Donkeys feel the cold

Donkeys are not well suited to cold wet environments and need extra protection in the winter, new research has found. The findings have been incorporated into an updated Defra Code of Practice.

The research was undertaken by Dr Britta Osthaus, Senior Lecturer in Psychology at Canterbury Christ Church University and Dr Leanne Proops, Senior Lecturer at the University of Portsmouth, both specialists in animal behaviour and cognition, in collaboration with international animal welfare charity, The Donkey Sanctuary.

The study found that donkeys, and to a lesser extent mules, are less able than horses to adapt to colder, wetter climates and therefore require additional protection in the winter to meet their welfare needs..

Researchers collected hair  samples from 18 donkeys (4 females, 14 males), 16 horses (6 females, 10 males) and eight mules (5 females, 3 males), in March, June, September and December. They measured weight, length and width of hair, as indicators of the insulation properties of the hair coat.

They found no significant difference in donkey’s  hair coats across the seasons. All three measures of the insulation properties of the hair samples showed that donkeys do not grow a winter coat.

The donkeys’ hair coat was significantly lighter, shorter and thinner than that of horses and mules in winter. In contrast, the  horses’ coats changed significantly between seasons, growing much thicker in winter.

The findings have been published in the Equine Veterinary Journal.

Lead author, Dr Britta Osthaus, Senior Lecturer in Psychology at Christ Church, said: “Despite their fluffy looks, donkeys are not as insulated as ponies. Although they are much hardier in other aspects, they need more access to water and windproof shelter.”

“It’s fantastic to see that our research has influenced national guidelines to improve animal welfare.”

Dr Faith Burden, Director of Research and Operational Support at The Donkey Sanctuary, said: “For many years it has been the ‘common sense’ advice given by The Donkey Sanctuary to ensure that donkeys and mules are given the right protection from our cold winters.

“This study now provides us with scientific evidence to show why the welfare needs of donkeys and mules differ slightly to those of horses and ponies, and how we can act to give them better protection from the elements.”

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For more details, see:

Hair coat properties of donkeys, mules and horses in a temperate climate
B. Osthaus  L. Proops  S. Long  N. Bell  K. Hayday  F. Burden
Equine Veterinary Journal (2017) Vol 50, Issue 3
https://doi.org/10.1111/evj.12775

Assessing pain in ridden horses with an ethogram

A new method for equine performance assessment has been tested on vets. Conducted by Dr. Sue Dyson, Head of Clinical Orthopaedics at the Centre for Equine Studies at the Animal Health Trust in Newmarket, the study assessed how accurately vets may be able to use an ethogram, developed by Dr. Dyson, to assess pain in ridden horses.

Earlier this year, the British Equine Veterinary Association newsletter carried a call for volunteer vets to participate in the study. Ten were chosen, representing a range of age and experience.

The study was conducted at World Horse Welfare’s centre in Norfolk on July 21. Twenty horse and rider combinations, together with a range of professional practitioners, volunteered their time to support the study, which has the potential to transform the welfare of ridden horses.

Initially the horses were assessed by Association of Chartered Physiotherapists in Animal Therapy (ACPAT) physiotherapist Jo Spear. The back was examined to check for any areas of muscle tightness or discomfort. Society of Master Saddlers (SMS) Saddle Fitter Liz Suddaby checked the fit, placement, balance and suitability of each horse’s saddle. The horses were then given a 15 minute ridden warm-up before executing an 8-minute purpose-designed dressage test.

Horses were scored for the presence of 24 behaviours that might reflect pain and lameness.

During the dressage test, the team of equine vets scored each horse for the presence of 24 behaviours that might reflect pain. The tests were filmed so that Dyson could make a comparison between her own real-time behaviour assessments and video analysis and so that the rider skill level could be scored retrospectively by Dr. Anne Bondi, BHSI.

The participating vets collectively commended the value of the ethogram. They said they would change their procedures for both pre-purchase examinations and investigations of either lameness or poor performance in the future.

Dr. Helen Whitbread of Deben Valley Equine Veterinary Clinic summarised: “This system is such a useful tool; most of the factors we were scoring were not a surprise, but by being able to quantify the pain in a way that a client can understand and relate to is priceless. Too often in the past our suggestions that a horse is demonstrating abnormal ridden behaviour because of pain has been brushed aside as ‘it has always done that’. Now I can say, for example: ‘Yes, it has scored >8 and is therefore likely to have been in musculoskeletal pain the whole time you have owned it’.”

