I am worried about one of my turtles (Red-eared turtles).

They are almost 2 years (or perhaps 2 years) old. One of my turtles does not want to eat. The other eats normally. That makes me discard issues with the aquarium temperature.

I checked their shells. They are strong.
I checked their ears. They open and close thme normally, and look normal in size and color (i.e. nothing changed in proportions these months).
I checked their nostrils. They look to have no cold and breathe well underwater. They also move as quick as always.
I always check when they eat. There's no fight for food (except when the other one follows my finger trying to eat it).

However, I noticed that the turtle that does not eat, has a tiny white rounded mark in the neck. That mark had another (brownish-like) color before. What's happening with my turtle and how do I help it?

I am worried about one of my turtles (Red-eared turtles).

They are almost 2 years (or perhaps 2 years) old. One of my turtles does not want to eat. The other eats normally. That makes me discard issues with the aquarium temperature.

I checked their shells. They are strong.
I checked their ears. They open and close them normally, and look normal in size and color, nothing changed in proportions these months.
I checked their nostrils. They look to have no cold and breathe well underwater. They also move as quick as always.
I always check when they eat. There's no fight for food (except when the other one follows my finger trying to eat it).

However, I noticed that the turtle that does not eat, has a tiny white rounded mark in the neck. That mark had another (brownish-like) color before. What's happening with my turtle and how do I help it?

I am worried about one of my turtles (Red-eared turtles).

They are almost 2 years (or perhaps 2 years) old. One of my turtles does not want to eat. The other eats normally. That makes me discard issues with the aquarium temperature.

I checked their shells. They are strong.
I checked their ears. They open and close thme normally, and look normal in size and color (i.e. nothing changed in proportions these months).
I checked their nostrils. They look to have no cold and breathe well underwater. They also move as quick as always.

However, I noticed that the turtle that does not eat, has a tiny white rounded mark in the neck. That mark had another (brownish-like) color before. What's happening with my turtle and how do I help it?

I am worried about one of my turtles (Red-eared turtles).

They are almost 2 years (or perhaps 2 years) old. One of my turtles does not want to eat. The other eats normally. That makes me discard issues with the aquarium temperature.

I checked their shells. They are strong.
I checked their ears. They open and close thme normally, and look normal in size and color (i.e. nothing changed in proportions these months).
I checked their nostrils. They look to have no cold and breathe well underwater. They also move as quick as always.
I always check when they eat. There's no fight for food (except when the other one follows my finger trying to eat it).

However, I noticed that the turtle that does not eat, has a tiny white rounded mark in the neck. That mark had another (brownish-like) color before. What's happening with my turtle and how do I help it?