The First Weeks: A Pet Parent’s Guide to Feeding Newborn Puppies and Kittens

Why the first 48 hours decide so much, what’s really in mom’s milk, the milestones to watch, and how to hand-raise an orphan if you have to.

Newborn puppies and kittens are born altricial, meaning helpless and completely dependent on their mother. They can’t regulate their own temperature, can’t see or hear for the first couple of weeks, and rely entirely on her for warmth, food, and immunity. It’s a fragile window: preweaning mortality is estimated as high as 40 percent, and most of those losses happen in the neonatal period, the first two weeks. Good nutrition and good management in this stretch genuinely save lives. Here’s what matters most, from the first nursing to the day they’re eating on their own, plus what to do if you find yourself raising an orphan.

The First 48 Hours: Why Colostrum Is Everything

In the first few days after giving birth, a dog or cat produces colostrum, a special first milk that delivers two things at once: concentrated nutrition and passive immunity. The immunity comes as antibodies (immunoglobulins) plus bioactive factors like lysozyme, an enzyme that blocks certain bacteria, and a lipase that helps newborns digest fat. Since a puppy or kitten’s own immune system isn’t fully developed until about 16 weeks of age, this borrowed protection is what keeps them alive in the meantime.

Here’s the catch that makes timing critical. Because of the structure of the canine and feline placenta, only about 10 to 20 percent of immunity transfers in the womb, the rest has to come through colostrum after birth. And the newborn gut can only absorb those intact antibodies for a very short window. A change called “closure” shuts that absorption down at around 48 hours of life.

The single most important nutritional event of a newborn’s life is getting adequate colostrum as soon as possible on the first day. Miss that roughly 48-hour window and the door to passive immunity closes, no later feeding can make it up.

Colostrum does one more quietly vital job: the fluid itself helps fill out the newborn’s circulating blood volume. Water turnover in neonates is very high, so steady fluid intake, and good milk production from the mother, matters as much as the milk’s nutrient content in these first days.

What’s Really in Mom’s Milk

Milk isn’t a fixed recipe; it shifts across lactation to match the litter’s changing needs. Dog and cat milk are both far richer than the cow or goat milk people sometimes reach for: they draw more calories from fat and protein and contain proportionally less lactose. Dog milk in particular is higher in fat and energy than cat milk. Both are notably high in iron and in calcium, which rises as lactation goes on.

Fatty acids deserve special mention. The long-chain omega-3 DHA is essential for normal brain and retinal development, and a newborn’s ability to make its own DHA is very limited, then disappears entirely after weaning. The milk only becomes rich in DHA and arachidonic acid if the mother’s own diet supplies them. That’s the real reason a quality reproduction diet during pregnancy and nursing matters so much: it’s how these critical fats reach the babies.

Knowing What Normal Looks Like

For the first weeks, a newborn’s whole job is eating and sleeping. They should nurse every few hours, at least four to six times a day, because their stomachs are tiny and can only hold a little at a time. Weak or infrequent nursing is a red flag, it often signals chilling, illness, or a congenital problem, and warrants immediate attention from an experienced breeder or vet. The developmental milestones are a useful yardstick: eyes open between 10 and 16 days, ears start working between 15 and 17 days, and the deciduous (baby) teeth come in between 21 and 35 days.

Temperature is a matter of survival. Newborns have no shivering reflex for their first six days, so they depend on an outside heat source, and the mother is the best one. Normal body temperature is low by adult standards, about 94 to 97°F for puppies and around 95°F for kittens in the first two weeks, climbing to the adult ~101.5°F by four to five weeks. Keep the environment warm (around 70°F when the dam is present) and free of drafts; chilling is one of the biggest threats to a newborn.

Track growth by weighing daily for the first two weeks, then every few days until weaning. A handy rule for puppies: they should gain roughly 1 to 2 grams per day for every pound of expected adult weight over the first three to four weeks, so a puppy headed toward 25 pounds should put on about 25 to 50 grams a day. Kittens are typically born at 90 to 110 grams and should gain 50 to 100 grams per week until they’re five to six months old.

Behind the scenes, a newborn’s digestive system is finely matched to milk: high lactase activity to handle milk sugar, the ability to digest milk fat very early, and milk protein supplied at exactly the quality and quantity their still-developing kidneys can handle. The mother’s milk alone supports normal growth until about three to four weeks of age. Supplemental milk replacer usually isn’t needed except with unusually large litters, and even then, splitting the litter into two groups that nurse every three to four hours often solves it.

