Sunday, May 1, 2011

Long Term Analysis on Mortality in 80 Breeds of Dogs

Oh my gosh, that title is so boooooring and no one will probably read this, but hey I find this stuff fascinating. It's my blog, darnit!

Between 1984-2004, more than 80,000 dogs died at one of 27 veterinary teaching hospitals in North America that submit data to the Veterinary Medical Database (VMDB). Researchers at the University of Georgia used records from the VMDB to assess the cause of death in the more than 74,000 dogs who fit the research criteria for the study. More than 80 breeds* of dogs emerged from the results.

I originally wanted to do a little chart of all the breeds and stuff, but thought that would be stealing too much from the actual research report. Sorry. You can read the overview at ScienceDaily, where all the cool kids hang out. (As I was searching for that article, I found this one in which dogs are full of flame retardants. This is not as cool as it sounds nor does it make dogs fire-resistant.)

But I will post a few interesting tidbits and of course include pertinent information on Pit Bulls, tragically called American Staffordshire Terriers in the journal article. No offense to you ASTers out there.

Cause of death was categorized in two ways - OS and PP, because science likes coding. OS = organ system and PP - pathophysiologic. Science likes big words too. Pathophysiologic = progression of disease or something.

Enter neoplasia, which you could call cancer but you'd be right and wrong. Neoplasia is cell growth gone wild. Sometimes it's totally benign abnormal cell growth, like those fatty lumps on old dogs. Sometimes it's ugly, nasty stuff, like a malignant cancer. Of all 80 breeds, including mixed breed dogs, only individuals from 11 breeds died from a "disease" or "trauma" at a higher rate than from cancer (and for a couple of those breeds, the other cause of death beat out neoplasia just barely).

Those breeds are: Australian Heeler (trauma deaths reign); Chesapeake Bay Retriever (trauma again); Dachshund & miniature Dachshund (trauma, hello broken backs); Jack Russell Terrier (traumatical); Maltese (congenital disease barely beating out neoplasia); Miniature Pinscher (trauma); Pekingese (TRAUMA); Pomeranian (trauma); Toy poodle (trauma); and Treeing Walker Coonhound (infectious disease).

The frequency of death within organ systems varied much more so than how the disease or trauma progressed (trauma probably doesn't progress so much as just kill the dog). So I will just give highlights.

Organ systems were divided into the following: Cardiovascular, Dermatological, Endocrine, Gastro-intestinal, Hepatic, Musculoskeletal, Neurological, Opthalmic, Respiratory, Urogenital, Unclear. Or heart, skin, hormone/glands, guts, liver, bones/muscle, brain/spine/neurons, eyeballs, lungs, get your head out of the gutter, unclear.

The breeds with the greatest frequency of death within each organ system are:
Cardiovascular: Newfoundland, Maltese, Chihuahua, Doberman, Fox Terrier
Derm: No one
Endocrine: no one
GI: Great Dane, Gordon Setter, Akita, Shar Pei, Weimie
Neuro: Dachshund, Miniature Dachshund, Dutch Pug, Miniature Pinscher, Boston Terrier
Muscle/Bones: St. Bernard, Great Pyrenees, Irish Wolfhound, Great Dane, Greyhound
Respiratory: Bulldog, Borzoi, Yorkshire Terrier, Afghan Hound, Walker Coonhound

For Pit Bulls: Cancer and Trauma for progression of disease. Gastrointestinal and Musculoskeletal for organ systems most affected.

Golden Retrievers and Boxers at the highest rates of cancer, which is consistent with previous research. Nearly half of all the Golden Retrievers and 44% of Boxers died because of it. Interestingly, the Bouvier des Flandres, a relatively unheard of breed, also had a very high frequency of cancer - 46% of individuals died from it. Most other breeds did not go above 30-35%.

Surprising to researchers too was the high rate of cardiovascular disease in Fox Terriers, and the high rates of respiratory disease in Afghan Hounds and Vizslas.

Cautionary notes from authors: VMDB = people who take dogs to teaching hospitals, but authors think this still represents the overall dog population. Study = cause of death, instead of just morbidity...i.e. some breeds may have higher frequency of certain diseases that do not lead to death but still pose concern or problems. Diagnosis = discretion of the veterinarian at the teaching hospital, not in an official necropsy result. Breed = no pedigrees available.

Still, interesting stuff.

And that is my conclusion.

*These dogs do not have pedigrees, per se. A breed had 100 individuals to be included. Mixed breed dogs had their own classification.

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