When I have a sick pet or pray for one, I always ask St Martin de Porres to intervene for me with healing. St Martin is one of my favourite saints. I have posted about him before, and I will include some more links below. St Martin started, with his sister, one of the very first dog and cat hospitals in the New World. One of the miracles attributed to St Martin was the bringing back to life of a dog which had been beaten to death. St Martin ate no meat and could not bring himself to use poisons around mice. He talked to them about their mischief in chewing holes in the church vestments, and they agreed to remain outside the church so Martin could feed them himself every day. From Wikipedia:
'Juan Martin de Porres was born in the city of Lima, in the Viceroyalty of Peru, on December 9, 1579, the illegitimate son of a Spanish nobleman, Don Juan de Porres. His mother was a freed slave from Panama, of African or possibly part Native American descent, named Ana Velázquez.
He was noted for work on behalf of the poor, establishing an orphanage and a children's hospital. He maintained an austere lifestyle, which included fasting and abstaining from meat. Among the many miracles attributed to him were those of levitation, bilocation, miraculous knowledge, instantaneous cures, and an ability to communicate with animals.'PRAYER TO ST. MARTIN de PORRES
Most humble Martin de Porres, whose burning charity embraced not only thy needy brethren, but also the very animals of the field, splendid example of charity, we hail and invoke thee! From that high throne which thou dost occupy, deign to listen to the supplications of thy needy brethren that, by imitating thy virtues, we may live contented in that state in which God has placed us, and, carrying our cross with strength and courage, we may follow in the footsteps of Our Blessed Redeemer and His most afflicted Mother, to reach at last the Kingdom of Heaven through the merits of Our Lord Jesus Christ. Amen.
• Prayers and Novena to St Martin de Porres
• Biography and further links