Could you clarify that some.
Do you mean they shake their heads like they have something irritating them and are trying to shake it off, or do you mean their heads are continuously trembling?
Are these indoor pet pigeons, or in a loft or aviary outside? Are they eating and drinking normally?
Can you check inside their mouths for anything unusual lke a yellowish 'growth'. Also see if they have any other symptoms like watery eyes or nasal discharge.
Pigeons may shake their heads a lot if they have a problem like ear mites, for example. We have had a pigeon in our aviary do that and it did turn out to be mites. Pigeons may do that also if they have a build up of mucous in the mouth.
hi john yes its loft pigeons they eat and drink normal and been treated for respiratory, if it is ear mites how do i treat them and with what thanks