Many people have heard the phrase “in heat” when it comes to dogs, but most don’t understand or know much about it. Essentially, female dogs are in heat during a time in their reproductive cycle, and it’s during this time they become receptive to mating with male dogs in order to breed puppies. The only way for pet owners to avoid their female dogs going into heat is to have them spayed.
So, what do you need to know about dogs in heat? The biological term for “in heat” is estrus. During estrus, a female dog’s estrogen levels increase and then sharply decrease. This causes mature eggs to be released from the ovaries, which is part of the reproductive cycle. If a female dog is in heat, she is capable of becoming pregnant if mating with a male dog takes place. Extra care should be taken for female dogs during the heat cycle.
Most pet owners decide to spay their female dogs before their first heat cycle, particularly if they don’t want to breed any puppies. For those dog owners who choose not to or cannot have their dogs spayed, it’s essential to know as much about dogs in heat as possible. This will help avoid any accidental pregnancies, ensure that their female dogs are healthy and cared for, and explain any behavior issues that might occur during the heat cycle.
Timing of Estrus
Though it can depend upon a dog’s breed, female dogs generally experience their first estrus between six and 24 months old. For small-breed dogs, estrus tends to occur earlier, whereas for large-bred dogs it can occur later. The frequency with which a dog will go into heat also varies with different breeds and even among individual dogs. However, a non-spayed female typically goes into heat twice a year, about every six months.
The heat cycle for a female dog lasts about three weeks. When it comes to male dogs being attracted to their female counterparts, this can last about 18 days. However, females are not receptive to mating advances made by males for the entire heat cycle. In fact, females are generally receptive to males for only about half of this time.
Signs of Estrus
There are both physical and behavioral signs of estrus in female dogs. During the heat cycle, your dog may seem nervous, more easily distracted, or more alert than usual. She may experience more frequent urination as well. These changes in behavior, physically and emotionally, are the result of the shift in hormone balance resulting from the estrus cycle.
When a female dog is ready to mate or be bred, she may initiate sexual interactions with other dogs. Signs of this include elevating hindquarters towards approaching males, deflection of the tail to one side, and tension in the rear legs.
There is generally vaginal discharge initiated by estrus, which is blood-tinged at first as the vulva is swollen. This can result in a female dog constantly licking herself, whether it’s her fur or vaginal area. When the female is receptive to males, this discharge decreases in amount and is more “straw-colored.”
Behavioral Changes of Dogs in Heat
Pet owners may notice definite behavioral changes in their dogs when they are in heat. Female dogs experiencing estrus are generally agitated easily and may pace restlessly during the cycle. They may also whimper and pant. This is not unusual behavior for this time and are just some of the symptoms of being in heat. If your female dog in heat isn’t allowed to mate or breed, this can feel very frustrating for her and be frustrating for you as a dog owner as well.
In addition, a female dog in heat may display several aggressive behaviors with other pets in the home during this cycle. Such behaviors may include:
- Pushy attitude
- Shouldering aside other pets
- Humping actions
- Attempts to dominate other animals
- Frequent urine marking just before and while in heat
These behavioral changes are temporary problems and subside once the heat cycle is over. However, for the safety of other pets and animals in the home, these behaviors should be understood and receive attention.
One way to address these behavioral changes is to separate the female dog in heat from other pets in the home until the heat cycle is finished. Another option is to let the animals figure out the situation on their own. Nature tends to take over, allowing animals to communicate and display their position in the pack as the situation dictates. Therefore, if your female dog in heat begins to act like a bully, the other pets will either accept the temporary behavior or they will assert their place.
Your dog may also experience appetite changes when in heat. Many dogs show a decrease in appetite, although some experience an increase. Regardless of appetite changes, it’s important to feed her nutritious food with a balance of fiber vitamins and other nutrients to keep her healthy during the heat cycle.
Caring for Your Dog When in Heat
It’s vital for pet owners to understand what to expect when their female dog is in heat, so they can provide her proper care and attention, ensuring her physical as well as emotional well-being.
