Janette.
I'd find a vet who you are happy with, one who will put Indies health and wellbeing first and who
you feel you can trust ,and discuss all of your concerns with them before her next booster is due.
There is a whole lot of "stuff" out there about over/under vaccinating that it's incredibly difficult to separate the fact from the fiction and to understand exactly whats what. Discussing it all with a vet who you are happy with is the best option IMO.
I personally don't believe that all ,or even the majority, of vets are out to boost their profits at the expense of our pets. I think you've just been unlucky.
I trust Billy's vet 100% . I do question him, lots!
but he's extremely knowledgable, keen, and always has an answer to my questions and never " skirts" over stuff. At the end of the day they way I see it is that HE is the expert ,not me
