Dog panting immediately after giving birth to puppies is a normal and natural occurrence. Your female dog has just experienced an ordeal and will take a few hours to settle down and clean herself and her new puppies. She'll also need some time to get herself used to the newness of the situation, especially if this is her first litter. If postpartum panting continues past the first day or so and happens frequently during nursing, this could indicate a problem. There are several things beyond stress and exhaustion that can lead to postpartum dog panting.
Incomplete Birth
If dog panting continues for several hours after puppies have been born, this could indicate that one or more puppies and/or a portion of the placenta have yet to release. If you are inexperienced with birthing puppies, it will be important at this point to have your female dog examined to make sure there are no internal problems preventing additional births. Medication is available to expel any remaining bits of placenta, after it has been determined that no pups are remaining.
Milk Fever
Milk fever is a condition which indicates low blood calcium levels and will produce many symptoms, including dog panting. Milk fever is also known by names such as puerperal tetany, ecalmpsia and hypocalcemia and can be life-threatening if not treated. This condition occurs when a female dog has trouble retaining sufficient calcium as her body converts it into the milk which feeds her puppies. If insufficient calcium levels are available, they are passed to the milk, leaving the mother dog with a depletion of this important mineral.
High Temperature
When dog panting is present, it's very important to look for other symptoms which may help you to discover if there's a problem, and what may be causing it. The most important factor will be the dog's temperature. Normal temperature for a female dog that's just given birth is around 101.5 degrees with a one-degree variation. If the dog is experiencing a fever, this is an indication that a serious problem likely exists and may quickly become an emergency situation. When the temperature is normal, however, it's usually recommended to keep a close eye for a day or two, in case other problems arise.
Prevention of Milk Fever
Especially when dog panting has led to milk fever in the past, your nursing female dog may be highly susceptible to these low calcium levels with each subsequent litter. It would seem that calcium supplements may be an option to prevent milk fever, but this is not the case. The gland that works to produce calcium and regulate it efficiently is a complex organ that will not respond favorably to an overload of calcium. Calcium and phosphorus levels must remain at a proper ratio of 1:1 in the diet. Sufficient levels of vitamin D are important, as well as feeding the pregnant and nursing dog healthy foods. Inspect the labels of commercially sold dog foods to avoid any grain-based diets, or search for recipes to make homemade meals using organic and natural ingredients.