Dog Muscular System
-All Muscles

The view and inspect all dog muscles, we hold the puppy by the neck and lift it carefully.
In this situation we will notice three different stages:

• From 0-5 days, is a flexing stage, the puppy with flex its extremities and spike;
• From 5-18 days this stage prevails and you can notice that all of the puppies extremities are extended;
• After the 18 days a balance is reached between flexing and extending their muscles, so now the puppy lets his extremities hang.

The Reflexes System: We can take into consideration several primary reflexes.

• The searching reflex: we hollow the palm of hour hand so that the puppy can stick its nose in. Instinctively the puppy will introduce its nose and will push forward.
• The lip reflex: if we touch the puppy's lips with one finger, its lips and tongue will begin movement.
• The suction reflex: if we introduce our finger inside the puppy's mouth it will apply the sucking motion.
• The cross-extension reflex: holding the puppy from its back, we pinch one of the posterior paws. The leg being pinched is flexed.

The Senses

• Taste: at birth the puppy has this sense well developed. If we place a sweet substance on its tongue, it will swallow. If we do the same with something bitter it won't like it.
• Smell: the smell is not well developed at birth. Nevertheless, if we cover the teats with a substance with a particular smell, the puppy with go straight to those teats.
• Vision: at birth the puppy cannot see, but their eyes have this contraction reflex to touch. Five days after the puppy is born his pupils contract when light is shined at them. After twenty days if we place the puppy in a dark room and shine a bright light, it will face the light.
• Hearing: at birth the puppy cannot hear. Twenty eight days later the reflex of startling to an intense sound appears. Twenty five days after birth the puppy turns its head towards the direction where the noise is coming from.

Muscle Growth: The puppy's development depends on its feeding. At birth, its skeleton consists of mostly cartilage, which will harden as it grows. Bone is formed protein, on which mineral substances are deposited. The dog will have completed its growth after about fourteen months. The period of maximum growth, when the puppy requires the most nutrition is between four to eight months after it is born. The formation of the bones requires the contribution of, proteins, calcium, phosphorous, magnesium, iodine, manganese, zinc, vitamins A, B6 and D. Different breeds the amount of calcium needed is sufficient in the food. On the other hand for the bigger breeds it is necessary that there is a calcium supplement that comes with its respective amount of vitamin D so that the dog can absorb the minerals. In the market we will find specific products for dogs in their growing stage. If the dog is fed with home made food, it should include meat, fish, guts, rice or pasta, and fat. A calcium and phosphorous supplement must also be added.