I have this Chihuahua puppy he's 10 months old. He was the older one, as there were only him and his sister. We've had both them mother and father and the two puppies but as we recently gave the female puppy away, the male puppy hasn't been the same. He has a sad look to his eyes and discharge out of his eyes. He gets beat up by his father, probably over the female (the mom). His fur is changing from dark brown to a lighter brown and it doesn't look healthy to me. What can i do to help him?

the discharge is a medical condition & did not come from his sister leaving.

you need to get them all to the vet & neutered as well. the male puppy can & will breed with his mother & that should not happen

[Yogi]

Sue hit it on the head. At 10 months the pup is at age to breed and therefore poses a threat to the adult male. Whether father or not he will constantly be attacked by the adult male. You need to get them all neutered and spayed promptly to avoid this. Discharge is a medical condition so a vet trip is in order.

Great advice, you should listen to it!