Sunday, November 26, 2017

Are smaller dogs better?

small dog, microdog, dog breeding, dog welfare
Phil is hoping whatever is in the oven is for him.

Small dogs are growing in popularity globally. Because I happen to cohabit with one, a colleague recently forwarded an article about some of the welfare issues around breeding for size (specifically, lack thereof). Not that I bred or even chose Phil, but that's another story.

Prospective adopters may be attracted to smaller dogs because of a perception that they are easier to care for than larger dogs (not always the case), they are cheaper to keep (definitely true when it comes to food and veterinary fees although there is significant individual variation), they’re easier to keep in high-density urban areas (often pet-friendly apartment complexes place a size or weight limit on dogs - this be a can of worms that I will leave unopened for this post), they’re easier to transport (that depends), they often live longer and they’re “cuuuuuuuuuuuuuuuute”.

This article raised a concern that because of the shrinking (in size) canine population around the world, some breeders tried to capitalise by breeding for miniature dogs, either by line-breeding, introducing smaller breeds or selecting for chondrodysplasia (abnormal development of cartilage and bone associated with shorter legs, made famous by Dachshunds, corgies and so forth).

None of the above strategies are foolproof and some may introduce inherited disease. The other issue raised is that unscrupulous breeders may try to breed “un-thrifty” dogs to create smaller animals, or even adopt out puppies at a very young age (I have seen the latter time and again through online selling of pets – the owners are mislead). Another technique mentioned which horrified me is the restriction of food to stunt the growth of puppies.

And small breeds aren’t perfect. Phil, the poster-child for dental disease (now living with zero teeth and the tiniest little jaw on the planet), is a good (or bad – depending on how you look at it) example. Smaller dogs are more prone to severe dental disease, retained deciduous teeth, bone loss and even jaw fracture. They’re also more prone to tracheal collapse, myxomatous mitral valve disease (MVDD), and different types of lameness (patella luxation, femoral head necrosis) than their larger counterparts (cruciate ligament rupture and hip dysplasia). Females are more likely to require a caesarean due to disproportionate foetal size.

Smaller dogs reportedly have increased risks of adverse drug reactions and anaesthetic complications, although the latter relate largely to drug dosing and anaesthetic monitoring/supply of an appropriate external heat source, which can be controlled.

They’re more likely to suffer from dehydration when they’re sick, e.g. with diarrhoea, because they’re tiny and lose a lot of fluid. They’re more likely to get sick from eating human food, simply because we tend to feed them proportionally more than we might feed a larger dog (these are generalisations) and they’re more likely to have behavioural problems. Again, the latter is likely – at least in part – to be due to our management of small dogs. Because there is a perception that they do little if any harm, humans tend to tolerate behaviours such as growling and snarling when moved off the couch, that would be unacceptable in larger breed dogs. They may miss out on opportunities to socialise if they’re being carried around. And their tiny bladders make them harder to toilet train, simply because they fill a lot more quickly. 

This is an issue because dogs may be surrendered to shelters or euthanased for problem behaviour.

The article is not an attempt to trash small dogs, or any dogs. Dogs are beautiful, majestic, amazing creatures. This is a people problem. The point it makes is that selection of a dog for size only is problematic, is it can be associated with (some unintended, some simply ignored) negative welfare impacts that are lifelong. The article is making a case for veterinarians to prepare for an increased case load of smaller dogs.

It’s a reminder that we need to really reflect on the way dogs are bred, and the traits that humans select for.


Freyer, JL (2017) The small dog trend: impact of size on pet health. Veterinary Focus 27(3):2-8