Vet News – Exotics News

Posted on June 30, 2013 by NerdyVet

This month Vet News Exotics Editor, Charlotte Hitch brings us a fascinating piece on the breeding of White Bengal Tigers.

EXOTICS:

Breeding White Bengal Tigers

Charlotte Hitch (Vet News Exotics Editor)

White tigers, which originate from South Asia, are becoming increasingly popular in zoos in the Western world. Despite the undeniable beauty of the sleek black and white coats and piercing blue eyes of the white tiger, much controversy has arisen about the ethics of breeding these animals.

Many people believe that the white tiger is a rare, separate species; one which is rapidly and alarmingly decreasing in numbers, and call for conservation programmes to be initiated in order to save the ‘Royal’ white tiger. However, this is a common misconception. The white tiger is not a species, but rather a genetic mutation of the normal orange and black Bengal tiger, caused by an abnormal recessive allele in a single gene, SLC45A2, which is only partially responsible for pigmentation of the animal. This explains the presence of black stripes on an otherwise colourless body – a condition called leucism (not albinism as some may think; which causes the whole coat to be white and the eyes to be pink).

For most zoo owners and directors, the primary reason for breeding white tigers is for profit. The scarcity of white tigers makes them a huge attraction in zoos, and one cub can make up to US$60,000 when sold.

The truth about the conservation of this ‘species’ is often hidden from the public – during the breeding process it is not uncommon for normal orange-coloured cubs to be born from a white tiger parent. In this case, the cubs are often sold or disposed of in ways which are far from humane because they do not show the rare colour desired by the breeder.

Since the white tiger is not a species on its own, and is caused by one mutated gene, until now the only way to produce white cubs was to extensively and continuously inbreed close relatives; e.g. daughter to father or brother to sister. In fact, it is thought that the whole population of white tigers originated from one single tiger.

A famous example of the problems that inbreeding may cause is the case of Kenny the tiger. Kenny was born with serious deformities, such as abnormally arranged teeth causing difficulty with eating and a ‘pug nose’ which prevents correct and efficient breathing.

Other white tigers may have bulging or crossed eyes due to incorrect routing of their visual pathways, club feet, hip dysplasia, cleft palates, immunological problems, scoliosis (curving of the spine), shortened tendons, or kidney problems. It has been reported that they also react abnormally to anaesthesia, and their blood coagulates at a slower rate than that of their orange counterparts, causing more severe bleeding. Consequently, treating the animals to correct some of the problems caused by inbreeding is therefore close to impossible.

Now that the gene which causes the white coat has been discovered, it may be possible to screen normal orange tigers to see if they are carriers of the recessive gene and selectively breed the carriers to produce non-inbred white tigers. However, even this has consequences; the white colouration of these animals means that they would be incapable of camouflaging themselves in the wild in order to catch prey. For this reason, all white tigers are bred for a life in captivity. Some may argue that we are simply causing suffering by wasting money and resources on animals which will never be able to survive in the wild, while the number of healthy wild Bengal tigers from a more varied gene pool dwindles at an ever increasing rate.

References:

http://www.youtube.com/watch?feature=player_embedded&v=UKwY7yV5sYo

http://www.wildcatsanctuary.org/the-truth-about-white-tigers/

http://www.digitaljournal.com/article/350943

http://www.thehindu.com/sci-tech/energy-and-environment/white-tiger-numbers-can-be-increased-without-inbreeding/article4745897.ece

http://advocacy.britannica.com/blog/advocacy/2010/02/white-tigers-conserving-misery/

Images:

Charlotte Hitch

http://advocacy.britannica.com/blog/advocacy/wp-content/uploads/white-tiger-2.jpg

Vet News – Exotics News

Posted on May 3, 2013 by NerdyVet

Our newest addition to the team is Charlotte Hitch, who has come on board the good ship Vet School Success to bring you some fascinating articles with a more exotic flavour. It’s great to have Charlotte on the team and she takes up the role of Vet News Exotics Editor. Welcome Charlotte 🙂

EXOTICS:

Lymphocytic Choriomeningitis Virus (LCMV) in Marmosets

Charlotte Hitch (Vet News Exotics Editor)

Lymphocytic choriomeningitis is an infectious zoonotic viral disease which affects a family of New World monkeys called Callitrichids, including the species Callithrix jacchus, or the common marmoset, an increasingly popular exotic pet especially in the United Kingdom and USA. In 1991, in a zoo in Texas, 5 of 7 pygmy marmosets died after exposure to infected neonatal mice. Hence, the LCM virus, once present in a population of Callitrichids, poses a significant risk to simian health.

