My cat meows constantly when left alone.

my cat used to do that constantly too, I just let him keep on doing it and he realized that if he keeps on doing that nobody will come. And he stopped the habit of meowing constantly.
I hope this helps

A good thing to do is to leave a T.V on, he will think someone is home and it will save the neighbors from complaining for sure… , As far as I can tell owning cats for over 30 years growing up with them also, some cats want company in their early years.!!

about the only thing you can do is make sure it has plenty of food and water.surely to my goodness a cat cant be to disturbing.

Source Link: cat meow