Okay, I have apparently gotten my cat hooked on dairy products, and I do mean hooked. If she doesn’t get some kind of dairy product at least once a day, she gets irate and refuses to have anything to do with me until I give her some. Now I’ve heard that giving cats milk daily for years can cause them to lose the ability to meow. Is this true? Because if I’m not able to ween her off the stuff, then I’m worried that she’ll stop talking to me.
Most cats are lactose intolerant.
I have two cats that love milk.
I’ve been buying them Cat-Sip (mentioned in the linked article) and they have been eagerly lapping it up.
It’s reduced lactose and comes in the sealed boxes so you can store in on your shelf for months, and only refrigerate it when you open it.
Petco has the small boxes for about $1.49 each. I go through about a box a week.
Switch them over. Better to be safe.
Oh, and I forgot to mention - thanks to Shayna and Spiny Norman for buying the cats their first two boxes of Cat-Sip - the cats love you forever.
We, on the other hand, simply admire and like you guys a whole bunch. Where have you been? We’ve missed you! 
In my experience, if a cat is lactose intolerant it shows up darned quickly. I’ve just adopted a kitten and she nabbed some chicken out of a plate of pasta with cream sauce recently. In less than an hour she was barfing all over the living room. I’ve also had cats that ended up with diarrhea shortly after eating dairy. On the other hand, I’ve had a couple of cats that could tolerate milk products and I’ve let them have a little every now and then as a treat. As long as dairy isn’t a major part of their diet (it’s not that nutritious for them) then I don’t think it’s harmful. I have to say I’ve never heard the meowing theory. But I’ve had one or two I would have liked to turn the volume down on in the past. 
A little cows milk is usually OK. Note the two emphasised words.
Cat-sip is fine, as is plain old lactose-reduced milk right there in your dairy section. Some cats who have some problems with cows milk are ok with that milk that has added acidopholus.