Dog Nipples In Heat Vs Pregnant

Signs of Heat in Female Dogs

When a female dog enters her heat cycle, known as estrus, her body shows several signs as she becomes receptive to mating with males. Some of the most common signs of heat in female dogs include:

Swollen vulva – The vulva will appear puffy and enlarged. This is a key sign that a dog is in heat. According to WebMD, the vulva may appear red and swollen during estrus.

Bloody discharge – There will often be a bloody discharge or bleeding from the vagina during estrus. The discharge may be blood-tinged initially and become redder as the heat progresses. According to PDSA, bleeding can last for around 9 days.

Increased urination – Dogs in heat may need to urinate more frequently. This is due to hormones that increase bladder sensitivity.

Tail flagging – The dog may hold her tail to the side or flag it out straight to expose her vulva to males.

Increased vocalization – Whining, barking, and howling may increase as the dog seeks attention from males.

Decreased appetite – Some dogs eat less during their heat cycle due to hormonal changes.

Noticing these signs can help owners identify when their dog is in heat. Being aware of a dog’s heat cycle is important for preventing unwanted pregnancies through separation or supervision during estrus.

Signs of Pregnancy in Dogs

Some of the earliest signs that a dog is pregnant include changes in her nipples. According to the Michigan Animal Hospital, the nipples will enlarge and swell very early in pregnancy as the dog’s body prepares to nurse puppies ( The area around the nipples will also swell. According to the American Kennel Club, nipples will become larger, swollen and red as early as one month into pregnancy (

As the pregnancy progresses, female dogs will also start to gain weight. The swelling abdomen is a very obvious sign of pregnancy in dogs. Per the AKC, abdominal enlargement becomes noticeable around 5 weeks into the pregnancy as the puppies grow ( Pregnant dogs will also experience an increase in appetite very early on as their caloric needs increase. They may start acting hungrier and begging for food.

Later in the pregnancy, dogs begin nesting behaviors like collecting blankets and pillows to create a whelping area. They also become more affectionate and clingy. Some dogs experience morning sickness and vomiting as well. All these signs indicate to an owner that their dog is likely pregnant.

Differences in Nipples

A dog’s nipples will undergo changes during both heat cycles and pregnancy. However, there are some key differences to note.

During a heat cycle, a dog’s nipples will enlarge as her body prepares for potential pregnancy, but they will not darken much in color. The nipples also will not produce milk during a regular heat cycle.

During pregnancy, a dog’s nipples will get larger, darker, and more prominent. The areolas around the nipples will enlarge. As pregnancy progresses, the dog’s mammary glands will begin producing milk in preparation for nursing puppies. The nipples will protrude more and secrete a milky fluid when squeezed gently.

According to the ASPCA, the most notable nipple changes happen around the fourth week of pregnancy, when the dog’s nipples grow larger and darker red in color [1]. The color change is caused by increased blood flow to the mammary glands. This helps differentiate a pregnant dog’s nipples from one in heat.

So while nipple changes occur with both pregnancy and heat, the darkening of nipples and milk production only occurs with pregnancy. Monitoring nipple changes can help determine if a dog is pregnant versus in heat.

Timing of Heat Cycles

Female dogs go into heat about every 6-8 months on average, although this can vary by breed. The interval between heat cycles tends to be 4-12 months. Smaller breeds may enter heat cycles up to 3 times per year. Larger breeds, like Great Danes and St. Bernards, may only go into heat every 12-18 months. The heat cycle itself lasts about 2-3 weeks from start to finish.

According to VCA Animal Hospitals, the heat cycle is broken into 4 stages:

  • Proestrus – vaginal bleeding and males are attracted but female will not allow mating
  • Estrus – vaginal discharge subsides and the female is receptive to mating
  • Diestrus – discharge subsides and the female will no longer accept a male
  • Anestrus – inactive phase until the next heat cycle

So the time when the female dog can actually get pregnant usually lasts about 5-10 days during the estrus stage. This is when ovulation occurs and the female is fertile. Tracking the stages of your dog’s heat cycle can help predict when she may get pregnant if an accidental breeding occurs.


Getting a Vet Checkup

It’s important to have your vet confirm your dog’s pregnancy as soon as possible after mating. A vet can run tests like a blood test, ultrasound, x-ray, or manual palpation to confirm if your dog is expecting puppies.

According to the AKC, before you breed your dog, take her to the vet for a prenatal checkup. The vet will make sure your dog is healthy enough for pregnancy and may recommend supplements like folic acid and calcium. Regular vet visits are crucial during the pregnancy to monitor your dog’s health and the health of the puppies.

Per WebMD, it’s a good idea to take a dog to the vet 2-3 weeks after mating for a prenatal checkup. The vet can answer any pregnancy-related questions and determine how far along the dog is based on symptoms. Monitoring your dog closely allows you to prepare properly for the arrival of puppies.

As noted on VCA Hospitals, abdominal ultrasound is the most reliable way to detect and monitor dog pregnancy starting as early as 3 weeks from breeding. Tracking the pregnancy week-to-week allows the vet to watch for any potential complications.

