What is a phantom pregnancy in dogs?
A phantom pregnancy, also known as pseudopregnancy or false pregnancy, is a condition that occurs in female dogs after an estrus or heat cycle. It is caused by hormonal changes in the body that mimic the signs of a true pregnancy even though the dog is not actually pregnant (1).
After ovulation, the corpus luteum in the ovaries secretes progesterone. This progesterone causes physical and behavioral changes that would prepare the body for pregnancy and nursing puppies, even though no puppies are present (2).
Some common symptoms of phantom pregnancies in dogs include (3):
- Nesting behaviors like digging and gathering toys
- Mothering or taking care of toys as if they were puppies
- Swollen or enlarged mammary glands that may even produce milk
- Increased appetite
- Lethargy or inactivity
These symptoms typically resolve on their own within 2-3 weeks after the start of the phantom pregnancy. However, some dogs may experience repeated or persistent phantom pregnancies that require veterinary attention.
Do all dogs go through phantom pregnancies?
Phantom pregnancies are surprisingly common in intact female dogs. According to the AKC, one report indicates that 87 percent of unspayed bitches show signs of false pregnancy two or more times in their life. However, the prevalence can vary significantly based on the breed.
Certain breeds seem more prone to phantom pregnancies than others. Herding breeds like Collies, German Shepherds, and Australian Shepherds frequently experience pseudo-pregnancies. Hound breeds like Beagles and Basset Hounds also have a higher tendency. On the other hand, breeds like Greyhounds, Whippets, and Italian Greyhounds have a lower prevalence. The reason for the breed differences is not entirely clear, but likely relates to genetics and hormonal factors.
In summary, while phantom pregnancies can occur in any intact female dog, they appear much more commonly in certain predisposed breeds. Herding breeds and hounds are the most likely to be affected. However, the majority of unspayed bitches will experience pseudo-pregnancy symptoms at some point in their lives.
What causes a phantom pregnancy?
A phantom pregnancy is caused by hormonal changes after a female dog’s heat cycle. According to the VCA Hospitals source https://vcahospitals.com/know-your-pet/false-pregnancy-or-pseudopregnancy-in-dogs, progesterone levels rise after estrus or heat, regardless of whether the dog was bred. This progesterone triggers changes in the uterus lining and mammary glands that mimic pregnancy. When a dog goes through estrus but does not get pregnant, her body still undergoes these hormonal preparations for pregnancy.
As the Blue Cross source https://www.bluecross.org.uk/advice/dog/health-and-injuries/phantom-pregnancies-in-dogs explains, the rise in progesterone after heat causes physical changes like mammary gland enlargement and maternal behaviors like nesting and mothering toys. Because the dog was not actually bred, these are “false” signs of pregnancy.
Signs and symptoms of phantom pregnancy in dogs
The most common signs and symptoms of phantom pregnancy in dogs involve both physical and behavioral changes.
Physical signs include:
- Enlargement of the mammary glands – the nipples may become enlarged and the glands can even produce milk (known as galactorrhea) (VCA Hospitals)
- Abdominal swelling or distention, giving the appearance of pregnancy
- Lethargy and changes in appetite
Behavioral signs include:
- Nesting behaviors like collecting toys or blankets for puppies
- Mothering or guarding toys as if they were real puppies
- Behavioral changes like depression or irritability
- Excessive licking of genitals
According to the Blue Cross, the most noticeable sign is enlargement of the mammary glands in preparation for nursing puppies. This is accompanied by mothering behaviors as if the dog is caring for a litter of puppies (Blue Cross).
Do dogs bleed during phantom pregnancies?
Usually dogs do not bleed from the vagina during a phantom pregnancy. The bloody vaginal discharge often attributed to phantom pregnancies in dogs is a misconception. Normal estrous cycles in dogs involve vaginal bleeding, but once pregnancy occurs – real or phantom – the dog’s progesterone levels remain elevated which prevents further estrous bleeding.
However, there are some exceptions. In rare cases, dogs may experience minor vaginal bleeding during a phantom pregnancy due to a drop in progesterone levels, called progesterone withdrawal bleeding. This bleeding is not from a true heat cycle, but rather from hormonal fluctuations. It is typically lighter and briefer than regular estrous bleeding. According to veterinarians, episodes of vaginal bleeding during phantom pregnancies are uncommon and not considered normal (VCAAnimal Hospitals).
So in summary – dogs do not normally menstruate or have estrous bleeding during a phantom pregnancy, but some minor bleeding can occasionally occur due to hormone changes. The characteristic signs of phantom pregnancy in dogs relate more to physical and behavioral changes than vaginal discharge.
How long do phantom pregnancies last?