When a female dog is in heat, she constantly releases pheromones, which will attract almost all male dogs in her vicinity. Therefore, it’s essential that dog owners be responsible for not leaving their female dogs alone or unattended outdoors while she is in heat. Male dogs are likely to become aggressive and even dig under or jump over fences to mate. Keeping your female dog indoors during the heat cycle will help eliminate the fear and chance of both unwanted puppies and attacks by neighborhood male dogs.
Unfortunately, it can be difficult, inconvenient, and unpleasant to keep your female dog inside while she is in heat. The discharge can be messy and odorous. A good option is to keep her indoors and confined to an area where this discharge would be easier to clean up, such as a tiled or concrete area in a basement or garage. Baby gates can be used for confinement if you don’t wish to shut your dog behind a door. Be sure to give her plenty of attention and interesting chew toys to keep boredom away.
Though your dog will keep herself clean with licking, it’s important to help your dog practice good hygiene while in heat. This could mean giving her a bath or wiping her down in certain areas when needed.
If pet owners decide to crate their female dog while she is in heat, it’s essential to place the crate where she can have social interaction with household members and many opportunities to be let out to exercise and go potty. Female dogs should not be made to feel punished during this normal biological, reproductive cycle. There are “dog diapers” available for purchase on amazon to contain the discharge and avoid messes.
It’s also essential that dogs in heat stay away from intact male dogs for three to four weeks. This means that pet owners with dogs in heat should ensure that they stay away from dog parks or doggie day care sessions. In general, neutered males are fine around females in heat. However, the risk of exposing a female dog within a month of being in heat to any intact male dogs is severe and can lead to significant consequences.
Breeding a Dog in Heat
Dog owners who intend to breed their dogs must be aware of the heat cycle and how to navigate it for successful mating. Typically, a dog is in heat for two to three weeks, in varying stages, although it depends on the size, breed, and general health of each individual dog. These stages of the heat cycle can help a breeder determine the ideal time to begin breeding and when to avoid mating.
The heat cycle starts as the proestrus stage, which lasts about nine days and is marked by a sudden increase in estrogen and maturation of eggs. Signs of this stage include an enlarged vulva and bloody discharge, which indicate a readiness to mate.
The estrus stage is what determines when to breed a dog in heat. It is during this phase when a female dog should be bred in order to maximize her chances of becoming pregnant. Estrus is the only time a female dog is able to be impregnated.
The estrus cycle lasts about 9 days as well, marking the time when the eggs are released and ready to be fertilized. During the estrus phase, the female dog will begin to show signs of interest in mating. This is when breeders are encouraged to start the mating between the male dog (sire) and female in heat (dam).
Dogs in Heat with Advanced Years
When a female human gets advanced in years, she experiences menopause in which her monthly cycles eventually stop as the body produces low levels of estrogen and progesterone for the rest of her life. This situation does not occur in dogs. Healthy female dogs will continue to go into heat on a regular basis throughout their entire lifetime. There have been cases of dogs as old as 15 becoming pregnant, which would be the equivalent of an 80 to 90-year-old woman.
Though female dogs will continue going through estrus cycles, there are changes that take place with age. Dogs generally don’t retain high levels of fertility in advanced age. Beyond the ages of five or six, it’s difficult for most dogs to maintain healthy pregnancies. This may especially occur sooner in larger breeds and later in smaller breeds due to the differences in the rates that they age and their life expectancies. The overall health status of the individual dog also plays a part.
Studies have shown that there is a relationship between the increasing age of a mother dog and a rise in death of newborn puppies as a result. There are also greater incidents of serious problems for the mother with advanced age and pregnancy, such as a difficult birthing process as well as low blood sugar and calcium levels.
Though female dogs are supposed to continue their heat cycling throughout their lives, it may occasionally appear as if their heats have stopped or become irregular. Some may experience “silent” heats during which the typical signs of swelling vulva and bloody discharge may be slight or go unnoticed.
