Pliny, Natural History 8.148-150:
“The Indians wish to breed dogs with tigers, and therefore they chain the females in the forest when they are in heat. They think that they are born too ferocious in the first and second litters, but they mellow in the third. Likewise, the Gauls attempt the same thing with wolves, and they use a dog got by this method as the guide and director of their packs; the other dogs follow him in the hunt, and obey him, for they even recognize chiefs among themselves.
(It is certain that the dogs near the Nile drink water as they run by, lest they offer an opportunity to the hunger of crocodiles.) When Alexander the Great was marching on India, the king of Albania gave him a dog of enormous size. Delighted by the appearance of the dog, Alexander ordered him to attack bears, then boars and deer. The dog simply lay there in idle contempt, and Alexander, being of such a generous spirit and offended by the laziness of an animal of such a size, ordered that it be put to death. Word of this reached the king, who sent another dog to Alexander, adding the advice that he should not waste its efforts on small trifles, but should send it against a lion or an elephant. He added that he only had two of these dogs; if this one were killed, none would remain.
Alexander wasted no time, and immediately he saw a lion broken before him. He then ordered an elephant to be brought in, and was similarly delighted by that spectacle. With his fur standing on end, he first sounded out with a tremendous bark, and then he rushed upon the elephant, jumping upon him, and attacking his limbs from here and there with such an artful form of combat (which was entirely necessary) that, in so harassing and then avoiding him, he made the elephant dizzy by the constant turning, and the earth sounded when it fell.”
E tigribus eos Indi volunt concipi et ob id in silvis coitus tempore alligant feminas. primo et secundo fetu nimis feroces putant gigni, tertio demum educant. hoc idem e lupis Gallis, quorum greges suum quisque ductorem e canibus et ducem habent. illum in venatu comitantur, illi parent; namque inter se exercent etiam magisteria. —
(Certum est iuxta Nilum amnem currentes lambere, ne crocodilorum aviditati occasionem praebeant) — Indiam petenti Alexandro Magno rex Albaniae dono dederat inusitatae magnitudinis unum, cuius specie delectatus iussit ursos, mox apros et deinde dammas emitti, contemptim inmobili iacente eo, qua segnitia tanti corporis offensus imperator generosi spiritus interemi eum iussit. nuntiavit hoc fama regi. itaque alterum mittens addidit mandata, ne in parvis experiri vellet, sed in leone elephantove: duos sibi fuisse, hoc interempto praeterea nullum fore.
nec distulit Alexander leonemque fractum protinus vidit. postea elephantum iussit induci, haut alio magis spectaculo laetatus. horrentibus quippe villis per tantum corpus ingenti primum latratu intonuit, mox ingruit adsultans contraque membra exurgens hinc et illinc artifici dimicatione, qua maxime opus esset, infestans atque evitans, donec adsidua rotatum vertigine adflixit, ad casum eius tellure concussa.