Rabies is a viral disease that affects the central nervous system of mammals, including dogs. It is transmitted through the saliva of infected animals and is almost always fatal once symptoms appear. However, rabies is also completely preventable through vaccination. This raises the question of how often dogs need to be vaccinated against rabies to maintain immunity.
What is rabies?
Rabies is caused by a virus in the genus Lyssavirus. While multiple variants exist, the most common cause of rabies in dogs is from the rabies virus variant associated with raccoons. Rabies affects the brain and spinal cord, ultimately resulting in death once clinical signs appear.
The rabies virus is transmitted through the saliva of infected animals. In dogs, transmission usually occurs through a bite wound from a rabid animal. The virus enters the wound and travels through nerves to the spinal cord and brain, where it causes inflammation of the brain and spinal cord.
Rabies symptoms in dogs
After an incubation period of 3-8 weeks, signs of rabies in dogs may include:
- Fever
- Loss of appetite
- Lethargy
- Personality changes, restlessness, irritability
- Aggression
- Jaw paralysis (inability to open the jaw)
- Increased sensitivity to touch, light and sound
- Seizures
- Paralysis
Once clinical signs appear, rabies is nearly 100% fatal. However, the disease is preventable through vaccination before exposure.
Rabies vaccination for dogs
Safe and effective vaccines for rabies have been available for dogs since the early 20th century. Rabies vaccination is a core part of responsible pet ownership and is required by law in most jurisdictions.
Types of rabies vaccines
There are currently two types of rabies vaccine licensed for use in dogs in the United States:
- Killed (inactivated) vaccines – These vaccines contain chemically inactivated rabies virus. They provide immunity within 28 days of vaccination.
- Recombinant vaccines – These newer vaccines contain a rabies glycoprotein produced through recombinant DNA technology, without use of inactivated virus. Immunity develops within 14 days of vaccination.
Both vaccine types are considered equally safe and effective. Killed vaccines have been used longer historically, but recombinant vaccines are becoming more widely adopted.
Administering rabies vaccines
Rabies vaccines are given as an injection, typically on the rear leg muscle. Puppies should receive their first rabies vaccine at 12-16 weeks of age. For adult dogs, a booster is given one year after the initial vaccine, then typically every three years thereafter. Some states require more frequent boosters by law, so be sure to adhere to your local requirements.
Some key points on administering rabies vaccines:
- Only licensed, inactivated vaccines should be used
- Follow label instructions for proper storage and reconstitution of vaccines
- Give the vaccine via intramuscular injection into the thick rear leg muscle
- Provide a booster one year after the initial vaccine, then every three years minimum unless local laws require more frequent vaccination
Rabies vaccines are very safe overall. Potential side effects are generally mild, including lethargy, fever, and local pain or swelling at the injection site. More severe allergic reactions are possible but quite rare.
Are repeat rabies vaccinations necessary?
Given that protective rabies antibodies persist for years after vaccination, this raises the question of whether repeat rabies vaccinations are truly necessary. Do dogs really need to be revaccinated every 3 years? Or does one vaccine confer lifetime immunity?
How long do rabies antibodies last in dogs?
Research into the duration of immunity after rabies vaccination suggests that protective antibody titers persist for much longer than the standard 3 year booster interval:
- Studies have detected rabies virus neutralizing antibodies in dogs up to 7 years after vaccination.
- One study found antibodies persisted for at least 10 years post-vaccination when dogs were given an initial dose at 16 weeks of age.
- Models suggest protective antibody titers may last up to 25-31 years in dogs when initial vaccination is done at 12-16 weeks.
Based on this evidence, some countries like the United Kingdom now allow rabies boosters to be given every 5 years after puppy shots, instead of every 3 years. However, intervals of longer than 5 years without a booster have not undergone extensive research yet.
Why repeat rabies vaccines are still recommended
Even though antibody levels remain high for years after vaccination, most experts still recommend periodic rabies boosters for dogs. Some reasons include:
- Modeling studies are still theoretical – real-world, large scale studies of longer booster intervals have not been done.
- Variability exists in antibody durations between individual dogs.
- Vaccines today may differ in potency compared to those used in past research.
- Local or legal requirements may still call for triennial boosters in many locations.
- A minor level of risk still exists with longer intervals between boosters.
For these reasons, the standard recommendation is still to provide rabies boosters every 3 years after puppy shots, even though the actual risk is likely very low for at least 5-7 years. Ultimately a dog’s rabies vaccine schedule should be developed in consultation with a veterinarian, accounting for local laws.
