[Ladymom]

Originally Posted by Woogie Man

I keep seeing this number (36 times more likely than all breeds combined) being used but I don't see the data to back it up. I've copied and pasted below some of the data from Dr. Tobias' research. I frankly don't see how you arrive at that number. To me, a more reliable statistic to go by would be the odds ratio. The Yorkie's odds are high, but not 36 times higher. Actually, the Havanese's odds are greater and, if you look, it seems many toy breeds have a much higher risk than other breeds.

Yorkies are at high risk for liver shunt...I don't mean to downplay that. I just can't relate the 36 times more likely figure to the data I've seen.

Table 1—Proportion of diagnoses of congenital portosystemic
shunts in dogs accessed from the Veterinary Medical Data Base
from January 1, 1980, to February 28, 2002
No of Reference Adjusted
affected hospital Odds confidence
Breed dogs (%) population ratio interval*
Mixed-breed dog 169 (0.05%) 331,234 1.0 NA
Havanese 6 (3.2%) 187 64.9 8.9–234.3
Yorkshire Terrier 483 (2.9%) 16,538 58.7 42.9–80.2
Maltese 100 (1.6%) 6,231 32 20.2–49.8
Dandie Dinmont
Terrier 4 (1.6%) 251 31.7 2.3–140.1
Pug 75 (1.3%) 5,681 26.2 15.7–42.5
Miniature Schnauzer 244 (1%) 24,411 19.8 14.0–28.0
Standard Schnauzer 36 (0.82%) 4,404 16.1 8.0–30.0
Shih Tzu 119 (0.78%) 15,274 15.4 10.1–23.4
Bernese Mountain
Dog 14 (0.76%) 1,825 15.1 4.7–36.8
Bichon Frise 32 (0.67%) 4,747 13.3 6.3–25.4
Cairn Terrier 27 (0.54%) 4,990 10.7 4.7–21.2
Irish Wolfhound 13 (0.5%) 2,594 9.9 2.9–24.7
Longhaired Dachshund 8 (0.5%) 1,602 9.8 1.9–30.0
Jack Russell Terrier 13 (0.43%) 3,025 8.5 2.5–21.2
Pekingese 33 (0.36%) 9,116 7.1 3.7–13.8
Miniature Pinscher 7 (0.36%) 1,964 7.0 1.2–22.7
West Highland
White Terrier 25 (0.31%) 8,163 6.0 2.6–12.2
Pomeranian 27 (0.29%) 9,411 5.6 2.7–11.6
Lhasa Apso 37 (0.28%) 13,359 5.4 2.9–10.2
Old English Sheepdog 19 (0.26%) 7,189 5.2 1.9–11.4
Shetland Sheepdog 59 (0.26%) 22,348 5.2 3.1–8.8
Chihuahua 25 (0.25%) 10,041 4.9 2.3–10.3
Scottish Terrier 14 (0.23%) 6,207 4.4 1.4–10.8
Miniature Dachshund 17 (0.2%) 8,699 3.8 1.3–8.7
Standard Poodle 22 (0.17%) 12,645 3.4 1.6–7.5
Toy Poodle 33 (0.16%) 20,833 3.1 1.6–6.0
Beagle 27 (0.16%) 17,328 3.1 1.5–6.3
Samoyed 14 (0.15%) 9,476 2.9 1.1–7.6
Golden Retriever 86 (0.14%) 63,466 2.7 1.7–4.2
Cocker Spaniel 75 (0.14%) 55,165 2.7 1.6–4.3
Doberman Pinscher 53 (0.14%) 38,428 2.7 1.5–4.6
Siberian Husky 18 (0.13%) 14,084 2.5 1.1–5.9
Labrador Retriever 87 (0.1%) 90,902 1.9 1.2–2.9
*99.9995% Confidence interval adjusted for 106 comparisons with
mixed-breed dogs.
NA = Not available.


The data copied in a hard to read format. here's the link so you can read it in a more intelligible form.

http://www.vet.utk.edu/clinical/sacs...breed_assn.pdf

That statistic came from Dr. Tobias' research. It is taken directly from the UT website:

What breeds are commonly affected with shunts?

Small breed dogs tend to have shunts that form outside of the liver ("extrahepatic"). In the United States, Yorkshire terriers have almost a 36 times greater risk of developing shunts than all other breeds combined.

Portosystemic Shunts FAQ