Interferon as potential treatment for periocular squamous cell carcinoma

Example of SCC, before (left) and after treatment

 with INFα-2b . (c) Martabano et al. For more photos, see

https://doi.org/10.1371/journal.pone.0297366.g001 

Injecting interferon alpha-2b (INFα-2b) may provide a new treatment for periocular squamous cell carcinoma in horses according to a recent report. 

Squamous cell carcinoma (SCC) is a type of skin cancer that commonly affects horses. 

 

SCC typically appears as nodules or masses on the skin or mucous membranes. These lesions can vary in size and colour but often appear ulcerated or crusted. SCC commonly affects areas with less pigment or areas exposed to sunlight, such as the eyelids, lips, and genital regions. 

 

Various treatment options may be considered including surgical excision, cryotherapy (freezing), laser therapy, topical medications, and radiation therapy.

 

A recent clinical investigation conducted by Brittany B. Martabano and colleagues from Colorado State University explored the efficacy of intralesional interferon alpha-2b (INFα-2b) treatment in 11 horses (12 eyes) diagnosed with periarticular squamous cell carcinoma (PSCC). The comprehensive findings of this study have been published in PLOS One.

 

Before commencing treatment, all horses underwent biopsy confirmation of PSCC diagnosis and were deemed healthy otherwise.

 

The treatment regimen involved injections, under sedation, of 10 million IU of INFα-2b every two weeks for a maximum of six sessions. The research team assessed the response by measuring lesion sizes before each treatment and subsequently at one, three, and twelve months after the end of the course of treatment. A response was considered positive if there was a reduction in tumour size exceeding 50%.

 

The researchers also checked for the development of antibodies against INFα-2b and assessed their potential impact on treatment response.

 

Results indicated that five out of twelve eyes (four out of eleven horses) responded positively to the treatment, with two eyes showing complete resolution of PSCC. No systemic adverse effects were observed, although local swelling occurred in six out of eleven horses during treatment, which resolved spontaneously.

 

All horses developed serum anti-IFNα2b antibodies, with no discernible difference in antibody concentration between responders and non-responders.

 

The researchers conclude that injecting IFNα2b into PSCC was well-tolerated in horses and led to tumour regression in 42% of treated eyes. They found no association between treatment failure and the development of IFNα2b antibodies.

 

 

For more details, see:

 

Intralesional interferon alpha-2b as a novel treatment for periocular squamous cell carcinoma in horses

Brittany B. Martabano, Steven Dow, Lyndah Chow, Margaret M. V. Williams, Maura K. Mack, Rebecca Bellone, Kathryn L. Wotman

Research Article | published 21 Feb 2024 PLOS ONE

https://doi.org/10.1371/journal.pone.0297366

 

Role of in-breeding in pregnancy loss

 A recent study conducted by the Royal Veterinary College (RVC) in collaboration with Cornell University sheds light on the role of inbreeding in mid and late-term pregnancy loss (MLPL) among UK Thoroughbreds. Interestingly, while inbreeding does impact MLPL, it has little effect on early pregnancy loss (EPL).

The research specifically explores the influence of genomic inbreeding levels on late-term pregnancy loss in horses. These findings provide valuable insights for breeding practices, which can help inform mating decisions to reduce the risk of miscarriages in Thoroughbreds.

 

Inbreeding, the mating of related individuals, is a common practice in the livestock industry and can be beneficial in controlled breeding programs for consolidating desirable traits within a population. However, excessive inbreeding heightens the likelihood of producing offspring with harmful homozygous recessive genotypes. This can lead to genetic disorders, reduced fertility, and decreased overall population fitness.

 

Approximately five to ten percent of equine pregnancies result in early pregnancy loss (EPL), while seven percent are lost between Day 70 of gestation and 24 hours postpartum (MLPL). Despite this, prior to this study, there had been no genomic analysis of the correlation between inbreeding levels and pregnancy loss in horses.

 

Led by Dr. Jessica Lawson, Alborada Trust Research Fellow at the RVC, and Professor de Mestre at the Baker Institute for Animal Health at Cornell University, along with former RVC PhD student Dr. Charlotte Shilton, the research team analysed DNA samples from 189 individuals. These samples included allantochorion and foetal DNA from early pregnancy loss (EPL) cases (n=37, gestation age 14–65 days), mid and late-term pregnancy loss (MLPL) cases (n=94, gestational age 70 days–24 hours post parturition), and hair or blood samples from adult UK Thoroughbred controls (n=58).

