In This Section –
- What is rabies?
- What is the cause of rabies?
- How does rabies spread?
- Is rabies zoonotic?
- What to do if you get bitten by a rabid animal?
- Signs and symptoms (stages of rabies in dogs)
- Treatment and management
- Prevention and control
- Key points
What is rabies?
Also known as hydrophobia, lyssa, or rage. Rabies in dogs is an acute, highly fatal, dreadful infectious disease with a death rate close to 100% caused by lyssavirus.
While it’s preventable and even treatable if diagnosed early, once the symptoms of rabies appear, the virus will kill the animal host in nearly 100% of cases.
What is the cause of rabies?
It is caused by a single-stranded RNA virus of the genus lyssavirus in the family Rhabdoviridae. The virus is truly neurotropic (affects the nervous system preferentially) and quite fragile.
It readily inactivates by elevated temperature, UV light, detergents, organic solvents, and also in dry saliva but can persist for many weeks under cool weather conditions.
How does rabies spread?
All warm-blooded animals including Canidae (dogs, wolves, foxes, jackals, coyotes) are susceptible hosts for rabies. Statistically, dogs are the most common carriers of rabies. Other common carriers include wild animals like foxes, raccoons, skunks, bats, etc.
Rabies transmits through direct contact with saliva or a bite from an infected animal. Other non-bite transmission ways – ingestion, inhalation, other mucosal exposure, human-to-human transmission, or organ transplantation are much less common.
The virus can also pass through an open wound such as a scratch or laceration through which it enters the bloodstream.
Once the virus enters the animal’s body, it replicates in the muscle cells and spreads from nerve fibers to the brain. Once rabies symptoms begin, the virus progresses rapidly.
Is rabies zoonotic?
Yes, it is zoonotic i.e., the animals already suffering from it can transmit it to humans.
Domestic dogs are the most common reservoirs of the virus with more than 99% of human deaths caused by dog-mediated rabies.
“Rabies is also transmittable to cats and is more likely to develop furiously in cats than dogs.”
What to do if you get bitten by a rabid animal?
Wash the wounds and scratches thoroughly with soap and water and disinfectants like iodine, ethanol, etc. to decrease the chances of infection.
Call your doctor straight away. If a cat or a dog causes the bite, try to confirm its vaccination status, and if a rabid animal causes the bite, seek medical advice and call the nearest animal control office in your area.
If a rabid animal has bitten you, you will receive post-exposure prophylactic treatment which involves one dose of immune globulin and five doses of rabies vaccine within 28 days to prevent the virus from spreading through your body. Only a handful of survivors exist after acquiring rabies.
Do not ignore the attack or simply treat the wound without any medical advice. For those who develop symptoms of rabies, survival is rare. It is pertinent to mention one incidence in Mizoram where a woman ignored the dog bite as she was asymptomatic. Later on, after 25 years of exposure, she started showing symptoms of rabies, which led to her death.
Individuals who are bitten by a rabid animal need the rabies vaccine and immunoglobulins ASAP for survival because once the symptoms appear, death is inevitable.
“Remember, quick action is the key to protecting yourself from rabies.”
Signs and symptoms (stages of rabies in dogs) –
There is no single symptom that would unfailingly identify a clinically ill animal as rabid.
However, there are five stages of rabies following inoculation: Incubation; Prodrome; Acute Neurologic Illness; Coma; and death.
- Incubation – The time between exposure and first appearance of clinical signs may range from days to years but most incubation periods observed are between 3 & 6 weeks.
It is the first stage where the symptoms are only starting to show to a different degree and include restlessness, withdrawal (shy & sad), licking the bite, aggression, etc. The dog will bark at people and other animals, or even at inanimate things, and even try to bite them.
- The prodrome phase – The prodromal symptoms include furiousness, dilated pupils, increased nervousness & irritability, hyperactivity, tremor, abnormal vocalization & sexual behavior, and difficult breathing sometimes accompanied by elevated body temperature.
