Bringing a new puppy home is an incredibly rewarding experience, filled with the joy of watching them grow and discover the world. The first seven weeks of a puppy’s life are a period of rapid development, marked by significant physical and behavioral changes. Understanding these stages is crucial for providing the best possible care and ensuring your puppy grows into a well-adjusted adult. Puppyhood is an extended process, potentially lasting up to 18 months, but these foundational weeks lay the groundwork for their future.
The Neonatal Stage: Weeks 0-2
This initial phase, spanning roughly the first four weeks, is characterized by complete dependence on the mother.
Development
Newborn puppies are fragile and require constant monitoring. It’s important to check for congenital defects like a cleft palate, which can impede nursing. Lack of hair on the tops of their feet might indicate prematurity. Daily weight gain is a critical indicator of health; any stagnation or loss can signal issues with the mother’s milk production, disease, or other medical problems, as low birth weight is linked to higher mortality rates due to risks of sepsis or hypoglycemia. The umbilical cord typically dries and falls off within three days, and this area must be checked daily for signs of infection, a common precursor to sepsis. Veterinarians will also check for umbilical or inguinal hernias during examinations.
Puppies in this stage cannot regulate their own body temperature and rely on their mother and littermates for warmth. Their rectal temperature should range from 95-99°F in the first week, increasing slightly to 97-100°F in the second week. Hypothermia can lead to reduced feeding, hypoglycemia, and even death. Fortunately, puppies develop the ability to shiver and regulate blood flow to extremities within the first week. Some toy breeds, like Chihuahuas or Miniature Dachshunds, may be born with an open fontanelle (soft spot) in their skull, which may not always close but usually doesn’t cause long-term issues.
A newborn puppy’s gastrointestinal tract is sterile at birth but quickly becomes colonized with bacteria. Meconium, a soft, yellow-brown stool, is passed in the first 48 hours. Normal stool is pasty and yellow or tan. Deviations can indicate problems: green or yellow watery stool may suggest overfeeding, white stools can point to lactose intolerance, foamy yellow stools might signal canine herpesvirus, and blood-tinged stool could be a sign of sepsis or coccidiosis.
A puppy can survive without food for about 24 hours, but beyond that, blood glucose levels decline, leading to hypoglycemia. Dehydration is also a significant concern, as puppies are composed of less than 80% water. Their developing kidneys cannot concentrate urine effectively, requiring frequent urination. Neonates have lower blood pressure and a faster heart rate, typically around 200 beats per minute, with initial breathing rates of 10-18 breaths per minute, normalizing to about 30 breaths per minute after the first day. By five to six days, they should be able to support themselves on their front legs, and by 14-16 days, on their hind legs.
Behavior
Puppies spend approximately 90% of their time sleeping, in a state of “activated sleep” that strengthens muscles. They possess reflexes like righting themselves, withdrawing from stimuli, and sucking and rooting to find a nipple. These reflexes are essential for their survival and early development.
Feeding
Mother’s milk is vital for a neonate’s immunity, gut health, and energy. Colostrum, the first milk produced, is thick and rich in antibodies, providing nearly all the immunity a puppy receives in the first 24 hours. After 24 hours, the milk composition changes to meet the puppy’s growing needs. Puppies should nurse within hours of birth, typically 8-10 times daily in the first week, with frequency decreasing thereafter.
Complications can arise, such as weak or rejected puppies. Ensuring no cleft palate is present is the first step. Small or weak puppies might need assistance with nursing, possibly via a bottle. If the mother rejects the litter, is ill, or lacks sufficient milk, finding a foster mother with a similar-aged litter is ideal. If no foster is available, a commercial or homemade puppy milk replacer can be used, under veterinary guidance. Stronger puppies may push weaker ones away, leading to malnutrition; ensuring weaker pups feed first can help. Cow or goat milk is not recommended due to nutritional imbalance.
Health Conditions
Puppies inherit immunity from their mother if she is fully vaccinated and has received colostrum within the first 16 hours. However, complications like hypothermia, dehydration, and sepsis are concerns for puppies with nursing difficulties or defects. Those without colostrum may develop gastrointestinal issues. Lack of maternal vaccination or immune support can increase susceptibility to viruses.
