to Pet Health Network or

Answers from vets about your pet:

Top 10 Reasons To Spay Your Pet

Reviewed by Dr. Peter Kintzer, DVM, DACVIM on Monday, April 6, 2015
Posted December 22, 2014 in Dog Surgery A-Z

Dr. Phil Zeltzman is a mobile, board-certified surgeon in Allentown, PA. Find him online at He is the co-author of “Walk a Hound, Lose a Pound” (

Chris Longenecker, a Certified Veterinary Technician in Reading, PA, contributed to this article.

Should you have your female cat or dog spayed? Are you on the fence? Are you dreaming of puppies and kittens? Deciding to spay a pet is sometimes a controversial, sensitive, even emotional topic. In addition, there are many myths out there...

There are many medical reasons to spay pets. Let’s go over just 10 of them.

1. Breast tumors
Over 25% of non-spayed female dogs will develop breast or mammary tumors! Spaying pets protects against them, depending on the timing. The risk of a dog having mammary tumors is 0.05% if a female is spayed before the first heat.  Then it shoots up to an 8% risk after their first cycle, and 26% after their second heat. If a dog is spayed after 2 years of age, then there is no more protection. However, it will protect her against other conditions, including pyometra (see below).  This is the reason why most vets typically recommend spaying before the 1st heat cycle.

In dogs, approximately 50% of mammary tumors are benign and 50% are cancerous. In cats, 90% of mammary tumors are cancerous, so spaying is even more important.

2. Pyometra
Pyometra is a serious condition where the uterus fills with pus. It is common in non-spayed dogs, and unusual in cats. In turn, pyometra can affect many organs, which can make a pet very sick or even kill her. One of the organs that classically gets damaged is the kidney. It can get worse: a “mature” pyometra can rupture or break. This leads to having pus all over the belly (septic peritonitis). Such patients can still be helped with more intensive care.

3. Unplanned pregnancies
Letting a non-spayed cat or dog roam is similar to gambling. Chances are, our little female friend will meet Mr. Not-Right.

Now… not only do you have to deal with the pregnancy, but in 2 months, you will need to make sure that the delivery goes well. Then you will have to keep the 1, 2, 3… or 10 babies or find them anew home. If mom can’t nurse, guess who needs to get up every 2 hours to bottle-feed the babies?

Share This Article

Dr. Phil Zeltzman is a board-certified veterinary surgeon and author. His traveling practice takes him all over Eastern Pennsylvania and Western New Jersey. You can visit his website at, and follow him at