What are rabies titer tests?
Instead of routinely giving rabies boosters, some veterinarians recommend testing rabies antibody levels through a titer test. This measures the level of rabies virus neutralizing antibodies present in the bloodstream.
Titer tests can be done instead of a booster to confirm antibody levels are still protective. If the titer test is positive, a booster vaccine is not necessary. However, if the titer comes back negative or equivocal, a booster is advised.
Some advantages of titer tests:
- Reduce over-vaccination if antibody levels are still adequate
- Can satisfy legal requirements instead of automatic boosters
- May minimize vaccine side effects
- Often costs less than a booster vaccine
The drawbacks are that antibody levels can wane quickly in some dogs, and getting a negative titer too soon can leave the pet unprotected. There are also no standardized reference ranges to interpret results. Typically two blood samples taken a few weeks apart are recommended when doing rabies titers.
Overall, rabies titers can be a useful option but may not provide complete assurance of immunity compared to a booster vaccine. Veterinarians consider many factors in recommending the best approach for each pet.
Key points on rabies vaccination boosters
To summarize the key considerations on rabies vaccine boosters in dogs:
- While antibody levels persist for many years after vaccination, most experts still recommend a rabies booster every 3 years or per local laws.
- Rabies vaccines are highly effective and safe, with serious adverse reactions being very rare.
- Some countries now give rabies boosters every 5 years instead of 3 years, and studies suggest even longer intervals are likely protective.
- Rabies titers can sometimes be done in place of boosters to measure antibody levels, but results may be unpredictable.
- Consult your veterinarian on the most appropriate rabies vaccination schedule for your dog.
- Ensure your pet’s rabies vaccinations are legally compliant and provide documentation when traveling or boarding.
While a lifetime rabies shot is not currently recommended, the evidence suggests rabies immunity lasts for many years beyond the standard 3 year booster interval. Research into whether longer intervals between boosters may be warranted is ongoing.
Frequently Asked Questions
How often do dogs need rabies shots?
The standard recommendation is a booster vaccination every 3 years after the initial puppy series. Some jurisdictions may legally require more frequent boosters, so adhere to local laws.
How much does the rabies vaccine cost for dogs?
Rabies vaccine costs typically range from $15-35 per dose, depending on the specific product used. Veterinary exam and office visit fees may also apply. Shop around, as prices can vary between veterinary clinics.
Do dogs need a rabies shot every year?
In most states and countries, rabies boosters are required every 3 years for dogs. No jurisdiction in the US requires annual rabies vaccination. Some Canadian provinces do still mandate annual boosters by law.
When should I get my dog a rabies booster?
Rabies boosters are due 1 year after the initial vaccine, then every 3 years thereafter in most cases. Mark your calendar so you don’t forget, as lapsed rabies vaccinations can put your pet at risk.
What if my dog is overdue for a rabies shot?
You should update your dog’s rabies vaccination as soon as possible if overdue. Some vet offices may require quarantine procedures before administering an overdue vaccine. Keep rabies shots current, as this disease has a near 100% fatality rate.
Why does my dog need the rabies vaccine?
Rabies is a fatal viral disease in mammals. Vaccination is important to protect your dog’s health and prevent spread of rabies to other pets and people. Rabies vaccination is required by law in most areas.
Are there exemptions for rabies vaccine?
In most states, the only exemptions are a documented medical contraindication verified by a veterinarian or short lapse in vaccination under special circumstances. No religious or philosophical exemptions exist, given the serious public health implications.
What are the side effects of rabies vaccine in dogs?
Most dogs have no side effects from rabies vaccination. When they occur, side effects are generally mild including soreness, swelling, or rash at the injection site, listlessness or fever. Severe allergic reactions are very rare.
Can I give rabies vaccine at home?
No, rabies vaccines may only be administered by a licensed veterinarian. Improper administration could result in failure to protect against rabies. Rabies vaccination certificates are also legally required, which must be completed by a veterinary office.
Conclusion
While a single rabies vaccine may provide immunity for many years beyond the standard 3 year booster interval, revaccination is still recommended to ensure adequate protection. Core vaccines like rabies are vital to responsible pet ownership. Follow your veterinarian’s advice and local laws regarding rabies booster frequency to keep your dog healthy and avoid legal issues. With proper vaccination, rabies is a completely preventable, fatal disease.
