There comes a time when many-a-worried dog owner may have to ask, “Is my dog pregnant?”. You might think the answer is a simple yes or no, but unlike humans, it can be difficult to gauge whether a dog is pregnant until the final few days of the pregnancy!
Typically, canine gestation is around 60-63 days long, beginning on the day of conception. Ideally you’ll want to know whether your dog is pregnant a few weeks in advance so you have time to prepare of course, but as we mentioned it can be difficult to spot. What makes matters more difficult is the fact that many females will experience pseudo-pregnancies, which are very similar to actually pregnancy – just without the pups!
If you think your dog is pregnant, but aren’t too sure, you can always confirm the pregnancy at your vet, see, ‘Detecting Canine Pregnancy’ below.
About the Canine Oestrus Cycle: When is Pregnancy Possible?
Like humans and other mammals, female dogs experience a cyclic period of fertility. Human females are typically fertile 12 times a year, experiencing monthly fertility cycles, whereas female dogs cycle only twice a year.
Each cycle of the canine oestrus cycle takes around 6 months, this means that a female dog is only fertile on average twice a year. Each fertile period lasts for around 21 days.
Dogs become sexually mature and able to conceive from between 8-18 months, although this number can vary wildly between breeds (and even within the same breed). Typically males will mature before females.
A single oestrus cycle can be split in to four distinct phases:
- Proestrus – Marks the start of being ‘in heat’ and lasts for around 9 days. During this phase, the female is not interested in advances by the males. Proestrus is usually accompanied by bloody discharge from the vagina. Copulation during this phase is unlikely to result in pregnancy, however canine sperm can last for up to 11 days in the uterine tract.
- Oestrus – The fertile phase of heat, marking the release of mature, female eggs. Oestrus lasts for up to 20 days. During this period, the female will stand to be mated and is interesting in the male’s advances. Copulation during this phase is likely to result in pregnancy.
- Dioestrus – During this phase, the female is subject to multiple hormonal changes – pregnant or not. These hormone changes can result in non-pregnant female dogs experiencing pseudo-pregnancies (also known as phantom pregnancies). Typically this phase will last for around 56-60 days in the pregnant female dog, although in non-pregnant bitches, dioestrus may last for up to 100 days.
- Anoestrus – This is the phase of the oestrus cycle where the female is non-fertile. This lengthy 4-5 month period makes up the bulk of the canine oestrus cycle.
So, females are fertile just twice a year during the oestrus phase of ‘heat’ (remember, heat consists of both proestrus and oestrus). The length of heat varies but can last from 5 days to 21 days.
The Signs and Symptoms of Canine Pregnancy
So if it’s likely that your female has been mated during her fertile phase, you are going to want to be checking for the signs and symptoms of canine pregnancy. Remember that non-pregnant bitches can undergo the same response to hormone changes, resulting in pregancy-like symptoms such as those listed below.
If your female is experiencing any of the below, you are probably going to want to get the pregnancy confirmed at your vet so you can prepare in advance of the birth.
The signs and symptoms of canine pregnancy include:
- Increased appetite
- Enlarged nipples
- Lethargy and increased tiredness/sleeping
- Noticeable personality and behavioural changes
- Firm abdomen
- ‘Nesting’ and territorial behaviour
- Clear vaginal discharge and more frequent urination
- ‘Morning sickness’
When whelping (birthing) is imminent:
- Decreased appetite
- Increased nesting behaviour
Detecting Canine Pregnancy
If you’re almost certain that your dog is pregnant, you will want to confirm that is the case by visiting your vet. They will be able to perform one of the following techniques allowing them to confirm whether or not your dog is truly pregnant:
- Ultrasound – From around day 20-25 of the pregnancy, a vet will be able to perform ultrasound on your suspected pregnant dog and confirm or dismiss pregnancy. Ultrasound uses non-invasive sound waves to detect the heartbeats and basic shapes of the unborn pups.
- Palpation – Someone experienced in canine pregnancy, such as your vet, will be able to palpate the abdomen of your bitch at around day 20 of the pregnancy to confirm or dismiss pregnancy. Without experience, it is difficult to differentiate between additional fat tissue (produced as a result of the dioestrus hormone changes) and unborn puppies.
- X-Ray – After day 45 of the pregnancy, X-rays can be used to detect the developing skeletal systems of the unborn pups. Using X-rays before this date is not recommended as the radiation generated can cause damage to the unborn pups.
- Hormone Testing – A relatively expensive method of detecting pregnancy typically reserved for breeders. These tests can detect certain hormones (such as relaxin) that confirm pregnancy.
Other Canine Pregnancy Considerations
If you are worried about unplanned pregnancies, you should consider getting your female spayed. This surgical procedure prevents future pregnancies and also has the benefit of reducing hormonally driven diseases such as mammary cancer. The alteration in hormone levels as a result of the operation may result in some behaviour changes in your female however.
If your female has become pregnant unexpectedly, you should try to determine which male is responsible. An overly large male in comparison to the female may negate the possibility of a natural birth. As a result, you might need to seek further veterinary advice.
Finally, the average litter size is around 6 pups, but could be anything upwards of 12! You should be prepared in advance and have a clear idea of how you will deal with the pups. Try to have rehoming options lined up in advance.