Question

In markets pooja sees that eggs of birds are available but never eggs of dogs why

Answer 1

Because:

Dogs are not oviporous . They are viviporous.

They cannot lay eggs but can give birth to a baby

Answer 2

Birds become oviparous which lay outside of their body so that become simple to collect the their eggs and also available in the market.

Apart from that the contrary dog become viviparous and not lays eggs but it gives young one.

Therefore the eggs become highly small that stay inside the bodies with no trouble of it.