Also as for Biopsies, they are not something i would choose to do on a live animal, they are often very unsuccesful as it is very unlikely for a live animal to have a liver with is affected completely, I had only one of mine biopsied (live) and her results showed only that she had a small chance...
30 horses in the midlands - I own a herd of horses that have proven liver damage caused by chemical insult. A neighbouring farmer sprayed them with chemicals. Some exhibited a number of sypmtoms including photosensitivity, weightloss, ataxia, alopecia etc etc, one dropped dead with no symptoms...