Can a Spayed Dog Still Go Into Heat?

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Can a Spayed Dog Still Go Into Heat?
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When your female dog is in heat, it can make for an unpleasant experience for everyone in the house. Not only do dogs in heat experience fluctuating hormones, they can even undergo behavior and personality changes as a result. Spaying is seen as a healthy and practical solution to these issues. But will a spayed dog still go into heat?

The spaying process

Spaying, or removing both the ovaries and the uterus of a female dog, should put an end to the dog's heat cycles. The ovaries produce hormones, particularly estrogen, which prompt the heat cycles. With the ovaries removed, these hormones will no longer be produced, and the dog's heat cycles will come to an end. You should also see an end of your dog's heat-prompted behavior and personality changes.

Vets don't recommend spaying dogs just because it ends their heat cycles. Spaying has the added benefit of reducing a pet's chance of developing mammary gland tumors, pyometra, and ovarian tumors. These three conditions can develop when a pet continuously produces estrogen. By removing the ovaries and stopping the estrogen production, the pet is likelier to live her life without developing these serious conditions.


Heat symptoms after spaying

Typically, spaying your dog will cause heat symptoms to go away. But if your spayed dog is displaying symptoms such as swelling of the vulva or bloody discharge from the vulva, is attracting male dogs, and shows submissive interaction with male dogs, there may be something else going on. It is possible that your female dog has a condition called ovarian remnant syndrome.

Ovarian remnant syndrome is caused when bits of ovarian tissue are left behind during the spay surgery. This tissue continues to release hormones, prompting a spayed dog to still go into heat every six-to-eight months. If your dog has ovarian remnant syndrome, you may not notice it right away since your dog's heat cycles may not begin until months or even years after the surgery has taken place.


Diagnosing ovarian remnant syndrome

If you notice your dog displaying heat symptoms even though she's been spayed, you should schedule a vet appointment to get to the bottom of the issue. Your vet will diagnose the condition in any number of ways.

Vaginal cytology, which is a swab of your dog's vagina, will let your vet test for cells that identify the presence of estrogen. Your vet may also test your dog's hormone levels to look for abnormalities that identify your dog still has ovarian function. If you can tell when your dog is in heat and get her into the vet's office during that time, your vet can perform an ultrasound. Depending on the size of the ovarian tissue that is left, your vet may be able to see the tissue on the ultrasound.


In some cases, your vet may need to perform exploratory surgery to determine if ovarian tissue is still present, as well as to locate that tissue. Your vet should be able to remove that tissue at the same time.

Treating ovarian remnant syndrome

The treatment for ovarian remnant syndrome is, luckily, a pretty simple one. Should your dog be diagnosed with this condition, your vet will need to perform surgery while your dog is in heat. Your vet will remove any remaining ovarian tissue during the surgery. This will stop your dog from producing estrogen and will bring an end to her going into heat.


If you find that your dog has ovarian remnant syndrome and it is not treated, your dog will still be at risk of developing conditions like mammary gland tumors, pyometra, and ovarian tumors. Be sure to speak with your vet about any concerns you have about your dog's diagnosis or treatment.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.