Some dogs naturally experience a very long period between their heats. Even up to 13 or 14 months can be normal. However, when an older female dog truly stops cycling, this can be an indication of a health problem. Ovarian cysts or ovarian cancer will disrupt a dog’s hormone production and therefore prevent the occurrence of a normal heat cycle.
Overall, nonstop, continuous cycling can have detrimental effects on a female dog’s body. Female dogs are naturally designed to become pregnant with each heat. They actually experience a “hormonal” pregnancy due to two months of high progesterone and low estrogen levels subsequent to each heat cycle regardless of whether or not they have mated. This perpetual condition across time puts them at very high risk for developing a potentially fatal uterine infection called pyometra after each heat.
To Spay or Not to Spay
Most experts in the veterinary and animal control fields highly recommend that pet owners have their female dogs spayed. Spaying a female dog prevents estrus, accidental pregnancies, and is considered to protect dogs from breast cancer as well as diseases of the reproductive system. However, there is recent research that indicates potential negative effects due to spaying, especially early spaying, of dogs.
Most veterinarians will spay a female dog when she is as young as two months old. However, since individual dogs vary in health, size, and breed, it’s best to consult your dog’s personal veterinarian for specific recommendations as to when it’s the best time to spay your dog.
There are many other reported advantages to having female dogs spayed. Some of these include:
- The toll it takes on a dog to give birth to a litter and raise puppies
- The lack of knowledge among non-sport canine owners about the care of pregnant dogs and nursing puppies
- Irresponsible contribution to the large number of excess and homeless animals euthanized each year
- Unsubstantiated health benefits of allowing a dog to have a litter before being spayed
- Unprevented female canine pregnancies can lead to premature aging or even death
- Females spayed prior to the first heat cycle tend to show a reduced risk for mammary gland tumors
Ultimately, experiencing estrus without being allowed to mate or breed can be difficult for your female dog, both physically and emotionally. Therefore, if you don’t plan to breed your dog, it’s better for her health and well-being, as well as your experience as a pet owner, to have her spayed. This is an indication to many of being a responsible and loving pet owner while taking every precaution to prevent unwanted puppies.
Not to Spay
The argument against having female dogs spayed is not so much against the act of reproductive surgery, but rather against spaying too early or incurring unnecessary health risks. Some reported risks and/or disadvantages of spaying are:
- Spaying doubles the risk of obesity, which can lead to debilitating joint disease, arthritis, heart disease, pancreatitis, and diabetes. Spaying changes a dog’s hormonal make-up and metabolism; therefore, owners should monitor and adjust their dog’s food and activity levels.
- Spaying increases the risk of a cancer called hemangiosarcoma, found in the spleen or heart.
- Spaying triples the risk of hypothyroidism, as the loss of reproductive hormones can affect the endocrine system. This can result in low thyroid levels, subsequent weight gain, and lethargy. Thankfully, this can be treated with a supplement taken daily.
- Spaying requires major surgery and general anesthesia, which can present risks of complications such as infection.
- Early spaying can increase the risk of hip dysplasia, torn ligaments, bone cancer, or urinary incontinence. Reproductive hormones help a dog’s bones, joints, and internal organs to develop properly, and early removal can compromise this.
Understandably, pet owners would not want their dogs to experience any of these health risks or concerns. Therefore, the best strategy in deciding whether to spay your dog or not is to express your concerns and consult with your dog’s personal veterinarian.
Ultimately, individual dogs will react differently to being in heat. For this reason, it’s important to give them focused love and attention. Dogs in heat experience behavioral and physical changes, which can make them either lethargic or agitated. Dog owners can support their female dogs at this time by adjusting to their level of activity and comfort.
Therefore, if your dog wants to sleep more during heat, then let her sleep. If she seems restless, try playing with her, brushing her, or petting her gently. With such attention and care, your dog will feel calm and at peace during her heat cycle.