Sheep’s ability to recognise human faces from two-dimensional images

Hi Readers,

I recently read an article which has led me to form a very strong opinion on the subject. There has recently been a study on eight sheep (Ovis aries, female Welsh Mountain) at the University of Cambridge. These sheep were being trained to recognise celebrity faces on a screen (Fiona Bruce, Jake Gyllenhaal, Barak Obama and Emma Watson). They were also tested to see if they recognised their handlers on a screen as well.

Training – Celebrities

Training involved the sheep moving around a specially-designed pen choosing the photograph of the celebrity. At one end of the pen, they would see two photographs displayed on two computer screens and would receive a reward of food if they chose the correct photograph (by breaking an infrared beam near the screen); if they chose the wrong photograph, a buzzer would sound and they would receive no reward. Over time, they learn to associate a reward with the celebrity’s photograph.

Test – Celebrities

After training, the sheep were shown two photographs – the celebrity’s face and another face. In this test, sheep correctly chose the learned celebrity face eight times out of ten.

In these initial tests, the sheep were shown the faces from the front, but to test how well they recognised them, the researchers next showed them the faces at an angle. As expected, the sheep’s performance dropped, but only by about 15% – a figure comparable to that seen when humans perform the task.

Test – Handlers

The researchers looked at whether sheep were able to recognise a handler from a photograph without pre-training. The handlers typically spent two hours a day with the sheep. When a portrait photograph of the handler was placed randomly in place of the celebrity, the sheep chose the handler’s photograph over the unfamiliar face seven out of ten times. In this test, the researchers observed an interesting behaviour. Upon seeing a photographic image of the handler for the first time (they’d not seen the photo version of this person before) the sheep did a ‘double take’. Checking first the unfamiliar face, then the handler’s image, and then unfamiliar face again before making a decision to choose the handler.

This experiment was very interesting and on reading how they made the experiment fair was very fascinating (see first article in references). However, what the researchers are now doing with the findings is something I do not agree with.

A team at the University of Cambridge have said: 

‘ “Sheep are long-lived and have brains that are similar in size and complexity to those of some monkeys. That means they can be useful models to help us understand disorders of the brain, such as Huntington’s disease, that develop over a long time and affect cognitive abilities. Our study gives us another way to monitor how these abilities change, particularly in sheep who carry the gene mutation that causes Huntington’s disease.”

Professor Morton’s team recently began studying sheep that have been genetically modified to carry the mutation that causes Huntington’s disease. ‘

Huntington’s disease

UK research carried out in 2012 found the figure for those affected by this condition to be about 12 people per 100,000. Huntington’s disease affects more than 6,700 people in the UK and is an incurable neurodegenerative disease. Together with colleagues in Australia, the team successfully bred a strain of Merino sheep carrying the human genetic mutation that causes Huntington’s disease.

Whereas I am, of course, extremely supportive of research needed for this awful disease, I do strongly believe against genetically modifying the sheep to give them the disease. Unlike animal testing where the animals are euthanized afterwards to minimise anymore suffering – a quick and humane process, from what I can gather the researchers are breeding the animals so the pain they feel due to the disease can be studied. The team could work on genetically modifying the faulty gene causing the disease in the first place rather than spreading the pain as a result of it, to another animal. Another concern I have is, the disease affects humans once they reach adulthood, if we are messing with another species’ genes how are we to know if effects will be the same? Will they suffer longer or less than humans? When will the sheep start showing symptoms? When looking into this study I have found no mention of ethical concerns – I, myself, am concerned for how the researchers will minimise the negative effect on the animals health.

What do you all think? Is the GM of sheep for the purpose of medical research justifiable?

I would love to hear all your thoughts.



Johne’s disease

Hi Readers,

A couple of years ago I was lucky enough to hear Peter Orpin speak about Johne’s disease in a cattle vet-farmer meeting. I thought this week it would be a good idea to revisit the disease and its causes.

Cause of Johne’s

M. paratuberculosis bacteria embeds itself in the wall of the ileum (lower part of the small intestine). As an immune response, infected tissues attempt to regenerate healthy tissue which leads to visible thickening of the intestines. This prevents nutrient absorption, resulting in weight loss.

Late in the infection, antibodies are produced and found in the serum (blood plasma without the proteins used in blood clotting) of animals and indicates clinical signs of disease – death will follow soon after this.

