The cause of disease

monica

  The Causes of DiseaseIt is likely that when considering the causes of disease you think first of infectious micro-organisms. You would be right to do so in that infectious disease plays a much bigger role in pig herds, particularly large intensive pig herds, than in animals kept individually such as dogs and cats. Nevertheless there are other non-infectious causes of disease which may also be damaging to the herd and to productivity and profitability. Causes of disease are considered here under nine main headines :
Infectious agents : Viruses ;Bacteria including; Chlamydia, Anaplasma and Mycoplasma ;Fungi ,Parasites
Non infectious agents : Trauma,Hereditary and congenital defects (developmental abnormalities),Nutritional deficiencies and excesses ,Toxic agents (poisons),Stress .



[ 本帖最后由 monica 于 2007-5-4 00:42 编辑 ]

山中的漫游者

today，stress maybe the first factor for pig's disease,such as high-fever disease.

hyy1012

what are the causes of stress upon all animals? environment, nutrition, disease, animal welfare or human?