General Chit-Chat

I have finished my exams today, they went OK but some papers were harder than others! I start my new modules on Monday. These are all modules I have chosen which will be good. These are the modules I am taking;

• Equine Nutrition
• Livestock Nutrition
• Equine Behaviour And Welfare
• Molecular Genetics Of Production Animals
• Emerging Veterinary Science

Hopefully the first few weeks will be quieter so I will be able to write some more posts! I will probably be writing more nutrition and behaviour posts over the next few months. I have got a big list of things I still want to write. I still need to write a post on The Spanish Riding School from when I went. I was going to write it when I went home over Christmas because the program was at home which had lots of information and nice photographs in it, however, I was too busy with revision and I forgot to bring it back with me. I will write it at some point though. Also I saw that a lot of you found my genetics post interesting so I might write some more on genetics in the near future.

Here is a video that I found as somebody posted a link to it on Twitter. It is a video of Badminton Horse Trials but from the year 1965. I found it interesting so thought I would put it on here. Click here to watch it!

Another video I wanted to show with you was one I saw on Facebook on Horse & Hound's page. It is of The Household Cavalry after they have gotten off the horses and they can't walk because their boots are so long. There must be some reason they have them like this but surely this couldn't have been good if they were actually in battle. Click here to watch.

Trooper is doing well at home, he has been a bit stiff recently so we might start giving him bute again, we could give him it every other day or just when he looks like he needs it. He is 22 years old so it is probably mostly to do with his age. I don't see any reason why we shouldn't give it to him if he is stiff because it is making him loosen up. Here is a random photo of him I had on my laptop to make the post look a bit more colourful! Trooper has got quite a long mane at the moment and I thought it looked cute but after seeing this photo I think he is due a haircut when I go home because it looks nice and smart here!

Also thank you to all my new followers and especially a big thank you to Ruffles and Wolfie who I think have sent them over here!

Love Laura
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Coat Colour and Diseases

Just a warning, this post is going to be long! Feel free to skim-read the parts you find interesting! I am doing this to help with my revision but thought it would be interesting to have on here!

This semester I have been doing a module called "Animal Breeding and Genetics". I find genetics interesting so have quite enjoyed this module. I have my exam in it this afternoon. We have had 2 different sections to the module, the first part was about Mendelian genetics. This is the usual dominant and recessive gene stuff. Then we have had a molecular genetics section, this is the new type of genetics with all the genomes being developed and using technology to look at what genes the animal is carrying. We have a seen question on this topic on the exam and the question can be seen below...

"With specific reference to genes involved in coat colour determination, demonstrate how molecular genetics has either corroborated or enhanced our knowledge gained from classical genetics."

Below is my answer I have written to it! I am going to put this on a schedule for when I have done the exam so nobody can copy my answer! I have decided to put a twist on it by discussing coat colour but also the diseases that are linked to it.

Introduction
Molecular genetics has allowed a number of improvements t be made when selecting horses to breed from. There are 11 genes involved with coat colour and they are under polygenic control. When looking at dominant and recessive genes, Mendelian genetics can be used. However, in many cases it is difficult to determine the genotype of the animal and predict their offspring outcome so molecular genetics are useful in these cases. There are also many diseases that are linked to coat colour that may need to be taken into account when selecting animals to breed.

Basic Coat Colours
There are three basic coat colours that are coded for in the genome, these are then altered by other genes. These are black, brown and chestnut. The extension locus is involved with the expression of red and black pigment while the agouti locus controls the distribution of it.

There are a number of genes controlling the white patterns on horses. These include the appaloosa gene, dominant white, tobiano and overo genes. There is a progressive grey gene that will result in an animal turning grey by the age of 6-8 years independent on what their previous coat colour was.

DNA Testing
The equine genome was made available in 2006 and this has allowed a wealth of new information to be developed. Coat colours and diseases linked to these can now be selected for or against using a DNA test. These are particularly useful when the horse has no breeding or pedigree records to distinguish the animal's genotype.

Polymerase Chain Reaction (PCR) can be used as a DNA test. A sample of DNA is taken from the horse and this method rapidly processes a number of copies of a section of the DNA. This can then be analysed to see if certain genes are present.

Image of PCR tubes (From Wikipedia)

Selecting For Health And Coat Colour
There are a large number of diseases in the horse that have been linked to their coat colour. Molecular genetics has allowed these links to be looked at and the causes behind them.

