VMC 221: Veterinary Immunology and Serology (1+1)

ACUTE ANAPHYLAXIS

• In cattle acute anaphylaxis is due to pulmonary hypertension.
• This is due to constriction of pulmonary veins leading to pulmonary oedema and severe dyspnoea.
• The smooth muscle of the bladder and intestine contract causing urination, defecation and bloting.
• The main mediators are serotonin (histamine is much less), kinins and leukotrienes.
• Heparin released from mast cells does not allow blood coagulation.