 

The study revealed that Thoroughbred pregnancies lost in mid and late gestation (MLPL) had significantly higher inbreeding metrics compared to UK Thoroughbred adult controls. Conversely, pregnancies lost early in gestation (EPLs) showed no significant difference in inbreeding metrics compared to controls.

 

These findings emphasise the importance of informed mating decisions in the Thoroughbred breeding industry. Moreover, they stress the need for further research to identify and characterise genomic changes that may prove detrimental to pregnancy.

 

Dr Jessica Lawson, Alborada Trust Research Fellow at the RVC, said: “This research provides critical evidence showing that mating highly related individuals does have a tangible effect on our breeding operations, as there is a real risk of a mare losing her pregnancy late in gestation and failing to produce a foal at all that season. 

 

“The take home from our work should be to carefully consider breeding choices that involve mating of highly related individuals as, ultimately, this may increase the chance of the foal inheriting mutations which may not be compatible with life. We are already working on the next step, looking to identify these changes so more specific advice can be provided in the future”.

 

This research was funded by the Thoroughbred Breeders Association, Horserace Betting Levy Board, the Alborada Trust, and partial PhD studentship funding from the Royal Veterinary College's Paul Mellon Trust for Equine Research.

 

For more details, see: 

Lawson JM, Shilton CA, Lindsay-McGee V, Psifidi A, Wathes DC, Raudsepp T, de Mestre, AM.

Does inbreeding contribute to pregnancy loss in Thoroughbred horses? 

Equine Vet J. 2024.

https://doi.org/10.1111/evj.14057

 

 

Edited press release. Read the original press release:

https://www.rvc.ac.uk/equine-vet/news/new-rvc-research-finds-inbreeding-is-contributing-factor-to-mid-and-late-term-pregnancy-loss-in-thoroughbreds

Effect of punch biopsy on sarcoid growth

 The common belief that taking biopsies of suspected sarcoids could make them worse may not be justified.

 Sarcoids, are the most common skin tumour of horses. Although typically benign, they can be locally aggressive and difficult to manage. They appear in various forms, including flat, nodular, verrucous, fibroblastic, and occult types. Bovine papillomavirus (BPV) has been implicated in the development of sarcoids, although the exact mechanism is not fully understood.

 

In standard veterinary practice, biopsies are a useful diagnostic tool for identifying the nature of swellings and masses. However, the fear of inadvertently worsening the condition has led many veterinarians to avoid biopsy procedures for sarcoids.

 

A recent small-scale study investigating the impact of punch biopsies on the growth of equine sarcoids challenges this assumption. The study failed to confirm the notion that biopsies could exacerbate the aggressiveness or spread of sarcoids.

 

Lien Gysens carried out the study with her colleagues at the Department of Large Animal Surgery, Anaesthesia and Orthopaedics of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. A full rereport of tth research is published in Veterinary Dermatology.

 

The study included six client-owned horses with a total of 11 sarcoids. These horses, all Belgian Warmbloods, presented with a range of clinical types: three occult, four nodular, two verrucous, and two fibroblastic sarcoids.

 

To qualify for inclusion in the study, the horses had to test positive for BPV-1/-2. This was determined using superficial swabs, scrapings, or fine needle aspirates (FNA), which were then subjected to quantitative PCR (qPCR).

 

 The research team examined the dynamics of tumour growth, focusing on factors such as thickness, area, and circumference, as well as viral load (VL) and Visual Analog Scale (VAS) scores in horses affected by sarcoids who underwent a single diagnostic punch biopsy.

 

The growth of each sarcoid was closely monitored on a weekly basis for nine months: from 12 weeks prior to the punch biopsy to 24 weeks following the procedure.

 

In this preliminary study, the researchers didn't find any clear trend in how sarcoids grew after a single punch biopsy. 

 

They observed significant changes in all growth parameters after the biopsy, but there wasn't a consistent direction of change – some grew larger, some smaller, and some stayed the same.

