The first 8 weeks of life are a time of incredible growth and development for puppies and kittens. While most pet parents meet their new companions after this stage, breeders, rescue workers, and fosters play a vital role in providing the care and support needed to help these young animals thrive.
From nutrition to socialization, every week brings new milestones, challenges, and moments of discovery. Let’s explore what happens in these formative weeks that set puppies and kittens up for a healthy, happy life.
Neonatal Stage (Week 0-2): Welcome to the World
Care: Newborn puppies and kittens are blind, deaf, and completely dependent on their mother (or a caregiver). They need a warm, quiet, and safe environment. If the mother is not present, they must be kept at a steady temperature of around 85-90°F.
Feeding: Newborns nurse frequently, about every 2 hours. In cases where the mother is absent or rejects her litter, finding a foster mother with a litter of similar age can be a lifesaving solution.
If this is not possible, bottle-feeding with milk replacer using proper technique and hygiene is essential to ensure their survival.
Physical Development: They mostly sleep and eat at this time. Their tiny bodies are focused on growing, and they rely on their sense of smell to find their mother. At birth, they still have their umbilical cord attached, which typically dries up and falls off within the first few days (around 3-5 days old). Caregivers should monitor the area for any signs of redness, swelling, or discharge, which could indicate an infection.
Some toy breed puppies may also be born with a fontanelle—a soft spot on the skull where the bones have not yet fused. In most cases, this closes as they grow.
Behavioral Development: At this stage, they are instinct-driven and will huddle together for warmth and security. They are uncoordinated but begin to learn how to move by crawling and they are gradually developing the ability to hold their heads up.
Newborns also respond to stimuli, wiggling or making small vocalizations when touched or picked up. These early reflexes help them communicate their needs and find comfort from their mother or caregiver.
Tip: Weighing them daily to ensure they are gaining weight. Lack of weight gain could signal a health issue.
Common Issue: Dehydration. If a puppy or kitten is lethargic or has dry gums, they may not be getting enough milk.
Transitional Stage (Week 2-4): Eyes Open and First Steps
Care: Kittens & puppies need warmth and a clean, soft sleeping area. Gently handle them to introduce human touch, as the critical socialization window is from week 3 to week 12-14. Deworming is recommended starting at 2 weeks, as long as they are healthy, and repeating every 2-3 weeks.
Feeding: Fully dependent on mom or caregiver as they are still nursing or bottle-feeding every 3-5 hours.
Physical Development: Their eyes begin to open (usually between days 10-14), but their vision is still blurry. Their ear canals open around the third week, and ears appear small and rounded.
All eyes will be blue and become their permanent colour overtime. Baby teeth start to emerge, starting with the front teeth, incisors. At this stage, they begin taking their first wobbly steps.
Behavioral Development: They start making little sounds and reacting more to their environment. By week 3, they begin recognizing littermates and engaging in early play.
Tip: It’s important to let their eyes open on their own, as one may open faster than the other. Avoid intervening or trying to manually open their eyes, as this can cause harm.
Common Issue: Eye infections can occur. If their eyes look swollen or gooey, gently wipe with a warm, damp cloth and contact your veterinarian.
Socialization Stage (Week 4-6): Playtime and Learning
Care: Socialization is key during this period. Provide a safe, stimulating environment with gentle handling and exposure to different sounds and textures. We want to start giving mom a break for a few hours to ease the separation process later.
Feeding: Start offering soft, moistened puppy or kitten food alongside nursing. By week 5, they will eat more solid food and nurse less frequently. Have water available at all times.
Physical Development: Their vision and hearing continue to develop. More baby teeth are appearing including canine and premolars. They become more coordinated, playing actively with their littermates and exploring their surroundings.
Behavioral Development: They start developing personalities, playing, and engaging in social behaviors. Puppies and kittens learn bite inhibition from their littermates and mom.
Tip: Introduce a shallow, easy to enter litter box for kittens and puppy pads for puppies. Positive reinforcement is crucial for early training.
Common Issue: They may experience teething discomfort. Provide soft chew toys to ease irritation.
Juvenile Stage (Week 6-8): Independence and Confidence
Care: At this stage, they benefit from a structured routine for feeding, playing, and sleeping. Continue positive socialization and introduce gentle training techniques. At 6 weeks, healthy puppy and kittens are able to get their 1st round of vaccinations against viruses they will be commonly expose to.
For puppies this includes Distemper, Adenovirus, Parainfluenza and Parvovirus, in vaccine called DAPP/DA2PP. For kittens, they are protecting against Rhinotracheitis, Calicivirus, and panleukopenia in a vaccine called FVRCP. From here they will receive a booster in 2-4 weeks.
Feeding: They are fully transitioned to solid food by week 7 and should be eating a high-quality puppy or kitten diet. Water should always be available.
Physical Development: Their motor skills improve, making them more energetic and curious. They have more stamina and are ready for longer play sessions. Able to run and play, and kittens are comfortable jumping off furniture.
Males’ testicles may have descended at this stage. By the end of week 8 all baby teeth and permanent eye colour will be present.
Behavioral Development: Will observe a spike in energy. Puppies and kittens will be more confident, independent and wanting to interact. Seeking out playtime with littermates, mom, and humans. They start responding to names and simple commands.
Tip: Expose them to new environments and people to build confidence. Additional periods of alone time for mom help prevent separation anxiety.
Common Issue: Adjustment to a new home can be stressful. A familiar blanket or toy helps provide comfort during transitions.
The early weeks of a puppy’s or kitten’s life are full of growth, discovery, and crucial development. These stages require patience, care, and close attention to their needs.
For future pet owners, understanding these milestones provides insight into the experiences that shape their new companion before they come home. Whether you’re raising a litter or preparing to welcome a new pet, these first 8 weeks lay the foundation for a lifetime of health, happiness, and love!
