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Frequently Asked Questions

Answers to questions concerning responsible pet ownership


Q: Why should I spay/neuter? Is it worth the expense?

Some health benefits of spaying/neutering:

  • Prevention of mammary adenocarcinomas (malignant tumors of the mammary gland) or testicular tumors.
  • Prevention of pyometra (septic uterine infection) or other uterine problems in older females.
  • Prevention of ovarian tumors, cysts, or other abnormalities.
  • Prevention of prostatic hyperplasia (enlarged prostate) and reduction of the likelihood of prostatic infection/abscess or neoplasia (tumor and/or cancer).
  • Prevention of unwanted/unexpected pregnancy (ultimately contributes exponentially to the pet overpopulation problem).
  • Prevention of injury/infection risks of whelping, especially in a difficult pregnancy (if the pups are too big, etc.).
  • Prevention of tendency to fight, or other aggressive behavior, in males. Bite and scratch wounds from fighting can cause permanent injury, abscess, or infection in cats and dogs.
  • Prevention of roaming/escaping/running away in search of a mate. This roaming often results in the animal being involved in car accidents, becoming lost/stray, caught by animal control, etc.
  • Prevention of acquiring diseases from infected animals (especially cats) via bite wounds or mating. Sexually transmitted diseases such as feline leukemia (FeLV) or feline immunodeficiency virus (FIV) are fatal.
  • Prevention of unwanted territorial marking behavior (both in dogs and cats).
  • Prevention of estrus in females that may result in blood staining in the house (dogs) or unwanted estrus behavior in cats.

A: Spaying/neutering has many benefits, including prevention of disease and unwanted behavior. The cost of any one of these occurrences far outweights the cost of spay/neuter surgery.

Debra L. Zoran, DVM, PhD
Diplomate, American College of Veterinary Internal Medicine

Q: If I spay/neuter my pet, will it become lazy?

Historically, pets have been spay/neutered around the time of puberty (5-8 months of age). Changes in the pet's behavior often occur around this time, but are due to many factors. Many animals, particularly cats, become less playful during this time. Although alterations in metabolism occur due to changes in hormone levels, these have only a small effect on the animal's overall activity level. Many pets seem to become less active after neutering, but the bulk of this effect has more to do with the age of the animal.

Because spay/neutering only affects sexually dimorphic behaviors, and does not affect learning, it will not impair an animal's ability to do work, hunt, guard, etc. Animals actually may be better able to focus on their task, since they will be less distracted by other dogs and cats. In addition, they will not be subject to the "emotional" effects of hormonal fluctuations.

Spay/neutered animals are three times less likely to develop behavior problems as intact animals. (Beaver, Canine Behavior: A Guide for Veterinarians. WB Saunders. 1999 p208).

A: A: Spaying/neutering will not detract from performance, and may actually enhance it.

Lore I. Haug, DVM
Friskies PetCare Resident in Companion Animal Behavior
Candidate, American College of Veterinary Behavior

Q: If I spay/neuter my pet, won't it get fat?

If you do not decrease your pet's food by 20-25%, it will get fat. Respiratory calorimetry measurements in kittens, a definitive measure of calorie requirements, have shown that energy requirements decrease about 20-25% after the kitten is spay/neutered. It does not matter whether it is a female or a male, the energy decrease is the same, nor does it matter whether you neuter them early or late (Root et al. Am J Vet Res 57:371-374, 1996). What is different between females and males is the effect of estrogen on food intake. Estrogen is appetite suppressing, so loss of estrogen from spaying a female will cause them to eat more if allowed food free-choice (Flynn et al. J AM Vet Med Assoc 174:1083-1085, 1979). This is one reason spayed females tend to be 4 times as likely to be overweight than intact females, and castrated males may be only twice as likely as intact males.

We have no calorimetry data from puppies like we have from kittens as of yet. However, the same anecdotal observations apply for both dogs and cats about spayed/neutered animals getting/being fatter. The epidemiological data from dogs is consistent with the cat-calorie findings. In my experience, dogs maintain their weight on 75% of what was prior fed to being spay/neutered. The estrogen effects are from both cats (Flynn) and dogs (Houpt).

A: If you adjust your pet's diet appropriately, it will not get fat.

William J. Burkholder, DVM, PhD
Diplomate, American College of Veterinary Nutrition

Other false impressions about spaying/neutering

Can early spay/neuter stunt my pet's growth?

No. Your puppy/kitten will develop normally. In fact, young animals tend to recover from surgery more rapidly than older animals. Dogs and female cats don't generally have secondary sexual characteristics, and male cats neutered at a young age will avoid "tomcat jowls" and the undesirable behaviors associated with intact males.

Is it true that a dog/cat should be allowed to go through one heat cycle?

No. In general, the risk of an unwanted pregnancy is too great. In some cases, a female dog with a history of vaginal infection may be allowed to go through estrus once with the hope of reducing these problems. The result is a hotly debated subject, and should be discussed with your veterinarian.

Additionally, spaying a female dog before her first heat will decrease the incidence of mammary tumors later in life.

One litter won't hurt anybody, will it?

Pet overpopulation affects everybody. Every litter born contributes exponentially to the problem. Did you know that two uncontrolled breeding cats and their offspring could produce a population of 80 million cats within 10 years?

In 1996, the Brazos Animal Shelter received 8,655 animals, while only 3,048 were claimed or adopted. You do the math . . .

But my animal is purebred with papers. I could make some money.

Many purebred animals are surrendered at the shelter. Breeders spent hundreds of years developing individuals breeds - and all of this hard work can be undone in just one mating. A dog should be proven in field trials or kennel club shows. It should be certified by veterinarians as free from genetic defects, such as hip dysplasia, heart conditions, and other undesirable traits.

Everyone thinks their dog or cat is the best in the world. That's great! But please visit your local shelter before you make the decision to breed. Don't be a part of the problem when you can be part of the solution!

Lisa M. Howe, DVM, PhD
Diplomate, American College of Veterinary Surgery