Normally, if Jack Russells have patches of colour, they're born with them.

It isn't at all unusual for Jack Russells to develop a lot of spots. Many can look white, but when they're wet, many spots will show through.

It's very unlikely that your pup will develop a patch at his age. As he grows and his coat thickens, the spots may not be so visible.

Has he had his tail docked?

 

Thanks for that, wasn't sure. His tail hasn't been docked, just looks a bit short on the pictures, here's a pic that shows it's full length

 

Ours had no spots at 9 weeks then he started to get a few in the winky area, he has loads now (6 months), very dark too. His look lovely though, gives him personality;o)....Steve

 

Oh yes, I see it now.

Has he lost a lot of coat recently?

Pups, at some point, shed their puppy coat and grow their adult one. That could be a reason why so many spots are showing through. His coat does look quite sparse.

 

He hasn't shed much hair at all really, sits on my lap most days as I work from home and you wouldn't know he's been there. The 3rd picture on the 1st post was taken on 3rd June, the pic I have just posted was taken earlier today

 

Sorry I can't help about the spots but just wanted to say welcome to PF and that Jax is adorable, he's got such a cheeky face :Happy.

 

That's the way mine is going now she looks like a dalmatian