Icelandic Horses are a distinct breed known for their unique characteristics and adaptability to harsh environments. Originating from Iceland, these horses are typically small yet sturdy, with a thick coat that provides insulation against cold climates. They are renowned for their five gaits, which include the traditional walk, trot, and canter, as well as two additional gaits: the tölt and the flying pace. These gaits contribute to their smooth ride and versatility. This page compiles peer-reviewed research studies and scholarly articles that explore the genetic traits, physiology, and behavioral aspects of Icelandic Horses, as well as their role in equine culture and management practices.
Schurink A, Wolc A, Ducro BJ, Frankena K, Garrick DJ, Dekkers JC, van Arendonk JA.Insect bite hypersensitivity is a common allergic disease in horse populations worldwide. Insect bite hypersensitivity is affected by both environmental and genetic factors. However, little is known about genes contributing to the genetic variance associated with insect bite hypersensitivity. Therefore, the aim of our study was to identify and quantify genomic associations with insect bite hypersensitivity in Shetland pony mares and Icelandic horses in the Netherlands. Methods: Data on 200 Shetland pony mares and 146 Icelandic horses were collected according to a matched case-control design. C...
Thorsteinsdóttir L, Torfason EG, Torsteinsdóttir S, Svansson V.The horse population in Iceland is a special breed, isolated from other equines for at least one thousand years. This provides an exceptional opportunity to investigate old and new pathogens in a genetically closed herd. Both types of equine gammaherpesviruses, EHV-2 and EHV-5, are common in Iceland. Genetic variation was examined by sequencing four genes, glycoprotein B (gB), glycoprotein H (gH), DNA polymerase and DNA terminase for 12 Icelandic and seven foreign EHV-2 strains. One Icelandic virus isolate, gEHV-Dv, induced syncytium formation, an uncharacteristic cytopathy for EHV-2 in equine...
Söder J, Bröjer JT, Nostell KE.Systemic hypertension is a prominent feature in humans with metabolic syndrome (MS) and this is partly caused by an enhanced endothelin-1 (ET-1) mediated vasoconstriction. There are indications that systemic hypertension might be a feature in equine metabolic syndrome (EMS) but if ET-1 is involved in the development of hypertension in horses is not known. Increased levels of cortisol have also been found in humans with MS but there are no reports of this in horses. Before blood pressure, plasma ET-1 and serum cortisol can be evaluated in horses with EMS, it is necessary to investigate the inte...
Hoffmann G, Bentke A, Rose-Meierhöfer S, Berg W, Mazetti P, Hardarson GH.Horses are often stabled in individual boxes, a method that does not meet their natural needs and may cause psychical and musculoskeletal diseases. This problem is particularly evident in Iceland, where horses often spend the long winter periods in cramped boxes. The aim of this study was to analyze the suitability of a group housing system in Iceland, but the results are also applicable to horses of other regions. Eight Icelandic horses were observed in an active stable system, and their behavior and time budget were recorded. Movement and lying behavior were studied with ALT (Activity, Lying...
Dicht S, Del Chicca F, Fürst A.Ectopic teeth occur because of failure of the first branchial cleft to close during development and are found mostly in young horses. Such dentigerous cysts are often located at the base of the ear, forming a notable swelling with a fistula, as it was the case with the two year old Iceland mare «Runa». In order to confirm the diagnosis, x-ray images were taken, which is also necessary to locate the ectopic tooth correctly. While operating, the whole cystic membrane should be removed and it is important to prevent adjacent nerves and blood vessels from damage. Prognosis for complete healing a...
Eydal M, Bambir SH, Sigurdarson S, Gunnarsson E, Svansson V, Fridriksson S, Benediktsson ET, Sigurdardóttir ÓG.Opportunistic infections with the free living nematode Halicephalobus gingivalis are infrequently reported in horses but the cases are widespread geographically. The nematodes are believed to penetrate wounds and subsequently reproduce within the host tissues. This paper reports two cases of a fatal disease in stallions of the Icelandic breed in Iceland. Case 1: a stallion, which sustained injuries to the mouth after an accident, developed severe neurological signs and had to be euthanatized. Histological examination revealed mild inflammation and malacia in the cerebellum associated with the ...
