An acute disease starts quickly and lasts for a short period when the animal either recovers or dies.
A chronic disease lasts for a long time and weakens the animal.
Diseases are said to be infectious (will spread from one animal to another) or noninfectious (will not spread from one animal to another).
Non-infectious diseases can be caused by poor feed and the lack of minerals, salts and vitamins that the body needs.
Non-infectious disease can also be caused by poisoning with chemicals or plants, by cuts, burns and broken bones.
Some diseases pass from the parent to the young (hereditary).
Many non-infectious diseases are chronic but they can be acute. They can cause large losses of meat, milk and wool. Working (draught) animals do not work well and the rate of reproduction can be low with the young being born dead or dying before they are weaned.
Chronic diseases are often thought to be "normal" but when the cause is known and eliminated production can be greatly increased.
Infectious diseases are caused when the body is attacked by tiny living germs.
Spread of disease
Infectious diseases can be spread by:
Direct contact between animals.
Germs in feed and water.
By faeces and urine from sick animals.
By flies, ticks, lice and fleas.
By dirty housing or shelters.
Young and old animals become infected more easily.
Preventing infectious diseases
Animals, like humans, must be clean in order to be healthy. The animal must be provided with clean feed, water, bedding and shelter.
Sick animals should be kept separate from the others.
Some diseases can be cured by drugs.
Vaccination can protect animals against some diseases.
Dead animals and waste should be disposed of.
Preventing non-infectious diseases
The chronic non-infectious disease may not be recognized as a disease.
The affected animals may not die but will not produce as much milk, meat or wool, or work as well as could be expected.
If we continually look for ways of improving feed, water, mineral and vitamin supplies we will find the way to control the non-infectious diseases.
This will lead to greater production of wool, meat and milk, draught animals will be stronger and more young will be produced.