There are remnants of three Indika (‘History of India’) from ancient Greece. The oldest is attributed to a Kteisias of Knidos (Ctesias of Cnidus) who is said to have traveled with the failed rebellion of Cyrus (the same trip as Xenophon). He gathered his account from stories the Persians told.  The following is taken from the summary made by the Byzantine scholar Photius in his Bibliotheca.

(There is a translation available free here. It leaves out anything about menstruation and sex.)

Ctesias, Indica (fragments From Photius’ Bibliotheca, Codex 72 47b-48b)

Appearance, Language, and Population

“On these mountains he says there are men who have a dog’s head. They wear clothing from wild animals. They do not speak with a voice, but they bark like dogs and thus understand one another. They have larger teeth than a dog and have claws similar to them but they are larger and rounder as well. They live in the mountains near the river Indus. They are dark-skinned and are completely just, just like the rest of the Indians they encounter. They know the language of the other Indians but they cannot speak it—instead they just make signs by barking or with their hands and digits like the deaf. They are called Kalustrioi by the Indians, which equates to Kunokephaloi among the Greeks [“Dog-heads”]. There tribe is almost 120,000 strong.”

᾿Εν τοῖσδε τοῖς ὄρεσί φασιν ἀνθρώπους βιοτεύειν κυνὸς ἔχοντας κεφαλήν· ἐσθῆτας δὲ φοροῦσιν ἐκ τῶν ἀγρίων θηρίων, φωνὴν δὲ διαλέγονται οὐδεμίαν, ἀλλ’ὠρύονται, ὥσπερ κύνες, καὶ οὕτω συνιᾶσιν αὑτῶν τὴν φωνήν. ᾿Οδόντας δὲ μείζους ἔχουσι κυνός, καὶ τοὺς ὄνυχας ὁμοίους κυνός, μακροτέρους δὲ καὶ στρογγυλωτέρους. Οἰκοῦσι δὲ ἐν τοῖς ὄρεσι μέχρι τοῦ ᾿Ινδοῦ ποταμοῦ, μέλανες δέ εἰσι καὶ δίκαιοι πάνυ, ὥσπερ καὶ οἱ ἄλλοι  ᾿Ινδοί, οἷς καὶ ἐπιμίγνυνται καὶ συνιᾶσι μὲν τὰ παρ’ ἐκείνων λεγόμενα, αὐτοὶ δὲ οὐ δύνανται διαλέγεσθαι, ἀλλὰ τῇ ὠρυγῇ καὶ ταῖς χερσὶ καὶ τοῖς δακτύλοις σημαίνουσιν, ὥσπερ οἱ κωφοί· καλοῦνται δὲ ὑπὸ τῶν᾿Ινδῶν Καλύστριοι, ὅπερ ἑλληνιστὶ Κυνοκέφαλοι· τὸ δὲ ἔθνος ἐστὶν ἕως δώδεκα μυριάδων.

Economics (Codex, 48b)

[Ctesias] says that the Kunokephalai who live in the mountains do not work the land but instead live by hunting. When they kill their prey, they cook it in the sun. They do tend many sheep, goats, and donkeys. They drink milk and milk-whey from sheep, and they eat the fruit of the Siptakhora which yields sweet amber. They dry this as well and store it in baskets in the way the Greeks store raisins. The Kunokephaloi build rafts, load them and send them as tribute which includes the amber, prepared purple flowers with 260 talents of amber annually and as much purple die and they send 1000 more talents as annual tribute for the king. The rest of the amber they sell to Indians for bread, grain, cotton. They also buy swords which they use in hunting for their quarry along with bows and javelins. For they are extremely talented at throwing javelins and shooting arrows. They are invincible in war because they inhabit mountains that are unreachable and high. The king gives them gifts every five years: 300,000 bows, the same number of spears, 120,000 shields, and 50,000 swords.”

