It's not always easy knowing if your dog is pregnant, so here are the signs to look out for - and what to do if she is.

When it comes to mating, dogs can be very discreet - and rather indiscriminate - so you may not know puppies are on the way. There are a number of signs you can look out for, but most are not apparent until your bitch is well into her pregnancy (which on average lasts between 61 and 65 days).

• Vaginal discharge will usually occur around one month after mating.
• The teats will become more prominent due to an increase in the blood supply around the base of the nipples. This should appear between 25 to 30 days after mating.
• Appetite is usually depressed during mid-pregnancy, but not in every case.
• The abdomen will enlarge and the total body weight of your bitch may increase by 20 to 55 per cent. This may not be noticeable until 45 to 50 days into the pregnancy.
• Behaviour may also change, such as displaying slight depression.
• Closer to the delivery date, your bitch will probably start to exhibit nesting instincts, such as scratching at the floor or in her bed, and displaying signs of increasing restlessness.

On average, you should be able to tell whether or not your bitch is pregnant at around one month after mating.

If you suspect your dog is pregnant, you'll need to see your vet for confirmation.

• The most commonly used method is ultrasound. This can be used after 28 days, but may not be able to predict accurately how many puppies there are. Ultrasound examinations are non-invasive and very reliable.
• Feeling the abdomen from about 21 days can be accurate, but it may be difficult if the dog is nervous or slightly overweight. If pregnant, the vet will feel a thickening of the uterus and "bumps" within. It isn't fool-proof, however, especially if there is just one pup in the womb or if the pregnancy is not as advanced as first thought.
• The puppies' heartbeats can be detected after about 25 days using a stethoscope or ECG. However it will be very difficult to determine how many puppies there are.
• An X-ray will pick up the skeletons of the puppies from around 49 days. It should also be accurate in determining how many there are. However, most vets prefer not to use X-rays as there is a danger of radiation damage.
• Endocrinological tests detect relaxin, a hormone exclusively produced by pregnant dogs.

Your vet will discuss which test is best for your pet, as some of these procedures may not be suitable at certain stages of pregnancy.