When the microbe is excreted, it can contaminate the soil or water. Outside the host animal, the organism multiplies poorly—if at all—but it can survive over a year in the environment because of its resistance to heat, cold, and drying.

The primary cause of the spread of Johne‘s disease is contact with the faeces or saliva of an infected animal.


Because of the slow, progressive nature of the infection, signs of Johne’s disease may not show up until years after initial infection.

  • long-lasting diarrhoea
  • weight loss despite good appetite
  • Bottle jaw may also appear – fluid accumulation in the bottom jaw causing an abscess

Once clinical signs appear the animal will not recover and will continue to deteriorate.

There is no treatment for Johne’s but as always PREVENTION IS BETTER THAN CURE. It is much more cost effective to prevent than eradicate the disease once it has started spreading through the herd invisibly. The primary source of contamination is manure from an infected adult animal. It is very important to know the status of Johne’s in a herd when buying cattle as this is an easy way for Johne’s to enter a herd.


A vaccine has previously been made available in the US to prevent the risk of Johne’s which uses a mixture of killed mycobacteria and oil. It can sometimes cause large lumps at the site of injection. Occasionally these lumps will become draining abscess-like lesions. Although the vaccine is given to calves less than 30 days old, the tissue reaction at the injection site may last for life.

Another vaccine is available made from live M. paratuberculosis (but not disease causing).

The efficacy of vaccines is controversial. Studies in the Netherlands have shown that herd owners who follow the recommended management changes to control Johne’s disease could be just as successful as those who vaccinate.

Has anybody ever seen this disease before when seeing practice? Let me know in the comments!




X-ray positioning

Hi Readers,

After just completing a week of work experience at an equine clinic I learned a lot about different scans and how they are taken. The vets discussed the different views with the vet nurses so this week I’ll be looking into the names of those views so as to understand the terms being communicated between vet and vet nurse.

This diagram helped me visualise the different positions the vets were referring to. I found a table which describes the meaning of each view.

Caudal Refers to parts of the head, neck, or trunk facing toward the hind part of the body from any set point. Also refers to those aspects of the limbs above the carpal and tarsal joints facing in the direction of the hind part of the body
Cranial Refers to parts of the neck, trunk, and tail facing the direction of the head from any set point. Also refers to superior or anterior aspect of a body part or limb above the carpal and tarsal joints
Distal Refers to any part away from the center of the body
Dorsal Refers to the back or posterior part of the body; opposite of ventral
Lateral X-ray beam enters either the right or left side of the body and exits on the opposite side
Mediolateral X-ray beam enters the limb medially and exits laterally
Palmar Refers to the posterior or inferior aspect of the forelimb from the carpus, distally
Plantar Refers to the posterior or inferior aspect of the hind limb from the tarsus, distally
Proximal Refers to the end of a limb or other part closest to the point of attachment
Recumbent Refers to the animal lying down
Rostral Toward the head or nares
Superior and inferior Refers to the upper and lower dental arcades, respectively
Ventral Refers to the abdominal or sternal surface of the body
Caudocranial The beam enters the caudal aspect of the limb and exits the cranial   aspect. Difficult or impossible to differentiate from the craniocaudal view.
Craniocaudal The beam enters the cranial (front) side of the limb above the carpus and exits the caudal (back) of the limb
Ventrodorsal The beam enters the ventral surface and exits the dorsal surface.
Palmar dorsal (plantar dorsal): Taken from the back to the front of the limb distal to the proximal end of the carpus.

Horizontal Beam Views – Horizontal beam views are views taken with the patient in lateral, dorsal, or ventral recumbent positions or with the patient standing in lateral, dorsal, or ventral standing positions.


In this example, the xray is being taken in the lateral position – so enters on left and exits on the right. It is recumbent as the animal is lying down and VD stands for Ventrodorsal which means the beam enters in the ventral surface (abdomen/sternal surface) and exists by the dorsal surface (back of the body).

In this example, the dog is placed in the dorsal recumbent position with it’s forelegs extended cranially. Therefore meaning: dorsal recumbent – lying on it’s back, forelegs extending cranially – it’s forelegs extended up by it’s neck.

Another thing I learned during this experience was the plate always has to be parallel to the xray beam – which seems obvious but when holding up the leg of a horse and holding the plate at the same time, it makes being exactly parallel that bit harder! I also saw an X-ray of a horse with kissing spine and watched them use the X-ray scan to medicate between the vertebrates which I thought was amazing that the vet knew exactly where to push the needle in and the angle to hit it at just using an X-ray they had taken.


