Abnormalities in Gestation for Dogs

Gestation for dogs can last anywhere from 56 to 72 days. During this time, a fetus will grow in the mother dog's uterus and will receive oxygen and nutrients from her.

Symptoms of a Pregnant Dog

When a dog becomes pregnant her hormone levels do not change, making a blood and urine sample unreliable. However, a knowledgeable veterinarian will be able to tap on a dog's abdomen and feel if there is any uterine swelling within the first 20 to 30 days of pregnancy. Ultrasounds and radiographs are other tools a vet will use to diagnose pregnancy in a dog.

A pregnant dog may be nauseous during the first few weeks of pregnancy and then develop an appetite later in the gestation period. When a dog is about 5 weeks pregnant, her abdomen will appear larger than usual. Mammary tissues develop after about 35 days of pregnancy.

How long dogs are pregnant depends on the breed of dog and how big her litter will be.

Abnormalities During Gestation

  • Canine brucellosis: A disease caused by bacteria that can affect pregnant dogs. This bacterium does not have many visible symptoms in a dog, but can cause a miscarriage in dogs that are 35 weeks along, embryonic death or the birth of stillborn puppies.
  • Canine herpes-virus infection: Can cause a pregnant dog to miscarry her puppies. In a non-pregnant dog, this viral infection can be a minor illness. If contracted during the first or last 3 weeks of gestation, a dog may have a spontaneous abortion or lose her puppies after birth.
  • Toxoplasmosis: The organism may choose a dog to serve as a host. When a pregnant dog has this infection, she could have a miscarriage. If there is a dog birth, the puppies could be born with defects affecting their respiratory and gastrointestinal systems and cause neurological disorders. Pregnant dogs can avoid infection by not being around cat feces or raw meat.
  • Mycoplasma or ureaplasma: When a pregnant dog is kept in an overcrowded kennel, she can contract mycoplasma or ureaplasma. These organisms can cause premature birth, still birth or a spontaneous abortion that results in the reabsorbing of a fetus.
  • Bacterial or viral infections: During complications in pregnancy, dogs can fall ill to a number of other bacterial or viral infections. Many of the viruses and bacteria a pregnant dog is exposed to can often be introduced when the breeder vaccinates the dog. Vaccinating a pregnant dog is often not recommended because of the complications it can cause during gestation.
  • Low progesterone levels: When a female dog has an insufficient amount of progesterone, a hormone that helps maintain a pregnancy, her body will think it is time to give birth to her puppies. This will cause the dog to miscarry her puppies. Replacement therapy can be administered to a pregnant dog with low progesterone levels to help prevent spontaneous abortions.
  • Other abnormalities: Other causes of complications during a dog's gestation period could be attributed to endocrine disorders (for example, hypothyroidism), nutritional deficiencies and genetic defects.

When puppies are expected, this can be an exciting time for a dog owner. A dog usually does not need a lot of intervention during her gestation period, but keep a watchful eye on her. Take your dog to the vet's office for scheduled visits so any potential problems can be caught before they cause complications to the pregnancy.