Step 1: Understanding the Question:
The question asks for the reasons behind Mrs. Pumphrey's anxiety regarding her dog, Tricki, as described in the story "A Triumph of Surgery."
Step 2: Key Concept from the Text:
Mrs. Pumphrey's worry stems from her observation of Tricki's deteriorating health, which, ironically, is a direct result of her over-pampering and overfeeding him.
Step 3: Detailed Explanation:
Mrs. Pumphrey was worried because Tricki had become listless and seemed to have no energy. He had become hugely fat, like a bloated sausage, with bloodshot and rheumy eyes. He refused to eat his favourite foods and had bouts of vomiting. He would just lie on his rug, panting, and showed no interest in going for walks or playing. She feared that he was suffering from a serious illness.