Theory:

What is rabies?
Rabies is a fatal viral disease that causes inflammation of the brain and spinal cord in humans and other mammals.
 
Causes:
It is caused by the rabies virus that spreads through the saliva of infected animals.
 
Rabies_virus_structure.jpg
Rabies virus
 
Modes of transmission:
It is usually transmitted by the bite of an infected dog, rabbit, monkey, cat etc. In certain rare cases, the virus can spread when the infected saliva gets into the open wound or the mucous membranes such as the mouth or eyes. The virus present in the infected animals' saliva, such as dogs enters their brain via the neurons.
The initial symptoms of this disease include:
  • A fever with pain that lasts for 2 to 12 weeks.
  • Hydrophobia (an extreme fear for water).
  • Exaggerations in behaviour.
Certain factors can increase the risk of rabies. They are as follows:
  • Travelling to countries in Africa and Southeast Asia where rabies is more common.
  • Getting involved in activities that make individuals prone to contact with the wild animals that have rabies.
  • Wounds to the head or neck that make easy for the rabies virus to travel to the brain more quickly.
Nervous system.svg
Route of infection
Prevention and treatment:
  • It is difficult is to detect rabies in the early stages.
  • Fatality can be prevented by vaccinating timely before the onset of symptoms.
  • By preventing the pets from small predators.
  • When an animal is bitten, it generally takes about two to twelve weeks for the symptoms to appear. Sometimes it may take as long as two years also.
Reference:
https://upload.wikimedia.org/wikipedia/commons/8/8c/Rabies_virus_structure.jpg