Appaloosa vs riding horse

Appaloosa and riding horse both are nouns.

Word	Noun	Adjective	Verb	Adverb
Appaloosa	Yes	No	No	No
riding horse	Yes	No	No	No

As nouns, riding horse is a hypernym of Appaloosa; that is, riding horse is a word with a broader meaning than Appaloosa:

Appaloosa: a hardy breed of saddle horse developed in western North America and characteristically having a spotted rump
riding horse: a lightweight horse kept for riding only

Other hypernyms of Appaloosa include mount, saddle horse.

Appaloosa (noun)	riding horse (noun)
a hardy breed of saddle horse developed in western North America and characteristically having a spotted rump	a lightweight horse kept for riding only