Puppies usually nurse on their mothers until they are 3 to 5 weeks old. Unfortunately, some dogs run out of milk for their pups before that. Some causes of failed milk production can be treated. However, it is easier to prevent the mother from running out in the first place.
Agalactia
Insufficient milk production is more common than agalactia, which is a total lack of milk. Agalactia can have many causes, some of which can be treated and sometimes reversed. Your veterinarian can help you determine the cause of the agalactia and treat it in an effective and timely manner. He can also help you seek other options for feeding the puppies, if necessary.
Physical Problems
Mastitis, an infection of the mammary glands, will often prevent a dog from lactating. Mastitis does not necessarily affect all of the nipples at the same time. Depending on the severity of the infection, it might not prevent milk from being produced.
A lack of hormones can also cause poor or nonexistent milk production. Not only do hormones signal the breasts to prepare for milk production, they also signal the body that more milk must be produced when the puppies consume it. Production of the hormones needed to replenish the milk is stimulated by puppies nursing. If the breasts become too full, then those hormones are not produced and milk stops flowing.
Inadequate Nutrition
Nursing puppies is hard work. It places a lot of strain on the mother’s body, increasing any nutritional demands she has. The mother dog should be fed a minimum of three times a day using a high-quality food that contains sufficient fat and protein for milk production. Otherwise, she will not be able to both sustain her weight and feed her puppies. The mother should always have enough fresh, clean water on hand, because fluids are needed for milk production.
Emotional or Psychological Problems
Mother dogs can easily become annoyed when nursing, resulting in stress. Stress can be a problem for first-time mothers or dogs who are already nervous. An overcrowded, busy, or noisy environment can place stress on a dog. Some stop producing milk because they can't cope with raising a litter in such surroundings.
Lack of bonding can also be a problem for first-time mothers. Mothers who don't allow their puppies to nurse will not release the hormones needed to produce milk.