Reactions of Animals to Diseases

Depending on the health status of the animal, it may respond to the invasion in any of the following processes:

1. Susceptibility: Disease Susceptibility is a condition in which the individual is at risk of getting infected by a disease. The animal is more likely to get a disease or lacks resistance to a disease. This might be due to genetics, or lifestyle risk factors such as aging, poor nutrition, infection, etc.

2. Tolerance: Tolerant animals or animal breeds can be infected with larger numbers of pathogens without suffering severe illness and death. The disease-causing organisms gain entry, multiply within the body cells, and may manifest in some symptoms but are unable to overwhelm the animal. e.g. The Muturu and N’dama cows are said to be tolerant to Trypanosomiasis.

3. Resistance: The inherent ability of an organism to resist or withstand the pathogen is called resistance. The invading organisms are destroyed by the animal’s body defences, thus the animal may remain in the environment where the disease organisms are prevalent without being clinically infected.

4. Immunity: The micro-organismsMicrobes are organisms that are too small to be seen without using a microscope. They include organisms like bacteria, archaea, and single-cell eukaryotes (organisms whose cells have a nucleus e.g. amoeba... More may gain entry and establish, but do not spread as a result of their destruction by the animal’s body’s immunity, which is made up of antibodies. The animals do not show any signs of the disease.

Types of Immunity:

1. Acquired Passive Immunity e.g. a young animal obtaining antibodies from colostrumColostrum is the first breast milk produced by the mammary glands of humans and other mammals immediately following the delivery of the newborn, and it's full of nutrients and antioxidants essential... More or milk.

2. Active Immunity e.g. through vaccination. A vaccine is a subdued or attenuated microbe brought about through heat or chemical treatment. When introduced into the animal body, it stimulates the production of antibodies and antitoxins without actually causing disease in the animal.

Difference between Resistance and Susceptibility to Disease:

The difference between resistance and susceptibility to disease is that an animal is said to be resistant to disease when it is not affected by an invading pathogenic disease-causing organism or pathogen, while the animal is said to be susceptiblelikely to suffer from a particular illness/disease or be affected by a particular problem. More to disease when it is not able to ward off the effect of the invading pathogenic organism, in which case it manifests disease symptoms.