Is there a law on how many dogs and cats are to be inside a house ?

No

I think more than 4 is pushing it unless you can care for them properly, and have a large enough area for them to roam and play

may dependmon where you live. check hoa if you have one, check local rules (city/county)

Some towns and HOAs can and do put limits on the number of pets. If I were you I'd ask them directly.

There is no law which explicitly puts a limit on the number of animals inside the house.however any abuse towards even one can lead to confistication of all.

No as long as their cared for.