Dangerous viruses and transmissible diseases have been around for ages, and rabies is one of the deadliest known infections. Although rabies is fairly rare in humans, the risk of contracting the virus from infected animals still leaves plenty of room for concern and fear amongst animal lovers. But not all animals contract and spread the virus in the same way.
Frogs cannot be infected by rabies like various other animals, including other amphibians, fish, and reptiles. Rabies is typically a mammalian virus that thrives in warm-blooded hosts. Since frogs are cold-blooded, they can not contract, carry, or spread the rabies virus to other organisms.
Many mammals including household pets can be infected with the rabies virus, and the risks extend to humans that contract the virus from infected organisms. However, quite a few animals do not serve as fitting hosts for the virus, including frogs. Join us as we discuss the rabies virus and why frogs are immune to infection.
What Is Rabies And Its Effects?
Rabies is a disease caused by a virus that attacks the host’s nervous system cells. The rabies virus belongs to the family of Rhabdoviruses, and it has a bullet-shaped appearance when observed using an electron microscope.
The rabies virus would generally enter the host’s cells and multiply. Once the rabies virus manages to enter the host’s organism, it is generally picked up by the organism’s peripheral nerves, and transported to the central nervous system, located within the brain and spinal cord.
The rabies virus then travels toward the brain at a rate of 12 to 100 mm per day, and the entire infection can last weeks or months depending on the host’s capacities and size (WHO, Rabies). The initially infected cell typically dies once the rabies virus spreads throughout the body and continues infecting other cells.
How Do Animals Get Rabies?
Within nerve cells, the virus multiplies and spreads to other parts of the body, including the salivary glands. Once the rabies infection reaches the salivary glands, the virus becomes incredibly contagious and begins seeking new hosts nearby.
Rabies is generally spread through the saliva of infected animals, which often drool and foam at the mouth spreading the virus in excessive quantities. The saliva of infected organisms carries high sums of the virus, which will infect new hosts upon entering the bloodstream.
However, the virus can be transmitted by other means as well. Humans and many other animals can contract the rabies virus if they are bitten or scratched by an infected animal. In caves with masses of infected animals, the rabies virus can spread by saliva droplets in the air, formally known as aerosol transmission.
Many land-dwelling mammals can contract and spread rabies, including wildlife such as raccoons, skunks, foxes, wolves, and coyotes, or pets such as cats and dogs. Although the transmission risks may be lower, small mammals such as squirrels and rabbits may also contract and spread the rabies virus.
Is Rabies Dangerous To Humans And Pets?
Although cases of human rabies infections are rare, they are extremely dangerous. Rabies infections typically lead to death in unvaccinated animals and untreated in humans, as there is no known cure for the disease. The only way to prevent rabies infections and outbreaks is to ensure that animals are vaccinated for the rabies virus.
There are some modern post-exposure treatments for humans, which may involve a series of abdominal injections. These treatments are generally quite successful in preventing rabies if treatment plans commence immediately after the initial exposure. Any pet or human needs to receive medical assistance after being bitten or scratched by any animal, especially if the animal appears to be ill.
Why Can’t Frogs Get Rabies?
Frogs cannot get the rabies virus, as they are not well-suited to the viruses’ needs. The virus requires very specific hosts with certain bodily functions and features, all of which are not present in amphibian species. As a result, frogs cannot carry the rabies virus or spread it to other organisms.
The rabies virus is mammalian and is exclusive to warm-blooded animals, which makes it far more likely to infect mammalian creatures. The rabies virus cannot exist in the environment, such as on surfaces or in the air for a long time, as it needs a living host to survive and spread to new organisms.
Since the rabies virus needs warm blood to survive, it does not infect cold-blooded animals and creatures such as reptiles and amphibians. Frogs are cold-blooded creatures belonging to the amphibian group, and they are naturally immune to the rabies virus as a result of their bodily functions.
Frogs also have a few behaviors that prevent infection from spreading, as they are susceptible to a wide range of other dangerous diseases. Frogs typically slough their skin periodically and consume it for additional nutrients. But, frogs carrying diseases generally throw their old skin away instead to avoid consuming harmful bacteria, fungus, parasites, viruses, and other pathogens.
Although all amphibians are deemed unsuitable for the rabies virus, some amphibian species have additional bodily features that keep the rabies virus from entering their bodies and infecting them. Scientific studies have found that Bufotenine blocks the rabies virus from infecting BHK-21 cells, and certain toad species often carry this toxin (Vigerelli et al, 2014).
What Animals Are Immune To Rabies?
All cold-blooded animals are naturally immune to the rabies virus, as the host being warm-blooded is a predominant necessity for the virus to survive. The rabies virus can only infect warm-blooded creatures, and animals belonging to the reptile and amphibian groups are immune to the virus as a result.
These groups include amphibians such as frogs, toads, salamanders, caecilians, and reptiles such as snakes or lizards. Fish and cold-blooded sea creatures are also immune to being infected or carrying the rabies virus.
More About Frogs and Diseases
Rabies infections are a serious risk for humans and beloved pets, and safe practices are always advised when around unknown animals (CTNF). The rabies virus does not pose a threat to frogs and amphibians worldwide. But, adventurous amphibian lovers should still give frogs their personal space, as it is never completely safe for anyone to touch or handle wild frogs.
- Guide: Safely Catch And Hold Frogs & Toads
- How to Know If Your Pet Frog is Dying
- How to Know If a Wild Frog is Dying
- Why Are My Tadpoles Dying?
Vigerelli, H., Sciani, J.M., Jared, C. et al. Bufotenine is able to block rabies virus infection in BHK-21 cells. J Venom Anim Toxins Incl Trop Dis 20, 45 (2014). https://doi.org/10.1186/1678-9199-20-45
World Health Organization, Rabies fact sheet N° 99.
Raboral V-RG®, What is rabies and what does it mean to me?