The hair coat of horses serves as a protective layer that adapts to seasonal changes and environmental conditions. It is composed of different types of hair, including the long guard hairs and the finer undercoat, which together provide insulation and defense against external elements. The condition and appearance of a horse's hair coat can reflect its overall health, nutritional status, and management practices. Factors such as genetics, diet, and grooming influence hair coat quality, while seasonal shedding occurs to accommodate temperature variations. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and management of hair coats in horses, as well as their implications for equine welfare and performance.
Miller AB, Murphy BA, Adams AA.Blue light therapy can be used in horses to alter the natural photoperiod and inhibit winter hair coat growth. Seasonal increases in ACTH occur in the fall season but are exaggerated in horses with pituitary pars intermedia dysfunction (PPID). Additionally, PPID horses frequently present with hypertrichosis. Thus, blue light therapy was proposed as a potential management tool for hypertrichosis and for investigating the impact of photoperiod manipulation on ACTH. Eighteen PPID horses, aged 18 to 31 yr, from a university-owned research herd were selected and assigned to either the control group...
Olvera-Maneu S, Carbajal A, Gardela J, Lopez-Bejar M.The monitoring of stress physiology includes studying a wide range of endocrinological mechanisms, which can be assessed using multiple tissue samples. This study aimed to evaluate the seasonal variations of hair C, T and DHEA-S in horses for a whole year, as well as to assess the variations between seasons of C/DHEA-S and T/C ratios as a retrospective measure of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axis activity. Ten pure-breed Menorca stallions were included in the study. The hair samples were collected approximately every two months following the shave-resha...
Mazzola SM, Colombani C, Pizzamiglio G, Cannas S, Palestrini C, Costa ED, Gazzonis AL, Bionda A, Crepaldi P.The satisfaction of leisure horses' behavioral needs has begun to be considered a priority, linked to the awareness that horses kept in single boxes may be deprived of social contact and the possibility to perform natural behaviors. Several factors may influence horses' quality of life also in the paddock, and there are very few data on the effects of those variables on leisure horses' chronic stress, measurable in terms of activation of the hypothalamic-pituitary-adrenocortical axis. Therefore, managerial choices faced by owners and stables managers are only based on experience, common sense,...
Pomorska-Zniszczyńska A, Szczepanik M, Kalisz G.Videodermoscopy is a novel, noninvasive technique used to examine the appearance of skin and its adnexa. The aim of this study was to assess specific dermoscopic parameters in Arabian purebred mares in particular areas of the body during the winter season. The study was performed in the winter season. Videodermoscopic evaluations of the hair and skin were performed over seven areas of the body: the forehead, mane, neck, chest, flank, croup, and tail. Twenty-one healthy, non-breeding Arabian mares aged 3 to 21 years were selected for the study. The Video-Dermatoscope Vidix 7 (Medici Medical SRL...
Ishii H, Shibuya M, Leung GN, Nozawa S, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.GW1516 is a peroxisome proliferator-activated receptor-δ (PPAR-δ) agonist that is banned in horseracing and equestrian sports. Long-term detection and longitudinal distribution of GW1516 in the mane of a horse are reported for the first time and this hair analysis could prolong the detection window of GW1516 for doping control. Methods: Mane hairs were divided into three segments (0-7, 7-15, and >15 cm from the cut end) and completely pulverized and homogenized for analysis. The pulverized hair samples were extracted with methanol followed by further purification and the extracts were a...
Cutler C, Viljanto M, Taylor P, Habershon-Butcher J, Muir T, Biddle S, Van Eenoo P.AC-262536 is one of a number of selective androgen receptor modulators that are being developed by the pharmaceutical industry for treatment of a range of clinical conditions including androgen replacement therapy. Though not available therapeutically, selective androgen receptor modulators are widely available to purchase online as (illegal) supplement products. The growth- and bone-promoting effects, along with fewer associated negative side effects compared with anabolic-androgenic steroids, make these compounds a significant threat with regard to doping control in sport. The aim of this st...
