Dogs bite around 4.5 million people in the United States each year, according to the Centers for Disease Control and Prevention. Rabies rarely occurs in the United States and almost never from dog bites. Worldwide, however, over 50,000 people contract rabies, a viral infection, the Merck Manual states, most related to dog bites. The incubation period can last up to seven years after a bite, according to Medline Plus, with an average of three to seven weeks. Symptoms occur late in the disease, which almost always kills if the rabies vaccine isn’t given before the appearance of symptoms.
Systemic Symptoms
Initial symptoms of rabies are systemic. The closer the dog bite is to the brain, the sooner symptoms first develop. Symptoms include fever up to 102 degrees Fahrenheit, malaise and headache, according to the Merck Manual. Loss of appetite, fatigue, muscle aches and nausea may also occur.
Furious Rabies Symptoms
The term furious symptoms describes excitability, irritability, restlessness, confusion, aggressiveness, stress and tension experienced after rabies develops from a dog bite. Furious symptoms affect 80 percent of people with rabies, the Merck Manual explains, and also include bizarre behavior, hallucinations and difficulty sleeping. Seizures and stiff neck may occur. Pupils appear dilated, and the person may exhibit increased sensitivity to light, sound and temperature.
During the furious rabies stage, attempts to swallow cause spasms of the throat and diaphragm, making it impossible to drink, the National Health Service states. This leads to hydrophobia, or fear of water. Soon just the sight or sound of water induces spasms, and the person may suffer delirium, spit, drool excessively and bite. This is the stage when dogs bite people. In between episodes of delirium, a person may think clearly but have extreme anxiety and distress. Treatment at this stage consists of supportive care and heavy sedation, with death normally occurring within seven to 10 days, Merck reports.
Dumb Rabies Symptoms
Dumb rabies symptoms occur less commonly than furious symptoms, affecting 20 percent of people who develop rabies after a dog bite, according to Merck. Dumb symptoms affect the spinal cord. Symptoms include widespread ascending paralysis leading to heart and lung failure and coma, the National Health Services says. Delirium and hydrophobia do not occur in dumb rabies, although the disease still has a fatality rate of nearly 100 percent within a week after symptoms start.
Bite Site Symptoms
Pain and a tingling, twitching sensation may develop at the site of the dog bite, the Nemours Foundation website Kids Health states.
