The landlord may also require a "pet health certificate" to give him/her assurance that the pet is in general good health, has received all state required vaccinations, and is parasite-free.

For example, you absolutely can require the animal have a current veterinarians health report and current vaccines.

Pretty sure that, regarding the service dog's "authenticity," you can only ask for written verification from the tenant's health provider that the service animal is necessary, in addition to the animal's vet records to show proof of vaccination status and in good health.

Can I require the dog to have current vaccinations? 

US rallied and Linus Pauling in Palo Alto created a vaccine..

I would require prospective tenants provide pet vaccine records as part of the application process.

Must be able to provide vaccinations records, non aggressive breed, are they ok with paying higher sec dep and having $25 fee per month for having pet?

Luckily I have not run into the issue yet but I plan on directing tenants to petscreening.com to check vaccination records, possibly known history (landlords can document pet history for future landlords), and legally validating if the animal is an assistance animal.

We required documentation that both the cat and dog were spayed or neutered and up to date on vaccines before approving the tenant.

you are very accurate in your statement.i agree, ultimately it is still up to us work the system and do our due diligence through self-study whether it's through investment mentoring clubs, radio, or books/seminars.LU is a fantastic place to build a foundation (no pun intended) for folks who are in the beginning stages and are timid about the progression. through its plethora of case studies and vendor spotlights, so much can be learned through the experiences and successes of like-minded people. oh, and thank you for mentioning the "smugness" (your word-not mine) that exists. i always thought that it was just me. now i see different. i've met Del. he's a good man. now i'm not going to say we're text buddies or we call each other up from time to time. but i've seen him work and he's a good man. i'm not a cat fan but just recently Del sent email blasts looking to find homes for 10 kittens that he had already cleaned up and vaccinated. i'm sure it's probably from one of his apartment complexes, but he didn't have to do that. a person with that type of compassion can't be all bad.