Not an expert but generally your dog has been vaccinated against certain diseases.Bats create Guano and rats or mice carry plenty of diseases so in my mind that would be the difference.These types of animals carry all kinds of illnesses that is dangerous to the public.

As we will hear this afternoon, the Centers for Disease Control is currently working with other institutions to study this issue and provide more information on the true health effects of mold infestation.

Service dogs are not considered pets.You have probably totally thought this through, but here's a couple of questions:Are you aware that birds stink to high heaven, and carry diseases that humans can get?

From there, like an airborne disease, the infestation spreads to all the other properties, crime rate goes up, drugs being deal in the alleys and the street corners, drug deals fone bad, shootings, murders.

There are dozens of diseases that stock can get and dozens of ways that bad contractors or renters can cost you money before you realize it. 

(sarcasm) :)We have 5 (FIVE)...........yes five.The key difference is NOT the cats but the owners who take care of them.Many owners do not properly care for their animals.Our cats have always been indoor cats. 2 were strays but were kittens when found.All our cats are domesticated an dhave been tested and cleared.They are spayed and neutered.They never go outside except for our porch on the balcony upstairs for a few minutes then they want to go back in.Having animals is expensive to take care of properly.You have to make sure they have regular vet visits to keep them healthy.Every 3 weeks we clip their nails,clean their ears,and comb them.We brush their teeth a few times a week and bath them occasionally.The only reason a cat will go outside of the litter box is if:1.they cannot access it2.The owners don't clean it enough (how would you like standing in crap to go to the bathroom).3.The owners have too few litter boxes for the number of cats4.The owners let sick cats or outside cats mingle with their inside ones which can lead to many diseases including feline leukemia.I would say in fairness to landlords as pet owners who own our house we are probably in the top 30% of pet owners as far as caring for them.The cats if you clip them every 3 weeks will not do damage to the carpets as the claws will not be sharp enough.Also if you have scratch pads they can that will help immensely.Pets cared for properly have shown to reduce stress,prevent strokes,and lower blood pressure for better heart health.As a landlord you would have to consider many pet owners would fall into the negligence category sadly.For this you have to take on bigger deposits to mitigate the risk.

Cities with greater density and reliance on public transportation are naturally going to be places where disease spreads faster. 

This shouldn't stop.Analysis-paralysis on the other hand if a deadly disease...symptoms include reading every book out there and watching real estate videos every day.

That ancient Hawaiian disease lackaloot worked to motivate me back in the day.I didn't know what I wanted to do when I was young.

But recently I've been hit by a series of tragic events, including death of my dear wife due to a disease, and my own health starting going downhill in spite of my best attempts to live a healthy lifestyle.