names

I don't think it would be a problem. I think dogs hear the overall sound of the name instead of the first letter. So, to your dogs, their names would sound more like "zACK" and "zO-EE". They sound enough different to me.

 I don't think it would be a problem. Unless you don't like the name Zack. Then you can tell your husband we all said no.

I would think the only problem would be my mouth forming the correct name. I had a friend who named all her kids and her dog starting with the letter "T", man I used to laugh as she would start to holler for any one of them. She went all the way through the list. I know people do that anyway, but in my case it would confuse me more.  

janobonano

 I don't think it would be a problem. Unless you don't like the name Zack. Then you can tell your husband we all said no.

 LOL....that is too funny!  to be honest, I'm not sure if I like it or not.  If I decide I don't, I certainly will tell him that!

 I don't know if anyone else has this problem, but I seem to have a heck of a time naming male animals.  For females it seems that there are so many more nice options.

Its the other way around for me!  I can name males with no problems, but when it comes to females, I have problems...lol! 

 I don't think there would be a problem with naming the new pup Zack.  They don't really sound too similar, but, I'd probably get confused with it starting with the first letter, too...  ;)

I agree, it would probably be more confusing for you than the dogs.  With Buster and Benny I am always mixing them up, it's that beginning 'b' sound.  Since Benny came with his name and I didn't really feel like changing it, I'll just have to live with my struggles.