Lily Toxicity

Hi Readers,

After completing my first day of work experience at a small animal veterinary hospital, one of the most interesting cases that really caught my attention was a cat with lily toxicity. I wanted to look into this a little further before I go back in tomorrow to see how it has progressed.

All parts of the plant, including the pollen and water from the vase, are considered toxic to cats and result in severe acute kidney injury. The exact toxic dose and nephrotoxicant mechanism is still currently unknown; however, the toxicant in the lily is considered water soluble.

Lily nephrotoxicity may cause symptoms such as inappetance, lethargy, hiding, vomiting, diarrhoea, halitosis (bad breath), dehydration, excessive or decreased urination or thirst, seizures and unfortunately death.

The decreased urination can cause hyperkalemia which is high levels of potassium in the blood. Potassium is an essential electrolyte which performs several functions such as:

  • regulating nerve impulse and muscle contractions.
  • maintains intracellular volume.
  • assists in maintaining blood pressure.
  • maintains heart function.
  • maintains the body’s electrolyte balance and acid/alkali levels in cells and tissues.
  • it also plays an important role in heart, skeletal, and smooth muscle contraction, making it an important nutrient for normal heart, digestive, and muscular function.

It is the role of the kidneys to remove excess potassium from the blood via the urine, if they are no longer functioning as efficiently potassium levels can build up. This is the case with lily toxicity as it causes acute kidney failure, causing frequency of urination to also decrease. With too much potassium the heart may begin to beat abnormally and in very severe cases, stop beating all together.

Treatment includes decontamination (like inducing vomiting and giving binders like activated charcoal), aggressive intravenous fluid therapy, anti-vomiting medication, kidney function monitoring tests, blood pressure monitoring, urine output monitoring and supportive care.

Once anuria (where kidneys fail to produce urine) develops, peritoneal dialysis or hemodialysis is the only potential treatment.

Peritoneal dialysis – A dialysis technique that uses the patient’s own body tissues inside the abdominal cavity as a filter. A plastic tube called a dialysis catheter is surgically placed through the abdominal wall, into the abdominal cavity. A special fluid is then flushed into the abdominal cavity and washed around the intestines. The intestinal walls act as a filter between this fluid and the bloodstream. By using different types of solutions, waste products and excess water can be removed from the body.

Hemodialysis – A medical procedure to remove fluid and waste products from the blood and to correct electrolyte imbalances. This is accomplished using a machine and a dialyzer, also referred to as an “artificial kidney.”

I believe this can only be carried out to an animal over a certain weight.



Feline Blood Donors

Hi Readers,

While walking around one of the veterinary school open days I noticed a sign that caught my attention. It was advertising for feline blood donors, which shocked me as I thought about the number of ethical questions it raised.

I looked into the procedure of cats donating blood a little more and found this article of the procedure that occurs when a cat donates blood:

Although the article is written in a method format, certain wording of the instructions such as ‘Locate healthy happy cat’ did begin to support my original fear that donor cats may be being used solely for ‘harvesting blood’ and forgotten that he/she is a live animal. As the veterinary profession develops and we use human procedures in the vet world, I feel that ethical issues are raised such as the problem of consent. While a ‘healthy happy human’ can agree to donating blood for a good cause, not all humans are comfortable with doing so – through fear of needles for example. Unfortunately, we will never be able to speak to our feline friends to ask whether or not they are comfortable with having their blood extracted.

Granted they do not understand what is happening, probably don’t have the same fears as us and I’m sure some cats sit purring away…but should we really be doing it to save a pet for human pleasure? After all, if the pet wasn’t living in a home and suffered, say, a car accident where he/she has lost a lot of blood…he/she would probably be left to die at the side of a road – like a badger or a fox – and not taken to a vet to have its blood replaced.

Another point I have considered is the possibility of someone who has their beloved pet that they’ve become very attached to and he/she needed blood, they may buy a certain cat just to use it’s blood. Similar situations are seen in humans for transplants. I’m sure many of you have seen ‘My Sister’s Keeper’ – I do think in cases when the animal cannot consent for themself, blood and actual organs are equal in the rights we have to extract from them, although admittedly blood tissue is less risky to transplant that a whole organ.