῞Οτι οἱ Κυνοκέφαλοι οἰκοῦντες ἐν τοῖς ὄρεσιν οὐκ ἐργάζονται, ἀπὸ θήρας δὲ ζῶσιν· ὅταν δ’ ἀποκτείνωσιν αὐτά, ὀπτῶσι πρὸς τὸν ἥλιον. Τρέφουσι δὲ καὶπρόβατα πολλὰ καὶ αἶγας καὶ ὄνους. Πίνουσι δὲ γάλα καὶ ὀξύγαλα τῶν προβάτων, ἐσθίουσι δὲ καὶ τὸν καρπὸν τοῦ σιπταχόρου, ἀφ’ οὗ τὸ ἤλεκτρον (γλυκὺς γάρ), καὶ ξηραίνοντες αὐτούς, σπυρίδας συσσάσσουσιν ὥσπερ ἐν τοῖς ῞Ελλησι τὴν ἀσταφίδα. Οἱ δὲ Κυνοκέφαλοι, σχεδίαν ποιησάμενοι καὶ ἐπιθέντες, ἀπάγουσι  φόρτον τούτου, καὶ τῆς πορφύρας τὸ ἄνθος καθαρὸν ποιήσαντες, καὶ τοῦ ἠλέκτρου ξ′ καὶ ς′ τάλαντα τοῦ ἐνιαυτοῦ, καὶ ὅτῳ τὸ φοινίκιον βάπτεται τοῦ φαρμάκου ἕτερα τοσαῦτα, καὶ ἠλέκτρου χίλια τάλαντα, ἀπάγουσι κατ’ ἐνιαυτὸν τῷ ᾿Ινδῶν βασιλεῖ. Καὶ ἕτερα δὲ κατάγοντες πωλοῦσι τοῖς ᾿Ινδοῖς πρὸς ἄρτους καὶ ἄλφιτα καὶ ξύλινα ἱμάτια· πωλοῦσι δὲ καὶ ξίφη οἷς χρῶνται πρὸς τὴν τῶν θηρίων ἄγραν, καὶ τόξα καὶἀκόντια· πάνυ γὰρ καὶ δεινοί εἰσιν ἀκοντίζειν καὶ τοξεύειν· ἀπολέμητοι δ’ εἰσὶ διὰ τὸ οἰκεῖν αὐτοὺς ὄρεα ἄβατα καὶ ὑψηλά. Δίδωσι δὲ αὐτοῖς διὰ πέμπτου ἔτους δῶρα ὁ βασιλεὺς λ′ μὲν μυριάδας τόξων, καὶ ἀκοντίων τοσαύτας, πελτῶν δὲ δώδεκα, καὶ ξίφη δὲ πεντακισμύρια.

Living Arrangements, Wealth, and Sexual Mores

“The Kunokephaloi do not live in houses but inhabit caves. They hunt wild animals with bows, javelins and they overcome some by running. For they run quickly. The women wash themselves once a month whenever they have their periods, but not otherwise. The men do not wash themselves but they do wash their hands. They anoint themselves with oil made from milk and they wipe themselves with skins. They do not have hairy raiment, but the women and the men wear skins that are well-tanned. The wealthiest wear linen, but there are very few. They do not have beds, but they made piles of straw. The man who has the most sheep is considered the wealthiest. The case is similar with their other possessions. All of them have tails which sit above their hips like dogs, but they are longer and harrier. The have sex with the females on four-feet, just like dogs. It is considered shameful to have sex in any other way. They are just and they are the most long-lived of all men: they live 170 and even 200 years.”

Τούτοις τοῖς κυνοκεφάλοις οὐκ εἴσιν οἰκίαι, ἀλλ’ ἐν σπηλαίοις διαιτῶνται. Θηρεύουσι δὲ τὰ θηρία τοξεύοντες, ἀκοντίζοντες, καὶ διώκοντες καταλαμβάνουσι· ταχὺ γὰρ τρέχουσι.Λούονται δὲ αἱ γυναῖκες αὐτῶν ἅπαξ τοῦ μηνός, ὅταν τὰ καταμήνια αὐταῖς ἔλθῃ, ἄλλοτε δ’ οὔ· οἱ δὲ ἄνδρες οὐ λούονται μέν, τὰς δὲ χεῖρας ἀπονίζονται, ἐλαίῳ δὲ χρίονται τρὶς τοῦ μηνὸς τῷ ἀπὸ τοῦ γάλακτος γινομένῳ, καὶ ἐκτρίβονται δέρμασι. Τὴν δὲ ἐσθῆτα ἔχουσιν οὐ δασείαν, ἀλλὰ ψιλῶν τῶν μασθλημάτων ὡς λεπτοτάτων καὶ αὐτοὶ καὶ αἱ γυναῖκες αὐτῶν· οἱ δὲ πλουσιώτατοι αὐτῶν λίνα φοροῦσιν. Οὗτοι δ’ εἰσὶν ὀλίγοι. Κλῖναι δὲ αὐτοῖς οὐκ εἴσιν, ἀλλὰ στιβάδας ποιοῦνται. Οὗτος δ’ αὐτῶν πλουσιώτατος νομίζεται εἶναι ᾧ ἂν πλεῖστα πρόβατα ᾖ· ἡ δὲ ἄλλη οὐσία παραπλησία. Οὐρὰν δὲ ἔχουσι πάντες καὶ ἄνδρες καὶ γυναῖκες ὑπὲρ τῶν ἰσχίων οἵανπερ κύων, μείζονα δὲ καὶ δασυτέραν· καὶ μίσγονται ταῖς γυναιξὶ τετραποδιστί, ὥσπερ οἱ κύνες· ἄλλως δὲ μιγῆναι αὐτοῖς ἐστιν αἰσχρόν. Δίκαιοι δέ εἰσι καὶ μακροβιώτατοι πάντων ἀνθρώπων· ζῶσι γὰρ ἔτη ρ′ καὶ ο′, ἔνιοι δὲ αὐτῶν καὶ διακόσια.