Zhao R, Yihan W, Zhao Y, Li B, Han H, Mongke T, Bao T, Wang W, Dugarjaviin M, Bai D.Different morphological structures of hairs having properties like defense and camouflage help animals survive in the wild environment. Horse is one of the rare kinds of animals with complex hair phenotypes in one individual; however, knowledge of horse hair follicle is limited in literature and their molecular basis remains unclear. Therefore, the investigation of horse hair follicle morphogenesis and pigmentogenesis attracts considerable interest. Results: Histological studies revealed the morphology and pigment synthesis of hair follicles are different in between four different parts (mane,...
Chiwitt CLH, Scurrell EJ, Featherstone HJ, Heinrich CL.A 15-year-old Cob mare presented with a 4-month history of chronic epiphora and intermittent blepharospasm in the right eye. On ophthalmic examination, two translucent aberrant hairs were identified at the third eyelid margin corresponding to an area of corneal fibrosis and neovascularization. Partial excision of the third eyelid was performed, and histopathology confirmed ectopic hair follicles. Two weeks later, clinical signs recurred in the same eye. Examination revealed another pair of aberrant hairs on the bulbar surface of the third eyelid near its leading edge. This portion of the third...
Gardela J, Carbajal A, Tallo-Parra O, Olvera-Maneu S, Álvarez-Rodríguez M, Jose-Cunilleras E, López-Béjar M.Horse transportation for temporary relocation during rest periods is a common and widespread practice among horse owners, either from sport competition or working tasks. This study aimed to determine the effect of a relocation period and the multiple factors associated with a rest period on hair cortisol concentrations (HCCs) in horses. Additionally, this study reports the seasonal effect on HCCs and hair growth over a year. Thirteen police horses, Pure Spanish stallions of various ages (5-13 y), were selected to participate in this study. Hair sample collection was carried out approximately e...
O'Brien C, Darcy-Dunne MR, Murphy BA.Photoperiod is considered the most dominant environmental cue allowing animals to anticipate and adapt to seasonal changes. In seasonally breeding mammals, changes in daylength alter pineal melatonin secretion and pituitary prolactin secretion. During the seasonal transition to shorter winter daylengths, increased production of melatonin and declining prolactin are associated with triggering winter coat growth in many animals. Similarly, studies have shown that artificial extension of photoperiod suppresses melatonin secretion and lifts prolactin inhibition to activate moulting. Four longitudi...
Brummer-Holder M, Cassill BD, Hayes SH.The use of hair as a sample matrix to determine the mineral status of an animal has received a lot of interest. The objective of this study was to determine if the trace element content in horse mane hair changed with age when evaluated in a group of horses representing a large age range. As a second objective, whole blood trace element content was evaluated, and its relationship to mane hair trace element content, as well as age, were tested. Therefore, mane hair and whole blood samples were obtained from 59 horses, ranging from 2 months to 26 years in age, housed on the same farm. Mane hai...
Cutler C, Viljanto M, Hincks P, Habershon-Butcher J, Muir T, Biddle S.LGD-4033 is one of a number of selective androgen receptor modulators (SARMs) that are being developed by the pharmaceutical industry to provide the therapeutic benefits of anabolic androgenic steroids, without the less desirable side effects. Though not available therapeutically, SARMs are available for purchase online as supplement products. The potential for performance enhancing effects associated with these products makes them a significant concern with regards to doping control in sports. The purpose of this study was to investigate the metabolism of LGD-4033 in the horse following oral ...
Meisfjord Jørgensen GH, Mejdell CM, Bøe KE.Horse owners may lack knowledge about natural thermoregulation mechanisms in horses. Horses are managed intensively; usually stabled at night and turned out during the day. Some are clipped and many wear a blanket, practices which reduce the horse's ability to regulate heat dissipation. The aim of this study was to investigate the relationship between hair coat characteristics, body condition and infrared surface temperatures from different body parts of horses. Under standard conditions, the body surface temperature of 21 adult horses were investigated using infrared thermography. From severa...