An article by International Cat Care discusses the issues with feline blood donation:

“Most cats, for their own benefit, need to be sedated for blood donation and this in itself carries a small risk. The drugs used in sedation often lowers blood pressure, and donating blood itself can also lower blood pressure due to removing some of the circulating blood volume. These effects on blood pressure and circulation can be a particularly important if a cat has some underlying disease that neither the owner or the vet is aware of – especially things like heart disease and kidney disease.”

This is of course very different to the procedure in humans and there are questions raised as to whether this is ethical or not.

I would be interested to hear your thoughts on feline blood donors!



Are hunting dogs spreading Bovine TB?

Hi Readers,

Whilst reading last month’s issue of ‘Veterinary Record’ I came across an interesting article about hunting dogs and the spread of bovine TB.

In January of this year, 3 cases of Mycobacterium bovis infection was confirmed by APHA. In March bovine tuberculosis was confirmed in a pack of hunting hounds in south-east England leading to the euthanasia of 25 dogs. Anti-hunting groups wanted to stop all hunting with hounds as a precaution, however officials have said there is little risk of bovine TB from hunting packs.

The Animal And Plant Health Agency (APHA) said, “TB in dogs caused by Mycobacterium bovis is very rare. There is no evidence to suggest the dogs play a significant role in the persistence of bovine TB in England and that hunting with dogs contributes to the spread of the disease amongst cattle.”

The dogs, which belonged to the Kimblewick hunt, voluntarily quarantined the dogs even though the government agencies did not impose restrictions.

The League Against Cruel Sports and Hounds Off asked for a strict ban on hunting with hounds as a biosecurity measure and requested an investigation of hunting with hounds and TB spread.

In 2011, research was carried out and the results from post-mortem examinations showed the presence of TB in Irish hunting hounds. This could be additional evidence for a potential risk.

Iain McGill, a former MAFF vet (Ministry of Agriculture, Fisheries and Food) comments that hounds run across fields, defecate on the fields – which is not picked up – eat cow pats and may pick up the bacteria from slurry spread on fields. The biosecurity is poor and to look scientifically, foot swabs should be taken of hounds and their faeces tested.

How the hunt hounds got the disease is not yet known but a possible route could have been consumption of contaminated carcasses or wildlife contamination of the kennel.

A spokesman for the BVA stated, “We are not aware of any evidence of a correlation between hunt areas and bovine TB incidence. We do not think that dogs running over a field present a significant risk of transmission.”

Having read this article I agree that it doesn’t seem that dogs spreading bTB is a huge risk. As APHA stated, the spread of Mycobacterium bovis by hound is very rare and cattle are more likely to contract it from other places. The Anti-Hunting groups may be using this incidence to aid their campaign however they have not produced any evidence to prove there is a significant threat in relation to hounds and the spread of bTB. The number of cases of bovine TB in dogs seems small so far this year.

I would love to hear your thoughts on hunting hounds spreading TB or any comments on hunting in general.



Veterinary Record Vol 180 No 24

Mental Health in Veterinary Medicine

Dear Readers,

I recently attended a Mental Health First Aid course so I am now a “Mental Health First Aider”. Many people have asked me what this actually means and unfortunately many have also initially thought I wasn’t serious when I told them.

In the veterinary profession mental health is an important part of the vets well being and good mental health results in a much happier lifestyle and enhances performance. This is also applicable to aspiring vets like myself, and our ability to have fun as well as study hard. The most important thing is to find that balance!

It has taken me a lot of time and I have put a lot of thought into how I could phrase this post, however if I could take away one thing from my course it would be to not be afraid of talking about mental health.

Mental health issues affect us as much as physical illness – the biggest problem is the stigma attached to mental health. People fear that if they talk about how they feel they will be pushed aside and thought of as ‘attention seeking’. They may feel as though they won’t get the promotion they wanted or an interview at a company they’ve always wanted to work for, living in fear that someone may find out their ‘secret’ of suffering with poor mental health and think less of them. Yet this attention is what they may well need to show themselves they have enough support around them to deal with whatever it is they’re struggling with. Just because people cannot directly see an illness definitely doesn’t mean it doesn’t exist.

I have looked at some statistics on mental health specifically in the veterinary profession and I found that:

  • 5% of VET STUDENTS wouldn’t want anyone to know if they were suffering from a mental health problem
  • 1 in 4 people in the UK have experienced a mental health problem in the last year
  • According to the results of a 2012 study of veterinary surgeons with a history of suicidal thoughts or behaviour, which was published in Social Psychiatry & Psychiatric Epidemiology, half the participants had not talked with anyone about their problems because they felt guilty or ashamed.
  • 24.5% of males and 36.7% of females in veterinary medicine have experienced depressive episodes since leaving veterinary school, which is about one-and-a-half times the prevalence of a U.S. adult throughout their lifetime.