The secondary effects of contracting LCM, an arenavirus-induced condition, include aseptic meningitis and Callitrichid hepatitis (CH), a commonly fatal disease which presents itself in the form of clinical signs such as dyspnoea (shortness of breath), anorexia (loss of appetite), lethargy (extreme tiredness), and jaundice (yellowish pigmentation of the skin and the ocular sclera). In basic terms, the pathology of CH consists of an inflamed liver which may be likely to develop cirrhosis or fibrosis, and metabolic disorders often follow.

The LCM virus can be carried by the common house mouse, Mus musculus, and can be caught through exposure to the faeces, saliva, milk, nasal secretions, semen or urine of an infected specimen. M. musculus are a reservoir species; they are able to carry and spread the virus to other species without being harmed or killed by it. Captive marmosets are particularly at risk due to unnatural contact with infected house mice, and also because of the difficulty in controlling such carriers.

Transmission can also be vertical, i.e. to unborn foetuses in utero through the placenta – possibly producing infected offspring.

While its effectiveness has not yet be confirmed, the drug ribavirin may be used on a trial basis to treat the initial LCMV infection; however once CH develops, the chances of survival are greatly reduced. Additionally, ribavirin is teratogenic (may lead to the formation of teratomas). The virus may be inactivated by hypochlorite solution, heat, UV light or gamma irradiation if disinfecting a contaminated area. Corticosterone, an anti-inflammatory drug, may be used to treat the encephalitic effects of the infection – reducing the cerebral and spinal cord inflammation. It is also highly recommended to avoid feeding captive marmosets mouse pups, as other proteinous food items such as mealworms should suffice; however this preventative method will be ineffective once infection has already occurred.

Currently, Callitrichid Hepatitis is incurable but treatable with increased rest and diet regulation, through reduction of dietary fats. Future developments in regenerative medicine may allow treatment of CH through intravenous transplantation of cord blood stem cells into the liver, replacing damaged hepatocytes and restoring normal hepatic and immune function. While these ideas are still in the development and pre-testing stages, precautions must be taken to control reservoir species such as mice to prevent rodent-borne transmission to captive marmosets.

References:

http://wildpro.twycrosszoo.org/S/00dis/viral/LCM/LCM.htm

Pathology and Immunohistochemistry of Callitrichid Hepatitis, an Emerging Disease of Captive New World Primates Caused by Lymphocytic Choriomeningitis Virus, American Journal of Pathology, Vol. 148, No. 5, November 1995

http://www.eaza.net/activities/tdfactsheets/010%20Callitrichid%20%20Hepatitis.doc.pdf

http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/Fact_Sheets/Lymphocytic_Choriomeningitis_Fact_Sheet.pdf

http://www.merckmanuals.com/vet/management_and_nutrition/nutrition_exotic_and_zoo_animals/nutrition_in_primates.html?qt=callitrichid%20hepatitis&alt=sh

http://hepatitis.stemcellcentre.org/en/

Picture credits:

http://www.rspca.org.uk/ImageLocator/LocateAsset?asset=image&assetId=1232729045758&imageSize=xLarge&mode=prd

Vet News – Small Animal News

Posted on May 3, 2013 by NerdyVet

Harriet Woodhall is our Small Animal Vet News Editor and this month she brings you an article on a subject that is gaining more and more recognition in clinical practice: feline arthritis.

SMALL ANIMAL:

Use of Meloxicam in Feline Osteoarthritis

Harriet Woodhall (Vet News Small Animal Editor)

Feline Osteoarthritis is a progressive condition in aged cats and a significant cause of chronic pain in the elbows, hips and knees. Although commonly accepted in dogs, for a while it was not thought that cats suffered from OA, causing it to be much under-diagnosed. Only now is it slowly being recognised.

