Rabies is a deadly infection that can affect any mammal, including you and your dog. Thanks to vaccination programs, rabies is not common in domestic animals. If your dog comes in contact with a wild animal showing signs of rabies, or if you have even the slightest suspicion he was exposed to the virus, contact a veterinarian immediately. Rabies kills infected animals, but humans can survive with early treatment.
Rabies is caused by a virus. It usually spreads through saliva, most often in a bite wound, but can also be transmitted by contact with infected brain tissue. It is not airborne and does not spread through blood. The virus attacks the brain and the nervous system, which in turn causes neurological symptoms, such as drooling, jerky movements and unusual behavior, that signifies rabies. The rabies virus causes encephalitis, or brain swelling, which eventually leads to brain damage through the death of cells and ultimately kills the infected host.
After incubation, which takes an average of three to eight weeks, the virus begins to affect both the nerves and the brain in what is known as the prodromal phase or early onset phase. This phase lasts two or three days. Symptoms vary widely between different dogs but often include fever, nausea and behavioral changes. A normally outgoing dog infected with rabies might suddenly become nervous and withdrawn, or irritable and aggressive.
When a dog reaches the second phase of a rabies virus infection, known as the "furious" stage, his nerves become extremely sensitive to any stimulus. Sounds, bright light and movement are overwhelming to him. Not every dog goes through this stage and some go straight to the final stage, but those who experience the furious stage often become especially aggressive and restless. It is during this phase that a dog is most likely to bite people or other animals, even if he is normally kind and gentle. He is contagious and can spread the virus during this stage, which can last from one day to one week.
In the final phase of a rabies of infection, commonly called the "dumb" or paralytic phase, a dog starts to lose control of his motor function, especially in his head and neck. His movements become jerky and unbalanced and he may have trouble swallowing. Drooling and foaming at the mouth are common during this phase. Some dogs may fall into a coma or have seizures. This stage lasts for about one week, and at the end the dog becomes paralyzed and dies.
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