Ask the Vet

My breeder told me that I should not spay my dog (Black Lab )  until she has had 2-3 heats. Can you give me some clarification?
Thanks,
 Dog lover in Boca Raton

We recommend spaying before the pets first heat cycle. This is to reduce the risk of developing mammary cancer. Spaying is routinely done between 5-6 months of age. I like to spay bitches that are usually between 4 and 6 months of age unless there are other health reasons not to. Also weight can play a factor in waiting to spay a bitch due to anesthetic risks. I like to wait until puppies are at least 4 pounds.  Sometimes we wait a little longer until these toy breeds get a little hardier
(above 4 lbs).

 Others (like breeders) may disagree citing many reasons to wait 1-2 heat cycles because it can damage growth and personality. I do not find that to be true at all.
I disagree strongly. Studies have shown waiting 1 or 2 heat cycles will increase the risk of developing mammary cancer later in life. (Up to 99%) Some develop malignant tumors earlier even as young as 3 years of age.

One of the most common cancers in bitches is mammary cancer and most will be malignant, spaying before the first heat cycle is crucial because in doing so you can prevent mammary cancer. Spaying up until the age of 2 will have some protective effect, but not nearly as much as much.

Studies have shown that spaying before an estrous cycle significantly reduces the chance of mammary tumors.

Spaying before the first heat virtually eliminates the later onset of breast cancer in dogs. Spaying between the first and second heat is still protective (much reduced incidence), but spaying after the second heat confers no protection.

Neutering male dogs before the age of 2yrs is as important (medically). Intact males are more likely to develop prostate disease, (including cancer) and or testicular tumors. There are more good reasons to spay and neuter your pets early in life then not.

Taking into account the breed of the dog, weight of a dog, weather this is a show dog, working dog; etc should dictate the best move for you and your pet.  Having our beloved house pets is such a blessing and we owe it them to take care of them in the proper way.
Talk to your veterinarian about this important time in your puppy’s life and together you both should make the proper decision.