The growth and development of puppies, their characteristic features, largely depend on their age. In order to properly organize the cultivation and upbringing of a puppy, you need to know and consider these features.
“By growth we understand the process of increasing the size of an organism, its mass, which occurs due to the accumulation of active, mainly protein, substances in it.” The growth of a dog is accompanied by an increase in its body mass and a change in its proportions.
“Under the development of the animal is understood the process of complicating the body, specialization and differentiation of its organs and tissues. In other words, development is a qualitative process that every organism goes through from a fertilized egg to an adult, capable of reproduction and similar in basic features to the parent organism. ”
The growth and development of puppies depends not only on their age, but also on the inherited makings received from their parents, as well as on their gender, conditions of keeping and growing, the number of puppies in litters. Males in most cases have greater growth and greater body weight. As a rule, puppies in small litters (two to five puppies) are larger than in large litters (eight to ten puppies or more).
Since ancient times in the practice of official dog breeding, there are five main stages of dog growth and development: intrauterine (embryonic) lasting 58–66 days, lactating - from birth to 30–45 days of age, puppies - from 1–1.5 to 6 months, young animals - from 6 to 8–10 months, young dogs from 8–10 months to 2–2.5 years.
A great contribution to the study of age-related characteristics of the growth and development of puppies was made by scientists of the I.P. Institute of Physiology Pavlov Academy of Sciences of the USSR (N.M. Vavilova, V.G. Kassil and others). They identified four periods in the individual life of dogs from birth to puberty and described in detail the changes that puppies' bodies undergo, their behavior in each of these periods. In addition, they made important practical, scientifically based recommendations for the education and initial training of puppies.
The first period: from the 1st to the 18-21st day of a puppy's life - a period of mostly unconditionally reflex adaptation.
Puppies are born blind and deaf, not adapted to independent life, in need of constant maternal care. However, from the first day of life, they are able to crawl a bit, find nipples and suck mother’s milk. Of the sensory organs, they function olfactory, gustatory, skin-temperature and vestibular. There is a large daily increase in body weight, including the brain. Puppies sleep most of the day. By the 15-18th day of life, they already see and hear, are able to perceive and differentiate (distinguish) environmental objects, develop conditioned reflexes, and form numerous conditioned reflex connections. By the 18-21st day of life, puppies are able to stand, walk, and then run, show a clear indicative reaction to external stimuli and develop defensive conditioned reflexes. Since that time, they gain life experience, learn to adapt to life in a constantly changing environment.
The second period: from 18-21 to 30-35 days - the period of primary conditioned reflex adaptation. As in the first period, there is an intensive daily increase in body weight, including the brain. Puppies become able to develop conditioned reflexes not only for food stimuli (dainty), but also for defensive reinforcement (hand pressure, etc.). However, the rate of formation of conditioned reflexes is still low; repeated exercises are required.
Puppies periodically depart from their mothers, get acquainted with the surrounding objects, participate in games with peers, gain life experience.
The third period: from 5-6 to 8-12 weeks - the period is exalted. This is the most important period in terms of the possibilities of raising and initial training puppies. The daily increase in body weight, including the brain, slows down. Puppies live already without a mother, all owners and their owners take care of their upbringing.
At this age, puppies are very similar in behavior. They are affectionate, inquisitive, contact. Their behavior is dominated by research activity. If in the second period of life when meeting with external stimuli (people, animals, etc.), the puppies are only wary, then in the third they approach them and try to examine them. So, for example, when meeting with strangers, they run up to them, sniff, caress, jump, and sometimes bark maliciously.
During this period, they easily develop positive skills associated with any activity. Therefore, starting from 1.5–2 months of age, after the puppy is accustomed to the nickname, one should proceed to the training to execute the commands “Place”, “To me”, “Walk”. At the same time, in the third period of life it is still difficult for puppies to develop inhibitory reactions necessary to train puppies to execute commands such as “Sit”, “Lie”, “Fu” only from the end of the third and beginning of the fourth period of puppies' life, when they already able to show inhibitory reactions. Failure to comply with this rule will nullify your efforts, and with a strong overload, the puppy cannot experience excessive braking, which in turn can cause an animal's disease.
In the third period, regular walks are required, gradually increasing in time and complexity of the environment, both for physical development and for the accumulation of puppy's life experience.
The fourth period: from 3-4 to 6-7 months - the period of formation of typological characteristics of the nervous system.
An observant dog breeder will notice that if puppies of 1.5–3 months of age are similar in behavior, then starting from 3-4 months their behavior is markedly different. Animals are revealed that exhibit a passive-defensive reaction to strangers and other complex stimuli. When meeting strangers, they do not run up to them, do not start a game, they just watch them from the side, and at the first manifestation by strangers of not even sharply expressed threatening actions, some puppies run away. Thus, from 3-4 months of age, the intensity of research activity decreases markedly and passive-defensive behavior is manifested.
The nature of the manifestation of a passive-defensive reaction is also noticeably changing. In young puppies, it arises only on simple stimuli, for example, on sudden light, sound, etc., perceived by appropriate analyzers (sensory organs). With proper upbringing (distracting the puppy with a game, a treat, and calming him down), this reaction quickly passes and is replaced by an orienting reflex (OR). In puppies 3-4 months of age or older, a passive defensive reaction is manifested not only to simple, isolated stimuli, but also to more complex, complex ones, such as new objects, people, animals. At this age, puppies are already able to exhibit analytical and synthetic activity. However, it should be borne in mind that the extinction of the passive-defensive reaction to complex stimuli occurs more slowly than to simple stimuli, and requires the owner of the puppy to take gentle, gentle treatment and repeatedly repeat the situation in which it manifests itself.
Changing the behavior of puppies from 3-4 months of age, namely the manifestation of a passive - defensive reaction, requires owners to pay increased attention, calm handling, timely adoption of measures to calm the animals.
It should be borne in mind that the puppies showed a passive defensive reaction only for the vast majority of puppies, but it can occur earlier (from 2–2.5 months of age) and later (after 4 months of age), which depends on the individual characteristics of the puppies and their breed.
6 period (from 1 to 3 years)
At this time, the dog’s attempts to impose his own line of behavior on you (take a dominant position) are quite likely. Inappropriate actions are also possible (unexpected aggression towards people and animals). Your task is to maintain perseverance, patience, firmness and self-control in the relationship, while not forgetting to maintain an adequate relationship with the pet, using good, gentle, but at the same time confident intonations. Becoming a leader for a dog is a difficult and painstaking task; you should conduct training and education classes during this period constantly. The dog is finally formed in the sexual plan, the processes of mental and physical development are completed.
8 period (from 7–8 to 10–12 years)
At this age, changes in dog behavior begin to occur. She loses her energy, becomes unable to quickly execute some commands, sometimes does not want to be alone for a long time, suffers from sleep disturbance. Alone, it can howl or bark for a long time, does not observe cleanliness (inflammatory diseases of the intestines, bladder, etc.). Possible impairment of vision and hearing. Some dogs may react nervously to various noises. You must be prepared for these changes, naturally perceive them and stock up on understanding and patience. Constant contact with a veterinarian is required.