Campana MG, Stock F, Barrett E, Benecke N, Barker GW, Seetah K, Bower MA.Despite the Icelandic horse enjoying great popularity worldwide, the breed's gene pool is small. This is because of a millennium of isolation on Iceland, population crashes caused by natural disasters and selective breeding. Populations with small effective population sizes are considered to be more at risk of selection pressures such as disease and environmental change. By analysing historic and modern mitochondrial DNA sequences and nuclear coat colour genes, we examined real-time population dynamics in the Icelandic horse over the last 150 years. Despite the small gene pool of this breed, w...
Albertsdóttir E, Arnason T, Eriksson S, Sigurdsson A, Fikse WF.The genetic evaluation of Icelandic horses is currently based on results from breeding field tests of riding ability and conformation. The effect of integrating competition traits and/or test status into the genetic evaluation was studied concerning estimation bias, predictive ability, accuracy, correlations between breeding values and ranking of sires. Breeding field test data included 19 954 records from horses assessed in 11 countries during 1994-2008. Competition data included 44 160 records from 7687 horses competing in Iceland and Sweden in 1998-2008. Test status was defined as attendanc...
Andersson LS, Swinburne JE, Meadows JR, Broström H, Eriksson S, Fikse WF, Frey R, Sundquist M, Tseng CT, Mikko S, Lindgren G.Insect bite hypersensitivity (IBH) is a chronic allergic dermatitis common in horses. Affected horses mainly react against antigens present in the saliva from the biting midges, Culicoides ssp, and occasionally black flies, Simulium ssp. Because of this insect dependency, the disease is clearly seasonal and prevalence varies between geographical locations. For two distinct horse breeds, we genotyped four microsatellite markers positioned within the MHC class II region and sequenced the highly polymorphic exons two from DRA and DRB3, respectively. Initially, 94 IBH-affected and 93 unaffected Sw...
Lorange JB.WorldFengur is the database that contains and functions as the studbook of origin of the Icelandic horse. Only pure-bred Icelandic horses, whose ancestry can be traced back to Iceland entirely, may be registered into WorldFengur. The WorldFengur project is a joint effort by the FAIC (Farmers Association of Iceland) and FEIF (International Federation of Icelandic Horse Associations) to construct an official and central database on horses of Icelandic origin located all over the world. It is used in this capacity in 19 countries so far; the number of data stored in the WorldFengur database has i...
Hamza E, Steinbach F, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis caused by bites of midges from the genus Culicoides. We have shown previously that peripheral blood mononuclear cells (PBMC) from IBH-affected horses produce higher levels of IL-4 and lower levels of IL-10 and TGF-β1 than those from healthy horses, suggesting that IBH is associated with a reduced regulatory immune response. FoxP3 is a crucial marker of regulatory T cells (Tregs). Here we have determined the proportion of CD4(+)CD25(+)FoxP3(+) T cells by flow cytometry in PBMC directly after isolation or after stimulation with Cu...
Rumpler B, Riha A, Licka T, Kotschwar A, Peham C.Weight boots are commonly used for Icelandic horses to increase the height of the flight arc of the forelimbs in toelt. Objective: To show the influence of weights and toelting speed on the height of the swing phase. Methods: Eight Icelandic horses (mean ± s.d. 12 ± 3 years old, 369 ± 46 kg) were used. Reflecting makers were placed on the dorsal side of each hoof. The motion was collected with a kinematic system (10 cameras, 120 Hz sample rate, 1.3 Mpixels resolution). The horses were ridden in toelt by 2 experienced riders on a treadmill at 2 different speeds (2.96 m/s ± 0.30 and 4.10 m/s...
Andersson LS, Axelsson J, Dubielzig RR, Lindgren G, Ekesten B.Multiple congenital ocular anomalies (MCOA) syndrome is a hereditary congenital eye defect that was first described in Silver colored Rocky Mountain horses. The mutation causing this disease is located within a defined chromosomal interval, which also contains the gene and mutation that is associated with the Silver coat color (PMEL17, exon 11). Horses that are homozygous for the disease-causing allele have multiple defects (MCOA-phenotype), whilst the heterozygous horses predominantly have cysts of the iris, ciliary body or retina (Cyst-phenotype). It has been argued that these ocular defects...
Albertsdóttir E, Eriksson S, Sigurdsson Á, Árnason T.Genetic evaluation of Icelandic horses is currently based on results from breeding field tests where riding ability and conformation of the horses are evaluated over the course of 1-2 days. Only a small part of registered horses attend these field tests, and it can be assumed that these are not a random sample of the population. In this study, the trait test status was introduced, describing whether a horse was assessed in a breeding field test. This trait was analysed to find out whether it has a genetic variation and how it correlates genetically to other traits in the breeding goal. Breedin...
