I have an 8 month old intact female chocolate labrador, Gracie. From about 10 weeks of age she started getting UTI infections. I took her to two different vets to determine what was causing this. I was told that she has a "juvenile vulva" and I was advised by both vets not to spay her until she has at least one heat. They said that if I spayed her before her first heat the vulva would not be able to mature and may result in having to do surgery to correct it. I have 2 questions, does anyone else have this problem with their dog and does anyone on know if it's possible for their first heat to be silent? She has been around 2 male dogs recently and neither would leave her alone, however neither dog tried to mount her. I'm suspecting that she maybe giving off some sort of scent. She is my third labrador and my other 2 were spayed at about 6 months before their heat cycle, so I'm not too familiar with the signs of a dog in heat other than what I'm reading on the internet.
signs of heat in a dog include: behavioral changes such as crankiness, clingyness, needing attention, humping other dogs, as well as physical changes: swelling of the vulva, nipple enlargement and vaginal bleeding. Yes, first heats can be silent or your girl could have a split heat. Split heat is when there are some of the above signs (often subtle) but not bleeding, then within a few weeks, the symptoms return (more noticably) and there the bleeding as well. My understanding is that with a "juvenile" vulva, you want the full blown heat with plenty of vulvar swelling. The theory is that the retracted vulva will not be quite so recessed after the heat cycle.
Heat cycles vary with each female. They do not necesarrily show any outward signs of heat other than bleeding.
Silent heats are possible. They can have a cycle yet have no swelling and no bleeding. The only was we will know something is going on is if we have an intact male near her and they are sniffing and trying to mount her. Keep the males completely away from her now, as she may be having a silent heat and they can and will breed her regardless if she is swollen.
Life isn't about waiting for the storm to pass. It is about learning to dance in the rain.