What koala cuddling can teach us about pets

Updated September 3, 2021

Having pets is such a rewarding part of being human. But have you ever thought how it is we can keep animals as pets? Why are some animals great as pets and others often a complete disaster? What’s going on? Today I want to explain why a small group of mammals are literally made to be our pets and why you should think very carefully before owning any others.

Of the 5500 species of mammal in the world, nearly all our pets and farm animals are one of:

  • Dog
  • Cat
  • Domestic rabbit
  • Guinea pig
  • Ferret
  • Brown rat
  • Mouse
  • Sheep
  • Domestic goat
  • Cattle (5 species)
  • Water buffalo
  • Donkey
  • Horse
  • Domestic camel (2 species)
  • Llama & Alpaca
  • Pig
  • Chicken

What makes these few animals special? Although they originally come from wild relatives, they are no longer the same. Most of them have spent many thousands of years living with us, and over that time they have changed in a very important way. And that change is mostly not physical.

The Wellcome Trust in the UK recently compared the DNA of wild cats with that of domesticated cats and found changes in 13 key genes. These genetic differences make changes to the reward centre of the brain, neurones producing ‘feelgood’ neurotransmitters, the fear response, and memory.

You can get the idea; these cats may look the same, but their brain and behaviour are very different. These changes are probably what allowed cats to not just live with humans, but to thrive with them and enjoy close human contact, things their wild cousins could never do.

The same thing has been observed in dogs. You can get a wolf cub, raise it with humans from an early age, but it will always be a wolf. It won’t be easy to train, never as social with people or dogs, and remain semi-wild. A wolf cub will never run up to a human the way a puppy will.

All the domesticated species are probably the same. Most have lived with us for thousands of years. Over that time we have chosen the animals who were friendlier to us, the friendlier ones have come into our settlements, or the ones least stressed by us have done better and had more offspring.

What this ends up with is a group of animals which have had strong selection for the genes that allow them to tolerate, and even enjoy the presence of humans. We end up with animals born to like being with us.

So now for the negative side. My recent British Small Animal Veterinary Association magazine has an article on diseases of sugar gliders. I have heard of these being kept as pets in the US ( where anything goes it seems) but this is the first I’ve heard of the UK. This is an Australian native, probably originally illegally exported. So I rang the local pet shop here in Adelaide and was told, ‘yes, we can sell you a Sugar glider, you just need a basic permit. I almost fell off my chair.

Although this is not actually illegal, it is certainly unethical. Here we have a marsupial with very complex feeding and housing requirements, limited adaptation to human contact who is very unlikely to be well cared for. In South Australia, the keeping of native mammals is not permitted except when they are rescued from the wild and cannot be released, but Sugar gliders and Hopping mice are excepted.

South Australia’s relaxed permit system has also allowed many ‘rescued’ native animals to be turned into pets with virtually no chance of release. All it takes is a vet willing to sign the form and there is no requirement for any further checks or inspections. Vets who work with these animals say the results for that animal’s health and mental wellbeing are often disastrous. (Other states allow only specialist wildlife rehabilitation groups to hold the animals).

Native and non-pet mammals are highly prone to stress-related diseases and poor housing (I do think reptiles and birds can do well if properly cared for). Many are prey species being forced to live with their predators (dogs and cats). To do it right you would need to provide them with the same sort of enclosures, environment and feeding you see when you visit the zoo. Even then, things don’t always go well.

And then there’s Koala cuddling. Just like with the Sugar gliders, or rescued natives, what you should be asking is ‘what is the animal getting out of this?’ I don’t deny that all these animals are very cute, but do they really want to be held by a human, however much the human wants to hold them? Of course not. I would expect these animals who look so cute are harbouring high levels of stress that we lack the ability to detect. Or maybe we just don’t want to know when our world leaders need entertainment..

As a vet who has worked in the UK, I treated gerbils, chinchillas, and hamsters. None of these looked like they were having much fun. Having also worked in a zoo, I can’t help but feel that we humans have a very complex relationship with animals. Listening to the public, they often want to cuddle the pandas or find some other way to connect with the animals. Sometimes the hardest thing is just to let them be themselves, and enjoy them the way nature intended.

It’s taken thousands of years of breeding and selection to get our pets the way they are. So you are probably right when you suspect your dog, cat, guinea pig, rabbit, ferret, rat or mouse actually likes or even loves you. With these special species it’s definitely a two-way thing, as any perceptive pet owner knows.

With any other species, we’re in danger of becoming Veruca Salt.

Related: Why Keeping Native Species Won’t Prevent Extinctions

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By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here.