When looking at the progressive grey gene it has been found that around 70% of these grey horses develop melanomas by the age of 15 years. Animals that are homozygous (have to copies of the same gene) for this trait are more likely to develop the condition.

There is a gene called the lethal white gene, this is also called overo. Carriers of the gene are hard to distinguish without a DNA test. It can result in a black normal foal being born. On the other-hand it can result in a white foal being born with intestinal tract abnormalities that will die soon after birth. This has been found to be due to a single base pair change (missense mutation) (Finn et al, 2009).

The dominant white gene is another gene that has diseases  linked to it. It has been found that the "KIT" gene is faulty in animals with problems here. This gene is involved with the development of blood, the gonads and skin pigmentation. Therefore mutations in this area can cause disease. This has been identified using molecular genetic tests. At least 14 different mutations have been found on this gene.

A Quarter Horse had a mutation of the KIT gene in the year 2000 and went on to become a prominant stallion. This mutation was called W10. There is now a diagnostic test available to detect for this mutation.

Hasse et al (2009) identified some of these KIT mutations using PCR. In four of the seven looked at, individual horses were responsible. The mutations were due to two frameshift mutations, two missense mutations and three splice site mutations.

Another problem seen in horses that is related to coat colour is congenital stationary night blindness, this is seen in appaloosa horses. In these horses, they will be cautious of light and may be difficult to train. Recently, molecular genetics has found a different expression of the TRMP-1 gene in the skin and the retina that is resposible for both night blindness and the leopard complex phenotype (Webb and Cullen, 2010).

With the molecular tests that are now available, there is no reason why horses carrying these mutations should be bred from. This would reduce the prevalence of these diseases. However, caution would have to be taken with this approach not to reduce the genetic diversity of the animals as this could also have a detrimental effect.

Evolution
Another potential use for molecular genetics when looking at coat colour is to asses the remains of horses that have been found from ancient history. Svensson et al (2011) looked at the coat colour from 26 horses from the Iron Age in Sweden. They used coat colour SNPs in the horses and PCR was used. They wanted to investigate regional differences or preferences for specific coat colour that may be related to traditions they had. They found black, bay and chestnut were all common, two horses were found with tobiano spotting. There were no clear geographical differences in coat colour between the horses looked at.


Conclusion
In conclusion, the use of molecular genetics has been an important development into the knowledge and understanding of equine coat colour. In the future, more research should be carried out into this area. It will help to improve the breeding of horses by not just selecting for coat colour but with the prevention of diseases. This knowledge from horses may also be used to look at other species such as donkeys and zebras.

I am sorry but I don't have all the references for this information, I have taken it from various sources!

I have chosen to take a full module on molecular genetics next semester as it is an important developing area in animal science at the moment.

Love Laura
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Trooper's Leg

It has been a while since I updated you all on Trooper's progress with his tendon injury so I thought it was time to write a post on it.

Before coming back to uni I did get to canter him which was good! I just did a small canter along one long side and he was fine. After a few more riding sessions I was trying to canter him for longer distances but we couldn't quite make it all the way around the arena without breaking into trot. My Mum has also cantered him so now I am back at uni she can carry on doing this. Because his injury was in his pastern on his hindleg I think we should take it easy before getting him to work with his hindlegs underneath him. Therefore he is quite on the forehand when I have been riding him.

I have been doing circles in walk and trot but not yet in canter. And in walk I have started schooling him a bit more and bringing him in to a slightly more collected walk.

He was on bute every day when I got home from university for Christmas. We reduced this down to one every other day and there was no difference so we have stopped giving it him now. He doesn't seem stiff on his leg.

It was at the start of September when he got the injury and wouldn't put his weight through the leg for more than a second and was noticeably lame in walk. He has made really good progress with the injury. We have always said how quickly he heals when he has a cut and this is the first time he has ever gone lame (and we have had him 13 years). My Mum has worked really hard with it while I have been at uni having to hose it twice a day and walk him in hand and ride him every day. He has also had treatments such as ultrasound treatment, physio and an injection of his plasma into the area. I think he is pretty much healed now and back to normal in himself now but I just want to make sure I take it easy building up his work.

When I next go home at Easter I will see what he is like then I  am planning on making a blog post on the time-line of his injury and rehab process with links to the blog posts.

Love Laura
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Horse Hairstyles?

I remembered these photos they other day and thought I would make a post on them. Below is a quote taken from Julian Wolkenstein's website (click here). Julian is an artist and has created a wide range of interesting images.