Drawing definite conclusions is challenging due to the limited number of tumours (11 in total) from only six horses with four different types of clinical sarcoids.

 

They conclude: “Our results indicate that post-biopsy lesion deterioration is not a general concept that applies to all sarcoids, and both deterioration or improvement are possible outcomes over a 24-week period. Further clinical studies with a larger sample size are needed before a definitive conclusion can be made.”

 

 

For more details, see:

 

Gysens L,  Martens A,  Haspeslagh M.  

Longitudinal pilot study examining the effect of punch biopsy on equine sarcoid growth dynamics. 

Vet Dermatol.  2024; 35: 148–155.

https://doi.org/10.1111/vde.13236

Collagen link to Thoroughbred fracture risk

 

Recent research conducted by the Royal Veterinary College (RVC) sheds light on the genetic factors contributing to bone fractures in Thoroughbred horses. The study reveals that horses with diminished levels of collagen type III have a higher risk of fractures.

Previously, the underlying genetic mechanisms behind these fractures had remained elusive. However, these new findings have enabled the RVC to identify a novel DNA variant associated with fractures, impacting the expression of collagen type III.

 

Bone fractures are common in Thoroughbred racehorses, due to the forces the bones can experience, and are a leading cause of euthanasia. Approximately 60 horses each year are euthanised on UK racecourses as a result. However, fracture is a complex condition, with both environmental and genetic risk factors affecting a horse’s susceptibility.

Led by Dr. Debbie Guest, Senior Research Fellow at RVC, the team developed a polygenic risk score to gauge disease susceptibility based on various genes. They were then able to use this information to select cells from horses whose risk placed them at the extreme ends of the population with either very low or very high risk. These cells were then used in laboratory studies to establish a cell model and investigate the genetic factors involved in fracture risk.

 

The research team’s findings indicate that bone cells from horses predisposed to fractures express collagen type III at reduced levels due to alterations in their DNA sequence in the region which controls how much collagen III is produced. 

This discovery provides a crucial step forward in identifying genetically high-risk horses. By understanding the genetic causes of fractures,, this research can help identify, diagnose, and manage high-risk horses, improving the health and welfare of Thoroughbreds in the racing industry.

 

Ongoing research aims to validate the risk-scoring system across different horse populations and further explore genetic factors using the established cell model.

 

For more details, see:

 

Palomino Lago, E.; Baird, A.; Blott, S.C.; McPhail, R.E.; Ross, A.C.; Durward-Akhurst, S.A.; Guest, D.J. 

A Functional Single-Nucleotide Polymorphism Upstream of the Collagen Type III Gene Is Associated with Catastrophic Fracture Risk in Thoroughbred Horses. 

Animals 2024, 14, 116. 

https://doi.org/10.3390/ani14010116 

New aid to wound healing?

Polymerisation of the synthetic
epidermis spray (c) Paindaveine et al

Recent research suggests that a synthetic skin spray could aid in wound healing by limiting the
formation of exuberant granulation tissue.  

Due to their nature, horses are prone to injuring themselves. Wounds on the lower legs are particularly likely to heal slowly, often involving exuberant granulation tissue (EGT). This excessive tissue growth, commonly known as "proud flesh," poses a significant challenge to equine wound management, as it hampers further healing by protruding from the wound site. 

 

A team of researchers based in France has been investigating the efficacy of a novel synthetic epidermis spray (SES)* in promoting wound healing. Led by Charlotte C Paindaveine from the Ecole Nationale Vétérinaire de Lyon, the researchers conducted a small-scale clinical trial to compare the healing outcomes of experimental surgical wounds treated with SES spray versus those treated with a standard bandaging technique. 

 

The study, detailed in a report published in PLoS One, involved creating standardised surgical wounds on the lower limbs of six adult Standardbred mares. These wounds were then subjected to treatment with either SES or a traditional bandaging method.

 

Hypergranulation and exudation of
the lateral wounds (right leg) treated
with bandaging, compared with wounds 
on left leg treated with spray.
(c) Paindaveine et al 

For the SES treatment, the spray, which comprised  ultraviolet polymerizable methacrylate monomers, comonomers, crosslinker and a photoinitiator was applied to the wound. The researchers explain that this layer was then polymerised using a 395 nm, 20 x 30 cm, 40 mW/cm2 UV light for 60 seconds at a distance of approximately 30 cm (Fig 1). They repeated the same procedure to fix a second layer of the product. The SES was only applied on day 0. No further application was made.

