Abstract class VS Enumerations (general OOP) - oop

Question

I really can't find how to decide which option is the best. I have a class "Product" which has a "RecommendedAge" for the animal intended to be fed, among other attributes.
Please note that I just want the different values from RecommendedAge for each species, I don't care about their numerical equivalent (what would be represented with a Discriminated Union, but I can't use that due to ORM issues).
As "RecommendedAge" possible values differ depending on the type of Animal de Product targets, I don't know which of the following (or any other) approach is the best (all pseudocode):
Class Product {
Id id;
String name;
RecommendedAge recommendedAge;
}
AbstractClass RecommendedAge {
}
Class DogRecommendedAge : RecommendedAge {
readonly const Int Big;
readonly const Int Small;
}
Class CatRecommendedAge : RecommendedAge {
readonly const Int Medium;
readonly const Int Tiny;
}
Or something like:
AbstractClass Product {
Id id;
String name;
}
Enum DogRecommendedAge {
Big = 0;
Small = 1;
}
Enum CatRecommendedAge {
Medium = 0;
Tiny= 1;
}
Class DogProduct : Product {
DogRecommendedAge dogRecommendedAge;
}
Class CatProduct : Product {
CatRecommendedAge catRecommendedAge;
}
This may be a very silly one, but I'm stuck. Thank you all.

Answer 1

What about just storing recommended ages during runtime instead of at compile time? In your pseudo:
class RecommendedAges {
readonly const RecommendedAge dog = new RecommendedAge(2, 5); // example value
readonly const RecommendedAge cat = new RecommendedAge(3, 4); // example value
}
Class Product {
Id id;
String name;
RecommendedAge recommendedAge;
}
Product p = new Product(1, 'dog food', RecommendedAges.dog);