Osteoarthritis is a type of arthritis involving the wearing of the cartilage that cushions the joint. Over time the exposed adjacent bones can rub together causing pain and reduced mobility.

At the present, diagnosis of osteoarthritis in cats is difficult due to the problems with physical examination. Much of the diagnosis has to be from relying on the owner’s observations. Clinical signs include weight loss, change in attitude, change in grooming habits and reduced mobility, among others. There have also been studies into observing radiographic changes, however these are not as severe as in dogs and some osteoarthritic cats have no observable evidence from the X-rays at all.

Scientists at the University of Montreal’s Quebec Research Group in Animal Pharmacology have completed a study that aims to improve the treatment and diagnosis of OA in cats.

In the study, 120 cats were examined and 39 were identified to have OA. Over 74 days the animals were measured for kinetic gait analysis (a way to measure limb impairment), daily activity levels (using an accelerometer) and their sensitivity to touch (withdrawal of paw after a certain amount of pressure). While on the study they were split into groups; a control group were given a placebo and the others were given different doses of Meloxicam.

Meloxicam is a NSAID (non-steroidal anti-inflammatory drug); this class of drug is the main treatment option for many other species suffering from OA. It is also practical for administration to cats: it is palatable, can be put in food and is easy to make accurate dosing due to its liquid formulation. The reason it has not been used much for cats is due to the potential for nephrotoxicity (toxic to the kidney), as many osteoarthritic cats also experience some level of CKD (chronic kidney disease).

The study found that cats had various levels of pain relief depending on their dosages; the cats with high dosages experiencing pain relief for 5 weeks after the dosage stopped. However, as expected, the pain relief does not extend to stroking or anything that is associated with touch.

Professor Troncy explained that “the development of adapted therapy protocols to correctly treat arthritis associated chronic pain will provide a better quality of life particularly in older cats and will in turn have a direct impact on owners, as their cat will be more active and sociable.”

As pain in cats is still a developing subject, the researchers are now looking into brain scans to try and understand the theory more and specifically look into the neurophysiological hypersensitive process. Meanwhile, Meloxicam is under consideration for use in cats by the European Medicines Agency in April.

References:

Bennett D, Ariffin S.M.bt.Z, Johnston P. (2012) Osteoarthritis in the cat: 2. How should it be managed and treated? Journal of Feline Medicine and Surgery, Vol 14(1) 76-84

http://jfm.sagepub.com/content/14/1/76.full.pdf+html

http://www.fda.gov/animalveterinary/newsevents/fdaveterinariannewsletter/ucm084115.htm

http://www.nouvelles.umontreal.ca/udem-news/news/20130219-diagnosis-and-treatment-now-possible-for-osteoarthritic-cats.html

http://www.news-medical.net/news/20130306/Drug-to-relieve-pain-of-feline-osteoarthritis-identified.aspx

Images:

http://www.ukvetsonline.co.uk/walton-lodge-veterinary-group?mp=359854

http://www.fabcats.org/owners/arthritis/info.html

Vet News – Equine News

Posted on March 2, 2013 by NerdyVet

Pippa goes on the hunt for more interesting equine articles, and this month gives us the lowdown on a serious disease for horses: Strangles.

EQUINE:

Strangles

Pippa Lyon (Vet News Equine Editor)

According to Redwings; the UK’s largest horse sanctuary, Strangles in on the rise with a fifth of horses admitted in 2012 testing positive for the disease. Numbers are expected to continue rising due to an increase in horse movement and many horses being sold at horse sales which are ideal conditions for the disease to spread.

Strangles is a highly contagious infectious disease caused by bacteria. The bacteria affect the lymph nodes causing the clinical signs such as: Loss of appetite, difficulty swallowing, high temperature, nasal discharge and swelling of the throat area as seen in the image. The bacteria are spread between horses by direct contact with contaminated food, water, equipment or people’s hands/clothing. Horses who are young, sick or who travel a lot are more at risk at contracted the disease due to the way it spreads.

