moquetztlani.

Headword: 
moquetztlani.
Principal English Translation: 

for a female dog to be in heat (see Molina)

Alonso de Molina: 

moquetztlani. (pret. omoquetztlan.) estar cachonda la perra. &c
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 060r. col. 1. Thanks to Joe Campbell for providing the transcription.