Yes, Cold Blooded Creatures Get Fevers Too: Here’s What You Need To Know

What do amphibians, reptiles and fish have in common? They are all ectotherms – cold blooded creatures. They are animals which cannot regulate their own body temperatures (like warm blooded animals can) and they rely on the external environment to change their internal temperatures. 

For long scientists wondered if sickness like cold, flu and fever were the lot of warm blooded creatures . As it turns out – they aren’t. Cold blooded creatures can fall ill too. 

How (?), you may ask. In order to understand this, we need to understand how fevers set in warm blooded creatures. 

All warm blooded creatures have a particular body temperature, which for them is considered normal. For example: 

• Humans – 98.6°F
• Dogs – 102.0°F
• Elephants – 97.7°F
• Horses – 100.4°F
• Goats – 103.4°F

If the body temperatures of these animals rises above this limit (as is the case during infections), the body tries to thermoregulate .i.e. bring the temperature back down, to normal. When the body fails to do this and the body temperature continues to rise, fever sets in. 

 

Cold blooded animals – representative image (Image source: Pixabay)

 

What about cold blooded animals?

Based on this, it’s important to note that for fever to set in, there has to be a biologically-set body temperature. But cold blooded animals don’t have a fixed temperature. Their body temperature falls or rises depending on the temperature of the external environment. 

So, how do they fall ill?

Well, cold blooded or warm blooded, all animals are susceptible to illness. Just as with their warm blooded cousins, cold blooded animals too may get infections from parasites or viruses, which can raise or drop their body temperatures abnormally. Just like warm blooded animals, ectotherm animals’ bodies too can handle only a certain level of heat and cold. If the change in temperature during the infection falls beyond this limit, illness similar to fever sets in. 

But the biggest mystery here isn’t just about how these animals fall ill, but it also includes what these animals do to get back to health. 

Changing behaviours for the sake of wellness

When fish, amphibians or reptiles fall ill, they indulge in what is known as a “behavioural fever“. If the animal is infected by a parasite or virus and experiences signs of ill health, it moves away towards areas which support warmer climates. For example, fish that normally prefer cold waters may swim towards warmer waters when they are ill. 

Why? 

Heat has the ability to deactivate viruses and destroy the proteins which assist in virus duplication. The same goes with parasites – heat can kill them too. 

So, a cold blooded creature that falls ill, will instinctively move towards a warmer place, in order to increase its body temperature, which will in turn help in killing or deactivating the pathogen in their bodies. 

 

Zebrafish (Image source: Imperial College London)

 

This instinctive “behaviour“, which ectotherms exhibit when they have “fevers“, is called “behavioural fever“.  Scientists speculate this behaviour could stem from the fact that the immune systems of cold blooded animals may actually function better when in warmer climates.

One of the best examples of cold blooded creatures who exhibit behavioural fever are Zebrafish. The moment they fall ill, Zebra fish will change their water-heat preferences and swim to warmer waters. The same goes for Guppies. 

When behavioural fever benefits the host 

For some time, it was assumed that behavioural fever was helpful only for ectotherms who were in the throes of infection & fever. But as it turns out, in some cases, the move to hotter areas benefits pathogens too. 

Schistocephalus solidus, a tapeworm found in the gut of  rodents, fish and fish-eating birds, actually thrive on heat. Once the parasite is in the hot climate, it grows stronger and changes the heat preferences of the fish and manipulate other atypical (and often self-destructive) behaviours in the animal. 

 

Virus (Image source: Pixabay)

 

Then there is the Cyprinid herpesvirus 3, which is a virus that attacks fish in the Carp family. This virus affects the genetic code of the fish it infects and overrides the genes which stimulate behavioural fever. So, the infected fish doesn’t move towards warmer waters (as it is supposed to), instead choosing to stay in colder waters, where the virus can gain in strength. 

What happens if a feverish ectotherm cannot move to warmer climates? 

