Ochratoxin, especially Ochratoxin A is a potent nephrotoxic mycotoxin in poultry as well as pigs. In kidneys, liver and heart of birds it causes degenerative to necrotic changes. Chronic exposure of ochratoxins has been associated with tumours of kidneys in rats, but there are no much reports of cancer due to chronic ocratoxicosis in birds.
Try to contact Philippe Guerre in Toulouse (France), is a veterinarian who worked on mycotoxicosis in poultry you can find in research gate. You can find reference on publication (e-mail)