Dyson continued: "The behavioural differences between the lame and non-lame horses in the study were very apparent. “

 “Early indications show that by giving vets a clear understanding of pain-associated behaviour markers they will be better able to recognise pain-related behaviour in ridden horses, which might reflect lameness, and to communicate potential performance problems more effectively with their clients.”

For more details, see:

Dyson, S, Berger, J, Ellis, A, Mullard, J. Development of an ethogram for a pain scoring system in ridden horses and its application to determine the presence of musculoskeletal pain. 

J Vet Behav: Clin Appl Res 

doi:10.1016/j.jveb.2017.10.008

An overview of this study will be presented at the Saddle Research Trust Conference in December.

To find out more about the Saddle Research Trust Conference on Saturday, December 8, 2018, and to buy tickets, visit www.srt2018.com or call 07948 303281.

Advances in heart treatment

Many horses are used in competitive sports and need to maintain peak performance.

Irregularities of heart rhythm may impact on peak performance. Conditions such as atrial fibrillation, with uncoordinated muscle contractions, result in reduced cardiovascular efficiency.

Traditionally,  treatment for atrial fibrillation was based on medication with quinidine sulphate. Although often effective, it may be associated with a high risk of side effects.

A promising new treatment for atrial fibrillation, transvenous electric cardioversion, is now available at the University of Veterinary Medicine  in Vienna. Targeted electric shocks are used to return the heart to its normal rhythm.

The new therapy, which is among  the routine treatment options in humans, is now offered by the Department for Equine Internal Medicine to their animal patients.

Jessica Cavalleri, head of the Department of Equine Internal Medicine explains that electric shocks are administered directly to the heart to reorient the muscle’s electrical activity.

Special catheters, which can measure blood pressure,  are used to introduce the electrodes to the heart. Pressure differences between the pulmonary artery, right atrium and right ventricle help confirm the electrodes are correctly placed.

An ultrasound scan is also used to visualize the catheter in the heart.

Before the horse is finally placed under general anaesthesia, the position of the electrodes is once again checked by means of an X-ray image.

The many control measures are an important safeguard, adds Dr. Hannah Junge, veterinarian of the clinical department.

The horse is then given a first shock under general  anaesthesia. Further pulses are given, as necessary. With each shock the current is gradually increased. Values of up to 360 Joules may be required.

The exact timing is important so that no dangerous cardiac arrhythmias are triggered.

Once the heart rhythm reverts to normal, the horse is kept under anaesthesia for a short period of time and then allowed to wake up.

The animal then remains in the clinic for three more days for monitoring. After a rest period of four weeks, a further inspection is carried out. Training can then usually resume.

In contrast to drug treatment, Cavalleri reports that the success rate is slightly higher and the risk of side effects is lower.

For more details, see (in German):
https://www.vetmeduni.ac.at/de/infoservice/presseinformationen/presseinformationen-2018/elektro-kardioversion/

Equine Behaviour Forum Scientific Seminar 2018.

The Equine Behaviour Forum (EBF) holds a scientific seminar each year where  invited speakers present reports on their research into equine behaviour. This year the seminar will be held at Myerscough College, Lancashire on Saturday 29th September from 10.30 am – 4.30 pm.

Rachel Bedingfield from Connection Training will be continuing our exploration of emotion with a talk amplifying the work of Jaak Panksepp and other neuroscientists along with equine ethology and expression of emotions. She will go on to show the relevance of this to helping your horse to feel calm, happy and playful whilst learning.

Dr Andrew Hemmings, Principal Lecturer in Animal Science, head of Academic Centre- Equine Management and Science Royal Agricultural University Cirencester, will talk about a strategic approach to training and management using behavioural indicators of brain activity.

EBFmember Justine Harrison will be talking about her experiences as an Equine Behaviourist. Justine is a certified member of the International Association of Animal Behaviour Consultants (IAABC) and an Accredited Animal Behaviourist with the Animal Behaviour and Training Council.

Everyone is welcome including non-members, at a cost of £15 per person (members) and £35 (non-members). Students £5.00.