Weaning: Introducing Solid Food

Around three to four weeks, two things line up: the mother’s milk can no longer fully meet the litter’s needs, and the babies become developmentally ready for semisolid food. Start them on a commercial food made for weaning, or a thick gruel of the mother’s food mixed with warm water, served in a shallow dish a few times a day, with the bowl removed after 20 to 30 minutes.

Don’t use cow’s milk to make the gruel, it has far more lactose than dog or cat milk and will cause diarrhea. And skip homemade “weaning formulas” unless you know their exact nutrient composition; many simply aren’t complete or balanced.

At first they’ll eat very little and keep nursing as their main meal, but by five weeks most are readily eating semisolid food, and by five to six weeks they can chew dry food. Nutritional weaning is usually complete by six weeks. Complete weaning, though, shouldn’t be forced until at least seven to eight weeks of age: by then the value of suckling is as much emotional and psychological as nutritional, and that extra time with the mother matters.

Raising Orphans: When You Become Mom

An orphan is any newborn without access to its mother’s milk and care, whether through the dam’s death, inadequate or poor-quality milk, or rejection of the litter. Hand-raising is hard, but with the right environment, diet, and technique, orphaned puppies and kittens can grow up perfectly healthy.

Environment comes first, because chilling kills. Without the mother’s body heat, you have to supply warmth: keep the ambient temperature around 85 to 90°F in week one, 80 to 85°F in weeks two through four, 70 to 75°F in week five, and about 70°F after six weeks. A heating pad is often better than a lamp because it preserves a normal day/night light cycle, and the heat source should create a gradient so the babies can move toward warmth or away from it. Keep humidity around 50 percent so they don’t dehydrate, and the box clean.

For food, a same-species foster mother is ideal but rarely available, so a commercial milk replacer is the next best, and preferred, option. Choose one formulated and tested specifically for puppies or kittens, with a nutrient profile that closely matches dog or cat milk.

Never feed orphaned puppies or kittens straight cow’s or goat’s milk, the lactose is far too high and causes severe diarrhea, and the protein balance is wrong. Avoid homemade formulas too, unless their exact composition is known and proven safe; most were built by trial and error and vary wildly. Remember as well that no milk replacer contains colostrum’s antibodies, so an orphan that never nursed colostrum needs an especially clean environment.

How much depends on age and weight, but in the early weeks intake is capped by stomach size: most newborn puppies handle only 10 to 20 ml per feeding, and kittens about a third to half of that, so the formula’s concentration matters. As a rough guide, orphaned puppies need about 130 to 150 kcal per kg of body weight daily for the first three weeks, rising to 200 to 220 kcal/kg after four weeks. Feed four to six times a day at even intervals, weigh regularly, and expect a slight dip in weight over the first two to three days as they adjust before steady growth kicks in.

You can bottle-feed or tube-feed. Bottle-feeding lets the baby suckle naturally and self-regulate, hold them in a natural nursing position with the head tilted slightly up and use a nipple that fills the mouth. Tube-feeding is faster and lowers aspiration risk in skilled hands, but the neonate can’t self-regulate, so the volume must be measured carefully every time. Warm fresh formula to about 100°F, and feed a slightly reduced amount for the first two or three feedings to ease the transition.

One job the mother normally does that’s easy to forget: after each feeding, gently massage the newborn’s anal and genital area with a damp cloth. This mimics her licking and stimulates urination and defecation, which orphans can’t do on their own at first.

The Pawchika Newborn Checklist

First days:

Make sure every newborn nurses colostrum within the first day, the immunity window closes around 48 hours.

Keep the whelping area warm and draft-free; newborns can’t shiver for their first six days.

Weigh daily for two weeks; watch for weak or infrequent nursing as an early warning sign.

Weaning:

Introduce a weaning food or warm-water gruel at three to four weeks in a shallow dish; never use cow’s milk.

Aim for nutritional weaning by six weeks, but don’t fully separate until seven to eight weeks.

If hand-raising orphans:

Use a tested commercial milk replacer that matches dog/cat milk; never cow’s or goat’s milk.

Hold the right temperature for their age, feed four to six times daily, and weigh regularly.

Stimulate elimination with a damp cloth after each feeding until they can go on their own.

The Pawchika Bottom Line

The newborn weeks reward attention to a few non-negotiables: colostrum in the first day, constant warmth, frequent small feedings, and steady weight gain. The mother does almost all of this naturally, and a good reproduction diet for her is what stocks her milk with the protein, energy, and DHA her babies need. When she can’t, a tested milk replacer and careful, clock-driven care can carry a litter through, just never reach for the cow’s milk in the fridge.