Dear JanetMarie:

The Catechism of the Catholic Church states:

2415 The seventh commandment enjoins respect for the integrity of creation. Animals, like plants and inanimate beings, are by nature destined for the common good of past, present, and future humanity. Use of the mineral, vegetable, and animal resources of the universe cannot be divorced from respect for moral imperatives. Man's dominion over inanimate and other living beings granted by the Creator is not absolute; it is limited by concern for the quality of life of his neighbor, including generations to come; it requires a religious respect for the integrity of creation. 

2416 Animals are God's creatures. He surrounds them with his providential care. By their mere existence they bless him and give him glory. Thus men owe them kindness. We should recall the gentleness with which saints like St. Francis of Assisi or St. Philip Neri treated animals.

2417 God entrusted animals to the stewardship of those whom he created in his own image. Hence it is legitimate to use animals for food and clothing. They may be domesticated to help man in his work and leisure. Medical and scientific experimentation on animals is a morally acceptable practice if it remains within reasonable limits and contributes to caring for or saving human lives.

2418 It is contrary to human dignity to cause animals to suffer or die needlessly. It is likewise unworthy to spend money on them that should as a priority go to the relief of human misery. One can love animals; one should not direct to them the affection due only to persons.

Animals are not to be treated at the same level of dignity as human beings or are to be given priority above humans (who are made in the image of God).

We are to respect and to care for animals, treat them humanely, and not subject them to unnecessary pain and suffering.

Neutering animals, animal contraception, and euthanizing them when necessary is in the best interest of the animal. Neutering not only controls the population (which is a good thing as it lowers the number of stray animals who suffer and starve) but helps the animal to be healthier and happier as a pet.

Euthanizing an animal when it is ill beyond hope, or beyond financial means to perform a procedure, prevents an animal from needless suffering. It would be a sin for a person to spend thousands of dollars on surgery for a pet when that money needs to go to pay the rent or put food on the table.

Bottomline: it is not a sin to neuter a pet, or when needed, to euthanize a pet. In fact, one may have a moral obligation to do so.

Cloning of human beings is a sin. Cloning of animals is not. As is stated in the Catechism quote above, "Medical and scientific experimentation on animals is a morally acceptable practice if it remains within reasonable limits and contributes to caring for or saving human lives."

God Bless,
Bro. Ignatius Mary