Population control of stray animals needed in Pakistan

In all my reading and hearing about volunteer animal care in Pakistan, I have never heard of any measures to actually improve the long term situation of stray animals in the country.
Most of their campaigns are to adopt and shelter animals. But does this solve the problem of uncared stray animals as a whole of improve the situation?

The control of population is seen as the solution to reduce poverty; especially in third world countries. I feel the same solution should apply here. To reduce the number of stray animals especially in the cities, a fraction of the animals brought to shelter should be sterilized.

This would prevent an uncontrolled birthrate of animals in need. Controlling the animal population should be part of the program to help them, otherwise we are left with countless stray animals in need.

Donations should partly be spent on this sterilization. With a stable and controlled birth rate of stray animals, they can be much more easily be helped.

Also endangered animals such as the snow leopard need to be moved out of the country to protect it from extinction.
There is no hope in the nearby future for endangered animals in Pakistan. If we are to conserve them we need to use donations and take further steps like the ones I suggested instead of simply giving them food and shelter.