Banse HE, Getachew F, Levy M, Smits J.Hair cortisol has been demonstrated to reflect hypothalamic-pituitary-adrenal axis activity (including Cushing's disease and stress) in several species. We hypothesized that hair cortisol concentrations are increased in horses with pituitary pars intermedia dysfunction (PPID) compared with healthy adult horses and that this difference is magnified in the fall, when circulating adrenocorticotropin (ACTH) is generally the highest. Cortisol from hair collected using clippers with a #40 blade from the neck was compared between PPID horses and control horses over several months in the fall (August-...
Lazzerini N, Coulon A, Simon L, Marchina C, Noost B, Lepetz S, Zazzo A.Carbon and nitrogen stable isotope time series performed in continuously growing tissues (hair, tooth enamel) are commonly used to reconstruct the dietary history of modern and ancient animals. Predicting the effects of altitudinal mobility on animal δ C and δ N values remains difficult as several variables such as temperature, water availability or soil type can contribute to the isotope composition. Modern references adapted to the region of interest are therefore essential. Methods: Between June 2015 and July 2018, six free-ranging domestic horses living in the Mongolian Altaï were fitte...
Prinsloo M, Hynd P, Franklin S, Weaver S, van den Boom R.Equine squamous gastric disease (ESGD) is common in horses and many factors, including stress, may play a role in lesion development. Hair cortisol concentration (HCC) provides a measure of medium to long-term stress and therefore, the relationship between HCC and ESGD was examined in this study. Hair samples were collected from 25 horses and gastroscopy was performed to determine the presence and severity of ESGD. Hair cortisol concentrations were lower in horses with ESGD (P = 0.014), and negatively correlated with lesion severity. Mares had lower HCC than geldings (P = 0.031), and a...
Rudolph W, Remane D, Wissenbach DK, Peters FT.Ingestion of hypoglycin A (HGA) in maple seeds or alkaloids produced by symbiotic fungi in pasture grasses is thought to be associated with various syndromes in grazing animals. This article describes analytical methods for monitoring long-term exposure to HGA, its metabolite MCPA-carnitine, as well as ergocristine, ergocryptine, ergotamine, ergovaline, lolitrem B, N-acetylloline, N-formylloline, peramine, and paxilline in equine hair. After extraction of hair samples separation was achieved using two ultra high performance liquid chromatographic systems (HILIC or RP-C18, ammonium formate:acet...
Kalashnikov VV, Zajcev AM, Atroshchenko MM, Miroshnikov SA, Zavyalov OA, Frolov AN, Skalny AV.The objective of the present study was assessment of gender differences in hair trace element content in English Thoroughbred horses (North Caucasus, Russia) using ICP-DRC-MS and calculation of the reference values. Trace element content in mane hair of 190 stallions and 94 mares (3-7 years old) bred in North Caucasus (Russia) was assessed using inductively coupled plasma mass spectrometry. Mane hair Co, Cr, Mn, Li, Si, and Sr levels in mares exceeded those in stallions by 77%, 63%, 64%, 42%, 39%, and 64%, respectively. Hair Fe and Si content was nearly twofold higher in female horses as comp...
Zahradnik E, Janssen-Weets B, Sander I, Kendzia B, Mitlehner W, May C, Raulf M.Exposure to horses can cause severe allergic reactions in sensitized individuals. The breed, American Bashkir Curly Horse is categorized as hypoallergenic, primarily due to reports of allergic patients experiencing fewer symptoms while handling this special breed. The possible reasons for this phenomenon could be lower allergen production and/or reduced allergen release into the air because of increased sebum content in their skin and hair compared to other breeds. Therefore, the aim of the current study was to compare different horse breeds in relation to allergen content in hair and airborne...
Ahmed YA, Ali S, Ghallab A.Animal hair examination at a criminal scene may provide valuable information in forensic investigations. However, local reference databases for animal hair identification are rare. In the present study, we provide differential histological analysis of hair of some domestic animals in Upper Egypt. For this purpose, guard hair of large ruminants (buffalo, camel and cow), small ruminants (sheep and goat), equine (horse and donkey) and canine (dog and cat) were collected and comparative analysis was performed by light microscopy. Based on the hair cuticle scale pattern, type and diameter of the me...