The disease is not usually fatal if treated, after diagnoses most horses make a full recovery with an intensive nursing regime in 2-5 days. However, if left untreated abscesses can form which can crush the windpipe or rupture which can prove fatal.

The key to conquering strangles is to know the signs and immediately isolate any horse which you suspect may have the disease. A vet will perform a physical examination by sampling discharge or taking a throat swab, the bacteria can then be identified and a diagnosis made.

Redwings have released a free information pack entitled “Strangles: Speak out!” which you can request by emailing welfare@redwings.co.uk

References

http://www.equine-world.co.uk/news_read.asp?id=1964&title=Horse%20Sanctuary%20Says%20Speak%20Out%20About%20Strangles#.USkF1qWpW8A

http://www.rvc.ac.uk/supervets/documents/equine/strangles.pdf

https://www.google.co.uk/search?hl=en&rlz=1C2TEUA_enGB465GB465&q=strangles&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&bvm=bv.42768644,d.d2k&biw=1241&bih=584&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=iAgpUZrrOqiO0AWfsIHICQ#imgrc=o4IHoVt-nLFi7M%3A%3BMz86MVv_vuvtGM%3Bhttp%253A%252F%252Fwww.equine-strangles.co.uk%252Fimages%252FStrangles_enlarged_lymph_nodes.jpg%3Bhttp%253A%252F%252Fwww.equine-strangles.co.uk%252FTreatment.asp%3B200%3B200

Vet News – Small Animal News

Posted on March 2, 2013 by NerdyVet

We have a NEW member of the Vet News Editorial Team in the form of Harriet Woodhall, who has taken on the mantle of covering articles of interest in the small animal sphere. So, big welcome to you Harriet and thank you for your first article, which this month is on Canine Diabetes Mellitus.

But before we start….. an intro 🙂

Harriet Woodhall

I’m 17 and will be applying for Vet School in September. I live just outside Cambridge along with two (adorable) black Labradors and some chickens. Aside from researching and studying I’m very interested in the conservation of wild species and enjoy playing piano.

SMALL ANIMAL:

Canine Diabetes Mellitus

Harriet Woodhall (Vet News Small Animal Editor)

It is estimated that approximately 1 in 500 dogs develop diabetes and although there are certain breeds that are more susceptible, (Golden Retrievers, Keeshond and Poodles being just a few), all breeds of dog can be affected, most often when middle aged or older.

The disease is caused by inadequate/complete lack of insulin from islet cells in the pancreas. Insulin is the hormone responsible for controlling the concentrations of glucose in the blood – this is achieved by preventing glucose production in the liver and making sure that excess glucose is put into storage.

Common signs of diabetes mellitus include polyuria (production of too much dilute urine), polydipsia (excessive thirst) and polyphagia (losing weight despite increase appetite). Cataracts are also often seen in diabetic dogs due to increased glucose levels. Along with the clinical signs, hyperglycaemia (high blood sugar levels) and glycosuria (sugar in the urine) are often enough of an indication for diagnosis. Diabetes is best diagnosed early, as when left untreated serious secondary complications can arise such as diabetes ketoacidosis.

Like humans, dogs can have insulin therapy, most having two insulin injections a day. Bitches should be spayed, as the hormone progesterone produced by the ovaries has a negative influence on insulin. In combination with injections it is recommended to have diet, exercise and weight control. For dogs, a diet high in fibre and complex carbohydrates is suggested, so glucose is more easily controlled and released more slowly.

Researchers in Barcelona have recently been able to cure diabetes in Beagles with gene therapy. The Beagles were given two extra genes which work together to reduce hyperglycaemia. One gene produces the insulin needed and the other produces an enzyme called Glucokinase, responsible for regulating the uptake amount of glucose from the blood. The genes are transferred by adeno-associated vectors, also a new technology. Using a non-pathogenic virus, the genes can be injected into the hind legs of the dog in a single session.