"Of course we view our animals with fondness, we often bestow our animals with human traits, little wigs, clothes, and such.

But with such a majestic creature as a horse our reaction is less whimsical,  the size and nature of a horse commands respect. They have been alongside humans for so much of our history.

This Pin-up series takes dressing animals up to a extreme, working with the horses natural hair, additional hair extensions and over all grooming with dramatic lighting provides a wry humour.

Our reaction is mixed, its not whimsical, but it is definitely not serious either, we are left questioning our relation to, and our projections on animals."

I love these images for the purpose of the photo but don't think I will go braiding Trooper's main into dreadlocks any time soon! What do you think of the images?

Love Laura
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Horse Jumpers

Even though it is coming to the end of the winter there are still a lot of nice jumpers around. I decided to do a blog post on some of the lovely horse (and one zebra!) ones I have seen. With the summers we have in the UK I am sure we will be wearing jumpers at some point!

These first two are by Wildfox Couture and are quite expensive at £97 and £95. I love both of these jumpers, not sure which one I like the best but if they were cheaper I would definitely buy one! Click here for the polo one, and here for the zebra one.

The next jumper is by Whistles and is from John Lewis. This jumper is £55 so also quite expensive but I love the horse picture on it. Click here to go to the website.

There is also a nice jumper with a horse on from Topshop which was £40 but has now been reduced to £20, it wont let me save the photo of it to put onto here. But if you want to see it click here. When I first wrote this post it hadn't been discounted but now it has and I have bought it! I might make a post at some point with my "horsey" items of clothing or jewellery that I own! 

Love Laura
xxxx

Insulin Resistance In Horses

After writing a post on the hormone leptin the other day (click here), I decided to write a post on insulin resistance in horses. Insulin and leptin have also been found to be linked. I have got my endocrinology module exam tomorrow so this is my last bit of revision on hormones.

Introduction
Insulin is a hormone that is released by the pancreas. If helps to bring the glucose levels down in the blood by putting the glucose into storage and preventing the body from absorbing more. This  is important as you do not want the levels to get too high.

Insulin resistance in the horse has been linked to a number of other diseases such as developmental orthopaedic disorders, laminitis , equine metabolic syndrome and Cushing's disease.

Insulin Resistance
Insulin resistance is seen in humans in the form of diabetes. Type 1 diabetes is from a young age and patients have a problem with their pancreas as it is not producing insulin. They will have high levels of glucose in the blood after they have eaten a meal.

Type 2 diabetes develops over time and is often seen in obese people. They will also have raised blood glucose levels but this is due to a high energy diet. The pancreas tries to compensate for this by producing more insulin but over time they will become de-sensitised to these high insulin levels. The pancreas can also stop working in some cases.

In animals, insulin resistance has been linked to foods with a high glycaemic index (GI), these are food that make the blood glucose levels raise more after eating them.

Animals can suffer from both types of diabetes but it is usually the type 2 form seen in fat horses and ponies. It is most commonly seen in native breeds. It has been found that small ponies have higher levels of circulating insulin levels than larger horses. Obesity increases insulin resistance and exercise will decrease it. Click here to be taken to a fact sheet on insulin resistance produced by thehorse.com which are an online guide to equine health care, it talks about the symptoms and treatments which I will not be talking about here.

There are a number of methods to test glucose resistance which I have learnt for my exam but I am not going to go through them here. If you would like more information then let me know.

Research
Sessions et al (2004) looked at the effect insulin resistance had on the oestrous cycle in mares. It was concluded that the condition may modify characteristics of the oestrous cycle, perhaps at the level of the ovary.

Treiber et al (2006) found that insulin resistance was linked to laminitis. Therefore characterising insulin resistance may help with the management of ponies to avoid laminitis and potential strategies to use such as reducing obesity, increasing exercise and moderating dietary carbohydrates, particularly starch.

Hyperlipaemia/ Hyperlipidaemia
Hyperlipaemia is linked to insulin resistance. This is a condition seen in horses when they go into a negative energy balance (they are using more energy than they have coming in from their feed). It is often seen in small, over weight ponies. Stress can also increase the likelihood of the condition, but the condition causes stress causing a viscous circle.

I first came across this condition when I was working at the Donkey Sanctuary. Donkeys often form strong attachments to another donkey and they told me if they were separated they could get stressed. This caused the donkeys to stop eating and their body would have to release fat to use as an energy supply. However, their body would keep releasing the fat and in the end it could be a fatal condition. Here is an information sheet produced by the Donkey Sanctuary on the disease. I had never heard of this condition in the horse before this module.

