I was really worried about Tricki this time. I had pulled up my car when I saw him in the street with his mistress and I was shocked at his appearance. He had become hugely fat, like a bloated sausage with a leg at each corner. His eyes, bloodshot and rheumy, stared straight ahead and his tongue lolled from his jaws.
Why was the narrator worried ?

Explanation

James Herriot was worried. Tricki.s condition was really bad. He saw him in the street with his mistress and was shocked at his appearance.