Monday, January 12, 2015

The Geometry of Canine Weight


Dog weights go up a lot with a very little increase in size, due to some very basic geometry.
  • A dog with a chest span of 14 inches has a chest that takes up 15.59 square inches of space.
  • A dog with a chest of 16 inches, however, is a dog that is taking up 20.37 square inches of space.
  • A dog with an 18 inch chest circumference is a dog that is taking up 25.78 square inches of space in the pipe.
  • A go-to-ground tunnel has an interiour space of 81 square inches!
  • Barry Jones, professional terrierman to the Cotswold Foxhounds in Andovers Ford, and a former Chairman and President of the Fell and Moorland Working Terrier Club, and the founding Chairman of the National Working Terrier Federation, spanned an average of 300 foxes a year and said "I have not encountered a fox which could not be spanned at 14 inches circumference."

This is just square area. Cubic area gives you even more impressive numbers. For example, something that is one yard on each side (height, length, depth) is one cubic yard, but something that is 3 yards on each side is 27 cubic yards (3 by 3 by 3). The same thing happens with dogs; as height increases, so to does length and width, and these dimensions compound each other.

In the end, it is not weight or height that determines a terrier's ability to work so much as chest size -- and of course a strong dose of desire, a big shot of nose, and a willingness to use its voice.

No matter how much desire a dog has, however, it cannot overcome too large a chest size. Flexability has nothing to do with except at the margins. Nothing is more plastic than water, and yet you still cannot put a half gallon of water in a pint bottle.

A den pipe is anywhere from 10 to 40 feet long -- far too long for a dog to excavate except, perhaps, at a few tight spots. A dog that is digging a lot to get to the quarry arrives at his or her destination exhausted, oxygen depleted due to dirt pushed behind it, and unable to properly maneuver to avoid the slashing teeth of the quarry. It is a disaster waiting to happen.

Few dogs are too little or too smart to work, but many are too large and too dumb.

1 comment:

jeffrey thurston said...

I get it about chest size now- I even obsessively look for small terriers at the dog park and on walks. I can span my piebald little guy but I have big hands and he has a 16" chest. The rough coat guy is 17". Too big for Back East terrier work for sure- and I guess that means classic terrier work. In my case I am happy taking them out hunting squirrels and having them run through culverts 10' or longer. They hunt for rats and have dug one out after killing it with teeth in the hole. They are enthusiastic prey driven maniacs compared even to the pits I see around. Since there are no foxes or woodchucks to speak of in my area when I do take them out it is usually to rock piles and larger tree trunk holes. They get right down to business in that situation- digging and exploring. When I do see a small dog with a tiny chest (on a walk or at the park) they seem to lack that JRT spirit- usually they are some kind of rat terrier mix and just seem a lot more mellow. Finally- why does the JRTCA have room in the standard for such large dogs?