Reader, I have just returned from a voyage down an alt-right rabbit hole. Battered, bloodied and bruised, I resurface with news of obese hedgehogs. Ten of them. From Israel. These are hedgehogs so morbidly obese that they can no longer roll into a ball. They have now been picked up by a wildlife hospital and put on a strict diet before, hopefully, they can be rereleased.

Why the alt-right rabbit hole? Because that’s where the message boards are at their most sinister and hilarious. Over at Breibart, commenters are discussing whether and to what degree these hedgehogs got fat off US government handouts. “It’s nice Israel has the money for this, compliments of American tax money!” says a typical poster, identified only as “Jim”.

Honest, guys, this isn’t what happened. What almost killed the hedgehogs was kindness. They almost died because we love animals so much. And the way we express that love is by feeding them. According to the veterinary charity PDSA, one in three dogs, one in four cats and one in four rabbits in the UK are now classed as overweight or obese.

Our willingness to feed wild and domestic animals into obesity is a demonstration of a short-mindedness we could do more to avoid

The Israeli hedgehogs weren’t pets, and humans weren’t deliberately feeding them. But they were leaving food out for stray cats, and the hedgehogs couldn’t refuse the free meal.

At this point you may be wondering why you should care about a few flabby hedgehogs. Lots of animals store fat, after all. Look at marine mammals – seals, whales, dolphins – who are loaded with the stuff. But their fat serves a purpose: insulation. And while hamsters and lemmings have enormous seasonal variations in fat covering, this is to see them through the winter months.

And large mammals? Elephants (in the wild) have little chance to store fat, being adapted to consume a food source that is low in calories. Cheetahs, like many predators, regulate themselves. After all, a heavy, lumbering cheetah won’t catch anything.

What then of birds and bird feeders? Do garden birds become morbidly obese through our wanton freebies? The answer seems to be no, partly because of their increased metabolism, perhaps, but also because flight brings with it its own constraint – a heavy bird can’t fly up to a bird table, after all. Plus, there are predators like hawks to take out the overweight birds.

Yet for hedgehogs things are different. Due to their prickly spines, hedgehogs have fewer predators, and so they have bloomed calorifically, storing fat for hard times that never come, which leads me to make a comparison with humans so obvious I shall avoid it, other than to point out that we are both omnivores with few natural predators, and we both stem from the same early branch of the mammalian family tree. As I said, obvious.

Yet there is a distinction between hedgehogs and humans, and it is this. We humans can be ceaselessly, wonderfully kind to other animals, and they cannot. This, to me, is a character trait of which we modern humans should be proud. But our willingness – our apparent desperation – to feed wild and domestic animals into obesity is a demonstration of a short-mindedness we could do more to avoid. We give because we love. They eat because, no matter which way we care to see it, they are animals. Bluntly, 10 fat hedgehogs is 10 fat hedgehogs too many. It fills me with sadness to be writing these words but … killing with kindness? Well, it’s still killing.

• Jules Howard is a zoologist and the author of Sex on Earth and Death on Earth