Why hasn’t my dog gone into heat? Female dog problems are a popular topic among breeders, but the truth is, most females have no problems. Dogs do everything to maintain their body, and if there is excess nutrition or vitamins, they reproduce.
When Do Dogs Go Into Heat?
Most female puppies will have their first heat cycle between eight months of age and two years of age. There is a great deal of variation in this, based on the breed, her mother’s history, nutrition, weight, if there are other intact (unspayed females) in their household, and time of the year she matures. In general, the smaller the dog, the earlier they go through puberty and enter their first heat.
How Often Do Dogs Go In Heat?
Dogs are also seasonally dependent and typically cycle twice a year. As soon as the days become longer, starting after the winter solstice, many dogs begin their “spring” heat cycle. So the first few weeks of January, many dogs are in heat. This repeats every six months for most females. However, some normal dogs do not go into their first heat until they are over two years old. Some only cycle once a year. Some only cycle when there is another female in the household or nearby that is in heat. Some will start a heat cycle, not ovulate, and go back into heat in a few weeks, known as a split cycle. These are all normal variations and of no reason for concern.
The reproductive cycle of a female dog is unlike that of a human, a cat, a cow, or a horse. She will not menstruate like a human. Menstruation is the shedding of the uterine lining that was prepared for a pregnancy. The bloody vaginal discharge in our female dogs is not from the uterine lining. Additionally, dogs do not go through menopause. Both male and female dogs remain fertile for their entire lifetime. Of course, breeding an elderly dog is not a good idea.
Dog Not Going Into Heat
The number one issue that costs us money is females that are not cycling. If we have a number of females not cycling, the first thing to look at is the diet and vitamins. Poor-quality protein and imbalanced vitamins can be the cause; you can correct cycling if they have the right diet, vitamins, and minerals. Inadequate diets often show up on the next litter. Mom gets pregnant, then has a deficiency in gestation and nursing, and eventually skips heats because of it.
In the wild dog pack, one or two alpha females will cycle, while the rest do not. There may be four or more females, but their ovaries will stay in anestrus (quiet ovary) and out of heat. This is good – the best genetics will breed while the rest contribute to feeding. Skipping heats can send normal adult females into anestrus, as well.
Avoid Skipping Heat
It’s hard on moms if you rest them and intermittently breed them. Typically, the first litter after the “rest” or “skip” is difficult for her, and there will also be fewer weaned puppies than average. When it comes to how often do dogs go into heat, if we do a good job feeding and whelping females, giving them everything to help them do their job, they can cycle again without issue at their normal six to seven month interval.
We also see this phenomenon in the kennel with the young female. We’ll skip heats to get the dog physically and mentally ready to raise a litter, but some will stop cycling. Small breeds, especially poodles, are notorious for doing this. This dog can easily be started again!
How to Trigger Heat in Dogs
If several females are not cycling, make sure everything is normal with their diet. Ask your veterinarian for help if there is any debate.
How to Bring a Female Dog Into Heat
When it comes to how to trigger heat in dogs, one key is to put the female dogs on a daily vitamin and mineral supplement. More vitamin and mineral issues have been diagnosed in the last few years – there are many reasons, but the important thing is that they are easy to correct. While inducing heat in dogs, we want optimum levels of all vitamins in the female but B vitamins are critical when moms aren’t cycling. Breeder’s Edge® B Strong provides the necessary B vitamins to get mom back on track.
Once mom is cycling again you can vary her vitamin and mineral supplementation based on breed. Small breeds generally do best if we keep them on B Strong. For large breeds, we switch to Doc Roy’s® Daily Care Extra.
Why Hasn’t My Dog Gone into Heat?
Most dogs will not cycle when there is less than 12 hours of light. Mother Nature tries to be sure babies are not born in snowstorms. If you don’t have lights, wait until spring. A good date for triggering heat cycle in natural light kennels is after Feb 14th.
Lighted kennels: Put them under lights at least 12 hours. Spectrum is not as important as the light intensity. A bulb of at least 100 watts is needed within 15 foot of the female. This is why keeping them in the house does not work. In kennels with good natural light, turning the kennel lights on from 5:00 to 9:00 p.m. usually does it.
Most dogs will trigger to start cycling (70 percent) if they have the ability. The next step is to ultrasound the uterus, ovaries, and fallopian tubes, but most of these issues will prevent the female from ever getting pregnant. Remove the female that is not cycling from the breeding females and replace her with one selected from a “push button female” – one who breeds easily and loves to raise puppies. Moms that are easier to handle and love being moms are much easier to manage effectively.
Managing females is all about getting the sire and dam’s genetics to the next generation. A consistent, predictable, fertile heat cycle is the basis of getting that done.
What to Do When Your Dog Is In Heat
Once you have decided all systems are “go” and you want to breed your female on her next heat, you need to carefully observe for signs of her heat cycle. The first day you see a bloody vaginal discharge is considered day 1 if you have been observant. Many clients do the white facial tissue test, blotting their females vulva once or twice a day to monitor for evidence of that bloody vaginal discharge indicating the early heat cycle. For the occasional dog with a “silent heat”, you may miss her if you don’t have a male dog in the household to point out her hormonal changes.
If you do plan to breed your female dog, you should not breed her on her first heat cycle. This is because she is still maturing herself and may not have a fertile heat. Additionally, she should not have babies while she is still a baby herself. Just like we discourage teenage pregnancies in humans, we discourage breeding very young dogs.
If you are not planning to spay your female puppy, you need to be very careful when she is around male dogs who have not been neutered. This is because some females will have a “silent” heat, where the only ones who know she is in heat are the female dog and her male boyfriend. Even if YOU don’t plan to do a breeding, they may have other plans in mind.
When to Breed a Female Dog in Heat
A typical females heat cycle is three weeks long. The first 10 to 14 days are called proestrus, the time during which she is preparing to be bred, but before she has ovulated. The next three to five days are her estrus period, the time after ovulation, when she is fertile. During this time, she is receptive to a male dog and a breeding can happen almost instantly, right under your nose. The next seven days, called diestrus, are past her ovulation but she may still smell interesting and may be receptive to the male dog. After diestrus, there is metestrus, followed by anestrus, the time period during which there is little ovarian activity.
Most females have a bloody vaginal discharge and swelling of their vulvas during proestrus. As she progresses, the discharge changes to a straw color, and her vulva becomes softer. This is typically her fertile period, estrus. Following this, the discharge disappears, her vulva recedes and she is no longer interested in the male or interesting to the male.
If you are serious about breeding your female dog, you should first spend a lot of time researching your breed, their health concerns, the health screenings selected for your breed by your breed club, selecting the right male for her, and educating yourself on how to properly breed, raise, and find homes for your puppies.
If you need help with a dog not going into heat or you have more questions on how to make a dog go into heat, call us at 800.786.4751.
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Written by: Marty Greer, DVM
Director of Veterinary Services
Marty Greer, Doctor of Veterinary Medicine, has 40+ years’ experience in veterinary medicine, with special interests in canine reproduction and pediatrics. She received her Doctor of Veterinary Medicine from Iowa State University in 1981. She’s served as Revival’s Director of Veterinary Services since 2019. In 2023, Dr. Greer was named the Westminster Kennel Club Veterinarian of the Year.