 

The control treatment consisted of a nonadherent permeable dressing secured with conforming cotton gauze and held in place with a cohesive bandage, which would be a common treatment of choice for superficial wounds in a field setting. The control treatment was repeated every 4 days until the end of the study to mimic field veterinary follow-up.

 

Wounds were assessed daily for the SES treatment group, and every 4 days for the control / bandaged group.

 

The researchers report that the synthetic epidermal spray allowed healing without the production of EGT but it did not reduce the median wound healing time compared to a standard bandaging technique.

 

They add that the exuberant granulation tissue observed in the control group that did not receive the SES decreased without any trimming procedure during the 60-day period.

 

They conclude: “The SES is potentially an interesting alternative for the management of secondary intention wound healing of superficial and non-infected distal limb wounds in adult horses because of its economical and practical aspects. 

 

*Novacika®, Cohesive S.A.S, France

 

 

 

For more details, see: 

 

Charlotte C. Pandaveine, Benoit Bihin, Olivier M. Lepage (2024) 

The effects of a synthetic epidermis spray on secondary intention wound healing in adult horses. PLoS ONE 19(3): e0299990. 

https://doi.org/10.1371/journal.pone.0299990

Effect of antibiotics on gut microbiome

Recent research has shown that even a short course of antibiotics can affect the microorganisms in the
gastrointestinal tract of horses. 

While antibiotics play a vital role in combating infectious ailments, their potential misuse has come under scrutiny, primarily due to concerns surrounding the emergence of antibiotic resistance. Consequently, there's a growing consensus to restrict antibiotic usage to essential cases.

 

Moreover, there's a growing recognition of the susceptibility of the equine gut microbiota to antibiotic-induced disturbances, which can lead to adverse, and occasionally severe, consequences. Although instances of severe, life-threatening diarrhoea in horses post-antibiotic treatment have been infrequent, they highlight the potential risks.

 

Now recent work has shown that even short-term courses of commonly prescribed antibiotics can bring about detectable changes in the gut microbiome.

 

A study conducted by Joseph L Parker from the Gluck Equine Research Center, College of Agriculture, Food, and Environment, University of Kentucky, in collaboration with colleagues, aimed to explore the impact of antibiotic administration on the gut microbiome of healthy horses. They evaluated this impact through assessments of faecal consistency, bacterial population counts, and qPCR panel analysis to detect specific disease-associated organisms.

 

Twenty-four healthy horses, comprising 12 mares and 12 geldings, with no prior exposure to antibiotics or anthelmintic treatment within the preceding three months, were selected for participation in the study. They were grouped into four treatment cohorts, one serving as a control while the others underwent a brief course of distinct antibiotic regimens: potassium penicillin/gentamicin via intravenous injection, ceftiofur via intramuscular injection, and trimethoprim sulphamethoxazole orally.

 

The research team collected faecal samples before treatment began,  on the day after treatment finished, and at 10, 14, 21, and 28 days after the start of treatment. 

 

They found that the response to antibiotic administration varied among the horses. However, all horses administered antibiotics had notably softer faeces compared to the control group. One horse developed severe diarrhoea and was consequently withdrawn from the study.

 

Bacterial population counts revealed that Lactobacillus spp. levels showed a marked reduction in all samples collected from horses the day after antibiotic treatment finished

Furthermore, horses subjected to antibiotic treatment demonstrated a significantly higher likelihood of testing positive for C. difficile or C. perfringens via faecal qPCR analysis.

 

The researchers suggest that more work is needed to explore the consequences of antibiotic-microbiota interactions in the horse.

 

 

For more details, see: 

 

J.L. Parker, A. Page, O. Jacob, V. Stanton, B. Davis, M. Flythe, E.N. Adam,

Equine fecal microbiota response to short term antibiotic administration,

Journal of Equine Veterinary Science (2024) 133, 104993

https://doi.org/10.1016/j.jevs.2023.104993

Advances in endocrinology take centre stage in latest EVJ

The endocrine system plays an essential role in balancing the horse's health. Unfortunately, it is
prone to malfunction.