Boehart S, Arndt G, Rindermann G, Gmachl M, Carstanjen B.To obtain morphometric values for the superficial digital flexor tendon, deep digital flexor tendon, accessory ligament of the deep digital flexor muscle, and suspensory ligament in the palmar metacarpal region of Icelandic Horses. Methods: 50 nonlame Icelandic Horses in training. Methods: Horses included 2 stallions, 30 geldings, and 18 mares from 4 to 20 years of age with a body mass index from 149.1 to 250.11 kg/m2. Transverse ultrasonographic images were obtained with an 8- to 10-MHz linear transducer and a standoff pad. In both forelimbs, the cross-sectional area, circumference, dorsopalm...
Heimann M, Janda J, Sigurdardottir OG, Svansson V, Klukowska J, von Tscharner C, Doherr M, Broström H, Andersson LS, Einarsson S, Marti E....Equine insect bite hypersensitivity (IBH) is a seasonally recurrent, pruritic skin disorder caused by an IgE-mediated reaction to salivary proteins of biting flies, predominantly of the genus Culicoides. The aim of this study was to define T cell subsets and cytokine profile in the skin of IBH-affected Icelandic horses with particular focus on the balance between T helper (Th) 1, Th2 and T regulatory (Treg) cells. Distribution and number of CD4+, CD8+ and Forkhead box P3 (FoxP3)+ T cells were characterized by immunohistochemical staining in lesional and non-lesional skin of moderately and seve...
Jensen RB, Brokner C, Knudsen KE, Tauson AH.Four Icelandic (ICE) and four Danish Warmblood (DW) horses were used in a crossover study with two treatments to investigate the effect of breed and the effect of stage of maturity of haylage on the apparent total tract digestibility (ATTD) of a diet consisting of sugar beet pulp, black oats and haylage early or late cut. Fibre was analysed as crude fibre (CF), acid detergent fibre (ADF), neutral detergent fibre (NDF) and dietary fibre (DF = non-starch polysaccharides (NSP) plus lignin). In haylage all analysed fibre fractions increased with advancing stage of maturity, with the cell wall comp...
Ragnarsson S, Jansson A.The aim of the present study was to compare digestibility and metabolic response in Icelandic and Standardbred horses fed two grass haylages harvested at different stages of maturity. Six horses of each breed were used in a 24-day change-over design. A total collection of faeces was made on days 15-17 and 22-24. Blood samples were collected on day 24 of each period and analysed for total plasma protein (TPP), plasma urea, non-esterified fatty acids, cortisol and insulin concentration. There were no differences in digestibility coefficients of crude protein, neutral detergent fibre or energy be...
Thorsteinsdóttir L, Torfason EG, Torsteinsdóttir S, Svansson V.Horses are hosts to 2 types of gammaherpesviruses, Equid herpesvirus 2 and 5 (EHV-2 and EHV-5, respectively). Both EHV-2 and EHV-5 are common in horses in Iceland. An Icelandic EHV-5 isolate was recovered by sequential culture in primary fetal horse kidney and rabbit kidney cells. Glycoprotein B, glycoprotein H, and DNA terminase genes of the isolate were fully sequenced, and the DNA polymerase gene was partly sequenced. To date, the glycoprotein B gene of EHV-5 was the only gene that has been reported to be completely sequenced in addition to small parts of the glycoprotein H, DNA polymerase,...
Ragnarsson S, Lindberg JE.Eight mature Icelandic geldings were used in an experiment arranged as a change-over design to evaluate the effect of feeding level on the digestibility of a high-energy haylage-only diet. The horses were fed a low feeding level 10.7 g dry matter (DM)/kg body weight (BW) (maintenance) and a high feeding level 18.1 g DM/kg BW (1.5 × maintenance) during two 23 days experimental periods. Total collection of faeces was performed for 6 days at the end of each period to determine the coefficient of total tract apparent digestibility (CTTAD). The CTTAD for DM, organic matter, neutral detergent fibre...
Hallamaa RE.Summer eczema, allergic dermatitis of the horse, was studied on 275 affected horses in Finland in 1997-2007. Features of the horses, clinical signs of the disease and owners' opinions of aggravating factors were recorded. Differences, especially, between two of the native Scandinavian horse breeds, the Finnhorse and the Icelandic horse, were evaluated. The study was based on clinical examination and information from the owners. Of the horses, 50% were Finnhorses, 26% Icelandic horses and 24% consisted of different breeds of ponies and other horses. Of the Finnhorses, 76% had summer eczema by t...