Vicious parasites and mind-control viruses aside, the inability to indulge in behavioural fever can have a massive, negative impact on cold blooded animals. This is in fact, very true of pets.

In the wild, cold blooded creatures have a lot of freedom to move to different places, in order to rid themselves of their illness and infection.  But pets stuck in aquariums and enclosures don’t have this luxury. 

Cold blooded pets like fish, turtles, tortoises, iguanas, lizards and snakes are cooped up inside their temperature-controlled tanks/enclosures for almost their entire lives; where they are subjected to the same temperature day-in-and-day-out. 

 

Caged animal – representative image (Image source: Pixabay)

 

Now imagine these pets fall ill and have a fever. Biologically they are programmed to leave and move to a place that is warmer, to heal themselves. But because they are stuck in their tanks/enclosures, these animals do not get the opportunity to get their bodies at the right temperature to kill the infection. 

When this happens, the fever and the infection only gets worse and in the worst cases, the pet dies. In fact, a large number of fish deaths in aquariums can be attributed to this.

So, what can pet owners do about this? 

Fish owners can set aside a separate tank where they can change the temperature of the water as required. Owners of amphibians and reptiles can create heat spots in corners of the enclosure by using detachable heaters and small light sources. This can give the sick pet an opportunity to self-heal. 

If however, your pet looks worse, it’s best to take him/her to a vet immediately. 

 

 

-NISHA PRAKASH 

P.S: Featured image: Iguana (Source: Pixabay)

The Fragile Mental Health of Baby Orangutans

P.S: * This article may be disturbing for some. Reader discretion is advised. 

 

If you thought baby humans were tiny and vulnerable, think again. Baby orangs take first place as one of the most fragile and breakable newborns on the planet.

A baby orangutan needs round-the-clock care up until at least 1 year of age. Just like human babies, they are absolutely helpless and powerless and need their mothers (or carers in captivity) to feed them, bathe them and give them lots of hugs. In the wild, babies stay with their mother for 8-9 years, learning how to be an orang.

But these days, due to increasing commercial activity in Borneo and Sumatra, orangutans are being ripped apart from their homes; many apart from their families. Deforestation, coupled with human-orang conflicts which at times leads to mum’s death, can be quite traumatic for baby orangutans.

Often, workers and resident villagers keep orphaned baby orangs illegally as pets. They even sell them on the black market to make a quick buck. This can be especially devastating for baby orangs. Fed the wrong food and kept in unhygienic and harmful conditions, these babies find themselves spiralling down towards abysmal health.

It has been found that baby orangs that experience trauma at a young age often develop PTSD and may go into depression or have anxiety attacks as adults. In extreme cases, this manifests itself as self-harm. It has been noticed how traumatized orangs bite or scratch themselves, pull out their fur and hurl themselves against the wall when unable to overcome the frustration and anxiety they have building within them.

This is where orangutan care centres are especially important. These centres help vets, animal experts and volunteers care for baby orangs and rehabilitate them back into the wild. Take a look at this video below of baby Joss, who was rescued from a house that kept her as a pet where she was ill-treated the entire time.

Many orangutans may even find it very difficult to forge meaningful relationships with other orangs and their human caregivers.

A case in point is Pony, a 17 year  old female orangutan who was rescued from a brothel, where she was sold as a sex slave when she was a baby. Pony was trained to perform unnatural acts with humans and this resulted in her developing serious PTSD and an intense aversion to humans; something which is slowing down her treatment.

Unwilling to interact with humans, Pony is isolating herself from other orangs and her caregivers. Not taught how to forage when young and having been alienated from her natural psychological development, she has made no progress in her healing and the prospect of her release into the wild looks bleaker by the day. Although rescued at age 7, Pony was too old to provide the care her younger cousins (like Joss in the video) were given. Now caregivers use a combination of medication and routine activities to keep her calm and help her regain her trust in humans. To know more about her, follow this link*.