Choi TLS, Kwok KY, Kwok WH, Tsoi YYK, Wong JKY, Wan TSM.Anabolic and androgenic steroids (AAS) are banned substances in both human and equine sports. They are often administered intramuscularly to horses in esterified forms for the purpose of extending their time of action. The authors' laboratory has previously reported an UHPLC/HRMS method using quadrupole-Orbitrap mass spectrometer in full scan and parallel reaction monitoring (PRM) mode for the detection of 48 AAS and/or their esters in horse hair. However, two injections were required due to the long duty cycle time. In this paper, an UHPLC/HRMS method using multiplexed targeted MS mode was de...
Wong JKY, Choi TLS, Kwok KY, Lei ENY, Wan TSM.Equine hair is becoming an increasingly popular biological matrix for doping control of horse sports; one of the reasons for this is the significantly longer detection window hair can offer. Hair analysis opens up the opportunity for longitudinal monitoring of drug exposure which would otherwise not be possible with the more traditional and common biological matrices, such as urine and blood. As such, there is a need for more multi-target screening methods covering a broad range of prohibited substances in equine hair at the required sensitivities for equine doping control. This paper describe...
Kalashnikov V, Zajcev A, Atroshchenko M, Miroshnikov S, Frolov A, Zav'yalov O, Kalinkova L, Kalashnikova T.A study on the Russian trotting breeds was conducted to assess the impact of horses' sporting results and the degree of accumulation of chemical elements in the hair. In the first phase of the research, the elemental composition of the mane hair of trotter horses (n = 215) was studied. Based on these studies, percentile intervals for the distribution of concentrations of chemical elements in the hair have been established, and the values of 25 and 75 percentile adopted as a "physiological standard" have been defined. In the second stage of the research into clinically healthy Russian trott...
Siwińska N, Żak A, Słowikowska M, Kubiak K, Jaworski Z, Niedzwiedź A.Hair is a more biologically stable material than other tissues and contains a relatively constant level of minerals, drugs or toxins. The content of essential elements in hair depends on dietary and non-dietary factors. The aim of this study was to assess and compare the effect of diet on the elemental composition and morphological properties of the hair of healthy Polish Konik horses. Mane hair was collected from 19 horses living in The National Park in Popielno in Poland. Six of these horses were free-ranged all year with permanent access to pasture, while 13 horses were kept in the stable a...
Gray B, Viljanto M, Menzies E, Vanhaecke L.The detection of drugs in human hair samples has been performed by laboratories around the world for many years and the matrix is popular in disciplines, such as workplace drug testing. To date, however, hair has not become a routinely utilised matrix in sports drug detection. The analysis of hair samples offers several potential advantages to doping control laboratories, not least of which are the greatly extended detection window and the ease of sample collection and storage. This article describes the development, validation, and utilisation of a sensitive ultra-high performance liquid chro...
Tomich LM, Pieper JB, Stern AW.Dermoscopy is a noninvasive diagnostic technique that allows visualization of structures of the superficial dermis not visible with the naked eye. Objective: To assess the usefulness and applicability of dermoscopy for evaluation of healthy equine skin. Methods: Twelve healthy horses from a research herd. Methods: Five regions (cheek, lateral neck, dorsum, flank and abdomen) were examined with contact dermoscopy using both nonpolarized and polarized light at both 17-fold and 24-fold magnification. These findings were compared to histological features of skin biopsies cut both longitudinally an...
Osthaus B, Proops L, Long S, Bell N, Hayday K, Burden F.There are clear differences between donkeys and horses in their evolutionary history, physiology, behaviour and husbandry needs. Donkeys are often kept in climates that they are not adapted to and as such may suffer impaired welfare unless protection from the elements is provided. Objective: To compare some of the hair coat properties of donkeys, mules and horses living outside, throughout the year, in the temperate climate of the UK. Methods: Longitudinal study. Methods: Hair samples were taken from 42 animals: 18 donkeys (4 females, 14 males), 16 horses (6 females, 10 males) and eight mules ...