Caring for a Pregnant Dog

Proper care during your dog’s pregnancy is essential to help ensure she stays healthy and is able to deliver her puppies safely. Here are some tips for caring for a pregnant dog:

Provide a high quality diet. Pregnant dogs need extra calories, vitamins and minerals. Talk to your vet about switching to a high quality puppy food or a special diet formulated for gestation and lactation. Feed pregnant dogs about 1.5 times their normal amount.

Allow gentle exercise. Your dog should continue light exercise like short leash walks during pregnancy. Avoid strenuous exercise, especially jumping or high impact activities that could cause injury. As your dog nears her due date, limit exercise to quick potty breaks.

Prepare a whelping area. Your pregnant dog will need a quiet, comfortable area to give birth and nurse her puppies. Set up a box or pen lined with blankets in a low-traffic area of your home a few weeks before delivery.

Monitor for complications. Contact your vet if you notice symptoms like vomiting, diarrhea, decreased appetite, abnormal vaginal discharge or fever, which could indicate pregnancy complications. Regular vet checkups are important during canine pregnancy.

With proper care and preparation, you can help support your dog’s health during pregnancy and set her up for a successful delivery.

Delivering Puppies

As your dog’s due date approaches, be alert for signs that labor is about to begin. Most dogs begin labor within 24 hours of their body temperature dropping below 100°F. Other signs include nesting behavior, restlessness, panting, and loss of appetite. Puppies are usually born every 30–60 minutes, with 10–15 minutes of hard straining between pups [1].

Labor in dogs occurs in three stages:

  1. Early labor when the cervix dilates and contractions begin. This stage can last 6-12 hours.
  2. Active labor when stronger contractions begin to move puppies into the birth canal. Puppies should be delivered during this stage which lasts 12-24 hours.
  3. After labor when the placentas are expelled after birth. This stage lasts 1-4 hours.

Contact your veterinarian immediately if your dog strains for over 30 minutes without producing a puppy, has foul-smelling discharge, goes over 24 hours in active labor, or shows signs of illness like vomiting or fever. Prompt medical care greatly improves the chances of a healthy delivery [2].

Caring for Newborn Puppies

Proper care of newborn puppies is critical for their health and survival. Here are some key tips for caring for puppies in their first few weeks of life:

Keeping puppies warm is essential. They cannot regulate their own body temperature for the first couple weeks. Keep whelping areas around 85-90°F. Use heating pads, blankets, and a warm whelping box. Monitor temperature often.

Helping puppies nurse is another vital task. Check that each is nursing every 2-3 hours. Assist weak or rejected puppies. Monitor nursing and watch for milk band confirmation. Supplement with bottle feeding if needed.

Closely monitor puppy weight and health. Weigh daily to ensure adequate milk intake. Watch for dehydration, infections, or failure to thrive. Consult a vet if issues arise. An ounce of prevention is worth a pound of cure with delicate newborns.

Caring for newborn puppies is intensive but rewarding work. With dedication and proper care in their first days and weeks of life, puppies have the best chances of growing into healthy, thriving dogs. For more tips, see PetMD article and VCA Hospitals.

Spaying Considerations

Getting your female dog spayed provides some important health benefits. According to the ASPCA, spaying before the first heat cycle (around 6 months old) can significantly reduce the risk of mammary tumors. Spaying also eliminates the risk of pyometra, a life-threatening uterine infection.

The ideal age for spaying is between 4-6 months old. Spaying at an early age prevents unwanted pregnancies while allowing normal growth and development. While veterinarians can perform spays on pregnant dogs, there are some additional risks and considerations.

Spaying a pregnant dog in the first trimester is generally safer than later in pregnancy, as the fetus is still small. However, the surgery may cause miscarriage. There is also a higher risk of bleeding. If spayed later in pregnancy, the fetuses must be surgically removed before the spay which complicates the procedure. Some vets may advise waiting until after delivering the puppies to spay, especially for high-risk dogs.

Preventing Unwanted Litters

The best way to prevent unwanted litters is by spaying or neutering your dog. Spaying females prevents them from going into heat and eliminates the possibility of accidental pregnancy. Neutering males reduces mating behaviors and prevents the ability to impregnate females. There are many health and behavioral benefits to spaying/neutering including reducing certain cancers, infections, and aggression. Consult with your veterinarian about the ideal age to spay or neuter your dog.

If an accidental mating occurs, there are some options to prevent pregnancy, but they must be used very quickly. Mismate shots such as Alizin can be effective if given within 2 days of mating. Emergency contraceptives like Estrumate can be used within 3-4 days. However, these are not 100% guaranteed to prevent pregnancy. Speak to your vet right away if an accidental mating occurs to explore your options. (Merck Veterinary Manual)

It’s important for pet owners to be responsible and prevent unwanted litters. Keep female dogs confined and away from males when in heat. Neuter males if you have no plans to breed. Watch your dog closely when outdoors to avoid roaming and mating. Take steps to prevent pregnancy before it happens through early spay/neuter or other precautions.

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