Can you put iodine on a guinea pigs nail injury?

No, you should avoid putting iodine on a guinea pig's nail injury.

Iodine is not safe for guinea pigs and can cause skin irritation. If the injury is minor and does not require veterinary attention, you can clean the wound with warm water and apply a thin layer of Polysporin or petroleum jelly to help keep the wound clean and prevent infection. If the injury is severe, seek veterinary care.