Legnani S, Zini E, Roccabianca P, Funiciello B, Zanna G.Dermoscopy is a diagnostic tool that has been introduced into small animal dermatology for the evaluation of hair and the skin surface. To the best of the authors' knowledge, the use of this technique on horses and the dermoscopic appearance of equine hair and skin have yet to be reported. Objective: To assess the feasibility of dermoscopy, and to describe hair and skin surface features of healthy warmblood horses. Methods: Thirty four client-owned, healthy adult horses. Methods: Six body regions (head, neck, dorsal thorax, ventral thorax, croup and mane) were examined with a smartphone-attach...
Balmer P, Bauer A, Pujar S, McGarvey KM, Welle M, Galichet A, Müller EJ, Pruitt KD, Leeb T, Jagannathan V.Keratins represent a large protein family with essential structural and functional roles in epithelial cells of skin, hair follicles, and other organs. During evolution the genes encoding keratins have undergone multiple rounds of duplication and humans have two clusters with a total of 55 functional keratin genes in their genomes. Due to the high similarity between different keratin paralogs and species-specific differences in gene content, the currently available keratin gene annotation in species with draft genome assemblies such as dog and horse is still imperfect. We compared the National...
Kaczensky P, Burnik Šturm M, Sablin MV, Voigt CC, Smith S, Ganbaatar O, Balint B, Walzer C, Spasskaya NN.The Przewalski's horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski's horse and / or the ecological conditions in its former range have changed in a way compromising the species' long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski's horse...
Sponenberg DP, Ito S, Eng LA, Schwink K.Hair samples of various colors of horses were analyzed for content of both eumelanin and pheomelanin by a procedure using high performance liquid chromatography. The results are in accord with generally accepted genetic hypotheses accounting for the various colors. However, the results support the hypothesis that the chestnut/sorrel group of colors is conditioned by the extension locus, not the brown locus. The results also indicate that the brown locus is a likely contributor to some rare color phenotypes.
Chau TH, Tipple BJ, Hu L, Fernandez DP, Cerling TE, Ehleringer JR, Chesson LA.Oxygen isotope ratios (δ O values) of hair largely reflect features of regional hydrology while strontium isotope ratios ( Sr/ Sr) are thought to reflect bedrock geology; combination of both isotope signatures may provide greater capacity for determining provenance and reconstructing travel history of an organism. To test this hypothesis, we compared the O-Sr isotope profiles of hair from domestic horses with known residency histories. Methods: Tail hairs were collected from a pair of horses pastured together for a period of 16 months, one of which lived in a different location for the 8 mo...
O'Neill W, McKee S, Clarke AF.The purpose of this study was to quantify the effect of flaxseed (Linum usitatissimum) supplementation on the skin test response of atopic horses. Six horses that displayed a positive skin test for allergy to extract from Culicoides sp. participated in the 42-day, placebo-controlled, double-blind, cross-over trial. Results showed that supplementation with flaxseed for 42 days in our experimental horses reduced the mean skin test response to Culicoides sp. This observation was concurrent with a significant decrease in the long-chain saturated fatty acids; behenic acid (22:0) and lignoceric acid...
Thompson DL, Hoffman R, DePew CL.Eight pony mares received 4 mg of recombinant porcine prolactin (rpPRL) daily for 45 d beginning on January 15; eight control mares received vehicle. Reproductive end points and various indicators of metabolism, hair shedding, and thyroid activity were monitored. Prolactin concentrations peaked in mares treated with rpPRL at 94 +/- 19 ng/mL 2 h after injection and were 5.1 +/- 1.7 ng/mL 24 h after injection. Treatment with rpPRL increased (P < .01) hair shedding within 14 d, which peaked at 28 d and then dropped precipitously. Binding of 125I-equine prolactin confirmed that antibodies were ...
Jørgensen GH, Aanensen L, Mejdell CM, Bøe KE.Horses may adapt to a wide range of temperatures and weather conditions. Owners often interfere with this natural thermoregulation ability by clipping and use of blankets. Objective: To investigate the effects of different winter weather conditions on shelter seeking behaviour of horses and their preference for additional heat. Methods: Observational study in various environments. Methods: Mature horses (n = 22) were given a free choice test between staying outdoors, going into a heated shelter compartment or into a nonheated shelter compartment. Horse location and behaviour was scored using i...
