At least five cases of a rare and incurable disease in dogs have been reported in the Perth metropolitan area amid revelations more than 70 animals became ill nationwide after eating a popular dog food brand.

Investigations by the University of Melbourne found 65 family pets and nine police and correction dogs nationwide were diagnosed with megaesophagus after being fed Advance Dermocare pet food in recent months.

Advance Dermocare pet food has been linked to an outburst of cases of a rare condition in dogs.

As of April 30, university researchers said Perth vets reported at least five confirmed cases of the disease, with the Animal Hospital at Murdoch University confirming it had treated one of the cases.

The Murdoch case was also reportedly linked to Advanced Dermocare dog food.