Hamza E, Torsteinsdottir S, Eydal M, Frey CF, Mirkovitch J, Brcic M, Wagner B, Wilson AD, Jungi TW, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis of horses caused by bites of Culicoides spp. IBH does not occur in Iceland where Culicoides are absent. However, following importation into continental Europe where Culicoides are present, >or=50% of Icelandic horses (1st generation) develop IBH but
Haase B, Brooks SA, Tozaki T, Burger D, Poncet PA, Rieder S, Hasegawa T, Penedo C, Leeb T.White coat colour in horses is inherited as a monogenic autosomal dominant trait showing a variable expression of coat depigmentation. Mutations in the KIT gene have previously been shown to cause white coat colour phenotypes in pigs, mice and humans. We recently also demonstrated that four independent mutations in the equine KIT gene are responsible for the dominant white coat colour phenotype in various horse breeds. We have now analysed additional horse families segregating for white coat colour phenotypes and report seven new KIT mutations in independent Thoroughbred, Icelandic Horse, Germ...
Svansson V, Roelse M, Olafsdóttir G, Thorsteinsdóttir L, Torfason EG, Torsteinsdóttir S.Horses are hosts to two types of gammaherpesviruses, equine herpes virus (EHV) 2 and 5. While EHV-2 is ubiquitous in adult horses, EHV-5 has been less frequently described. Due to strong serological cross-reactivity, EHV-2 and -5 cannot be discriminated in broad spectrum antibody tests and are thus commonly referred to as gamma-EHV. Total IgG and IgG subclass response against gamma-EHV were determined in serum from 41 healthy Icelandic horses, thereof 20 adults, 10 foals aged 10 months, and 11 foals aged 1-4 months. Additionally, in 10 of the adult horses, interferon (IFN)-gamma and interleuki...
Brøkner C, Nørgaard P, Hansen HH.The ingestive and post-digestion effect of a blend of special essential oil compounds (EO) on eating, chewing and faecal parameters were measured in horses. Ingestive effects appear after no adaptation. Post-digestion effects appear after adaptation. Six Icelandic horses were assigned to two groups in a Latin Square subplot design with EO treatments to four different roughage types and four different concentrates. The horses were fed four different roughage meals and two different concentrate meals on each of the four sampling days. Eating time and saliva were observed during meals. Jaw moveme...
Marti E, Ehrensperger F, Burger D, Ousey J, Day MJ, Wilson AD.Immunoglobulin E (IgE) mediates the immune response to parasites, but can also cause allergies. In humans maternal IgE is not transferred to cord blood and high levels of cord blood IgE are associated with subsequent allergy. In horses, both maternal IgG and IgE are transferred via colostrum; the IgE levels in the mare's serum, the colostrum and the foal's serum are correlated but the consequences of IgE transfer to foals are not known. By about 6 weeks of age the levels of IgE in foal serum have dropped to a nadir, at 6 months of age the level of IgE has risen only very slightly and is no lon...
Marti E, Gerber V, Wilson AD, Lavoie JP, Horohov D, Crameri R, Lunn DP, Antczak D, Björnsdóttir S, Björnsdóttir TS, Cunningham F, Dérer M....Allergic diseases occur in most mammals, although some species such as humans, dogs and horses seem to be more prone to develop allergies than others. In horses, insect bite hypersensitivity (IBH), an allergic dermatitis caused by bites of midges, and recurrent airway obstruction (RAO), a hyperreactivity to stable born dust and allergens, are the two most prevalent allergic diseases. Allergic diseases involve the interaction of three major factors: (i) genetic constitution, (ii) exposure to allergens, and (iii) a dysregulation of the immune response determined by (i) and (ii). However, other e...
Starke SD, Robilliard JJ, Weller R, Wilson AM, Pfau T.Walking and running are two mechanisms for minimizing energy expenditure during terrestrial locomotion. Duty factor, dimensionless speed, existence of an aerial phase, percentage recovery (PR) or phase shift of mechanical energy and shape of the vertical ground reaction force profile have been used to discriminate between walking and running. Although these criteria work well for the classification of most quadrupedal gaits, they result in conflicting evidence for some gaits, such as the tölt (a symmetrical, four-beat gait used by Icelandic horses). We use established pattern recognition meth...