These are difficult statistics to read and I have purposefully left out some of the more shocking data. When attending the course I was asked by a lady “How are you coping with this? You are very young.” I found the comment very interesting, while yes I agree that some of the topics we covered were very profound I feel as though as young adults we are protected from topics such as suicidal crisis and psychosis and we tend to shy away from learning more about them. On the other hand, young people who have suffered with mental health issues may have isolated themselves resulting in the knowledge adolescents and teenagers have of mental health being very limited – perhaps this is the reason even adults believe myths and false information that society has made up about certain mental health conditions as a result of not knowing enough.

Everyone I know has in some way helped another person by listening when something has been bothering them, proving as humans we naturally do care about the feelings and thoughts had by a friend/peer. What we need to change is how we treat the idea of putting a ‘label’ or a name to the certain mental health problems – this label is nothing to be afraid of. Admitting you’re struggling to someone you trust, appears to be half the battle! A friend with a mental health problem is still a friend. The same person you have been friends with for 10 years is still the same person and it is a compliment to you if they feel they can trust you enough to tell you they are struggling with depression, anxiety or any mental health problem for that matter.

One of the important things to note about mental health in this occupation is the raised suicide rate in vets compared with other professions. On this course a lady mentioned she had heard this described as ‘the cowards way out’ or a ‘sign of weakness’. I hope that one day society will believe that the controversial and very difficult topic of assisted suicide in terminally ill people, will be seen as the same reason people chose to take their own lives when they feel their poor mental health is also terminal as they do not feel they could ask for the help and support they desperately need.

Thankfully wonderful organisations such as Mind Matters run by the Royal College of Veterinary Surgeons exist. They offer training and vet helpline numbers, which clearly shows the support for mental health is developing and increasing and that this area of society is heading in a very positive direction. The Mind Matters twitter page inspired me to look for a mental health first aid course and I have inserted the link to their website below:

Mental Health can still be controversial and people have many different ideas on certain issues. I would very much enjoy hearing your thoughts or am happy for people to get in contact with me if you would like to know more about the course I attended and how to sign up yourself!


Stats references

Ethics in pig farming

Hi Readers,

After a long period of revision and exams I am back and very excited to start my many weeks of work experience I have lined up this summer!

Today I’m going to be investigating pig farming as I always ensure I do some research into any new animal before working with them on work experience. I’m so glad I have the chance to work with such intelligent creatures in the summer and want to also look into the breeding of these animals and how they are kept beforehand.

It was brought to my attention that there are lots of laws and regulations on pig farming when listening to a talk on “Compassion in World Farming” in my school by Eileen Greeves that must be adhered to when keeping pigs.

The topics included are: Pig housing and design (making sure they have enough material to investigate and have the ability to stand up, lie down and rest without difficulty and able to see other pigs at all times), Feeding and watering pigs (making sure they’re fed at least once a day and have the correct amount of water available to them dependant on their size), Health and welfare (getting any necessary medical treatment at the correct time and dose), Protecting animals from hazards and emergencies (stock should be moved to a more suitable area if there’s no natural or artificial shelter to protect grazing stock from extreme weather – heat waves, flooding or being buried by snow).

However what caught my interest was the following criteria.

Mutilating pigs

Boar tusks

Boar tusks should only be reduced in length when there’s evidence that it’s needed to prevent injuries to other animals/for safety reasons.


Pigs shouldn’t be castrated wherever possible and other ways should be used to reduce aggression and avoid boar taint. Boar taint is an unpleasant smell that is smelled during the heating of pork. Boar taint occurs particularly in meat of adult male pigs due to changes in the hormonal system when the animal is growing older. Boar taint rarely occurs in female pigs or castrated male pigs. Research has shown that there are three  substances that can cause boar taint: androstenone, skatole and indole. Androstenone – substance that is important in the development of the sperm cells in male animals. Skatole – produced during the degradation of certain amino acids in the body. Skatole – affects both male and female animals. Castration of male piglets lowers the concentration of Skatole significantly.

