Changes

===Clinical signs===

===Clinical signs===

Clinical outcome depends on the susceptibility of pigs and virulence of the strain of erysipelas. Pigs are susceptible after maternal antibody has waned (after 3 months) and before protective immunity is acquired (3 years).

Clinical outcome depends on the susceptibility of the pig and the virulence of the strain of Erysipelas. Pigs are susceptible after maternal antibody has waned (after 3 months) and before protective immunity is acquired (3 years).

Changes in diet, extremes of temperature and fatigue are thought to predispose to infection.

Changes in diet, extremes of temperature and fatigue are thought to predispose to infection.

3 forms of disease occur: Hyperacute, Acute and Chronic.  

3 forms of disease occur: Hyperacute, Acute and Chronic.  

The hyperacute form is more common in younger pigs, who may present dull, collapsed or pyrexic with a scarlet tinge to the skin. This form can also present with cases of sudden death.

Sudden death, more common in younger pigs. May be found dull, collapsed or pyrexic with a scarlet tinge to the skin.

In the acute form, anorexia and pyrexia are the two most common clinical signs in younger pigs. Affected animals still die but normally after a day during which time they become dyspnoic. Older pigs tend to be pyrexic, anorexic and polydypsic.

Anorexia and pyrexia are the two most common clinical signs of the acute form in young pigs. Affected animals still die but normally after a day during which time they become dyspnoic.  

All pigs show, pink/purple raised areas or extensive diamond-shaped plaques over the skin within 24-48 hours of developing clinical signs. If pregnant sows are infected at this time they may abort.

Older pigs tend to be pyrexic, anorexic and polydypsic.

Pigs show, pink/purple raised areas or extensive diamond-shaped plaques over the skin within 24-48 hours of developing clinical signs. If pregnant sows are infected at this time they may abort.

Following the chronic form of the disease, affected animals can completely recover, sometimes lesions resolve within a week however they can become necrotic and slough.  

Affected animals can completely recover, lesions may resolve within a week, or become necrotic and slough. Ear tips may also be lost.  

The bacteria localises in joints causing destruction of the synovial membrane lining, hyperaemia, villus formation and lymphocyte and plasma cell infiltration resulting in chronic serofibrinous polyarthritis.

The bacteria localises in joints causing destruction of the synovial membrane lining, hyperaemia, villus formation and lymphocyte and plasma cell infiltration resulting in '''chronic serofibrinous polyarthritis.

Initially joints are hot and swollen leading to stiffness, lameness, non-weight bearing on affected limbs and eventual ankylosis. Discospondylitis can also occur if animals are chronically affected.

Initially joints are hot and swollen leading to stiffness, lameness, non-weight bearing on affected limbs and eventual ankylosis.

Discospondylitis can also occur.

Additionally valvular lesions may develop in the heart causing chronic valvular [[Endocarditis| endocarditis]], vegetative thrombosis of mitral valves and asymptomatic or congestive heart failure sometimes resulting in sudden death following stress.

Additionally valvular lesions may develop in the heart causing chronic valvular [[Endocarditis| endocarditis]], vegetative thrombosis of mitral valves and asymptomatic or congestive heart failure sometimes resulting in sudden death following stress.