Contact: Judith Turner, Tel: (01423) 770144, email: equiphile@talktalk.net

Or look at the EBF facebook page [11April]:

https://www.facebook.com/groups/970610492997325/ 

Effect of insulin on the laminae

Most cases of laminitis are associated with metabolic disturbances – often involving elevated blood levels of insulin. How the hyperinsulinaemia results in laminitis is not fully understood.

One possible mechanism has been identified in a recent study that showed that insulin weakens the structural integrity of equine lamellae.

The laboratory study used explants (small portions of hoof wall, lamellar tissue and distal phalanx) maintained in tissue culture medium.

Half of the explants were kept in plain culture medium; the other half were grown in medium supplemented with insulin (2.5 μg/ml).

After eight hours the explants were subjected to biomechanical testing.

The authors report: “Lamellar explants that had been incubated in medium supplemented with insulin failed at significantly lower load (P = 0.0001) and lower stress (P = 0.001) and had greater elongation to failure (P = 0.02).”

They conclude that insulin weakens the structural integrity of equine lamellar explants.

They suggest that this laboratory model will be useful for further studies hyperinsulinaemia‐induced lamellar failure.

For more details, see:

Ex vivo effects of insulin on the structural integrity of equine digital lamellae

Sandow, C., Fugler, L.A., Leise, B., Riggs, L., Monroe, W.T., Totaro, N., Belknap, J., Eades, S.

EVJ (2018)

https://doi.org/10.1111/evj.12964

Does oral sulphadiazine-trimethoprim reach the uterus?

Bacterial infections of the endometrium (the superficial layer of cells lining the uterus) are an important cause of conception failure. 

Treatment often involves local administration of antibacterial agents directly into the uterus.

Potentiated sulphonamide drug combinations, such as sulfadiazine and trimethoprim, are commonly used in equine practice. They have a broad spectrum of activity and are well distributed throughout the body tissues.

Could oral administration of a suspension of sulfadiazine and trimethoprim (SDT) have a place in the treatment of bacterial endometritis?

Studies at the School of Veterinary Medicine, Louisiana State University, Baton Rouge, looked at the concentration of SDT in both the blood and endometrium of healthy, in season, mares after the administration of an oral suspension of sulfadiazine and trimethoprim.  

Mares were treated five times at twelve hourly intervals. Blood was collected to monitor the concentration of SDT during the study and an endometrial biopsy was taken after sixty hours to measure the SDT concentration in the endometrium.

The Minimum Inhibitory Concentration (MIC) is the lowest concentration of an antibiotic that inhibits the growth of a given strain of bacteria.

The research, led by Gabriel Davolli, found that, after five consecutive treatments, the sulfadiazine and trimethoprim reached concentrations in the endometrium above the MIC – and so likely to be effective -for pathogens (such as Streptococcus equi zooepidemicus and Escherichia coli) that are commonly involved in uterine infections.

The work is reported in the Journal of Equine Veterinary Science.

The authors conclude: “the oral suspension of sulfazdiazine-trimethoprim should be an efficacious and viable treatment for bacterial endometritis.”

For more details, see:

Concentrations of Sulfadiazine and Trimethoprim in Blood and Endometrium of Mares After Administration of an Oral Suspension

Gabriel M.Davolli, Kelli N.Beavers, Victor Medina, Jennifer L.Sones, Carlos R.F.Pinto,  Dale L.Paccamonti, Robert C.Causey

Journal of Equine Veterinary Science (2018) 67:27-30

https://doi.org/10.1016/j.jevs.2018.02.022

New approach to worm control

A worm-eating fungus brings new hope in the fight against parasitic gastro-intestinal worms.

Anthelmintic resistance is now a widespread and growing problem. It is becoming increasingly clear that we cannot rely on chemicals alone to control gastro-intestinal parasites. 

Consequently, alternative worm control strategies are being investigated. One method showing promise is the use of a fungus that attacks the free-living larval stages of parasitic worms and so reduces the number of infective larvae on the pasture. 

Duddingtonia flagrans is a nematophagous fungus (from the Greek for “worm eating”). The fungus grows rapidly in fresh faeces and its chlamydospores (resistant spores) can survive the passage through the gastro-intestinal tract of the horse. These fungal spores have no effect on the animal and only germinate once passed in the faeces where they develop into nematode-trapping fungal nets.

Recent work in Australia showed that feeding BioWorma®, a supplement containing the Duddingtonia spores, produced substantial reductions in infective larvae on pasture surrounding faeces of treated horses, cattle and goats.

