Summer 2010

Since 1967, Royal Canin has been at the forefront of developing innovative nutritional responses in the field of dog breeding. Even if nutrition is fundamental in breeding, it cannot give all the keys for success. Application of reproduction techniques is the deciding factor.

Breeder's Handbook: Maternal Behavior

By Bretaigne Jones, DVM
Senior Veterinary Services Manager

One of the best traits a bitch can have in the eyes of a breeder is good mothering ability. Unfortunately, the mothering behavior of the bitch or the female relatives of the stud dog (especially mothers and daughters) is not often a primary consideration when choosing the dogs to be bred. Mothering ability has a strong hereditary aspect, but other factors exert influence as well.

Hormonal aspects of maternal behavior
There are four hormones that trigger aspects of mothering behavior: estrogen, progesterone, prolactin, and oxytocin.

Estrogen is the most active hormone in reproduction from its primary actions in stimulating the physical and behavioral changes associated with estrus (swollen vulva, bloody vulvar discharge, and pheromones to attract male dogs), to its secondary role as a primer for mammary development, lactation, and maternal behavior. In order for the estrogen molecule to trigger a response, the target tissue must have estrogen receptors on the cell membranes. The location of the receptors within the brain and their concentration will determine the type and strength of the response.

The second maternal hormone, progesterone, is recognized as the pregnancy hormone. The ovarian follicular cells start to change after ovulation and secrete progesterone to maintain pregnancy. It has some effect on inducing maternal behavior, particularly when its receptors are primed with estrogen.

Just before birthing, progesterone levels drop abruptly, with a concurrent rise in prolactin, the third maternal hormone. This combination of level changes seems to be largely responsible for stimulating immediate mothering behavior such as nesting and protective maternal aggression. Prolactin’s function is largely stimulatory for lactation. Both actions of prolactin, maternal behavior and lactation, are enhanced if estrogen has “primed” the tissues.

Lastly, oxytocin is released from the pituitary gland in response to the physical pressure of a puppy against the cervix during labor. One of the actions of oxytocin is to synchronize contractions of the uterus in birthing and to stimulate the let-down of milk. In conjunction with the other hormones, it stimulates maternal recognition of her pups and care behavior.

Behavioral elements of mothering    
Other than the behavior exhibited in the estrus cycle and breeding, there are not behaviors specifically associated with pregnancy until the dam nears labor and delivery. At that time, she will exhibit nesting behavior, typically searching out a protected, private place where she can feel safe.

Once the puppies are born, if appropriate hormonal activity has occurred, the dam will begin her mothering by licking them. Initially it is the scent of her amniotic fluid that communicates that the puppies are hers. The dam performs the licking in order to stimulate breathing and to dry the pups’ coats. Later she will lick the genitalia of each pup to stimulate urination and defecation since the pups won’t eliminate on their own until about three weeks of age. The bitch will also use licking on the heads of the pups to guide them to nurse.

Negative maternal behaviors    
Some postpartum behaviors, however, are undesirable. Dams may be aggressive to their pups, especially when the pups are making noise. Causes of this aggression can be varied. The first consideration is if the bitch is in pain. Mastitis is a condition that can cause pain and can trigger aggressive behavior toward the pups. Aggression can also be triggered if the bitch does not recognize the pups as her own. Inadequate levels of oxytocin can influence this recognition, as the hormone makes the brain receptive to the amniotic fluid smell immediately after birth and pheromone secretion. Another factor is if the pups are removed and cleaned up so thoroughly immediately after being born that when returned to the bitch they no longer have the amniotic fluid scent to identify them as hers.

In extreme cases, aggression can escalate to cannibalism of one or more of the pups. This type of cannibalism is called kronism. Again, pain can be the cause, and as before, mastitis needs to be considered.

Another trigger is pre-eclampsia, a condition where the bitch’s blood calcium (unbound) is too low, but she isn’t yet exhibiting the classic signs of seizures, fever and weakness. Other causes can be hereditary (a lack of estrogen receptors, which negatively impacts the action of other hormones), psychological (first-time mom, very nervous, and so on), and physiological (elevated neurotransmitter release due to too much noise, too much foot traffic in the nursery, overcrowding in the nursery area, and other stimuli.).

On a less aggressive level, rejection of the pups can also be a problem. If it is just one or two pups, it may indicate something is wrong with those particular pups; whereas if it is the entire litter, the problem usually lies with the dam. It can be more common in first-litter bitches. Usually if it involves just one or two pups, they may be cold or too still.

The three big threats to the survival of neonates are hypothermia, hypoglycemia, and dehydration. If caught soon enough, the pup can be slowly warmed, or if dehydrated, it can be bottle fed to stimulate activity. Warning: One should never attempt to feed a cold puppy, as they are not capable of swallowing and may aspirate the milk into their lungs instead. Once the puppy has reestablished a normal body temperature, the dam will accept it. It is important to note that occasionally rejection will escalate to cannibalism.

Summing up
In summary, maternal behavior is a composite of hormonal, physiological, and genetic factors.

Undesirable maternal behavior can be triggered by a variety of factors, such as hormonal (lack of receptors, inadequate production, or lack of stimulation), inexperience, nervous disposition, stress, or in reaction to pain.

It is important to consider all of these factors when assessing a bitch’s mothering ability.

© 2010 ROYAL CANIN USA, Inc.
All photos courtesy of Royal Canin

Ronald N. Rella, Director, Breeder Services
Customer Service | Phone: 919-233-9767 | Email:

© The American Kennel Club 2010