Fjeldsgaard BE, Paulsen BS.Extracts of horse dander (HD) and horse hair and skin scrapings (HHSS) have been compared with respect to their content of proteins and carbohydrates. The protein content of HD is more than double that of HHSS, while the carbohydrate content is of the same order. SDS-PAGE and IEF, both combined with immunoblotting, and CIE/CRIE showed the IgE-binding ability of the proteins/glycoproteins present in the two extracts. SDS-PAGE/immunoblotting showed the presence of mainly the same IgE-binding bands in the two extracts. Nine were detected in HD, and seven in HHSS. Four of these were glycoproteins....
Watts LM, Browne JA, Murphy BA.A comprehensive understanding of the equine circadian clock involves the evaluation of circadian clock gene expression. A non-invasive and effective method for detecting equine clock gene expression has yet to be established. Currently, research surrounding this area has relied on collecting tissue biopsies or blood samples that can often be costly, time consuming and uncomfortable for the animal. Methods: Five mares were individually stabled under a light-dark (LD) cycle that mimicked the external environmental photoperiod during a time of year corresponding with the vernal equinox. Hair foll...
Kooistra LH, Ginther OJ.The effects of photoperiod on reproductive activity and hair changes in pony mares were studied in 2 experiments. In experiment I, the effect of a fixed daily photoperiod on the onset of the breeding season was studied in 36 mares from Nov 13, 1973, to June 13, 1974. The 4 treatment groups were as follows: daily photoperiod equivalent to the normal day length (control group); constant light 24 hours a day with no dark (L24:D0 group); 16-hour daily photoperiod with 8 hours of dark (L16:D8 group); and 9-hour daily photoperiod with 15 hours of dark (L9:D15 group). The intervals from beginning of ...
Medill SA, Janz DM, McLoughlin PD.Steroid-hormone concentrations from non-invasively obtained biomarkers, like hair, can provide a representation of circulating hormones diffused over relatively long time periods (e.g., weeks or months). The hormone cortisol is often associated with physiological or even psychological stress, while testosterone is strongly associated with male development and reproductive success. Increasingly, studies are using hormone levels derived from hair to make inferences among both domestic animals and wildlife. For horses, all previous hair hormone analysis has been done on companion or working anima...
Bowling AT, Stott ML, Bickel L.Microsatellite DNA markers in a mare's hair bulbs not concordant with markers in her blood confirmed the hypothesis of chimaerism which had been proposed to explain the apparent parentage exclusion of the mare from her suckling foal. Parentage analysis for this foal based on genetic markers not originating from blood cells of its dam supported a parentage verification conclusion.
Cerasoli F, Podaliri Vulpiani M, Saluti G, Conte A, Ricci M, Savini G, D'Alterio N.Horses have always been animals used for companionship, work, transportation, and performance purposes over the history of humanity; there are different ways of managing horses, but studies on how horse welfare is influenced by different activities and managements are scanty. Understanding how the management, the environment, and the different uses of horses can affect the level of stress and well-being is important not only for people associated with horses. Three groups of horses with different management, environments, and activities were selected: (1) stabled horses ridden frequently, (2) ...
The measure of hair cortisol concentration (HCC) is becoming an emerging approach to monitor mid-/long-term stress in animals, so it is more and more important to develop accurate and reliable methods. In the light of this, the aim of the present study was to compare mane HCCs of 47 horses with different managements, by means of an immunoassay (ELISA) and liquid chromatography coupled to hybrid high-resolution mass spectrometry (LC-HRMS/MS). After the washing step, the ground hair was extracted with methanol. The extract was evaporated and redissolved in two different aqueous solutions, depend...
