5 Deadly Diseases That Are Wiping Out Animal Populations Across The World

Animals can catch a cold, they can also get arthritis and obesity-related illnesses. But here are 5 scary diseases plaguing animals in the wild, which resemble something right out of a horror movie. If we don’t act fast, we may end up losing these animals for good. 


All living creatures fall ill. But for the most part, knowledge about animal diseases is scarce. Research into this niche area has always been challenging. For one thing, scientists need to know what clues to look for, when diagnosing an animal with a disease. For another, enough numbers in the species need to exhibit the same symptoms, for the illness to be even considered an illness and not a chance affliction.

Here is a list of 5 animal diseases that scientists didn’t know existed, but which now are changing the face of science and animal conservation:

  • Chytridiomycosis

Species affected: Frogs

Considered to be the deadliest disease in recorded animal history, Chytridiomycosis is caused due to exposure to the chytrid Batrachochytrium dendrobatidis fungi. They are a type of zoosporic fungus which infects frog species and causes hyperkeratosis i.e. thickening of the skin.

Frogs breathe, drink and consume electrolytes through their skin and when the fungus causes the skin’s pores to clog and the skin to thicken, the only available airway of the animals closes. This causes skin infections, cardiac arrests and finally results in death.

As of today, Chytridiomycosis has resulted in the extinction of almost half the frog population in the world. Any colony that faces this disease sees a 100% mortality rate within a few months. Unfortunately, scientists don’t know why or how this disease spreads, leaving us without any means to protect our amphibious brethren.

Image: Top – A Healthy Frog; Bottom: A Frog Infected With Chytridiomycosis
  • Snake fungal disease

Species affected: Snakes in Midwestern and Eastern USA

Ophidiomyces ophiodiicola, aka, Oo is a fungus that not many know about. A keratinophilic fungus from the family Onygenaceae, it feeds on keratin, a substance that makes up fingernails, rhino horns and snakeskin.

The epidermis of the snake is covered with scales which are made of keratin. The Oo attacks the snake when it’s at its most vulnerable, infecting it with a fatalistic disease. Snakes tend to have a very weak immune system post-hibernation and it is then that the Oo enters the body of the body and eats away at the scales. Without the scales, the snake’s skin starts to disintegrate, exposing it to harsh weather and other infections.

This fungus has been recorded as having decimated massasauga and timber rattlesnake populations by 50% and has also put these animals on the endangered species list. Not much is known about this fungus and its impact on other snake species.

Image: A Snake Infected With Fungal Disease
  • Sea star wasting syndrome

Species affected: Starfish

The 1980s saw starfish populations facing a fatal infection. Lesions appeared on their arms, leading to severe infection. This infection caused the arms to fall off, making their bodies turn into a mushy, paste-like substance. A few days after the lesion first appeared, starfish wound up on the beach, wasted away to death.

Image: A Starfish Afflicted By The Wasting Syndrome

The sea star wasting syndrome has since the 1980s been a cause for concern for scientists. For long, there was no known cause visible to them. But in 2014, researchers discovered a virus they named ‘sea star associated densovirus’ on the bodies of the starfish. But studies of starfish fossils show that the species have been living with this virus for millennia. Research is still ongoing to understand if this virus is the cause of the disease or not.

As of now, the virus has led to the extinction of 3 American starfish species and has culled the population of 19 other species by half. The worst part, this disease has now spread to sea urchins, which are the starfish’s prey.

starfish wasting
Image: Time Frame Within Which Wasting Happens; In This Picture, Wasting Occurs Within 4 Hours
  • Colony collapse disorder

Species affected: Bees

Bee colonies around the world have been dying out and the reason isn’t clear why. The colony collapse disorder results in the traditionally conscientious worker bees deserting the queen bee, nurse bees and larvae, leaving them to fend for themselves. Unable to find sustenance and protection after food runs out, the queen, nurses and larvae die, leading to a complete collapse in the colony.

Assumed to be a rare occurrence at firsts, scientists were shocked to see the disorder affecting thousands of colonies in North America and Europe. Researchers believe this disorder could have occurred due to a variety of reasons, starting from invasion by parasitic mites called varroa destructor to a change in the chemical constitution in the bees’ bodies due to a viral infection. Scientists have also speculated that pesticides containing neonicotinoids may also be a reason for this disorder.

The colony collapse disorder has far-reaching consequences apart from the loss of billions of bees. The thread that rejuvenates the ecosystem, bees help humans in multiple ways. With the worker bees’ refusal to indulge in their normal behaviours, we may find ourselves in serious trouble.

  • Hemorrhagic septicemia

Species affected: Saiga antelope

Saiga antelope, renowned for their unique appearance, have made headlines again. But this time, it’s for a rare disease that’s wiped out one-third of the species in the past few years. This is a cause for concern, as the species population is teetering on the edge of extinction. More than 15 years of poaching and habitat loss have resulted in the death of 95% of the saiga population in the wild.

Assumed to be caused by a virus or a tick, the saiga antelope suffer from hemorrhagic septicemia or blood poisoning that results in internal haemorrhaging. This disease was noticed to have spiked during the calving season, a time when both mothers and calves are at their most vulnerable. The deadly disease took out almost 134,000 mothers and calves within a span of two weeks.

Thankfully, research has been able to confirm the exact cause of the disease and now we know the culprit is the Pasteurella multocida type B bacteria. Studies show that the bacteria reside in the antelope’s noses from birth. But the humid conditions in the nostrils act as a fertile breeding ground for the bacteria, leading to the formation of large colonies in the saiga’s bodies. These bacteria release deadly toxins into the animal’s bloodstream, resulting in blood poisoning and then death.


Saiga Mother and calf
Image: A Saiga Mother and Calf Die Due to Septicemia


Armed with this knowledge, we may finally be able to save this critically endangered species from extinction. Now, all we need to do is find a solution for the other diseases and lend a helping hand to these endangered creatures.




Featured Image: Thousands of saiga antelopes lie dead in a field in Khazakstan of blood poisoning.

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