Why Is My Dog Attracting Males? Symptoms of Ovarian Cysts in Dogs

Why Does My Dog Show Signs of Heat After It’s Over?

“My dog concluded her first heat about 4 weeks ago (no more swelling, no more male dog interest, etc). However, since then, she seems to have gone back a stage or two, lying down as if encouraging mating. She has some swelling, and some male dogs are starting to show interest again. We were followed across the park by a male that couldn’t be called back in a way that surprised his owner.

Is this just her hormone levels settling back down, or is there something to worry about? There is no sign of discharge, but I am a bit worried about letting her go back to doggy daycare.”—David

Vet Response

This is something you should check on. There are several possible causes of prolonged estrus (heat), but the one I would be most concerned about is an ovarian cyst or tumor. It would be helpful to know the age and breed of the dog.

Symptoms of Ovarian Cysts

Most dogs with an ovarian cyst have never had puppies, are a large dog breed, and are usually about 9.5 years old (although the range is quite wide) [1]. Dogs with a functional ovarian cyst still produce hormones that simulate heat and will attract males, may have a swollen vulva, and sometimes even allow mating. Some of them will also have vaginal discharge, but not in all cases.

Ovarian cysts not only cause the behavioral changes you have seen (which would definitely make her a problem if you took her right back to doggy daycare), but they can also lead to a form of pyometra (uterine infection) because of endometrial hyperplasia (a swollen uterine lining).

Note: An ovarian cyst is not an emergency, but if you do not get this taken care of and she develops pyometra, it can become a life-threatening emergency.

Testing

In order to find out if she has an ovarian problem, she will need a physical exam by your regular veterinarian to look for signs of prolonged estrus. After the physical exam, your regular veterinarian may want to do a blood cell count to see if there are any signs of an infection of the uterus. An ultrasound is most likely to tell you if there are any problems with the ovaries, but it may or may not be necessary. If the results are still not clear, the vet may want to test the hormone levels in her blood.

Treatment

I do not know if you plan on breeding her later on or if you are just waiting until she is older to have her spayed, but the most common treatment to take care of an ovarian cyst or tumor is just to have her spayed at the time the cyst or tumor is removed. (If she is older, this is the best option since she has an increased chance of developing pyometra as she becomes older.)

If you plan on breeding her, there are some hormonal treatments (like gonadotropin-releasing hormones), but they are much less successful than just removing the ovaries. If she is an older dog, definitely have her spayed at this time, but if she is a young dog and you still hope to let her have puppies, you can discuss the alternatives with your regular veterinarian.

Sources

1. Knauf Y, Köhler K, Knauf S, Wehrend A. Histological classification of canine ovarian cyst types with reference to medical history. J Vet Sci. 2018 Nov 30;19(6):725-734. doi: 10.4142/jvs.2018.19.6.725. PMID: 30304884; PMCID: PMC6265583. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265583/

This article is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from your veterinarian. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2024 Mark dos Anjos, DVM