Usually I try to stress how much fun dog carting and related activities can be; however a little knowledge of the science behind such work will ensure that it is always fun and safe for your dog.
First, zoology 101: For decades I have been pointing out that canines are unique amongst domestic draft animals. They have a flexible back like a cat and this serves them well except when pulling carts and backpacking. The simple implication is that weight should not go on the back of a dog. Being ignorant of this fact has led people to ordering harness from a horse harness maker, just scaled down, or trying to use sled dog harness for carting. Backpacking however is where this knowledge is most important and the message is getting out, albeit slowly. On the Traildog internet list just recently someone posted emphatically that backpacks go on the shoulders of the dog and I yelled out “yeah!” Unfortunately, most of the packs for dogs that are sold commercially are designed to put the weight on the back rather than over the front legs.
Another consideration is that there should be some “tonque weight” on a dog pulling a cart and that weight should be on the shoulders only, never on the back. In other words, when carting your dog always use harness designed for the purpose.
People assume that if something is mass produced and sold in retail stores, it must be right. One of the good things about the recent food recalls for pets and people is that such assumptions are being called into question. A smart consumer is an informed consumer.
Second, physics 101: A common question concerning the loads used in the Canadian Draft Dog tests is why they are so light, especially since many of the dogs entered are over 100 pounds. The answer can be found in an interesting bit of trivia – a grasshopper can jump 40 times its height whereas an elephant can’t jump at all. This is because as an animal gets four times larger, it only becomes twice as strong.
In the draft dog tests the loads to be hauled are fixed for ease of administration and hence had to be set to accommodate the various size and relative strengths of dogs and the variable terrains. When I was in the army I learned that the truck we called a deuce and a half was actually rated for twice the load (five tons) on the highway; in other words when used off road, the load rating had to be cut in half. Similarly we have to take into account that our draft dogs are not being tested on paved roadways.
The backpack loads appear to be the most controversial. The test rules require the load to be 1/6th of the dog’s weight to a maximum of 25 pounds. Many experts claim that a dog can pack 1/3rd or even half his weight. However I have to assume that each of these experts is thinking of a particular breed or type of dog and not considering the basic physics that I have described above. To illustrate, if a 30 pound dog can pack 1/3rd his weight, that would be a 10 pound load. But a 120 pound dog, who is four times bigger would be faced with a 40 pound load even though he is only twice as strong and should therefore have only 20 pounds or 1/6th of his weight in his packs. Thus the Draft Dog rules very rightly uses 1/6th to accommodate all dogs as well as caps the weight to ensure that we don’t overload any dog; in other words we err on the side of safety.
End of science lesson but hope it helps you to cart and backpack more safely with your dog.
Peter Maniate has been writing columns for the Newf News, the magazine of the Newfoundland Dog Club of Canada, since 1979. In 1996 he started writing a Newfoundland dog column in the Breedlines section of Dogs in Canada magazine on behalf of the Newfoundland Dog Club of Canada. When Dogs in Canada ceased publication at the end of 2011 he continued the Breedlines column in the Newf Newfs.
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