Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Councils of Ancyra, Gangra, Neocæsarea, Antioch and Laodicea, which Canons were Accepted and Received by the Ecumenical Synods.: Canon XVII

Canon XVII.

Defilers of themselves with beasts, being also leprous, who have infected others [with the leprosy of this crime], the holy Synod commands to pray among the hiemantes.

Notes.

Ancient Epitome of Canon XVII.

A leper who goes in to a beast or even to leprous women, shall pray with the hybernantes.

Λεπρώσαντας is from λεπρόω not from λεπράω and therefore cannot mean “have been lepers,” but “have made others rough and scabby.”  It is only in the passive and in Alexandrian Greek that it has the meaning to become leprous.  Vide Liddell and Scott.

There seems but little doubt that the word is to be understood spiritually as suggested above.

The last word of the canon is also a source of confusion.  Both Beveridge and Routh understand by the χειμαζόμενοι those possessed with devils.  Suicer however (Thesaurus) thinks that the penitents of the lowest degree are intended, who had no right to enter the church, but were exposed in the open porch to the inclemencies (χειμών) of the weather.  But, after all it matters little, as the possessed also were forced to remain in the same place, and shared the same name.

Besides the grammatical reason for the meaning of λεπρώσαντας given above there is another argument of Hefele’s, as follows:

Hefele.

It is clear that λεπρώσαντας cannot possibly mean “those who have been lepers” for there is no reason to be seen why those who were cured of that malady should have to remain outside the church among the flentes.  Secondly, it is clear that the words λεπροὺς ὄντας, etc. are added to give force to the expression ἀλογευσάμενοι.  The preceding canon had decreed different penalties for different kinds of ἀλογευσάμενοι.  But that pronounced by canon xvii. being much severer than the p. 71 preceding ones, the ἀλογευσάμενοι of this canon must be greater sinners than those of the former one.  This greater guilt cannot consist in the fact of a literal leprosy; for this malady was not a consequence of bestiality.  But their sin was evidently greater when they tempted others to commit it.  It is therefore λέπρα in the figurative sense that we are to understand, and our canon thus means; “Those who were spiritually leprous through this sin, and tempting others to commit it made them leprous.”