Can anyone tell me if you need planning permission to put kennels and runs in your back garden?

That would depend on how big they were.  My run adjoins a shed so I didn't need planning permission.  If in doubt, give your local planning office a call.

They are about 6ft high, 6ft wide, 6ft long each and theres 3 of them. It suddenly occured to me this morning that I may not be able to put them up, I will call them in the morning.

Planning permission for kennels guidance

Have a look on your local councils website, planning pages, they give advice on what types and size of structures need planning consent.

Thanks all, have contacted the council and they are sending me some info through the post but its not looking like we need planning permission as its not a permanent fixture.

Basically same as sheds and green houses.