Please, as it is Halaal to eat chicken and it is Haraam to eat carnivorous animals, can a Muslim consume a chicken that eats its dead young ones or a goat that does this?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

It is permissible, in principle, to eat the meat of animals like cattle, birds and chicken and the like, with the exception of animals with canine teeth [and birds with claws]. Allaah says (what means): {It is Allaah who made for you the grazing animals upon which you ride, and some of them you eat.}[Quran 40:79]

Moreover, Abu Moosaa Al-Ash'ari said: "I saw the Prophet eating chicken." [Al-Bukhari]

However, if the cattle or chicken are fed on impurities like dead animals and excrements in exceptional cases, and this is not their essential food, and the condition of their meat is not changed because of eating such impurities, then it is permissible to eat them. However, if the taste of the meat of these animals changes due to being fed on impurities, or they are fed mostly on impurities, then these animals are those referred to by the Prophet as dead meat and he prohibited us from eating them or drinking their milk. Ibn 'Umar narrated that "the Prophet forbade us from eating or drinking the milk of an animal that eats impurities and dead animals." [At-Tirmithi]

Therefore, if the chicken and the goat that you are asking about are mostly fed on dead animals, then it is forbidden to eat them unless one feeds them with pure food to an extent that their flesh becomes pure or that they are kept away from eating impurities until the effect of impurities is gone. The evidence is that Ibn Abu Shaybah reported that Ibn 'Umar used to prevent the animal from eating such food for three days.

Allaah Knows best.