What breed? Does my gray white crested piggie (grayson) have roan?

[figinwhistles]

the blondie is his brother charlie and they are best friends Grayson is constantly sick and his colouring and health issues have me thinking he might have roan

 

[ItsaZoo]

Roans have pure white hairs intermixed throughout the colored hairs on their bodies. So brush the fur backwards and see if there are completely white hairs mixed in. My understanding is the roan’s health is no different than guinea pigs who don’t carry the roan gene. However, when two roans have offspring, a lethal white can result and they have genetic deformities.

 

[figinwhistles]

thank you so much!