St Roch is a French Saint who, during the Middle Ages, developed a following because he cared for those who fell ill from the bubonic plague. When he became ill, he isolated himself in a forest, where a dog brought him food each day from his master's table.
We don't know of any local dog-friendly feasts today that commemorate St Roch, but we like the story of St Roch and his bond with a dog.
St Roch was said to have been the son of a rich merchant, born about 1350 in Montepellier, in Southern France. He chose to live as a hermit. On a pilgrimage to Rome, he caught the plague and, abandoned by others, was taken care of in a woodland by a dog who fed him and would not leave him.
Old English paintings depict St Roch — also known as Rocco, Roke, and Rollox — as a pilgrim with a sore on his leg who is accompanied by a dog with a loaf of bread in his mouth. St Roch was reputed to have cured many people suffering from the plague. After his death in 1610, a cult for the cause of St Roch as the patron of plague sufferers spread across much of Europe. Many miracles were claimed to have happened at his tomb.
Reynard of The English Chemical Theatre adds
It is possible that the Roman termination of the canicular days [Dog Days] was originally extended in England from the 11th to the 17th August to incorporate the feast day of St Roch, patron saint of dogs, on the 16th. Certainly within the Church of England it is reasonably common for some parishes to hold an animal service around this time, where domestic pets and animals are blessed within the church building. I can't say authoritatively whether this is connected to old traditions of the dog days and St Roch or not, although it is doubtful whether the practice itself has a lineage preceding the twentieth century.The declaration of St Roch as a patron saint means that humans can pray for his intercession for the healing of invalids. We hope this typically includes dogs!