The March issue of the Equine Veterinary Journal (EVJ) highlights the latest work advancing veterinary understanding of equine endocrinology.

  

In a press release, EVJ guest editor Melody de Laat, said “Knowledge, diagnosis and treatment of equine endocrinopathies has improved dramatically over the past 25 years, with progress driven by the publication of peer-reviewed papers and the application of evidence-based medicine.” 

   

Obesity, PPID (Equine Cushing’s), insulin dysregulation (ID), thyroid disorders and the effects of corticosteroid administration are all covered. Articles include:

 

• ·     The BEVA Primary Care Clinical Guidelines provide evidence-based recommendations for the diagnosis and management of PPID, directed at equine practitioners in an ambulatory setting. The evidence review supports clinical signs such as hyperhidrosis, regional adiposity, epaxial muscle atrophy, laminitis, weight loss, recurrent infections or delayed healing, behaviour changes, or polyuria and polydipsia as prompts for moderate suspicion of PPID in animals of more than 10 years of age. The review supports the assessment of basal plasma ACTH concentrations or ACTH responses to exogenous thyrotropin-releasing hormone (TRH) administration. It also supports the use of pergolide as a therapy for PPID.

• ·   Lumbar vertebral bone density is decreased in horses with pituitary pars intermedia dysfunction explores the infrequent finding of pathological fractures in aged horses with advanced PPID.

• ·       Influence of feeding and other factors on adrenocorticotropin concentration and thyrotropin-releasing hormone stimulation test in horses and ponies and Clinical implications of imprecise sampling time for 10- and 30-minute thyrotropin-releasing hormone stimulation tests in horses stresses the importance of exact timing when these samples are collected. 

• ·      Obesity and obesity-associated metabolic disease conditions in Connemara ponies in Ireland showed a 50% prevalence of laminitis in obese ponies. 

• ·       Development of a body condition index to estimate adiposity in ponies and horses from morphometric measurements presents an alternative method for measuring adiposity.

• ·          Associations between feeding and glucagon-like peptide-2 in healthy ponies looks at the role of glucagon-like peptide-2 in the development of hyperinsulinaemia in ID.

• ·         Expression of the GCG gene and secretion of active glucagon-like peptide-1 varies along the length of intestinal tract in horses demonstrates that both the large and small intestines are sites of equine GLP-1 secretion and that the genetic coding is identical in horses with and without ID.

• ·            Relationships between total adiponectin concentrations and obesity in native-breed ponies in England and Short-term induced hyperinsulinaemia and dexamethasone challenge do not affect circulating total adiponectin concentrations in insulin-sensitive ponies show that total adiponectin is not as strongly correlated with body condition, body shape and breed as expected and inducing short-term ID does not alter total adiponectin concentrations. 

• ·            Factors associated with insulin responses to oral sugars in a mixed-breed cohort of ponies and Epidemiological investigation of insulin dysregulation in Shetland and Welsh ponies in Australia determine that the insulin response to oral sugar is associated with multiple variables but cannot be predicted from the physical appearance. 

• ·            Insulin, but not adiponectin, is detectable in equine saliva using an automated, commercial assay in a pilot study in the UK demonstrates that insulin is measurable in equine saliva, but this method is not currently a viable alternative to blood. 

• ·        The effect of pre-dosing with metformin on the insulin response to oral sugar in insulin-dysregulated horsesshows the lack of efficacy of metformin (dosed at 30 mg/kg) on the insulin response to an oral sugar test.

• ·           Intra-articular trimacinolone acetonide injection results in increases in systemic insulin and glucose concentrations in horses without insulin dysregulation shows that intra-articular triamcinolone does not result in circulating insulin concentrations likely to induce laminitis in insulin-sensitive animals. 

• ·           Diagnosis and management of thyroid disorders and thyroid hormone supplementation in adult horses and foals reviews thyroid gland pathophysiology in adult horses and foals, blood thyroid hormone concentrations and the use of T4 supplementation in equine practice. 

 

“This robust collection reflects the continual dedication of equine veterinary researchers to developing our understanding of equine endocrinology,” said Professor Celia Marr, Editor of the EVJ. “Such work is enabling the application of evidence-based medicine to improve the diagnosis, management, treatment and quality of life of animals with endocrine disorders.”

