I am positive that Norman the pug had a portosystemic liver shunt. Some of the blood bypasses the liver and is not detoxified. The reason I believe this is that he was having petit mal seizures when I got him at ten-weeks-old. I didn't recognize them as seizures until later.
At six months he developed grand mal seizures, and there is no mistakings those. At first he was having six or seven a night, and I thought I was going to have to put him to sleep at six months.
I was able to get rid of 95% of the seizures by switching him to a raw-foods diet. Dogs, after all, don't eat kibble in the wild, especially with grains in it. Still, he was having one mild one a week instead of six major ones a day.
He was fine for three-and-one-half years, then went downhill but fast. He apparently also developed a non-cancerous tumor pressing on his heart and lungs, and I think that is what really did him in.
He also had the beginnings of kidney failure, but he could have lived another five years with that. It turns out ammonia is one of the main poisons not removed with the liver shunt, which caused the seizures and kidney failure. I suspect I extended his life from one year to three-and-one-half years.
If I had to do it over, I would have given him milk thistle every day, which cleanses and regenerates the liver, and also fed him six small meals a day instead of two big ones, and given him kefir every day, and distilled water.
I think those things would have reduced the seizures even more, and put off the kidney failure for a few years more. Still, though, there was the problem of that tumor inside him. I would have bought a stethoscope and checked him every month, since the vet said he could hear his heart on one side but not the other, which meant something was growing inside him on one side, affecting his heart and lungs.
Norman was born with the shunt, probably because he was a runt. He grew to 12 pounds, which is very small for a pug. People always thought he was a puppy.
He had a good life, short as it was. He was the funniest dog I ever saw, although he was appallingly stupid. Someday I'll get another one.