and will result in them dying from malnutrition.

I shut them down. And will walk away if they don’t give it up.

I am not going to debate what is more healthy for my companions. They eat better than I do.

I've met some Vegans who have said all sorts of crazy stuff.
They also never miss a chance to tell you they're a vegan.

I'm not trying to say Veganism is wrong, it just doesn't apply to everything or everyone.

It's not natural. Although I've never discussed this with a vegan before.

As a vet and someone who works in animal welfare I spend quite a bit of time explaining why this is wrong from an animal welfare perspective. If we choose to have animals in our lives we have a duty of care to them and must provide for their 5 welfare needs, one of which is a suitable diet. Cats are obligate carnivores and need meat to remain healthy. Dogs can be vegetarian/vegan technically but they are naturally omnivorous. If people want a vegan pet they should choose a vegan species such as a rabbit.

My instinct is to steal their pets from them. I'm a vegetarian with some vegan leanings, but human anatomy and dietary requirements are vastly different from that of dogs and cats. I'd never torture them with a diet consisting of tofu and lentils. Frickin' loons, man!

Be careful about transposing an alternative human dietary choice onto an animal which is different in its behaviours and physiology. You can kill them with your "kindness".

Check the teeth. It's a great indicator of what they're to eat.

I would change the subject

Every vegan I've had the displeasure of knowing in person has turned out to be bat-shit crazy so I think I'd have like no patience whatsoever and would simply pity their animals.
Not entirely sure what my reaction would be beyond shaking my head, it would totally depend on the situation.

Who cares?

I worry, I am an animal lover, but not vegetarian, I consider myself no better or worse than other mammals, it wouldn't worry me if my corpse was consumed by animals, in fact I would prefer that. It is only cruelty I have an issue with, the slaughtering and the raising. I think it could be animal abuse not giving the animal the food it needs.

If you have a pet you do whatever it takes to assure their health and happiness. Your preferences don't matter.

my vet told me that the felines are the only true carnivore out there. humans choose to eat what they do. its not because we don't believe in killing either is it? if we take the knife and cut the head of lettuce off for harvest didnt we just kill it? every time we blink we kill microorganisms in our eye. maybe some day religion will be killed and humanity can progress even more.

Only if you want your pet to be extremely miserable, unhappy and most likely unhealthy too.

Cats are obligatory carnivores. I would explain that to a friend who tried to vegan-ize their cat. One warning, then I'd absolutely call the SPCA or Humane Society and report them for abuse.
Dogs can survive without meat but it is a balancing act that most people don't have the time or money to make happen. A friend who is vegan and has a dog has no problem when I visit and pull out some meat for her dog. Been doing it for years, she can't bring herself to buy meat for him but since I don't have the same hang-up, it's a loophole she's okay with. I usually just bring a hotdog or something, but when I was watching him for her while she was on vacation, I totally sent her photos of me and Doggo eating steaks.

I just tell them next time you eat a salad and a tiny aphid is in it- then they are a true monster.

Cuspids/Canines. If the argument is "nature", you cannot argue against the presence of the cuspid.

I guess if they grow up that way, what else do they know, but you better never give them meat, they will be wondering why you kept it from them all their life, or is it a new wonderful.....lol

Get pet rabbits instead. Or guinea-pigs.

Dogs maybe. I've met a few very healthy dogs who were on a plant based diet.

Cats? No way. Stop forcing an obligate carnivore to eat a diet for which they have not evolved, just to satisfy a moral position the cat is unable to comprehend.

(Source: Vegan for 19 years with 2 omnivore cats)

Cats are predators and require meat. Dogs CAN subsist on a vegan diet, but the owner has to be VERY CAREFUL about what the dog eats. Dogs need protein, too, but they can get by on certain types found in non-meat related foods.

Cats need that hard protein, though.