As the first successful study of its kind, there will need to be more evidence using a larger test sample. However, it seems the future use of gene therapy could provide a more effective and practical method of controlling diabetes in dogs

References:

http://www.pet-diabetes.co.uk/diabetes-mellitus-dogs.asp

http://www.diabetes.co.uk/info/DogsWithDiabetes.html

http://www.caninsulin.co.uk/

http://www.newscientist.com/article/dn23163-gene-therapy-cures-diabetic-dogs.html

http://www.caninediabetes.org/caninediabetespg.html

Callejas D, Mann CJ, Ayuso E, Lage R, Grifoll I, Roca C, Andaluz A, Ruiz-de Gopegui R, Montane J, Munoz S, Ferre T, Haurigot V, Zhou S, Ruberte J, Mingozzi F, High K, Garcia F, Bosch F. Treatment of Diabetes and Long-term Survival Following Insulin and Glucokinase Gene Therapy.

(Picture: http://www.ccrnatacna.org/diabetes-mellitus-in-dogs-92.html)

Vet News – Farm News

Posted on March 2, 2013 by NerdyVet

Els has taken a really interesting look this month at the news surrounding a new PCR test available to aid large animal vets in their important work.

FARMING:

New PCR Test available for bovine mycoplasma

Els de Vrijer (Vet News Farm Animal Editor)

Bovine mycoplasma is a bacterial infection that is responsible for several diseases in the cow. Although it mainly causes respiratory disease, it can also be responsible for abortions, mastitis and arthritis. Clearly, this leads to huge economical losses within the dairy industry: €500 million per year in the European dairy industry alone. The disease is a tricky one to conquer. It is hard to diagnose due to its inconsistent gene expression and varying response to treatment. M. bovis is also very similar to another bacterium, m. agalactiae, varying by only 8 nucleotides in its genetic makeup. It is also incredibly slow and difficult to culture, and treatment with antibiotics is not cost-effective. Therefore, the main means of controlling the disease lies with prevention. Recently, a new PCR test for m. bovis has become available, making the future for the control of the disease much brighter.

PCR testing is a method of copying fragments of DNA, which can then be used to locate the presence of a pathogen in an organism. Firstly, the DNA strand is separated using a thermocycler at a high temperature. The mixture is then cooled and sequences of nucleotides that have complementary bases to each end of the DNA fragment that needs to be copied, called ‘primers’ are attached. These provide a starting sequence for the copying of DNA. Then, the temperature is increased to around 72°C to provide the optimum temperature for DNA polymerase to work at. This adds other nucleotides to the DNA sequence, thereby copying the DNA. In a short amount of time, several copies of the DNA can be made. These can then be compared to the DNA of the bacterium to see whether it is present. It is a rapid and efficient method of pin pointing the disease – this particular test takes only 2.5 hours before the results are ready. “The improved sensitivity of this new test means that veterinarians will be able to monitor dairy herds for sub-clinical infection using samples from the bulk tank,” said Eric Sellal, Head of Animal Health EMEA at Life Technologies.The scientists have improved upon the previous test by locating a new target gene on the mycoplasma bovis genome, which is clearer to locate.

Hopefully, this new test will provide veterinarians with a tool for quickly locating this pathogen and preventing its rapid spread throughout the herd.

References:

www.mrcvs.co.uk

www.microbewiki.kenyon.edu

https://www.addl.purdue.edu/newsletters/2004/fall/mycoplasma.htm

http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2011.0750.x/full

AQA Biology A2 textbook – Glen Toole and Susan Toole (Nelson Thornes)

Vet News – Farm News

Posted on March 2, 2013 by NerdyVet

Emma’s article this month is on the concerns that the Schmallenberg virus may be present in wild animal populations, acting as a reservoir for the important infection.

FARMING:

Scientists believe that SBV may affect wild animals

Emma Plowright (Vet News Farm Animal Editor)

Scientists in Europe are concerned that wild animals may be acting as a ‘reservoir’ for the midge-bourne Schmallenberg virus (SBV) which has been detected on nearly 1,000 farms in England and Wales.