The placebo-controlled trials were conducted in different seasons and bioclimatic regions of Australia (New South Wales, Queensland). 

Faeces were collected from worm-infected animals after they had been treated with either the D flagrans supplement or a placebo. The manure was placed on pasture plots and the researchers monitored the numbers of parasitic larvae on the pasture around the faecal pats over an eight-week period.

They report that a minimum daily dose of 3 × 104 D flagrans spores/kg bodyweight reduced parasite larvae in the pasture surrounding the faeces by 53–99 % over the eight-week period after treatment in horses, cattle and goats.

Other work has shown that, unlike some chemical wormers, the fungus does not harm dung beetles or other organisms found in the faeces.

BioWorma® is about to be approved for sale in Australia and New Zealand. It should be available in the United States shortly and in Europe within the next year or two.

For more details, see the following open access article:

Field evaluation of Duddingtonia flagrans IAH 1297 for the reduction of worm burden in grazing animals: Pasture larval studies in horses, cattle and goats

Kevin Healey, Chris Lawlor, Malcolm R.Knox, Michael Chambers, Jane Lamb, Peter Groves

Veterinary Parasitology. Vol 258, pp 124-132

https://doi.org/10.1016/j.vetpar.2018.06.017

Origins of equine dentistry

Humans were removing horses’ teeth to relieve their pain over 3,000 years ago, according to scientists.

A team of scholars, led by William Taylor of the Max Planck Institute for the Science of Human History, examined horse remains from an ancient pastoral culture which roamed the steppes of Mongolia and eastern Eurasia between 1300 to 700 BC.

Horses congregate near a deer stone site in Bayankhongor, in central Mongolia's Khangai mountains. (c) William Taylor

The Deer Stone-Khirigsuur Culture is named after the standing stones (‘deer stones’ - often decorated with images of deer) and burial mounds (khirigsuurs) it built across the Mongolian Steppe. These sites were used for ritual burial of hundreds – maybe thousands – of domestic horses.

Through careful study of skeletal remains from these burials, Taylor and colleagues found that Deer Stone-Khirigsuur people began using veterinary dental procedures to remove baby teeth that would have caused young horses pain or difficulty with feeding. In particular, they found evidence of attempts to remove temporary central incisor teeth that had not erupted correctly.

These findings provide the earliest directly dated evidence for veterinary dentistry. They suggest that innovations in equine care by nomadic peoples c 1150 BC allowed horses to be used for increasingly sophisticated mounted riding and warfare.

Drawing on insights from his Mongolian colleagues, Jamsranjav Bayarsaikhan and Tumurbaatar Tuvshinjargal of the National Museum of Mongolia, Taylor argues that the development of horseback riding and a horse-based pastoral economy was a key driver for the invention of equine veterinary care. 

The incorporation of bronze and metal mouthpieces for riding spread into eastern Eurasia during the early first millennium BC. It gave riders more control over horses and enabled them to be used for new purposes – especially warfare.

But using metal to control horses brought with it new problems – such as painful interactions with the “wolf tooth” - the vestigial first premolar tooth present in some animals. Dr Taylor and his colleagues found that as herders began to use metal bits they also developed a method for extracting the problematic “wolf tooth”. The first evidence they identified for wolf tooth removal dated to about 750BC.

"We may think of veterinary care as kind of a Western science," Taylor says, "but herders in Mongolia today practice relatively sophisticated procedures using very simple equipment. The results of our study show that a careful understanding of horse anatomy and a tradition of care was first developed, not in the sedentary civilizations of China or the Mediterranean, but centuries earlier, among the nomadic people whose livelihood depended on the well-being of their horses."

Co-author Dr Nicole Boivin, director of the Department of Archaeology at the Max Planck Institute, commented: “In many ways, the movements of horses and horse-mounted peoples during the first millennium BC reshaped the cultural and biological landscapes of Eurasia. Dr Taylor’s study shows veterinary dentistry – developed by Inner Asian herders – may have been a key factor that helped to stimulate the spread of people, ideas, and organisms between East and West.”

For more details, see: 

Origins of equine dentistry

WTT Taylor and others.

PNAS July 17, 2018. 115 (29) E6707-E6715

https://doi.org/10.1073/pnas.1721189115

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