If castration must be done, a method must be used that doesn’t involve tearing tissues. Farmers can castrate pigs up to 7 days old, as long as they’ve been trained to do so – older pigs must be castrated by a vet.

Tail docking

Pigs should be separated or stocking densities cut down to reduce aggression. If those methods fail then tail docking should be a last resort on pigs over 7 days old and must be:

  • carried out under anaesthetic and additional prolonged analgesia (painkillers)
  • carried out by a vet
  • done by a quick and complete cutting of the tail

Tail docking is performed to reduce tail biting and cannibalism among pigs.

Teeth clipping

Corner teeth shouldn’t be routinely reduced in piglets. Only if there’s evidence that they’re injuring a sow’s teats or other pigs’ ears or tails, and farmers are trained to do so, can they do this.

Carrying out grinding or clipping routinely is not allowed. When steps have been taken to improve the environment or management of pigs to prevent tail biting but there’s evidence it’s still happening, you can carry out grinding or clipping. But this should only be:

  • done in the first 7 days of the piglet’s life
  • a uniform reduction of the corner teeth

Nose rings

It is not allowed to put nose rings in pigs kept continuously in indoor housing systems.


In reading these rules and measures put in place to prevent certain behaviours in particular I have found that pigs can be rather aggressive compared with similar sized animals I have worked with (ie. sheep). I researched this a little more and found there are a few reasons for this. Piglets show aggression to other piglets within the first week of life while forming a teat order (they always suckle the same teat so much form this teat order). Introducing new pigs into a group may lead to aggression as the pigs establish social ranks. Pigs may spend 1–2 minutes nosing each other, vocalising, and then biting until one of the pigs retreats. It may take several days to establish a hierarchy in older pigs.

Crowding and limited amounts of food increase aggression. During breeding, boars may fight and become very vocal; boars will strut shoulder to shoulder, champ their jaws (producing pheromone-rich saliva), then finally face each other and attack. Serious injuries may result, especially among boars that still have their tusks. Breeds with lower body fat are more aggressive when handled.

Tail biting was one of the behaviours that really caught my attention. Tail biting is seen mostly in confined pigs. Overcrowding and boredom seem to be the main causes. Free-ranging pigs spend 5–10 hours daily looking for food and rooting, whereas pigs kept in pens consume meals in a short time. Slatted floors without bedding, low-salt diets, and low-iron soil seem to prompt pigs to start tail biting. Once the problem starts, blood from the injured tail seems to arouse the other pigs and can even lead to death of the victim however it rarely advances to pure cannibalism.

In terms of cannibalism, this is seen in first time mum gilts (young female pigs), cannibalism accounts for 4% of piglet deaths and is estimated to affect about 18% of litters. It is most common immediately after giving birth when the sow is stressed. Usually, the sow will bark to warn piglets walking by her head and then later attack them, biting them to death. This may raise some ethical questions such as should they become so stressed that they resort to killing their young? Can this be helped? Does it happen in smallholdings where space isn’t so much of an issue? From a veterinary point of view, how could we ensure that in farms that number decreases in order to help farmers produce as many piglets as possible?

I look forward to working with such a different species and hope I learn more about their behaviour in a commercial setting. As always, thoughts and personal experiences are very much welcomed in the comment section.





Inspired by table salt – cyanide poisoning

Hi Readers,

I was eating my dinner early this week and I noticed on the salt bottle that an anticaking agent called ‘potassium ferrocyanide’ was used. I began to wonder, as I remembered learning in biology that cyanide is a competitive inhibitor, what the “ferro-” prefix signified and how the “ferro-” prevents it from inhibiting our enzymes.

After carrying out some online research I found that the ferrocyanide has its cyanide ions very tightly bound to the iron atom and stays with the iron right through the digestive system. The ferrocyanide cannot freely pass through the plasma membrane.

Nitrites can be used to treat for cyanide poisoning. The nitrites oxidise some of the haemoglobin’s iron converting the haemoglobin into methemoglobin. This releases more cytochrome oxidase enzyme (more of the enzyme which is being inhibited by the cyanide, which is preventing cellular respiration).

Cyanide binds to methemoglobin, forming cyanmethemoglobin. Treatment with nitrites is not really safe as methemoglobin cannot carry oxygen, and severe methemoglobinemia may occur and needs to be treated in turn with methylene blue (which used to be used to directly treat cyanide poisoning). Sodium nitrite is rapidly effective but can cause life-threatening toxicity (methemoglobinemia), whereas sodium thiosulfate – which can also be used to treat cyanide poisoning – has a delayed effect but is far safer.