A team from the Universite de Liege in Belgium who have been monitoring the disease in wildlife have noted that it can also affect roe deer and red deer. One member of the team has called for “specific surveillance of wild animals for SBV”

If pregnant ewes are infected, the virus causes deformities and neurological abnormalities in. An expert at the University of Nottingham has stated that although we can confirm that deer get the disease, it is not currently known how they will be affected. The placental structure of a deer differs from that of cows and sheep meaning that, at present, it is not known if the virus can cross the placenta.

SBV has a huge economic impact and figures from the University of Nottingham show that some farms are suffering up to 30% losses; this can have a devastating effect on farmers’ livelihoods. Professor Trevor Drew of the UK government’s Animal Health and Veterinary Laboratories Agency spoke recently of the difficulties in trying to control the disease: it is midge Bourne and “It is just impossible to control midges across an area the size of Europe”

Alick Simmons, the UK’s chief veterinary officer, has stated that he believes the disease “will either through vaccination or through natural spread become less of a problem over time”, adding that several vaccines are currently being developed. He also pointed out that some areas which were affected by the virus last year were not affected so severely this year.

References:

http://mrcvs.co.uk/en/news-story.php?id=9178

http://www.farmersguardian.com/home/hot-topics/schmallenberg-virus/schmallenberg-has-infected-majority-of-english-and-welsh-farms/52237.article

http://www.farmersguardian.com/home/hot-topics/schmallenberg-virus/farmers-warned-of-schmallenberg-effects/52227.article

Vet News – Equine News

Posted on February 7, 2013 by NerdyVet

This month’s Equine news comes from our very talented reported, Pippa Lyons.

EQUINE:

The Horse Meat Scandal

Pippa Lyon (Vet News Equine Editor)

The discovery of horse DNA found in value burgers at Tesco and Iceland in the UK earlier this month has come as a shock to many members of the public. A total of 27 products were analysed and 10 of them were found to contain horse DNA. Although both Tesco and Iceland have apologised and removed the products for sale, the offending goods could have been on sale for months!

But why are the British so disgusted by the idea of eating horse meat? Many European countries indulge in the practice frequently and there is no risk to health. Plenty of us are quite willing to eat pigs, cows, chickens and sheep but the thought of eating a horse is taboo. Dr Rodger Mugford suggests that as people see horses as pets we tend to give them extra qualities and values, “As soon as you give an animal a name, how can you eat it?” Horses were a crucial part of our country’s development, working in various different fields and helping in wars which gives them a sentimental value. The reality is, there is a lot of horse meat in our food chain. When horses are worn out or unwanted this is where they end up. In 2011 12,000 horses were killed for their meat in the UK alone and with supermarkets constantly battling for lower prices the suppliers are forced to give better deals which in the case includes horsemeat.

The problem escalates when horses are slaughtered without valid passports and enter the food chain. 8 of these horses have recently been found to contain the anti-inflammatory drug phenylbutazone or “bute” which causes cancer in humans. Any horse that has been administered the drug should have in recorded in their passport; however forged passports are becoming increasingly common for some people to sell horses for meat. Although none of these horses were sold on the UK market, they may have been shipped abroad. The sources of the horsemeat are currently being investigated, hopefully leaving the British public to appreciate where their food may originate and how the animals are treated.

Sources:

http://www.bbc.co.uk/news/magazine-21043368

http://www.bbc.co.uk/news/uk-21181499

http://www.bbc.co.uk/news/world-europe-21034942

http://www.bbc.co.uk/news/magazine-21059425

Vet News – Farm News

Posted on February 7, 2013 by NerdyVet

The third article from our Vet News Farm Editorial Team is by Pippa Plowright, on a study into illegal badger shooting.

FARMING:

10% of welsh farmers report killing badgers illegally

Emma Plowright (Vet News Farming Editor)

A study carried out by the University of Bangor, the University of Kent and Kingston University has shown that around 1 in 10 farmers and 14.5% of cattle farmers, in Wales admitted to killing a badger illegally in the 12 months preceding the study.

Previous research has suggested that badger culling may have a positive effect if at least 70% of badgers in an area are killed. This culling should be carried out by trained marksmen and is, at present, not permitted.

