For the yorkies we give rabies after 20 weeks, here in my state it is required by law that they have it by 6 months old. my vet is like me, he does not like to over do . He usually recommends wait past 20 weeks although he says it is safe to do it at 12 weeks. A lot depends on the size of the puppy , if it is a small tiny one he will say:"ohhh hummmm why dont we wait a couple more weeks, but if you want we can do it today..." then i know , he prefers to wait.
I will ask him again about the ferrets... i got curious my self. I remember well , we were talking about brands and prices, he told me that he had switched to the "merial" brands because he did have many ferrets and they are prone to have reactions and he had no reactions since he had switched. We were also discussing the 3 year rabies instead of one year. By the time i was not aware that was the same shot, and legislation passed here allows you to have the rabies done every 3 years if you do the first time, then the second can not be longer than one year apart... then he can validate it for 3 years and so on... it sounds confusing huh...
Anyways, by the time we had the ferret talk i was thinking the 3 year rabies was different from the one year one... and that was years ago.
My vet treats me different i know. He does not recommend me to give too many shots, lepto is a no-no, gyardia vaccine he finds it non-effective, no corona, lime disease he only gives to people living near the woods as we have "deer" , lots of them...
I am sure it all depends on how one talks to their vet too. I remember we use to disagree a lot, me and my vet...kkk... now we developed a trust and a relationship. I changed my ways and so did he... we both compromised and learn from each other i think.
XOXO