Wesley is a five yr old entire Dobe. He lives with two neutered bitches. Over the last couple of weeks he has been harassing the bitches. Licking their wee , licking their 'bits' dribbling, whinging and he's been off his food. This has never happened before. He has never shown any interest before. He's never humped anything. He is definitely hyper.
Any suggestions would be gratefully received.

How long have you had him ?

Had him from 8 weeks old

Could there be a bitch in season nearby that's causing him to act this way, could be someone new in the area, or a puppy having her first season.

Some spayed bitches can give off an unusual smell. One of my girls did & my sisters 2 males used to sniff her fairly often, this is just a thought but yes it could be his wires are crossed with a bitch close by...

Most likely a bitch in season in the area, but also check that neither of your bitches has any vaginal or urinary infections as that can make some dogs think they are in season. I've even known dogs believing a bitch was in season because she had a wound, as there was blood smell on her.

I'm confused and n March you only had 2 Dobes & you now have 3 dogs, 2 spayed bitches & an entire dog, so is one of your bitches new to you & have you had their anal glands & urine been checked?

No, I have one entire dog who lives with two neutered bitches that's all. One of the bitches belongs to my daughters boyfriend. She's staying, as she has done for years, for a couple of weeks.
All dogs have a health check every six months ....this was a couple of weeks ago.