Awareness about these endangered creatures and how they are being abused can help us find ways to save them and protect them. We may not be able to do much for Pony, but we may certainly be able to save others from this terrible fate if we try. Share this post and spread the word about the harrowing journey these little ones face.

-NISHA PRAKASH

 

Featured image: Orangutan babies

Pig Anorexia: A Little-known Disease That’s Decimating Porcine Populations Globally

“Anorexia nervosa is a complicated disorder and genes aren’t everything. The genes load the gun but the environment pulls the trigger.”

-Dr. Janet Treasure

 

When Dr. Janet Treasure, senior lecturer at the London Institute of Psychiatry conducted her research into the origins of Anorexia nervosa in humans, she found herself following a path not many knew about; but which could explain how Anorexia functions in human beings.

This path less travelled by, was the study of a disease that only few knew existed and which hardly any understood – Pig Anorexia.

 

(Representative image only. Source)

 

The day the pigs came calling

It was in 1962 at a farm in Ontario, Canada that the resident pig keeper noticed something amiss with the new litter of piglets. The tiny creatures had been recently weaned from their mother and were being fed by hand by the farm boys.

While things seemed fine at first, the pig keeper noticed the piglets had stopped eating soon after, often starving themselves for days until they were just skin and bones. With this starvation came the vomitting, the weakness and the weight loss.

The hunger, combined with the deteriorating condition of the body, soon grew too much for the tiny piglets to cope with and the entire farrow lost its life.

This was the very first case of ‘pig anorexia’ as it soon came to be called and it is a disease that has affected pigs the world over.

 

(Representative image only. Source)

 

The HEV

The Hemagglutinating Encephalomyelitis Virus (HEV) is a RNA virus that affects porcine, aka pigs. As an RNA virus, it affects the pigs’ RNA, infecting the animal at the cellular level.

In every living creature, the DNA is the genetic blueprint of the body and it dictates the physiological and psychological make-up of the creature. The RNA is an acid present in the cells, which carries messages from the DNA and stimulates the production of proteins. These proteins are used by the cells to develop and control the functioning of the various organs inside the animal’s body.

Multiple RNA strands work within the cells of an animal’s body throughout its life. Ultimately, the RNA are responsible for the health of the proteins, the cells and the animal itself.

Now imagine if the HEV were to infect the RNA of the piglets. Each and every time an infected RNA would stimulate the production of proteins in the body, the proteins and by extension the cells, would be infected too.

Slowly over time, the HEV starts infecting the piglets from the cellular level by making their cells and organs diseased.

How does HEV spread?

HEV is just like any other virus and it spreads from contact with body liquids. These liquid spread between snout-to-snout contact and can also spread to pigs through indirect contact with boots, jackets, farm equipment etc. if pig saliva or mucus is splattered on them.

It’s been observed that most porcine populations are exposed to these viruses everyday. But only 1% – 4% of the population ever experience an active attack. Piglets are the most vulnerable to the virus, given their lack of immunity and strength.

Infected piglets will often have microscopic lesions inside their snout, on their tonsils and on the walls of their stomach. When the virus spreads, it moves to the lungs, small intestine and finally the brain through the sensory nerves. It is when the virus reaches the brain that piglets exhibit full-fledged anorexia-like symptoms.

The HEV has been observed re-writing the signals sent to the brain, changing the behaviour of the piglets. The affected piglets display low hunger levels at first and soon start skipping meals. During later stages of the disease, they may vomit extensively and may start dehydrating as a result. The muscles start to wear-out and soon, the piglet is just skin and bones. Death is an inevitable result of the disease.

The HEV-induced infection is a porcine-only infection and does not spread to humans.

 

(Representative image only. Source)

 

Why is it called pig anorexia?

Anorexia nervosa is an eating disorder in humans, where the sufferer stops eating or refuses to eat and starts exhibiting a variety of symptoms including:

• Sudden loss of weight
• Listlessness
• Depression
• Constant vomiting and diarrhoea
• Extreme weakness and lethargy
• Hormonal imbalances
• Low tolerance to heat or cold

Pigs infected by the HEV  display symptoms  so close to Anorexia nervosa, that the disease has been named Pig Anorexia.

