They might be breeders, or they might be animal hoarders, or they might be crazy... any way you look at it, it's an absolute NO to me. 

In an attempt to offset the risk/damage that I believe the pets will cause, on average, over time, I charge the following per animal:Cats: $200 move-in fee, plus $25 per monthDogs: $200 move-in fee, plus:- $25 per month for a small dog (less than 25 lbs) - $50 per month for a medium dog (25-50 lbs) - $75 per month for a large dog (50+ lbs) Additionally, I must meet the animal, and preferably at their current residence, prior to move-in.

If a tenant has an emotional support animal or service animal, none of the "pet" language applies, though.You should create an Animal Addendum, or Animal Clause, that applies to all animals, whether they are pets or not. 

If there is a dog I would require the animal to be inside kennel while I am there. 

If you do allow it, just be sure to explicitly state on the lease and explain verbally that they are allowed "2 Guinea Pigs" only and that any other animals are prohibited without your prior written consent.

call animal control. 

They have moved in a animal so I did not enter on my own. 

Put a monthly charge PER ANIMAL in your agreements. 

Call the city or county health department they should take care of the testing since it's a wild animal.

If the animal causes damages, you can charge the tenant for those damages.Best to establish a Service Animal/Assistance Animal policy proactively.