The concept of “five freedoms” is viewed as a tool to evaluate and represent nonhuman animal welfare. These freedoms are not mutually exclusive and differ in their extent of attainment at the farm level. At the herd level, the freedom
from pain, injury, and disease may be the most complicated freedom. Painful conditions, such as lameness in pigs, are seldom mentioned as challenges to pig welfare, regardless of their high prevalence. A disease such as lameness may affect all of the five freedoms. Lameness is often closely associated with pain, an important constituent of the five freedoms. Pain may persist for longer than the clinical signs and may not be visible due to hiding behavior. Inflammatory pain alters nociceptive information processing, leading to long-term adverse welfare consequences. Lameness can cause poor welfare and contribute to disease in a vicious cycle. A lame pig may not be able to move about and meet its feed and water requirements, taking away the freedom from hunger and thirst despite feed and water availability. At the herd level, shelter and resting areas are provided, considering the normal healthy pig, and sick pens are often devoted to extreme cases only. The absence of a “gold standard” restricts diagnosis of lameness and evaluation of the effectiveness of therapeutic measures when practiced. Lameness also hinders an animal’s ability to perform normal behavior. Often, conspecifics increase competition for resources and may aggravate the condition. The freedom from fear and distress is also violated when a pig becomes lame as the ability to demonstrate the survival instinct is physically restricted. Despite these obvious links between the effects of lameness and five freedoms, pig welfare is often
determined on easily measurable, systematically applied terms such as space allowance.