 

The March issue is available to read free:

 

https://beva.onlinelibrary.wiley.com/toc/20423306/2024/56/2

Funding offered for Cushing’s and Insulin Resistance research

The Equine Cushing's and Insulin Resistance Group Inc. (ECIR Group) is now accepting funding requests for 2024. These proposals should focus on researching Equine Metabolic Syndrome/Insulin Resistance (EMS/IR) and Pituitary Pars Intermedia Dysfunction (PPID). 

The ECIR Group's mission is to improve the well-being of equines with metabolic disorders through a blend of basic research and practical clinical experience. Their primary objective is to prevent laminitis. 

 

"Quality scientific research is critical to the continuous advancement of knowledge to benefit metabolic equines." said Dr. Kathleen Gustafson, ECIR Group Inc. Research Director. "Our goal in 2024 is to fund research and encourage collaboration between scientists, scholars, veterinarians, and hoof care professionals to positively affect the health and welfare of these equines."

 

"Through the sharing of their in-the-barn experience, ECIR Group supporters have helped build effective protocols for metabolically challenged equines." said current President, Nancy Collins. "It is an honor that now, through member financial support, the ECIR Group has expanded to also fund equine metabolic research."

 

Proposals seeking funding should focus on EMS and PPID, covering topics such as diagnosis, diet, hoof care, exercise (referred to as DDT/E) and preventing laminitis. Any proposals meeting these criteria will be considered.

 

Applications must be submitted via the ecirhorse.org research portal. Deadline for submission is May 31, 2024.

 

Researchers will find more information at https://www.ecirhorse.org/research-proposals.php

Joint Helicopter Command Horse Rider Safety Survey

 Are you a horse rider? Do you have friends or family members who also enjoy riding horses?
You can help promote horse and rider safety by completing an online survey.

The United Kingdom Ministry of Defence Joint Helicopter Command (JHC) is collaborating with the British Horse Society (BHS) to raise awareness about a crucial initiative concerning horse and rider safety.

 

Helicopters present a significant risk of startling horses. Due to their flight instincts, horses can easily become alarmed by sudden movements or loud noises, prompting them to flee from potential threats. The sudden appearance and noise of a helicopter can trigger such a response in horses, potentially leading to hazardous situations for both the animals and individuals involved.

 

Understanding the natural instincts and sensitivities of horses is crucial, as it allows pilots and horse owners to take necessary precautions to ensure the safety and well-being of horses in areas where helicopters are present.

 

As part of ongoing efforts, JHC, in partnership with The British Horse Society, has developed the Horse Riding Safety Survey aimed at collecting valuable insights from riders across the UK. 

 

As a member of the horse-riding community, you can help to shape future safety measures by completing the survey.

To take part, go to:

 

 https://forms.office.com/e/adyKzB3D3x

Lameness main cause of vetting “failures”

(c) Henktennapel Dreamstime.com

Research from the Royal Veterinary College (RVC) has found that lameness ranks as the most common adverse
finding in pre-purchase examinations (PPEs) conducted on horses in the UK.

The aim of the prepurchase examination is to carry out a thorough clinical examination of the horse on behalf of the potential purchaser to identify any cliiinical issues that might make the horse unsuitable for its intended purpose, whether that be elite competitions, breeding, or leisure riding.

 

In the United Kingdom, PPEs generally consist of either a two stage (two stage vetting [2SV], i.e., general physical examination at rest and basic trot in-hand) or a five stage-examination (five stage vetting [5SV], i.e., general physical exam at rest and after exercise, lameness evaluation including strenuous exercise with re-evaluation after a period of recovery).

 

In the United Kingdom, The standard PPE consists of five stages, (five stage vetting [5SV],ie general physical examination at rest; walk and trot in hand;  strenuous exercise; rest and a second trot up)

 

Sometimes it may not be possible to complete all five stages or the purchaser may request a limited examination, in which case the examination can be limited to the first two stages (two stage vetting, 2SV).

 

PPEs yield recommendations based on the veterinary surgeon's assessment at the time of examination. As such, PPEs are largely subjective and often the subject of impassioned debate.

Despite their widespread use in equine practice, PPEs have been the subject of limited research.

