Arlington Dog and Cat Hospital

857 Passaic Avenue
Kearny, NJ 07032


Important Reasons to Spay or Neuter Your Pet


Just about everyone has heard the phrase,"It's important to spay or neuter your pet".  And it's true! But we're never told why. . . .Besides controlling the pet population, there are several health benefits to your pet after being spayed or neutered.  The ideal age to spay or neuter your pet is 6 months.  Is your pet older than 6 months?

 It's okay! It's never too late! 




Why should I have my dog spayed?

We recommend spaying all female pets. The benefits to your pet's health and to help reduce the pet overpopulation crisis make this decision easier. It should be remembered that owners of Guide Dogs for the Blind, Hearing Dogs for Deaf People and Dogs for the Disabled routinely have their dogs spayed and this does not affect their ability to perform their duties in any manner whatsoever.


spaying_your_dog_1_2009What are the advantages of spaying in the female dog?

  • Prevention of "heat" or estrus
  • When in "heat", the female experiences an urge to escape in order to find a mate. This unwanted and dangerous behavior is eliminated.
  • Elimination of the hormone fluctuations that cause false pregnancy following the "heat cycle"
  • Prevention of uterine infection known as pyometra
  • Prevention of breast cancer. Dogs spayed before their first "heat" have less than 0.5% chance of developing breast cancer.
  • Elimination of the risk of uterine and ovarian cancer


Is spaying performed for any other reason?

The operation may be performed for several medical conditions. These include:

  • Treatment of intractable false or phantom pregnancy
  • Treatment of irregular or abnormal cycles due to ovarian cysts
  • Treatment of uterine infection (pyometra) or cancer
  • Dystocia (difficult birthing) or post caesarean-section surgery
  • An aid to correction of certain behavioral abnormalities



Is neutering performed for any other reason?

Neutering may be used in an attempt to treat certain forms of aggression. In older dogs, the operation may be performed to treat testicular tumors and some prostate gland conditions. It is also used to control hormonal (testosterone) dependent diseases such as perianal adenomas.


What are the disadvantages?

Most of the perceived disadvantages are false. The most quoted of these are that the dog will become fat, lazy, and useless as a guardian. Obesity is probably the most commonly quoted disadvantage of neutering. In most cases, obesity is the result of overfeeding and not exercising enough. By regulating your dog's diet and caloric intake, you can prevent obesity in both neutered and intact males.

Neutering doesn't cause a change in personality, guarding instincts, intelligence, playfulness and affection.


Common myths:

Spaying or neutering your pet does not:

*Alter his/her personality in any manner.

*Cause laziness or hyperactivity.

*Reduce his/her instinct to protect your family or home.

*Cause immature behaviors.

*Postpone or delay normal behavioral maturity. 

Looking out for Estrus or "heat cycles":

When does a female dog have her first estrus cycle?

Dogs will have their first estrus cycle when they reach puberty.  Estrus is the stage of the reproductive cycle in which the dog can become pregnant; sometimes a dog that is in estrus is said to be "in heat" or "in season". On average, puberty or sexual maturity is reached at about 6 months of age, but this can vary by breed. The smaller breeds of dogs tend to have their first estrus cycle at an earlier age, while the large and giant breeds of dogs may not come into heat for the first time until they reach eighteen months to two years of age.  

Estrus is the stage of the reproductive cycle in which the dog can become pregnant.


How often does a female dog come into heat?

Most dogs come into heat twice per year, or about every six months, although the interval can vary between breeds, and from dog to dog. Small breed dogs may cycle three times per year, while giant breed dogs may only cycle once every 12-18 months. When young dogs first begin to cycle, it is normal for their cycles to be somewhat irregular. It can take up to 2 years for a female dog to develop regular cycles.  There is no season of the year which corresponds to a breeding season for domesticated dogs. 


How long does estrus last?

Although this can vary with the individual dog, on average a dog will be 'in heat' for 2-3 weeks. The onset of estrus is characterized by swelling of the external vulva. Next, the dog will develop a vaginal discharge. Estrus ends when the discharge completely disappears and the vulva returns to its normal size.

When does a female cat have her first estrus cycle?

Cats will have their first estrus cycle, or 'heat' when they reach puberty.  On average, puberty or sexual maturity first occurs in cats at about 6 months of age, but this can vary slightly by time of year. 

How often does a female cat come into heat?

Cats are "seasonally polyestrus", which means that they have multiple estrus cycles during the breeding season. The breeding season for cats will vary according to geographic and environmental factors such as temperature and the number of daylight hours. 

How long does estrus last?

  Each heat generally lasts several days - it can be as short as 1 day or as long as 7 days. If the queen is not mated during estrus, she will "go out of heat" for a short period of time, usually   1-2 weeks. Thus, the average complete estrus cycle of a cat is 1-3 weeks. 

At what stage of the estrus cycle is the cat able to get pregnant?


Cats are "induced ovulators", which means that the act of breeding stimulates or induces ovulation or the release of eggs from the ovaries. Therefore the queen can be bred at any time during the active stage of estrus or heat. 



This client information sheet is based on material written by: Ernest Ward, DVM   © Copyright 2009 Lifelearn Inc. Used and/or modified with permission under license.