Final answer:
The symptoms in the puppy indicate a parasitic infection, which can be caused by protozoa parasites like Giardia lamblia or cestode parasites like Echinococcus granulosus. These parasites can be transmitted through contaminated water, soil or contact with infected animals.
Step-by-step explanation:
The symptoms of bloated abdomen, dull hair coat, and poor weight gain in a puppy are indicative of a parasitic infection. There are several types of parasites that can cause these symptoms in dogs, including protozoa parasites like Giardia lamblia and cestode parasites like Echinococcus granulosus. These parasites can be transmitted through contaminated water, soil or contact with infected animals. In severe cases, these infections may require antibiotics for treatment.