 

The research team from the Royal Veterinary College (RVC), comprising Dr. David Bolt, Senior Lecturer in Equine Surgery; Dr. Jason Tupper, Head of the RVC Equine Practice; and Annabel Shelton, a graduate of RVC's BVetMed program in 2023, scrutinised 133 PPE certificates belonging to a mixed, non-racing horse population sourced from three primary equine practices. 

 

The analysis encompassed an evaluation of the examination format (e.g., 2SV or 5SV), use of diagnostic imaging modalities (e.g., radiographs), purchase price, animal characteristics, intended use of the horse, PPE outcomes, and any prejudicial findings uncovered during the examination.

They found that a 5SV was performed on 68.5% of horses compared to 34.1% which underwent a 2SV.

 

Of the 133 horses examined, 57.1% had prejudicial findings, the most common of which was lameness. Other prejudicial findings included diagnostic imaging findings (14.5%); respiratory system findings (6.6%); skin conditions (5.3%); and cardiac abnormalities (3.9%).

 

Unsurprisingly, horses with a higher purchase price were more likely to undergo the full 5SV, and undergo pre-purchase radiography. They were also more likely to have prejudicial findings identified.

 

Dr Tupper said: “A pre-purchase examination can discover a number of issues before buying a horse. This study reveals lameness to be the commonest issue. Few horses are perfect when it comes to temperament and health. The vetting process determines the issues and the vet can then help the purchaser weigh up their significance and decide if they can compromise and accept the issues or not. Further studies can now focus on the cost/benefit of radiology as part of the vetting procedure and the potential use of gait analysis.”

 

The researchers hope that their work will stimulate future investigations into the merits of 5-stage (5SV) and 2-stage (2SV) PPE formats, as well as the diagnostic techniques employed. This will, in turn, help to better inform prospective horse buyers when considering their purchase.

 

For more details, see:

 

Prejudicial findings regarding suitability for intended purpose during pre-purchase examinations in a mixed horse population—A retrospective observational study in the United Kingdom. 

Shelton AV, Tupper J, Bolt DM. 

Equine Vet J. 2024.

https://doi.org/10.1111/evj.14061

Effect of day length on growth

 Can the growth and maturation of yearling Thoroughbreds be accelerated by artificially extending the day length? A Japanese study has been exploring this possibility.

Hokkaido, the mostly northerly of Japan's main islands, is the primary breeding ground for over 97% of Thoroughbreds in the country. Hokkaido experiences cool summers and cold winters, with shorter days during the winter season.

 

Mutsuki Ishimaru and colleagues conducted a study to examine the impact of artificially extending daylight on changes in body composition in young Thoroughbreds raised and trained in Hidaka, Hokkaido, Japan. 

 

The study involved 73 horses aged 21-24 months.

 

The treatment group, comprising 41 horses (22 colts and 19 fillies), underwent extended photoperiod (EP) treatment from December 20 to April 15. This was achieved by placing a 100-watt white bulb in each horse box, providing 14.5 hours of light and 9.5 hours of darkness. 

 

A control group of 32 horses (16 colts and 16 fillies) remained under natural light conditions with no additional lighting. All horses had 1-2 hours of pasture time daily and followed a standardised training program.

 

The research team assessed body weight (BW), rump fat thickness (RFT), fat-free mass (FFM), and percentage of fat (%F) as indicators of body composition. 

 

In the control group, there was a moderate increase in BW and FFM, but no significant difference in BW and FFM between December and later months. In contrast, the EP group exhibited continuous growth until April, with significantly higher BW and FFM in February, March, and April compared to December.

 

The researchers suggested that the hypothalamic-pituitary-gonadal axis was activated earlier in the EP group, leading to elevated circulating IGF-I or gonadal hormones. 

 

They concluded that young Thoroughbreds under extended photoperiod conditions in Hokkaido may tolerate more high-intensity training than those under natural light conditions during the winter season. Additionally, there is potential for these horses to perform at an early stage in 2-year-old racing.

 

For more details, see:

 

 

Effects of an extended photoperiod on body composition of young Thoroughbreds in training. 

Mutsuki Ishimaru, Atsushi Okano, Akira Matsui, Harutaka Murase, Kenji Korosue, Kentaro  Akiyama, Kazuyoshi Taya. 

