Failure to grow

Natural growth is defined as the normal increase in the size of an individu al. In the dog and the cat, growth occurs in the first 6 to 24 months of li fe. Many factors contribute to the normal development and growth of an anim al. Genetics, environmental influences, endocrine and metabolic processes, nutrition, and concurrent disease should be considered when failure to grow is observed. This failure may manifest itself as an abnormal rate of growt h or a decreased extent of growth. Failure to grow is a relative concept; as such, it requires knowledge of th e expected growth pattern of the specific individual. Owners may not notice that an individual animal does not increase in size appropriately, and thi s may only be determined at the time of the first physical examination by a veterinarian. Determination of appropriate growth for an individual can be difficult in veterinary medicine, because breed sizes vary and many mixed- breed animals exist. With a purebred animal, animals of the same age, gende r, and breed can be used as a reference when growth development is uncertai n. With mixed-breed animals, littermates of the same gender can be used for comparison if they are available. If littermate sizes and development are not known, comparison with the normal growth pattern of an individual of th e same age and gender within the main breed of the mix can be attempted. The growth of an animal is influenced by many factors; as such, it may be d ifficult to determine the specific contribution of each of the different fa ctors involved. For example, an individual animal with a disease process ma y not grow due to energy loss caused by the disease itself; at the same tim e, it may be unable or unwilling to take in sufficient nutrition as result of a concurrent decrease in appetite. Consideration of the duration of abno rmal growth may also be helpful in determining the underlying condition(s).