Positional changes from standing to lying down are extremely difficult and cause severe pain. Death often follows within 48 hours of the incident as a result of acute renal failure. This type also occurs during a race where a dog exhibits stress with pain upon palpation of the basic, hindquarter and upper-arm muscle groups. This type occurs 24 to 72 hours following a race. Pain in the muscle groups and associated distress is not witnessed at the time of the race.
Heat is dissipated from the body via the circulatory system.
Hydrogen ions are eliminated from the body by a complex series of buffer systems. When an unfit dog is subjected to excessive work, there is a tremendous production of hydrogen ions that cannot be eliminated by the overcapacitated buffer systems. As a result, osmotic pressure increases within the muscle cells and causes them to swell. The swollen cells restrict local blood circulation to the muscle groups because of direct pressure on the arterioles, venules and capillary bed. The vascular constriction also prevents removal of heat from the overworked muscle, which further complicates the situation.