The animal welfare charity is concerned the birds have been gaining access to waste products from a local brewery or alcohol producer.
RSPCA officers have collected a number of birds exhibiting the same symptoms in recent weeks.
Birds from places such as Dawlish, Seaton, Colyton, Exmouth, Exeter, Sidmouth, Starcross and Budleigh Salterton have been treated.
“Disappointment” over North Devon funding settlement
There could be up to a five per cent drop in core spending power
Controversial Exeter road consultation to begin in the New Year
Drivers ‘rat-run’ through hospital to dodge Exeter road closure
Exeter care agency rated 'inadequate' and in special measures
Bosses at Horizon Care insist change
Raw sewage spews into Plymouth suburb estate and woods
Concerns raised for public health and wildlife in Woolwell
Councillor stands under trees to stop chainsaw massacre
Emergency preservation order now in place
