Why are wild pigs in California turning blue inside?

[Catherine]

The insides of wild pigs in California are blue, seriously blue. The reason is not so good.
Rat poisons are usually  dyed so that the poisoned animal appears dyed. The wild pigs have been eating rat poison.
They haven't eaten enough to kill them, but it is enough to dye their insides.
Other animals in the area are probably exposed as well. That means rat poisons are being eaten by non target animals.
The poison is in the food chain. Predators like hawks and owls could easily ingest a lethal dose.
Humans are at risk too.

https://www.sciencealert.com/wild-pigs-t...g-warnings

Poison for pest control is very dangerous for the environment. Once it is out there, it is impossible to control.
It can keep on poisoning the environment for years to come. We need to find better ways of dealing with rats.
Humans are at risk from these poisons. Once it is in the food chain we can be poisoned too.
Whether we eat a poison contaminated animal or poison contaminated food, we are at risk.
If we don't care about the environment, we should at least care about ourselves.
Of course, to care for ourselves, we do need to care for the environment.

[LPC]

This is very disturbing. When we lived in France in the deep countryside, we had a problem with mice and rat as they were attracted to the animal feed.

Our solution was simple and non-lethal. We got several ultrasonic repellers, which use a certain frequency irritating to rodents but harmless for other animals and humans. The rodents stayed away, and that was enough. No poison.

Apart from the health risks of poison, the death which rat poison induces is painful and extremely unpleasant.

[Catherine]

You are right, here has to be a kinder better way than poison. Once that poison is out there in the environment, it just keeps on killing.
The wild hogs probably ate rodents that died from the poison. That means other animal have eaten  poisoned rodents. 
The wild hogs are pretty tough and they tolerate a fairly high poison level. Owls and hawks would not be so lucky.

I have heard of the ultrasonic repellers. It sounds like they work very well on rodents and they do no harm to anything else.
It would certainly a less cruel and less dangerous alternative.