Female dogs go into heat twice annually. The cycle lasts about 21 days and is marked by mood changes and bloody discharge. Owners who do not want to breed their animals should keep them under constant supervision during the cycle.
How Pregnancy Happens
Length of Gestation
If a female becomes pregnant, gestation will last from 58 to 68 days, with an average length of 63. While there is no such thing as a canine pregnancy test, a veterinarian can sometimes determine pregnancy one month after breeding by feeling the dog's abdomen.
Changes During Pregnancy
There are few noticeable changes during the first month. During the last three weeks, you might notice an enlarged abdomen, although its size will depend upon the size of the litter. In the last two weeks of pregnancy, the dog's mammary glands will begin to enlarge, and milk might be present in the days leading up to birth.
Many dogs exhibit behavioral changes during the last two weeks of pregnancy as they begin to prepare for the puppies' arrival. A mother might nest, shredding paper or carpet to create a space to give birth. She might also become irritable and restless, and some dogs experience incontinence.
Nutrition and Exercise During Pregnancy
During the first half of the pregnancy, you should add some high protein foods to your dog's diet. Eggs, beef, chicken and liver are good sources. During the last five weeks, you should feed your dog up to double the amount she normally eats. She will also need more food while nursing.
You should exercise your dog as normal. Once she nears the end of the pregnancy, she might slow down or tire more easily. Slow walks or gently play is fine, as long as she tolerates it.
Your dog will need a space to give birth--it's messy, so make sure the area can be easily cleaned. Most dogs prefer privacy, and your dog will appreciate soft bedding or newspaper to move as she sees fit. While it is not likely you will need to intervene, you should talk to your vet about what to expect and what you can do to help your dog. You should also have an emergency plan in case your dog needs assistance.