They'll find buyers.
cat and dog
they give birth to multiple
aka every time they give birth
they can have 1-10 babies
those animal shelter, gets crowded
and animal get put down all the time there
a quick google search and you will be shock
if the cat you find is old
good chance it will get put down
people only want to buy new cute baby animal
not old fart
kinda like how people prefer to buy new cars not old cars from the 1920 and etc...