I decided to look into cyanide poisoning in cattle, and the most frequent cause of acute and chronic cyanide poisoning in livestock is ingestion of plants that either contain cyanogenic glycosides (young plants, new shoots, and regrowth of plants after cutting often contain the highest levels of cyanogenic glycosides) or are induced to produce cyanogenic glycosides and cyanolipids.


The affected cattle should be treated immediately by drenching with sodium thiosulphate. 60 g should be given in 600 ml of water. This can then be repeated hourly until the animal recovers.

The most effective treatment for cyanide poisoning is an intravenous injection of sodium thiosulphate. This is best administered by a vet at a dose rate of 660 mg/kg as well as oral/intraruminal doses of 30 g in 100 ml of water. The animals may require repeated intravenous doses if they relapse.

Sodium thiosulphate in a high dose can be effective when given up to 30 minutes after the ingestion of a toxic dose of cyanide, but it must be given as soon as possible.

Symptoms may include:

  • rapid laboured breathing
  • irregular pulse
  • frothing at the mouth
  • dilated pupils
  • muscle tremors
  • staggering

The mucous membranes are bright red in colour due to oxygen saturation of the haemoglobin.

If large quantities of cyanide are absorbed rapidly enough, the animals detoxification mechanisms will be overwhelmed and the animal will soon die. Affected animals rarely survive more than 1-2 hours after consuming the lethal quantities of cyanogenic plants and usually die within 5-15 minutes of developing clinical signs of poisoning.

Again, as I regularly mention, PREVENTION IS BETTER THAN A CURE! In order to prevent possible cyanide poisoning:

  • Graze sorghum, sorghum crosses, or john-songrass plants only when they are at least 18-24 inches tall.
  • Do not graze plants during drought periods when growth is severely reduced or the plant is wilted or twisted.  Slowed growth and the inability of the plant to maturefavours the formation of cyanogenic compounds in the leaves.
  • Do not graze potentially hazardous forages when frost is likely (including at night). Frost allows conversion to hydrogen cyanide within the plant. It is best not to allow ruminants to graze after a light frost as this is an extremely dangerous time and it may be several weeks before the cyanide potential subsides.
  • Do not allow access to wild cherry leaves.

Have any of you ever seen this in real life? I look forward to hearing any thoughts!



“Fixing a broken heart”

Hi Readers,

Following a talk I recently had at school on UCAS applications as I start to think about applying to university, an interesting point was raised as a side topic by our guest speaker. He mentioned that zebrafish, a fish of no economic value to commercial fisheries, might help to extend our generations’ lifetime by almost 20 years.

The zebrafish is a special animal to biologists because its body is transparent. Therefore zebrafish are transparent early in their life cycle, so it is easy for researchers to see their hearts and blood vessels grow. Their hearts begin to develop after just 12 hours, and they reach adult size – about 3cm long – in about three months. They can provide research results barely three days later. If researchers modify the fish’s genotype at the egg stage, they can see a change in organ shape or dynamics very quickly.

In this 30-hour-old zebrafish embryo, you can observe developing organs like the retina (R), the brain (B), spinal chord (SC), the muscle (M) and the heart (H).

Heart tissue damage may occur when a person has suffered from a heart attack which affects their quality of life. Understanding what proteins allow human heart cells to multiply and regenerate, as they do in these fish, could help develop drugs that help our hearts to heal themselves.

If a person has a heart attack, the heart tissue lacks blood and therefore oxygen, causing it to become damaged or dead. Zebrafish can repair their hearts, unlike humans – heart muscle cells near the damaged area lose their muscle properties and revert back to stem cells. Scientists know that a protein called Mef2 is needed to turn zebrafish stem cells into heart muscle cells.

Dr Yaniv Hinits and colleagues believe that zebrafish muscle cells near wounds are able to turn Mef2 on and off – turning Mef2 off to revert to stem cells, before growing and turning Mef2 back on to repair the heart. Their team has been awarded a grant to find out if controlling Mef2could be used to treat damaged human heart tissue. They will study Mef2 in detail, find out if it can heal the heart after injury, and test if other proteins thought to influence recovery after heart attack are working through Mef2.

From my understanding, the grant was for three years and started 1st July 2014. I hope we hear some results in a few months time from this promising experiment.