Curious, how are liver shunts found?
 

i'm just curious; what kind of test is performed to find liver shunts?

is it adviseable to perform this test once a year?

does the test involves needles or xray, etc?

thanks for your help :)

Start with a bile acid test (BA) What you have to do is fast the pup for 12 hours, draw blood to test, feed wait draw blood again. The result of the second test compared to the first test should tell you if the blood is flowing through the liver as it should and the liver is working to remove the toxins.
Due to the fasting requirement and other factors, it is unadvisable to test less than six months of age unless the pup is presenting symptoms. Buying a 3 or 4 month old puppy that has been tested before sale, really won't assure you of much of anything except that it managed to survive a 12 hour fast.
Symptoms of a shunt can be circling, head pressing sometimes vomiting/diarrhea. However, these symptoms are not just a shunt there can be other causes.
Shunts can vary in severity and location, within the liver or around the liver. Some can be corrected with surgery, some cannot, some can be managed with diet and certain medications. It has been often presented in the undersized although not always and a larger Yorkie can still have a shunt.
Testing the parents does not do a thing because if they are not exhibiting symptoms and they don't actually have a shunt but they can be carriers of the shunt genetically.
Ultra sound now available with better and better equipment has pioneered the detection and verification of shunts on a live animal. At one time, a dog or puppy may have died from a shunt but no one would have known as at death the veins etc collapse, blood gases wouldn't be normal and an autopsy would not tell the vet pathologist what happened.
Shunts have now finally been considered to be a genetic condition which it took a long time to ascertain. The right gene has to be present on two locci of both parents to produce a shunt pup. there is not yet any testing that can do genetic mapping of the genotype of the parents that can locate whether or not a Yorkie is a carrier for shunt and therefore is at risk to produce a shunt puppy.
This is why it is imperitive that before you breed you know the backgrounds of the pedigree behind both parents used in a breeding program. When you don't know, you increase the risk of a shunt puppy occuring.
Shunts are also manifesting in crosses as the gene code doesn't care if it is being carried by two Yorkies, two maltese, or one of each breed in a mating. The less you know about the background of the parents, the kennels they came from, the higher you are at risk to produce a genetic condition such as shunt or Legge-perthes from that mating.

thanks for the info! your explanation is really helpful. thanks :)

Great - informative reply, Lorraine.

Carol Jean