Primary host of echinococcus granulosus is

Options

A. Sheep or Goat
B. Dog
C. Human beings
D. pig

Answer

### Step-by-Step Solution:

1. **Understanding Echinococcus granulosus**: Echinococcus granulosus is a type of tapeworm, commonly referred to as the dog tapeworm or hydatid worm. It is an endoparasite that primarily resides in the intestines of its host.

2. **Identifying the Primary Host**: The primary hosts for Echinococcus granulosus are typically canines, which include dogs, as well as other carnivorous animals such as cats and foxes. These animals are where the adult tapeworm resides and reproduces.

3. **Recognizing Incidental Hosts**: While humans can become infected with Echinococcus granulosus, they are not the primary host; instead, they are considered incidental or accidental hosts. This means that humans can carry the cysts of the parasite, but they do not support the adult form of the tapeworm.

4. **Eliminating Incorrect Options**: Other animals mentioned, such as pigs (which are hosts for Taenia solium) and sheep/goats (which are hosts for Fasciola hepatica), do not serve as primary hosts for Echinococcus granulosus.

5. **Conclusion**: Based on the information gathered, the primary host of Echinococcus granulosus is indeed dogs, along with other carnivores like cats and foxes.

### Final Answer:
The primary host of Echinococcus granulosus is **dogs**.

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