It can get extremely challenging to diagnose the presence of HEV in pigs. For one, symptoms resemble other diseases like Encephalitis, Vomiting & Wasting Disease or the Classical Swine Fever (or Hog Cholera). The only way now to identify if a porcine herd is a victim of the HEV, is to understand their origins and their environment.

Of birth and breeding

Pig pens are extremely fertile incubation areas for the Hemagglutinating Encephalomyelitis Virus (HEV).  Once the virus takes root, it cannot be eliminated. The reason for this is the lack of a cure. To this day, there is no clinical cure available to help affected piglets.

But, there is something pig breeders can do to reduce herd vulnerability.

Piglets get high immunity from the colostral antibodies found in the mother’s milk. Putting piglets onto the teat at the earliest can reduce chances of an infection by half. Second, keeping the pen clean and free of fecal matter can reduce chances of infection further.

But this still won’t be enough. It’s been observed that susceptibility to the HEV is also affected by genetics. Pigs birthed naturally, without human intervention have the highest chance of survival as they have the most natural genetic structure which is designed to combat fatal illnesses.

However, with humans preferring leaner bacon cuts over thicker ones, pig farmers are deliberately isolating and promoting those genes which give rise to thinner piglets. This type of genetic manipulation, makes the piglets weaker and more susceptible to infections, including the HEV.

Dr. Janet Treasure said, anorexia is as much about genes as it is about the environment. When combined with the weak genes, the poor rearing environment and pathetic post-birth care practices can double the chances of piglets developing anorexia-like symptoms post-weaning.

(Representative image only. Source)

 

Pig anorexia – shattering the body and the mind

Physically, the impact of HEV-induced pig anorexia is nightmarish. Thousands of pigs die each year because of the lack of veterinary care. Exposure to infected piglets often puts other healthy animals too at risk and increases the headcount.

However, it isn’t the physiological impact alone that needs to be considered. Pigs are extremely emotional and cognitive creatures. They are inquisitive, temperamental and borderline-compassionate.

A 2013 research∗by Reimert, Bolhuis, Kemp, & Rodenburg showed how untrained pigs when introduced into a new pen of trained pigs, adopted the behaviours and mannerisms of their trained counterparts, after sustained exposure to them. These behaviours and mannerisms included everything from the way the tails were held to the vocalizations made to the choice of food the pigs were making. This could be an attempt at social acceptance by the pigs or a mimicry of a positive stimulus-response behaviour.

Now let’s apply the same logic here. Imagine if new pigs are introduced to an infected herd which displays signs of starvation, depression and social isolation. The new pigs too are more likely to mimic this refusal of food and they may socially isolate themselves, following the example of the herd.

This psychological impact that the HEV has on healthy pigs, can lead to true pig anorexia, with pigs refusing to eat out of fear, anxiety or depression.

 

(Representative image only. Source)

 

The human connect

The idea that pig anorexia could bring about a breakthrough in the study of anorexia in humans was unthought of. But during her study, Dr. Treasure realized how similar pigs were to humans in terms of psychology and social behaviour.

Her study into pig anorexia helped her understand a key component about Anorexia nervosa – while genes do play a vital role in indicating susceptibility to the disorder, it is the environmental factors that finally trigger the condition. Essentially, people may be pre-disposed to anorexia through genetics, but this pre-disposition is unlikely to have a major negative impact so long as the person’s upbringing is filled with love and support.

Just like fecal matter in pig pens, constant negative feedback from family can make people more likely to suffer from anorexia. Remove this environmental contamination and you reduce the subject’s vulnerability to the disorder. This insight is now helping medical professionals find lasting  treatments for anorexia in humans.

 

-NISHA PRAKASH

 

Note:

∗ 2013 Research – Please check Pg.115 

P.S: Featured image