Love Laura
xxxx

Strangles

For my bacteriology exam I have been researching about strangles. This is a disease I find particularly interesting as the livery yard where I keep my horse has been affected in the past. This is part of my revision but thought I would write it on here!

Strangles is caused be a bacterium called Streptococcus equi. It is usually transmitted via nasal secretions and can survive in water for 1-2 months. It has an incubation period of 7-12 days in the horse, so after being infected it will take this long before symptoms will be seen. Horses aged 1-5 years are mainly affected.

The source of an outbreak can be a clinically infected horse or a symptomless carrier (this may be an infected horse that has recovered). Most horses recover after a month but some of them will go on to become carriers.

Symptoms
The symptoms are swelling and infection of the throat region. There is usually a fever of 102- 106 degrees. The horse may have nasal discharge and a cough. They may have depression and be unwilling to eat. It also causes enlarged lymph nodes in the pharyngeal region (in the throat) and other complications. The horse may  find it difficult to swallow. After 7-10 days the lymph glands can rupture release thick yellow pus.

Diagnosis
The diagnosis can't rely on the symptoms along as they are not specific to strangles. They send away swabs to the laboratory to get confirmation. the swabs are taken from the nasal cavity or from an abscess. A toxin is produced by the bacteria that breaks red blood cells down, in the lab they may look at the ability to ferment other sugars to tell it apart from other bacteria.

PCR may be used which is a diagnostic test that looks at the DNA of the bacteria to tell it apart from others. However, there is another species that is 90% the same. The primers used in this process are also important. This method can also tell the bacteria apart from the type the animal is given in a vaccine.

ELISA is another method which could be used. This looks at horses and the immune response against organism. This is quick and easy to do lots of horses.However, it takes 14 days for the immune response to develop so it may not work before this time. It may also give false positives from horses that were infected but are not any more. 

Treatment

The treatment is to use penicillin but the abscesses must be drained. There is a low mortality. They will need to take repeated swabs from the horse and need 3 negatives before they get the all clear. A guttural pouch wash may be done to detect carrier horses as this is where they carry the infection. Antibiotics may be given to healthy horses that have come into contact with infected horses. Rest is important along with the prevention of spread of the disease to other horses.If an abscess bursts, it is important to keep the wound clean. New horses moving onto a farm should be isolated for 4-6 weeks. Infected horses should immediately be isolated and stables should be infected along with water and feed buckets.

Vaccines

Vaccination is possible if the disease is persistent. The vaccine is given in the upper lip. Both intramuscular and intranasal vaccines are available. Most horses develop an immunity during recovery from strangles, which persists in over 75% of animals for 5 years or longer. This shows that immunity from a vaccine is possible if the right vaccine is developed.

Hope that was interesting! This information is from a variety of sources and unfortunately I have not written in my notes where it came from!

On our farm horses are not isolated when they move on which is an important factor and I think should be carried out. After our farm became infected with strangles, some isolation stables were made and used for a while but as the farm got busier these stables became full time stables for horses that had been there for a while.

The riding school horses were mainly affected when we had the infection. One of the new ponies they had could have been a carrier. We had a field with infected horses in and another with the non-infected horses. We thought Trooper's neck was swollen one day so they vet said to put him in with the infected horses. It turned out he was fine but he wasn't allowed to move back into the other field after he had been in with the infected ones. He never caught it though so maybe he was already immune.

Love Laura
xxxx

Ban Chinese Lanterns

Some of you may remember my post on the dangers of Chinese lanterns. It has become my most highly viewed post and I think this highlights that a lot of people are feeling the same way about them. When the come down during the night and land in fields they can harm your horses. I have found them twice in our horses' field and once one of the horses had cut its mouth trying to eat it.

On my facebook page it has been brought to my attention that there is now a petition that can be signed to ban the use of these Chinese lanterns in the UK. All you have to do is fill in your name, address and email address and then click the link on an email to confirm your email address. They need 100,000 people by August so get everyone you know to sign up. I have added the link of this to the bottom of my old post as well so people that may come across the post can sign it.

Click here to sign the petition!

Thank you!

