It is important that if you notice signs that your chihuahua is pregnant that you make a visit to the veterinarian. Pregnancy and especially birth are difficult for this breed of dog, and only experienced breeders should take the task of breeding these animals.
Within the first few weeks of pregnancy, your chihuahua may become more tired than usual. Her behaviour (such as becoming more affectionate) may also change.
You may notice that your chihuahua is becoming more hungry, or may even become picky when eating. Sometimes pregnant chihuahuas experience nausea.
Your dog may start urinating more due to an enlarged uterus.
If the female's nipples become enlarged and begin to protrude from the body, then it's possible she could be pregnant. The nipples may also darken.
The closer your female gets to whelping, her behaviour may become erratic. She may start to shred things or become grumpy.
Most chihuahuas give birth within 9 weeks of becoming pregnant. The closer she gets to whelping, the more agitated she may become, and it is recommended that you have a vet assist in the birth.