Cymbaluk NF.Housing temperature effects on growth, feed utilization and feed digestion of 12, 7-mo-old Standardbred colts were evaluated for 22 wk beginning in late November. Colts were assigned to one of two treatments: housed in a barn heated at 10 degrees C (warm) or housed in a barn with no external heat supply (cold). All horses were allowed outdoors for 4 h daily. Mean temperatures of the warm and cold barn from November to April were 10.9 +/- .66 and -5.2 +/- 1.72 degrees C, respectively. Hair coat weight of cold-housed colts was 1.4- to twofold (P less than .05) that of warm-housed colts from Dece...
Kwok KY, Choi TLS, Kwok WH, Wong JKY, Wan TSM.Anabolic and androgenic steroids (AASs) are a class of prohibited substances banned in horseracing at all times. The common approach for controlling the misuse of AASs in equine sports is by detecting the presence of AASs and/or their metabolites in urine and blood samples using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). This approach, however, often falls short as the duration of effect for many AASs are longer than their detection time in both urine and blood. As a result, there is a high risk that such AASs could escape detection in the...
Wong JKY, Choi TLS, Kwok KY, Lei ENY, Wan TSM.Equine hair is becoming an increasingly popular biological matrix for doping control of horse sports; one of the reasons for this is the significantly longer detection window hair can offer. Hair analysis opens up the opportunity for longitudinal monitoring of drug exposure which would otherwise not be possible with the more traditional and common biological matrices, such as urine and blood. As such, there is a need for more multi-target screening methods covering a broad range of prohibited substances in equine hair at the required sensitivities for equine doping control. This paper describe...
Zahradnik E, Janssen-Weets B, Sander I, Kendzia B, Mitlehner W, May C, Raulf M.Exposure to horses can cause severe allergic reactions in sensitized individuals. The breed, American Bashkir Curly Horse is categorized as hypoallergenic, primarily due to reports of allergic patients experiencing fewer symptoms while handling this special breed. The possible reasons for this phenomenon could be lower allergen production and/or reduced allergen release into the air because of increased sebum content in their skin and hair compared to other breeds. Therefore, the aim of the current study was to compare different horse breeds in relation to allergen content in hair and airborne...
Tomich LM, Pieper JB, Stern AW.Dermoscopy is a noninvasive diagnostic technique that allows visualization of structures of the superficial dermis not visible with the naked eye. Objective: To assess the usefulness and applicability of dermoscopy for evaluation of healthy equine skin. Methods: Twelve healthy horses from a research herd. Methods: Five regions (cheek, lateral neck, dorsum, flank and abdomen) were examined with contact dermoscopy using both nonpolarized and polarized light at both 17-fold and 24-fold magnification. These findings were compared to histological features of skin biopsies cut both longitudinally an...
Gray BP, Viljanto M, Bright J, Pearce C, Maynard S.The detection of the abuse of anabolic steroids in equine sport is complicated by the endogenous nature of some of the abused steroids, such as testosterone and nandrolone. These steroids are commonly administered as intramuscular injections of esterified forms of the steroid, which prolongs their effects and improves bioavailability over oral dosing. The successful detection of an intact anabolic steroid ester therefore provides unequivocal proof of an illegal administration, as esterified forms are not found endogenously. Detection of intact anabolic steroid esters is possible in plasma samp...
Schlupp A, Anielski P, Thieme D, Müller RK, Meyer H, Ellendorff F.The beta2-agonist clenbuterol is commonly administered for therapeutic purposes in the horse, but its use an an anabolic agent is illegal. Clenbuterol can be detected in blood and urine for a relatively short period after administration and detection in hair could enhance the analytical range and be used to determine the history of clenbuterol application. Objective: That detection in mane or tail hair is possible over an extended period. Methods: Four horses received 0.8 microg clenbuterol hydrochloride/kg bwt b.i.d. for 10 days. Four other horses were used as untreated controls. Blood, urine...
Kalashnikov V, Zajcev A, Atroshchenko M, Miroshnikov S, Frolov A, Zav'yalov O, Kalinkova L, Kalashnikova T.A study on the Russian trotting breeds was conducted to assess the impact of horses' sporting results and the degree of accumulation of chemical elements in the hair. In the first phase of the research, the elemental composition of the mane hair of trotter horses (n = 215) was studied. Based on these studies, percentile intervals for the distribution of concentrations of chemical elements in the hair have been established, and the values of 25 and 75 percentile adopted as a "physiological standard" have been defined. In the second stage of the research into clinically healthy Russian trott...
