No. होता turns the sentence into a statement of general fact. If you were talking about one horse, you might drop होता but this particular sentence establishes that all horses always always are animals.
Why this Horse is an animal wasn't accepted? And by the way since it was general truth so there was no need to specify the before horse
I keep confusing “animal” (जानवर) with “young” (जवान). Hopefully I don’t embarrass myself in front of a native speaker.
OK seriously, this case or tense or whatever it's defined as linguistically SURELY has an English equivalent which translated should be "Horses are animals." Can we make this acceptable or put this grammar point further in the tree so there is no confusion with adjectival conjugation?