in article , Liz at
wrote on 1/18/04 7:03 AM:

"Rex" wrote in message news:oPiOb.150333$X%
Thanks for all the replies. The vets checked his tooth and found no problems
there .. Just in case we had a tooth cleanup done as well.
The vet saw him do that and thought it might be arthristis on the neck ..
The x-rays apparently confirmed that as well. The whole thing started about
a month ago, when he started vomitting frequently and this was just a side
occurance. Also had blood work done on him and kidneys etc seem alright. He
appears to be hungry. When we put the food out he rushes to the dish but
simply does'nt eat enough.. We have'nt looked at ear infections. .. To the
touch and visual examination his ears seem OK. He is 13 years old.

I entered those signs in Cornell consultant and got only two
diagnoses: rabies and the one below. Although the condition below is
more common in young animals, you might want to look into it.

-Difficulty in prehending or chewing food
-Vomiting or regurgitation, emesis
-Head shaking, headshaking

PORTOSYSTEMIC SHUNTS, HEPATIC MICROVASCULAR DYSPLASIA, IN DOGS AND
CATS

Portosystemic anastomoses or shunts can occur in dogs and cats,
allowing venous blood to bypass the liver. Most common in young
animals. In portosystemic shunts, vascular communications between the
portal and systemic venous systems allow bypass of the liver. Hepatic
microvascular dysplasia has been described in dogs; small intrahepatic
portal vessels and portal endothelial hyperplasia allows communication
between portal and systemic circulation. Hepatic microvascular
dysplasia can be an isolated disease or can be present in conjunction
with portosystemic shunts. The presenting signs may be primarily
related to the digestive tract, or there may be signs of neurologic
disease due to hepatoencephalopathy. Hyperammonemia, ammonium biurate
crytalluria, and bile acid elevation can occur. Diagnosis confirmed by
contrast venography, although in hepatic microvascular dysplasia
biopsy is required for diagnosis. A syndrome resembling idiopathic
noncirrhotic portal hypertension has been reported in Doberman
Pinschers; these dogs lacked intrahepatic arteriovenous fistulae,
portal vein atresia, or intrahepatic fibrosis. Uric acid stones
associated with shunts can cause signs of bladder disease.


Last months Cat Fancy had an article about this condition. Perhaps you
could find it at your library.

Karen