The nuns just waited till the bishop had gone and then whistled their dogs back again.

Dogs were easily the favourite pets, though monkeys, squirrels, rabbits, birds and (very rarely) cats were also kept.

One archbishop had to forbid an abbess whom he visited to keep _monkeys and a number of dogs_ in her own chamber and charged her at the same time with stinting her nuns in food; one can guess what became of the roasted flesh or milk and wastel-breed! It was a common medieval practice to bring animals into church, where ladies often attended service with dog in lap and men with hawk on wrist; just as the highland farmer brings his collie with him today.
This happened in the nunneries too.

Sometimes it was the lay-boarders in the convents who brought their pets with them; there is a pathetic complaint by the nuns of one house 'that Lady Audley, who boards there, has a great abundance of dogs, insomuch that whenever she comes to church there follow her twelve dogs, who make a great uproar in church, hindering the nuns in their psalmody and the nuns thereby are terrified!'[17] But often enough the nuns themselves transgressed.
Injunctions against bringing pet dogs into choir occur in several visitation reports, the most amusing instance being contained in those sent to Romsey Abbey by William of Wykeham in 1387, just about the same year that Chaucer was writing the _Canterbury Tales_: 'Item,' runs the injunction, 'whereas we have convinced ourselves by clear proofs that some of the nuns of your house bring with them to church birds, rabbits, hounds and such like frivolous things, whereunto they give more heed than to the offices of the church, with frequent hindrance to their own psalmody and to that of their fellow nuns and to the grievous peril of their souls--therefore we strictly forbid you all and several, in virtue of the obedience due to us that ye presume henceforward to bring to church no birds, hounds, rabbits or other frivolous things that promote indiscipline....

Item, whereas through hunting dogs and other hounds abiding within your monastic precincts, the alms that should be given to the poor are devoured and the church and cloister ...