I am now back at university studying for my exams. I start exams on Tuesday and finish on the 28th so I probably wont be posting much until then. Sorry I did not take any good photographs of Trooper over the winter. The weather was rainy and I kept forgetting my camera! He is coming on really well with his rehab work after his tendon injury and we have just started cantering him before I came home. I have spotted him rearing and bucking in the field with no problem so I think it is pretty much healed now. We have reduced his bute down to every other day so the next thing will be stopping that all together. Hopefully when I am home at Easter he will be back to his normal level.

Love Laura
xxxx

War Horse Premier

Here is a link to the Horse and Hound story on the War Horse premier. They took the horse, Joey, on the red carpet. Not sure what Trooper would have made of that! On the video I am sure at around 30 seconds in a photographer shouts "Joey mate, just here please!" to get the horse to look at the camera... Haha, I'll have to try that one next time Trooper is looking the other way.

http://www.horseandhound.co.uk/news/397/311033.html

Love Laura
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Leptin Hormone in Horses

Today I am revising for my endocrinology module which is all about hormones. It is quite an interesting module but my brain is dropping off to sleep writing out notes so I thought I would write a post on here on some of research from journals that I can also use in my exam.

I am going to write about a hormone called leptin. This is produced by the fat in the horse and is involved with controlling the appetite. It also has other effects on the immune system and on regulation of temperature. It is controlled by the ventro-medial hypothalamus in the brain where there are receptors. A lot of the work that has been carried out into leptin has been done at mice. When it was first discovered, there was great interest into it's effects in relation to obesity in humans but it has been found to work differently in humans than other animals due to the type of diet we eat.

What is leptin?
Animals that have higher levels of fat will have higher levels of leptin circulating in the plasma. This will in turn reduce the appetite telling them to stop eating as much. It will also increase the appetite in horses that are thin, this is thought to be an adaptation to starvation in the wild and they will try and find food harder when it is scarce.

Affects with day-light
Melatonin levels are high in the night and low in the day and cause leptin levels to. There has been controversy in results regarding the effect melatonin has on leptin as some has found it increases it and others have found it decreases it (Kus et al, 2004). If it increases leptin levels then appetite would be down regulated during the night which would make sense. However, it is thought that the involvement with melatonin is a response to the scarce food available during winter. In the winter the days are shorter so there is more melatonin produced and if it decreased the levels of leptin it would increase the appetite. It is also thought to work the other way around during the summer (Alonso-Vale et al, 2005).

Leptin and feed restriction
When horses have had their feed restricted, the concentration of leptin decreased 6 hours after the restriction and the levels did not recover straight away when the were fed again. This shows that leptin is affected by what the horse is eating but it takes time to have an affect. The slow response to leptin increasing was thought to be due to the energy being eaten in the feed going to the tissues that needed it the most after feed restriction before being stored as fat. It was also thought that this could be an adaptation to when food is scarce, the leptin levels stay low so the horse will eat as much as possible for a period of time in case their food is restricted again (Buff et al, 2006).

When mares have a poor body condition they do not reproduce well. This is seen in lean mares that do not cycle through the winter (go into anoestrous). Leptin may act to signal to the reproductive system if sufficient body fat is present to support a pregnancy. Leptin treatments have been found to increase sexual development in both male and female mice. Leptin levels vary during foetal development and are correlated with foetal size.

A number of other factors have also been found to effect leptin concentrations. Males had higher serum concentrations than females, this was a surprising result as females are thought to have more fat.There has also been found to be an increase in leptin levels with age. This is as expected as young animals often have a lower level of body fat and a greater need of nutritional resources. The greatest levels were seen in horses older than 12 years (Buff et al, 2002).

So why do some horses get fat?
For some horses it may be down to the owner feeding them a high grain, high energy diet, they have not evolved to eat this kind of feed and the high energy intake from eating just a small amount will not be controlled by leptin. It has also been suggested that some ponies (small and fat ones) may be leptin resistant. In the same way people or horses that are diabetic are insulin resistant. This will therefore mean they have high levels of circulating leptin but it will not be having an effect on their appetite as the horse's tissues fail to respond to leptin.

Hyperleptinemia can happen. This is often seen at the same time as hyperinsulinaemia which is the equivalent of diabetes in horses. It has been suspected that hyperleptinaemia may be a result of reduced insulin sensitivity which causes an increase in insulin concentrations which effects the leptin levels (Caltabilota et al, 2010). This may also predispose horses to laminitis.

(Some of this information is taken from Applied Animal Endocrinology by Squires).

Love Laura
xxxx