Early Quenya
lopo-
verb. to gallop, run (of animals)
lopo
noun. lopo
lapatte
noun. rabbit
lópa
noun. horse, mare
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
The Qenya Lexicon of the 1910s had a verb ᴱQ. lopo- “gallop, run (of animals)” under the early root ᴱ√LOPO, contrasted with ᴱQ. loqo- “run (of human beings)” (QL/56).
Neo-Quenya: Derivatives of √LOP continued to appear in Tolkien’s later writings, such as N. lobor “horse” and lopoldë “rabbit”. I would therefore retain ᴺQ. lop- to describe the four-legged run of these and similar animals, meaning “gallop” or “✱lope”.