Phantom pregnancies typically last 2-3 weeks from the time symptoms first appear. However, some dogs may experience phantom pregnancy symptoms for several months. The duration can vary depending on the individual dog.
In most cases, phantom pregnancy signs begin to fade within a few weeks once prolactin levels start to lower. Some dogs may only exhibit symptoms for 7-10 days before hormone levels return to normal. But in some cases, especially if pseudopregnancy is artificially induced through medication, symptoms can persist for 8 weeks or longer.
If your dog’s phantom pregnancy lasts longer than a month or two with no signs of symptoms subsiding, consult your veterinarian. They can run tests to check hormone levels and may recommend medical treatment to help end the phantom pregnancy.
With patience and care, phantom pregnancies will eventually come to an end on their own as the dog’s hormones rebalance. But if the symptoms become severe or problematic, there are ways vets can intervene to shorten the duration.
Risks and complications
Phantom pregnancies can lead to some risks and complications if left untreated, especially if the condition becomes prolonged. Two main risks are:
- Mastitis – The continued production of milk can cause inflammation and infection of the mammary glands (mastitis). This is very painful for the dog and requires antibiotic treatment.
- Uterine infections – Some dogs may develop an infection in their uterus, known as pyometra. This is a result of hormonal changes and can become life-threatening if not treated promptly with antibiotics or spaying.
In addition, some dogs can develop behavioral problems if the phantom pregnancy becomes severe. They may become extremely protective of their “puppies” and aggressive if their space is invaded. Others can experience anxiety and restlessness from the hormonal imbalances. Consulting with a veterinarian and trainer is advised if behavioral issues arise.
Most phantom pregnancies resolve on their own within 2-3 weeks. However, the risks above demonstrate why it’s important to keep an eye out for complications, especially if the symptoms persist longer than normal. Seeking veterinary advice can help mitigate risks and get your dog back to her normal self.
Sources:
https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub/conditions/phantom-pregnancy-in-dogs
https://vcahospitals.com/know-your-pet/false-pregnancy-or-pseudopregnancy-in-dogs
Diagnosing phantom pregnancies
To diagnose a phantom pregnancy, veterinarians will start with a complete physical exam and take the dog’s full medical history. They will look for physical signs of pregnancy that are not actually present, like weight gain, enlarged mammary glands, or abdominal distention.
Blood tests are often done to check hormone levels. Levels of the hormones estrogen, progesterone, prolactin, and relaxin may be abnormally high and indicate a phantom pregnancy. These tests help rule out true pregnancy or other conditions.[1]
Medical imaging such as ultrasounds or x-rays can also determine if there are puppies present. A lack of fetuses confirms the diagnosis of phantom pregnancy.
In some cases, exploratory surgery may be done for absolute confirmation if the dog’s health dictates it. But in most cases, a combination of physical exam, medical history, bloodwork, and imaging is sufficient.
[1] https://vcahospitals.com/know-your-pet/false-pregnancy-or-pseudopregnancy-in-dogs
Treating Phantom Pregnancies
Phantom pregnancies will usually resolve on their own within 2-3 weeks without any treatment. However, some medications and symptom management may help ease a dog’s discomfort during a phantom pregnancy.
Since phantom pregnancies are caused by hormonal fluctuations after heat, they are typically self-resolving once hormone levels return to normal. According to the VCA Hospitals, most phantom pregnancies in dogs last 2-3 weeks.
While phantom pregnancies resolve on their own, the symptoms can cause discomfort for dogs. Two common symptoms that may require management are:
- Mammary gland engorgement – The mammary glands become enlarged and produce milk, even without any puppies. This engorgement can be painful.
- Mothering behavior – The dog treats toys or other objects as surrogate puppies. This mothering instinct can lead to distress if their “puppies” are taken away.
To help with mammary engorgement, veterinarians may prescribe diuretics or drugs to suppress lactation, such as cabergoline. Applying warm compresses to the mammary glands can also bring relief and reduce swelling.
For mothering behaviors, it’s best to avoid stimulating the dog further by playing along with the pseudo-mothering. Gradually remove any surrogate puppies without causing distress. Providing distractions with walks, playtime and attention can also curb mothering instincts.
Preventing phantom pregnancies
The best way to prevent phantom pregnancies is to get your dog spayed. Spaying stops the heat cycle and hormonal changes, so it will prevent future phantom pregnancies (Purina). Most dogs can be safely spayed around 6 months old. However, a dog should not be spayed during an active phantom pregnancy episode. It’s best to wait until the symptoms have subsided.
For intact dogs, discouraging mothering behaviors during a phantom pregnancy may help shorten the duration. Take away any toys or treats she may be mothering. Limit her access to dark, quiet areas where she may nest. Increase exercise and interact with her normally to discourage brooding behaviors (PDSA).
