why do large dogs die sooner and prone to cancer more

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Henry CGC

i love the snow
Barked: Sat Feb 28, '09 11:30am PST 
is it because they are have not been bred over the years as good as small dogs?
Sandy Baby- ♥

I may look- little, but I'm- ALL dog!
Barked: Sat Feb 28, '09 6:08pm PST 
That's a really good question. thinking

I suppose it would have something to do with breeding. I, too, wanna see what some people have to say about this. I've thought about it before and come up with nothing.

I'm pretty sure that it does have something to do with breeding, though.

Classic Beauty
Barked: Sat Feb 28, '09 6:16pm PST 
I think that part of it is because of the size of the body.. Like the bigger the dog, the harder the organs and body has to work to function..

Compare the actions of a great dane getting up and running compared to a jack russell...

More weight to move, bigger bones and bigger muscles=more for the heart and lungs and everything else to pump blood to.

I don't think I am explaining this very well.. But if you think about it for awhile, and compare it in human terms..

A person that is carrying more weight has more health problems because it puts more stress on the body. (i know obeseity and natural, healthy large breed dogs aren't the same but..)

I am tired, I will stop blabbering, but I thought I would try to help

Walter RL1- AoE CGC

I'm a rescue!
Barked: Sat Feb 28, '09 7:25pm PST 
I've wondered about that two because I've noticed that dogs are really the only egregious exception to the rule: the bigger you are, the longer you live.
Keiko- (4/8/98-12/5- /12)

Queen fuddy- duddy
Barked: Sat Feb 28, '09 7:50pm PST 
I guess it depends on you definition of "large dog". Are you talking giant breed, such as great dane, irish wolfhound? Or large as in rottweiler, lab sized?

B/c golden retrievers and boxers are very prone to cancer, as are great danes.

Some may have to do with breeding. You breed a dog to be larger, and it is possible the outcome of that is to be more prone to cancer. No one knows the reason why or where cancer started being prevelent in these breeds.

As in the large breed dogs (or what I call medium sized...........lol), i think it has more to do with breeding. I'm guessing along the lines, cancer appeared in some lines, but by then, the dogs would have been bred many times over as cancer does not normally appear until a dog is middle aged or older. So unwittingly it was passed to the offspring and on and on and on it goes until it is riddled in the breed.

As far as dying sooner, for giant breeds............it does have to do with their size. you cannot have that large size w/o comprmising somewhere. It puts an incredible amount of stress on the joints, as well as on the heart. Look up acromegaly (or pictures of very tall people.........most have pituitary tumors) and you will see the same problems when humans grow too large beyond normal. Major joint problems and heart problems. They normally don't live past middle age. Same for dogs. Most don't live past what we consider to be middle age for dogs. Although with advances in medicine and diet, many are living past what the average age used to be.

Yorkshire Terror
Barked: Sun Mar 1, '09 11:42am PST 
I read somewhere that the growth rate of puppys who turn out to be big dogs has something to do with artheritis and hip dysplasia. The bones grow too big to0 fast, where small dog's bones don't have so much growing to do. I'm not sure if this has anything to do with the cancer, but it explains why big dogs have more bone health problems.

Dog About- Rosedale

Barked: Sun Mar 1, '09 11:58am PST 
I think Keiko has it right. The giant breeds (which are even larger now than they were several generations ago) suffer much more wear and tear on their bodies and organs over the years than a smaller dog. Many large dogs are euthed due to extreme mobility problems as they age...and many experience issues such as cardiomegaly (enlarged heart) related to their size.

As for cancer there are several theories out there...growth patterns and hormones being related to some cancers (mostly the bone cancers/osteosarcomas)..which is why the common neutering age in larger dogs has been adjusted from what used to 8 months to only after the dog is done growing. Also, cancer is still common in smaller dogs..it is the type of cancers that tend to differ. Osteosarcoma is rarer in the smaller breeds, as is lymphoma.

Another theory is that dogs are simply lasting longer (all sizes) than they used to, where 20 years ago a Great Dane was expected to live 6-8 years. Now, with better breeding, health care and diet they often live 10-12 years...the longer they are in our toxic environment the more exposure to carcinogens there is. Even in humans there has been an upswing of cancers in the elderly..thought to be caused by the fact that we are living long enough for them to form where as a hundred years ago the average age at death was considerably lower.