These symptoms usually evolve very rapidly into more advanced stages (within hours or a few days).
- Acute neurologic illness – The third stage is when neurologic symptoms occur.
These symptoms are classified into three forms: Encephalitic (also considered “furious”), Paralytic (also considered “dumb”), and a rare non-classic form.
The encephalitic (furious) form characterizes extreme aggression (mad dog syndrome), rage & attacking behavior, foaming at the mouth (saliva may adhere to the lips and face), excessive drooling, and the dog may bite moving or inanimate objects.
The paralytic (dumb) form is most common in dogs. They may lie quietly for extended periods with peculiar staring expressions. Other frequently observed symptoms are pupillary dilatation, partial paralysis of the lower jaw & tongue leading to drooling of saliva, and inability to swallow.
The final form is non-classic and rare, generally associated with seizures and more profound motor and sensory symptoms.
Coma – Stage four is the coma stage and usually begins within 10 days of stage three. The animal may have ongoing hydrophobia, develop prolonged apnea periods, and have flaccid paralysis.
Death – Following the onset of stage four, the clinical illness progresses towards extensive paralysis, with or without convulsions, and then stupor and death.
The range in length of illness from the onset of symptoms to death is from a few hours to a week and is rarely longer than 10 days.
After rabies infects your dog, it won’t necessarily undergo all of the above stages and may even skip some of the symptoms.
Without a clear-cut rabid bite history, rabies is often a diagnosis of exclusion. No single test is enough to rule in or out rabies.
However, diagnosis is based on clinical symptoms and confirmed by various laboratory tests like direct fluorescent antibodies, mouse inoculation techniques, tissue culture infection techniques, and polymerase chain reaction.
To be 100% accurate, testing requires any part from the affected brain, so it isn’t possible until the animal has died.
Treatment and Management –
There is no effective treatment for rabies. Prevention is the mainstay of treatment including programs involving domestic animal vaccination, education, and monitoring.
Once symptoms appear, there’s no way to treat rabies in dogs. If your veterinarian suspects rabies, your dog may be quarantined or euthanized since they could spread the virus.
Wound care is the first step in the treatment of any individual with a feared rabies exposure. Appropriate wound care alone is almost 100% effective if initiated within three hours of inoculation.
Prevention and Control –
- The best way to prevent rabies is to vaccinate your pet on schedule.
Anti-rabies vaccination for prophylaxis to dogs: Primary vaccination to be given in 3 months. If vaccination is given before 3 months, a booster should be given after 1 month and then annually. If vaccination is given after 3 months, a booster should be given after 1 year.
Anti-rabies vaccination post-exposure: 0, 3, 7, 14, 28, 90 days i.e., if the dog has been vaccinated against rabies, it will receive the booster vaccine.
- To minimize the risks, keep your pet away from stray dogs and wild animals (raccoons, foxes, bats).
- Keep your dog on a leash during regular walks and especially when camping or hiking.
- Spread the word about rabies regarding wound washing and vaccination to control it.
- Important components of the prevention of human rabies are the avoidance of potentially infectious contacts and proper prophylaxis treatment (Post-exposure prophylaxis and Pre-exposure prophylaxis).
Obviously, the elimination of dog rabies and the prevention of human rabies has not made the progress we once expected.
Key points –
- Rabies is a viral disease that spreads by domestic and wild animals.
- It is a fatal zoonotic disease and a dangerous public health problem.
- It is usually transmitted by bite, saliva, and an open wound with the most common carriers being raccoons, dogs, bats, and foxes.
- Individuals who are bitten by a rabid animal need the rabies vaccine and immunoglobulin ASAP for survival.
- There is no certain cure for rabies except supportive care. Once the symptoms appear, death is inevitable.
- Regular anti-rabies vaccination should be given to all pets.
- Despite the optimism generated by the few rabies survivors, survival continues to be an exceptionally rare occurrence.