Slowed growth and below-normal weight gain usually happen at the same time, although occasionally they develop separately.

By definition a decrease in growth and weight gain is limited to the growing animal. Similar pathogenic mechanisms cause weight loss or an emaciated condition in an adult patient.

Potential growth and weight gain are genetically and partially environmentally determined.¹ They differ according to species, breed, and sex, and marked differences in potential growth exist within a breed. In ruminants the size is greater in the offspring of multiparous females than in those from primiparous females at birth, but the potential for growth may not differ overall.^2-5 The normal or minimum growth and weight gain rates for common breeds of the various large animal species are outlined in the section on assessment of growth and weight gains.