Vaccinations
No vaccinations are typically required during this neonatal period.
The Transitional Stage: Weeks 2-4
This stage marks the beginning of more independent development and sensory perception.
Development
Puppies typically double their birth weight by around 10-14 days. Daily or every-other-day weighing remains important for monitoring growth. Around three weeks, puppies begin to concentrate urine, leading to less frequent urination and a more yellow hue. Their elevated heart rate normalizes by about four weeks. Locomotion begins around 18-21 days, though it appears uncoordinated. Active learning commences at three weeks, with the suckling reflex still present. Puppies’ eyes and ear canals open between 10-14 days. Vision and hearing are poor initially but improve as the corneas clear and external ear canals open.
Behavior
The critical socialization window opens at three weeks and closes around 12-14 weeks. Positive interactions with new people, places, and objects during this period are vital to prevent fearfulness later in life. Abrupt weaning or separation can have lasting negative behavioral effects.
Feeding
Feeding frequency reduces to about four times a day, with the mother potentially limiting nursing duration. From three to four weeks, their diet remains liquid. Weaning begins with short separations from the mother, feeding a high-protein (25-30%) gruel made with puppy food and water, offered before nursing to decrease dependence on the mother.
Health Conditions
Environmental factors can lead to issues like sepsis, hypothermia, dehydration, and hypoglycemia. Maternal immunity typically still provides protection.
Vaccinations
Vaccinations are not yet recommended. Deworming with a veterinarian-approved general dewormer every two weeks can help reduce parasitic load until regular prevention products can be started.
The Socialization Period: Weeks 4-7
This is a crucial period for developing social skills and independence.
Development
After four weeks, puppies are no longer considered neonates. Urine leakage of glucose and protein ceases by six weeks. In male puppies, testicles should descend between four and seven weeks. Vision and hearing are now well-developed, allowing them to fully experience their surroundings. They continue to gain weight rapidly, aiming for approximately 50% of their adult body weight by four months.
Behavior
Puppies learn discipline, social skills, play, and bite inhibition through interaction with littermates and their mother. Introducing positive human interactions now helps prevent fear responses. Puppies with prior health issues may be at higher risk for behavioral problems, including aggression, fear, and separation anxiety. It’s important to consult a veterinarian for guidance. While puppies can be messy and prone to accidents, isolating them in crates can hinder learning and increase fear. Keeping them involved in family activities promotes better socialization.
Feeding
Puppies require three times the resting energy requirement to fuel their growth. They are weaned from mother’s milk, transitioning to a softened high-protein gruel. Separation periods from the mother gradually increase. By six weeks, they should be separated for about four hours daily, with full weaning typically occurring between six and eight weeks.
Health Conditions
If a puppy did not receive adequate colostrum or immune support, they are at risk for common preventable diseases like parvovirus, distemper, kennel cough, adenovirus, and leptospirosis, as well as intestinal parasites. Contact a veterinarian immediately if you suspect your puppy is ill.
Vaccinations
The DAPP vaccine series (Distemper, Adenovirus, Parvovirus, parainfluenza) can begin at six weeks, followed by boosters every two to four weeks. The Bordetella vaccine may also be administered, with the schedule depending on the formulation. All vaccinations should be given by a veterinarian to ensure proper storage and administration. Deworming continues every two weeks, and flea, tick, and heartworm prevention may begin under veterinary supervision, using puppy-specific formulations.
References
- Herron, Meghan. Veterinary Information Network. The Basics of Puppy Behavior and Problem Prevention. 2011.
- Malese, P. Veterinary Information Network. Puppy Behavior Lab: Starting Puppies Off “On the Right Paw!” 2014.
- American Animal Hospital Association. 2022 AAHA Canine Vaccination Guidelines. 2022.
- Fortney, William. Veterinary Information Network. The “Normal” Newborn Puppy and Kitten. 2010.
- Lindell, Ellen. Clinician’s Brief. Developmental Stages of Puppies. July 2020.
- Regina Humane Society Inc. Puppy Developmental Stages and Behavior.
Featured Image: iStock.com/Lakshmi3
