Microphthlamia (Lethal Gene)

Microphthlamia or better known as the Lethal gene is caused by breeding a roan x roan or Dalmatian x Dalmatian together.


Studies show that there is a one in four chance of guinea pigs born from the breeding of a roan x roan or Dalmatian x Dalmatian will result in having a lethal baby. Many affected guinea pigs will die. Responsible breeders will never intentionally mate these breeds.


Sings of a lethal guinea pig.


·         Born dead or has a short life.

·         A lethal guinea pig is always born completely white with red eyes this is not just a colour but because these guinea pigs are born without any skin pigmentation.

·         Born blind in one or both eyes

·         Born with no eyes

·         Born deaf in one or both ears

·         Missing teeth or other teeth deformities

·         Low immune system

·         Neurological Problems



Lethal guinea pigs can be very lovable pets and live a normal life although they will need ongoing vet care to make sure they stay happy and healthy.

Photos of a Microphthlamia (Lethal gene) Guinea pig below.




     Some Guinea Pigs may have the Roan or Dakmatian gean without it being visible.

         What is a roan?

A roan is a breed of guinea pig with white hairs mixed with another solid colour.


Photos Below




         What is a Dalmatian?  

A Dalmatian is a breed of guinea pig. Dalmatian Guinea Pigs are known for the design on its coat - it basically resembles a Dalmatian with a white background covered with black spots.


Photos below