It is thought ‘Uncontrolled’ shooting such as that investigated in this study is likely to disrupt badger populations, causing the disease to spread further. This is because social groups within the population may be disrupted causing the surviving badgers to spread further than they otherwise would, passing on the disease both badgers and cattle.

A particular type of study was used in which dice are rolled in order to decide whether or not the respondent should answer truthfully. This means that those who behaved illegally are protected whilst giving only a five per cent error margin.

Researchers who carried out the study have stated that this information should be taken into account by policy makers as ‘studies investigating the effects of badger culling on TB outbreaks in cattle have not factored in the prevalence of illegal badger killing, and its potential to spread disease’

Last year the Welsh government opted against culls in favour of a badger vaccination scheme, which has been opposed by some due to its cost. It was announced this week that further measures will be put in place to prevent the spread of bovine TB.

Sources:

http://mrcvs.co.uk/en/news-story.php?id=8966

http://www.bbc.co.uk/news/uk-19939393

http://www.guardian.co.uk/environment/2013/jan/17/livestock-farmers-kill-badgers-study

http://www.defra.gov.uk/publications/files/pb13691-bovinetb-policy-statement.pdf

Vet News – Farm News

Posted on February 7, 2013 by NerdyVet

The second of our Vet News articles this month comes from our Farm News Editor, Hannah Johnstone:

FARMING:

Liver Fluke becoming an increasing threat to sheep in the UK

Hannah Johnstone (Vet News Farming Editor)

Liver Fluke is a flat worm which has a complex life cycle heavily dependent on prevailing weather systems, with the optimum being moist and warm. Liver Fluke infestation has a number of steps in the cycle, firstly eggs are deposited by both sheep and cattle in faeces, the eggs in the faeces hatch and are then carried on the intermediate host known as the mud snail. The mud snail then deposits fluke cysts onto grass which the livestock consume. Once within the livestock the young fluke hatch in the intestine to then migrate to the liver, the young fluke are now egg laying adults which takeover the bile system. The cycle covers a 6 month period but is very dependent on weather conditions.

Liver fluke affects both sheep and cattle and is mainly seen in western areas of the UK and becoming more common in eastern areas. Over the end of last year liver fluke infestation is increasing in frequency affecting sheep of all ages. The disease has 3 different forms Acute this type is common around August to October; sheep die suddenly from haemorrhage and liver damage. It is the worst type and 10% of sheep are at risk having a massive knock on affect financially. Sub-acute; the sheep become weak; lose their appetite, depressed with rapid loss of body condition as well as poor fleece quality. Chronic; has similar affects as sub-acute seeing severe emaciation which can cause profits to half by reduction of lamb crop and ewe mortality. With the first 2 types; blood samples show raised liver enzymes and chronic liver fluke can be diagnosed by eggs in faecal samples. Liver fluke is treatable though use of triclabendazole and improved nutrition.

Vulnerability of sheep varies; farms with high stock intensity are vulnerable as well as areas prone to flooding. But the key factor affecting vulnerability of sheep in the UK is the weather. At the end of 2012 sheep were ten times more likely to suffer compared to 2011. David Wilson farm vet and spokesman for NADIS (national Animal Disease Information Service) stated “The very wet summer conditions will have resulted in heavy contamination of many pastures with Liver Fluke infective stages during the summer and autumn”. It is these infective stages that are putting livestock at major risks “many infected animals will subsequently suffer from chronic fluke disease, causing ill thrift and poor production if not effectively treated”. As the weather continues to become increasingly moist and wet, the figures of sheep with liver fluke will remain high having potentially a huge burden financially on farmers through not only loss of sheep but the cost of treatment needed.

Sources:

http://www.vetsonline.com/actualites/detail/62170/liver-fluke-remains-a-major-threat-to-uk-sheep-.html

http://www.nadis.org.uk/bulletins/liver-fluke-control-in-sheep.aspx

http://www.farmersguardian.com/home/livestock/livestock-features/sheep-focus-liver-fluke-in-sheep/28888.article

http://mrcvs.co.uk/en/news-story.php?id=8749