[Skeletal development in the dog in relation to nutrition].

Growth hormone (GH) and insulin-like growth factor I (IGF-I) play important roles during growth, including effects on enchondral ossification. GH plasma concentration is strongly influenced by the nutritional status of the dog. Fasting induces a non-responsiveness of the liver to GH, leading to a decrease in IGF-I release by the liver and a delay in growth. Overfeeding leads to abnormal skeletal development, i.e., osteochondrosis and hip dysplasia. Subnormal plasma concentrations of sex hormones lead to a delay in physiologic epiphysiodesis, whereas high levels of sex steroids may induce premature physeal closure. Dietary calcium, phosphorus, and vitamin D are important factors in the process of enchondral ossification. If these nutrients are inadequate, imbalanced, or oversupplemented, skeletal development in young growing dogs can be disturbed, leading tot severe pathologic changes. Energy requirements decrease gradually during the first year of life and unrestricted feeding can easily lead to pups being overweight. The protein requirements are strongly influenced by the quality and digestibility of protein sources in the food. In dog foods 12-14 g protein/1000 kJ appears to be adequate for growth. It is likely that the two most commonly made mistakes in dog nutrition in the Netherlands, are oversupplementation with energy and/or calcium. Restricted feeding is advised during growth and no food-additives are required when commercially prepared complete dog foods are used.