Puppy development

Puppies grow and change very quickly in their first few weeks of life. Knowing how they grow and develop will help you understand the changes they go through so you can ensure all their needs are being met. This is a very enjoyable stage of a puppy’s life, for mother puppies and owners.

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Newborn puppies vary in size according to breed (or mix of breeds), with smaller breeds weighing around 75-150g at birth, and larger breeds 250-350g. Whatever their starting size, puppies should double their weight in their first week of life! In the first week they may still have some of their umbilical cord attached to their tummy, but this will gradually dry out and then be lost. In the first couple of weeks puppies spend most of their time asleep or feeding and are heavily dependent on their mothers, especially for both food and warmth. They also need to be stimulated to pass wee and poo for the first few weeks and their mothers do this by licking around their anal area. Males can easily be distinguished from females from birth as they have an obvious prepuce (the sheath of the penis) just below the umbilicus (tummy button).

In the first few weeks of life puppies are unable to support their own weight, so move by crawling around on their tummies. They can paddle their limbs but not support themselves until after two weeks of age. Puppies are born completely blind and deaf (eyes and ears closed at birth) but do have the senses of taste and touch. Their eyes will start to open around 10-14 days but will be blueish and hazy in appearance, and puppies’ eyesight gradually improves until around 8 weeks of age.

Newborn puppies do not have well developed immune systems but will share their mother’s immunity to some diseases as they are able to receive antibodies in the milk produced in the first 48 hours after birth (colostrum). It is important that the mother is up to date on vaccinations so that the puppies are also protected. The mother should also have been treated for worms to prevent her passing these on to the puppies, but the puppies should also be treated at around 2, 5 and 8 weeks. Talk to your veterinarian about a suitable deworming product and protocol.

Puppies continue to grow well over the next few weeks. They begin to be able to control their body temperature and they can wee and poo by themselves, which means they become slightly less dependent on mum. Puppies are born without teeth their baby teeth come through at around 2-4 weeks (watch out for chewing at this age!) and the mother becomes less enthusiastic about them nursing so they may begin to wean.

By 3 weeks, puppies can hear, see and move around more. The world opens up to them and they start to pay more attention: observing what is normal and learning to interact with their mother and siblings, but also with people. They begin to bark and wag their tails: important methods of communication for dogs.

For puppies to develop normal toileting behaviors, they need opportunities to leave the nest and eliminate voluntarily in specific areas. This process starts at 3 to 4 weeks of age.   

Access to appropriate elimination substrates at an early age is necessary to prevent difficulty with housetraining. Puppies need opportunities to leave the nest to prevent them from soiling themselves or their sleeping area. Preferences for elimination substrates may develop by 8 weeks.   

Consequently, early experiences with substrates will influence adult dog recognition of elimination substrates later in life. It may be problematic when certain substrates are used, such as elimination pads for puppies, because they look similar to rugs, towels, or bathroom mats. The future desired elimination substrates for the puppy should be provided as early as 3 weeks of age. 

Weaning should now be progressing, with the puppies still nursing but also eating solid food a few times a day. A good quality, complete diet specifically for ‘weaning’ or ‘growth’ should be used, to give the correct balance of energy and nutrients for optimal development. Initially puppies favor wet food, or dry food softened with water. Fresh water should be readily available.

This period is also known as the first socialization window. Puppies need to remain with their mum and littermates for stability, but they are rapidly learning all about the world and finding their independence. At this stage puppies must have lots of positive interactions with different types of people of all ages, other animals and household objects to ensure confident adult dogs who are able to deal with situations they encounter in their later lives. Puppies now become more vocal, growling and barking, and they learn to play with their littermates, including the use of play stances such as the play bow, and bite inhibition.

Puppies are usually fully weaned by around 7-8 weeks of age and become much more independent, hugely keen to explore the world and confident in their interactions with people and animals they know. Around 7-8 weeks they experience their first ‘fear period’ where puppies will become wary of novel objects, animals and people, so a good amount of socialization needs to have happened before this.

The immunity from diseases that they received from their mothers will start to reduce around this time, and it is important that they start their own vaccinations. Puppies are usually vaccinated against canine distemper, canine herpesvirus, canine parvovirus, parainfluenza and leptospirosis. Dogs must also legally be microchipped and registered by 8 weeks of age.

At this stage puppies will often leave their mother and siblings to go to new homes: earlier rehoming should be avoided as the puppies would miss out on vital lessons in communication and socialization. Vaccination courses will be started, which means that careful socialization can continue in the outside world as well as in the home environment. Basic training can begin in a positive manner, including house training.

Once puppies are allowed to go outside, they can begin regular walking. Puppies are often very energetic and require a lot of stimulation, but care must be taken not to increase exercise too quickly which can put strain onto their growing joints – especially in large breeds who do not fully mature until a lot later. Plenty of training and mental stimulation such as food puzzles can be good substitutes to help reduce energy levels.

Between 3 and 6 months of age, puppies can experience ‘teething pain’ as their adult teeth come through (just as in people) and may enter a frantic chewing phase. At this stage you should give puppies plenty of suitable toys and materials to chew on to minimize damage to property and people!

From 6 months of age, puppies enter an adolescent phase. Dependent on breed they will approach sexual maturity and a discussion with your veterinarian about the best time to neuter will be helpful around this age. Puppies need continued training and socialization at this stage in order to continue to develop into confident, friendly adult dogs.