Journal of Veterinary Medical Science, (2024), Vol 86, pp 58-65, 

https://doi.org/10.1292/jvms.23-0349 

 

Study: Curly Horses promote immune tolerance in allergic individuals

(c) Dawny16161 Dreamstime.com

 American Bashkir Curly Horses are claimed to be hypoallergenic, but this has not been clinically proven. 

The origin of these horses remains uncertain, with their additional name "Bashkir" stemming from the misconception that they were originally imported from Russia to America. Some theories suggest a Spanish immigrant origin in South America.

Established in 2010, Curly Farm Klappholz combines Dr. Wolfgang Mitlehner's medical practice specialising in internal medicine, allergology, pulmonary, and bronchial medicine with a holiday home and riding school featuring Curly horses. This facility provides a safe environment for allergic riders to interact with and ride Curly Horses.

 

Dr. Mitlehner has conducted studies on allergic patients who have ridden Curly horses to investigate their allergic responses to these animals.The work culminated in a report published in the journal Pneumologie

 

This collaborative study involved Susanne Mitlehner from Curly Farm Klappholz, Dr. Wolfgang Mitlehner, Alexandra Mitlehner, Hans Caspar Mitlehner, Peter Stoll, and Ines Swoboda from the University of Applied Sciences in Vienna, along with Monika Reissmann from Humboldt-University of Berlin.

 

The team examined the impact of exposure to Curly Horses on 141 patients allergic to horses by assessing their lung function and nasal patency during interactions with the animals. They discovered that repeated engagement with Curly Horses, including activities such as riding and grooming, resulted in a reduction in allergic riders' reactivity. This improvement was evidenced by enhancements in FEV1, PEF, and PNIF measurements.

 

PNIF, FEV1, and PEF are standard measures used to evaluate nasal obstruction, allergic rhinitis, and lung function, particularly in conditions like asthma.

 

Repeated interactions with Curly Horses, including riding and grooming, resulted in decreased reactivity among allergic riders, as evidenced by improvements in FEV1, PEF, and PNIF measurements.

 

Further visits, involving extended periods of riding totalling up to 40 hours or more, continued to reduce reactivity to Curly Horses. It's noteworthy that allergic reactions to horses occurred in only 72 out of 1312 riding hours, with the majority occurring within the initial ten hours of riding.

 

In a subset of 41 out of the 141 patients, additional investigation explored whether repeated exposure to Curly Horses could induce tolerance to other horses. These patients participated in a tolerance induction study and underwent annual testing for horse allergy using a nasal provocation test. The results revealed that exposure to Curly Horses led to immune tolerance to other horses in 88% of patients who completed the study.

 

Dr Mitlehner elaborates “To understand the mechanism causing hypoallergenicity, we performed IgE immunoblots to determine whether Curly Horse hairs contain IgE binding proteins.” 

 

IgE immunoblots play a significant role in allergy diagnostics. By examining the pattern of IgE antibodies adhering to various allergens on the membrane, clinicians can identify the specific allergens to which a patient is sensitized. This information is vital for diagnosing allergies and formulating suitable treatment plans, such as allergen-specific immunotherapy (allergy shots) or recommendations for allergen avoidance.

 

The study revealed no differences in IgE reactivity between Curly and non-Curly Horses. Additionally, patients participating in the immune tolerance induction study did not exhibit reduced IgE reactivity to hairs from Curly or non-Curly Horses, despite having developed tolerance.

 

“However, we did find increasing levels of anti-horse IgG antibodies in the study patients.” Dr Mitleehner added.

 

“Overall, our data strongly suggests that continuous exposure to Curly Horses can induce immune tolerance, rendering these patients non-reactive to horses. The reason for the reduced clinical allergenicity of Curly Horses remains unclear, but the data suggest that blocking IgG antibodies may be of importance for immune tolerance development.”

 

For more details, see:

 

Horse allergy: Curly Horses can mediate immune tolerance

Alexandra Mitlehner, Caspar Mitlehner, Monika Reißmann, Peter Stoll, Ines Swoboda, Wolfgang Mitlehner

Pneumologie (2024); 78(01): 47-57
https://doi.org/10.1055/a-2101-9533

 

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