It’s a Big Problem – genetic and other causes of canine obesity
Dr Eleanor Raffan from Cambridge University spoke at today’s KC Breedwatch Education Day on the subject of canine obesity. Here’s my summary of her presentation.
Obesity is a big problem – pet obesity is in the news. Health problems resulting from obesity include:
- Joint problems
- Breathing in Brachycepahlics
- Cancer (in people, obesity is now a bigger cause of cancer than smoking)
- Obese dogs die younger.In one study, fat Labradors died 2 years earlier than lean ones
- Worse quality of life
- Interestingly, there is little evidence that diabetes is linked with canine obesity, unlike in people
In the overall canine population, obesity is far more significant as a health issue than low prevalence genetic issues. (We know this from the VetCompass project)
Simplistically, the causes of obesity are too much food and not enough exercise. This is simplistic but important from a management point of view. We have to remember that most of dogs’ evolution was in a resource-scarce environment, so biologically, it makes sense to lay down fat (energy) for when food is scarce.
The genetics of obesity:
Eleanor conducted research into Labradors, a breed commonly found to be obese. She identified the POMC mutation in overweight dogs – dogs with 1 copy of the mutation weighed more than wildtype and those with 2 copies weighed yet more, and this explained most of the variation in weight. The presence of the mutation also correlated with dogs’ food motivation.
The POMC mutation interrupts the leptin pathway, which regulates appetite, so dogs with the mutation don’t know when to stop eating!
75% of Labradors are wildtype but this was as low as 20% in Guide Dogs. Temperament and “trainability” are the main drivers for selection of assistance dogs, and “positive reinforcement” with food reward is a mainstay of puppy training. Eleanor, therefore hypothesised that dogs carrying the POMC deletion may be more likely to be selected as assistance dogs.
The POMC mutation also exists in Flatcoated Retrievers, a breed not normally associated with obesity. Interestingly, Golden Retrievers don’t have the POMC mutation. The observations of these two breeds were particularly interesting for today’s audience who felt FCRs were generally not considered to be overweight in the show ring, in contrast to some GRs, which can be overweight.
So, we do need to recognise that an obsession with eating and consequent tendency to become obese is hard-wired into some dogs’ genes.
Owners should establish good feeding habits with puppies – bonding can be done without food. Give fewer treats (a mid-sized Dentastix contains 75 calories).
Dry foods are very calorie-dense. they taste and smell good, so are very attractive to dogs. It can be useful to switch from bowls to feeding in a Kong throughout the day. This keeps greedy dogs happy.
Establish good exercise habits. I recently shared information on a Canadian study of owners which showed 26% had no intention to exercise their dog at all, 33% were “failed intenders” and only 40% were active intenders (people who said they would walk their dogs and actually did so). It’s no good saying “I intend to walk my dog”; you actually have to take them out every day!
How to cope with an obese dog:
Vet weigh-loss diets are typically high in protein and fibre, both of which sends signals to the brain to say the dog is full. These are expensive.
Download a copy of the Body Condition Score chart and regularly assess your dog. A “healthy weight” is a BCS of 4-5 (out of 9).
Get help from your vet; many run obesity clinics.
Messages for judges:
Dogs could look “right” but may actually be fat. Judges must feel the dog’s body and assess whether or not its “shape” is actually caused by it being fat.
I resisted the temptation to comment on the fact that very few Miniature Dachshunds would be likely to be fat in the show ring. Judges weigh them and exhibitors know the correct size and body condition required. In contrast, it is obvious even from the ringside that some Standards are “well-covered” and in soft condition as well as being over the desired size specified in our Breed Standard.
Follow Eleanor on Twitter @GOdogsproject.