Boyer S, Garcia P, Popot MA, Steiner V, Lesieur M.A sensitive and specific method has been developed to detect semi-quantitatively testosterone in horse hair samples. The method involved a washing step with sodium dodecylsulfate aqueous solution. The mane and tail hair samples (100mg) were dissolved in 1 mL of sodium hydroxide for 15 min at 95 degrees C in the presence of d3-boldenone used as internal standard. The next three steps involved diethyl ether extraction and a solid phase extraction on Isolute C18 (EC) cartridges eluted with methanol. The residue was derivatized by adding 100 microL of acetonitrile and 30 microL of PFPA then incuba...
Dunnett M, Lees P.Analysis of human hair for drug residues is being used increasingly as a diagnostic tool in the investigation of drug use and abuse. Hair analysis is complementary to urine/blood testing in that it can provide an extensive historical record of drug use, is noninvasive, impersonal and can facilitate retesting. However, the technique has not been studied in horses. Objective: That the systemic administration of drugs in horses could be identified by the detection of drug residues in hair. Objective: To evaluate hair analysis as a potential retrospective diagnostic test for drug administration in...
Ahmed YA, Ali S, Ghallab A.Animal hair examination at a criminal scene may provide valuable information in forensic investigations. However, local reference databases for animal hair identification are rare. In the present study, we provide differential histological analysis of hair of some domestic animals in Upper Egypt. For this purpose, guard hair of large ruminants (buffalo, camel and cow), small ruminants (sheep and goat), equine (horse and donkey) and canine (dog and cat) were collected and comparative analysis was performed by light microscopy. Based on the hair cuticle scale pattern, type and diameter of the me...
Olvera-Maneu S, Carbajal A, Gardela J, Lopez-Bejar M.The monitoring of stress physiology includes studying a wide range of endocrinological mechanisms, which can be assessed using multiple tissue samples. This study aimed to evaluate the seasonal variations of hair C, T and DHEA-S in horses for a whole year, as well as to assess the variations between seasons of C/DHEA-S and T/C ratios as a retrospective measure of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axis activity. Ten pure-breed Menorca stallions were included in the study. The hair samples were collected approximately every two months following the shave-resha...
Choi TLS, Kwok KY, Kwok WH, Tsoi YYK, Wong JKY, Wan TSM.Anabolic and androgenic steroids (AAS) are banned substances in both human and equine sports. They are often administered intramuscularly to horses in esterified forms for the purpose of extending their time of action. The authors' laboratory has previously reported an UHPLC/HRMS method using quadrupole-Orbitrap mass spectrometer in full scan and parallel reaction monitoring (PRM) mode for the detection of 48 AAS and/or their esters in horse hair. However, two injections were required due to the long duty cycle time. In this paper, an UHPLC/HRMS method using multiplexed targeted MS mode was de...
Asano K, Suzuki K, Chiba M, Sera K, Asano R, Sakai T.The concentrations of 28 elements (Al, Br, Ca, Cl, Co, Cu, Cr, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Se, Si, Sr, Ti, V, Y, and Zn) were measured in mane hair by the particle-induced X-ray emission method. Except for Br, Cl, K, S, and P, the trace element concentrations in mane hair of horses are similar to literature values for human hair. The values obtained are not dependent on the horse's age, breed, and sex and could be used as reference values in the assessment of diseases and nutritional status in equines.
Meyer W, Neurand K.Scanning electron microscopy (SEM) demonstrates efficiently species-specific differences of hairy skin (integumentum commune) of domestic mammals (pig, cat, dog, horse, cattle, sheep, goat). This technique is very helpful in characterizing the typical structural features of the epidermal layers, the arrangement of the collagen fibre bundles and the elastic fibre network in the dermis, the external and internal construction of hair follicles and hair shafts, and the functional development of skin glands. It is also possible to observe certain domestication effects, especially where the hair coa...
