Which/what animals could get buff if they were trained to lift weights?

Presuming they could be trained/motivated, I presume that all mammals could develop extra muscle by exercising just like humans. Monkeys would be setting all sorts of records and get freaky huge.

Is this self evident in the real world? Do draft animals, for example, develop noticeably more muscle mass than more sedentary members of their species?

I’ve seen pictures of “buff” dogs: I’m guessing that you could design a training program to get your dog swole.

What about other species? Could a fish muscle up? I’m doubting anything with an exoskeleton could, but maybe?

What’s the straight dope on bodybuilding in the animal kingdom?

“Buff” dogs(and others) are a mutation.

Other animals get all the exercise they need for their niche.
Besides, do you really want to get this guy any bigger?

It’s bad enough even without weightlifting.

It’s not a question of whether you should; it’s a question of whether you (physiologically) can.

These animals are why I’m guessing the answer is yes.

But is it really just a mutation?

Humans can’t be unique in our ability to increase our muscle mass with a consistent routine of weight lifting!

Don’t horses get stronger and more buff from drawing wagons and being riden? Race horses appear to be more buff than ones that just hang out in the pasture.

Years ago, we had a cat who, due to a birth defect, had underdeveloped and useless back legs. She learned to walk on her front legs, with her butt balanced in the air. This gave her forelimbs much more exercise than is normal for a cat, with the result that they had huge muscles.

I used to road my dogs similar to how they do sled dogs. They would wear a harness and pull against my slow moving truck. They got very buff doing this.

Out of curiosity, why did you do this?

I cannot contain myself: Why?
And do I understand you correctly that you harnessed your dogs, took a leash/rope, tied it to your truck, started driving in one direction, with the dogs pulling in the opposite direction?
Or am I missing something?

These were field trial bred bird dogs. For the national trials they had to be able to run at a very fast pace for 3 hours. This requires serious conditioning.

Is this limited to mammals? Would a bird get bigger wings if it used weight resistance to train for faster/stronger flight?

I used to say (jokingly) that when I grow up I will get a large gorilla, train it to lift weights, give it steroids, shave it, and have it follow me around to intimidate my enemies.

Are free range chickens meatier than battery chickens?

Meatier or more muscular? Because those chickens at Costco are pretty damn meaty and may appear buff.