Lorange JB.WorldFengur is the database that contains and functions as the studbook of origin of the Icelandic horse. Only pure-bred Icelandic horses, whose ancestry can be traced back to Iceland entirely, may be registered into WorldFengur. The WorldFengur project is a joint effort by the FAIC (Farmers Association of Iceland) and FEIF (International Federation of Icelandic Horse Associations) to construct an official and central database on horses of Icelandic origin located all over the world. It is used in this capacity in 19 countries so far; the number of data stored in the WorldFengur database has i...
Olstad K, Ekman S, Björnsdóttir S, Fjordbakk CT, Hansson K, Sigurdsson SF, Ley CJ.Recently, the central and third tarsal bones of 23 equine fetuses and foals were examined using micro-computed tomography. Radiological changes, including incomplete ossification and focal ossification defects interpreted as osteochondrosis, were detected in 16 of 23 cases. The geometry of the osteochondrosis defects suggested they were the result of vascular failure, but this requires histological confirmation. The study aim was to examine central and third tarsal bones from the 16 cases and to describe the tissues present, cartilage canals, and lesions, including suspected osteochondrosis le...
Jansson A, Stéfansdóttir GJ, Ragnarsson S.This study investigated the variation in plasma insulin concentration (PIC) in a group of Icelandic horses in training, considered to be healthy and examined possible relationships between PIC and gender, age, body size, body condition score and management factors such as feed allowance and subjective level of fitness. Results: Plasma insulin concentration ranged from 0.2 to 13.9 mU/l, body condition score from 2.3 to 4.0 and concentrate allowance from 0 to 4 kg. There was a significant effect of concentrate allowance (P = 0.0007) and body condition score (P = 0.004) on PIC. For every 1...
Rørvang MV, Ničová K, Sassner H, Nawroth C.Many frameworks have assessed the ultimate and ontogenetic underpinnings in the development of object permanence, but less is known about whether individual characteristics, such as sex or training level, as well as proximate factors, such as arousal or emotional state, affect performance in these tasks. The current study investigated horses' performance in visible and invisible displacement tasks and assessed whether specific ontogenetic, behavioral, and physiological factors were associated with performance. The study included 39 Icelandic horses aged 2-25 years, of varying training levels. ...
Hallamaa RE.Summer eczema, allergic dermatitis of the horse, was studied on 275 affected horses in Finland in 1997-2007. Features of the horses, clinical signs of the disease and owners' opinions of aggravating factors were recorded. Differences, especially, between two of the native Scandinavian horse breeds, the Finnhorse and the Icelandic horse, were evaluated. The study was based on clinical examination and information from the owners. Of the horses, 50% were Finnhorses, 26% Icelandic horses and 24% consisted of different breeds of ponies and other horses. Of the Finnhorses, 76% had summer eczema by t...
Schurink A, van der Meide NM, Savelkoul HF, Ducro BJ, Tijhaar E.Insect bite hypersensitivity (IBH) is a common allergic skin disease in horses, caused by biting insects of the Culicoides spp. In The Netherlands, Culicoides spp. of the Obsoletus complex are the most important midges involved in IBH. The aim of the present study was to identify and quantify associations between several endogenous (host) and exogenous (environmental) factors and immunoglobulin E (IgE) reactivity against Obsoletus complex-derived whole body extract or seven recombinant allergens, measured by ELISA. Data from 143 Icelandic horses and 177 Shetland ponies were analysed using mult...
Rumpler B, Riha A, Licka T, Kotschwar A, Peham C.Weight boots are commonly used for Icelandic horses to increase the height of the flight arc of the forelimbs in toelt. Objective: To show the influence of weights and toelting speed on the height of the swing phase. Methods: Eight Icelandic horses (mean ± s.d. 12 ± 3 years old, 369 ± 46 kg) were used. Reflecting makers were placed on the dorsal side of each hoof. The motion was collected with a kinematic system (10 cameras, 120 Hz sample rate, 1.3 Mpixels resolution). The horses were ridden in toelt by 2 experienced riders on a treadmill at 2 different speeds (2.96 m/s ± 0.30 and 4.10 m/s...
Peters M, Grafen J, Kuhnen C, Wohlsein P.A 13-year-old Icelandic crossbred horse was presented with headshaking and progressive impairment of chewing. A slowly growing mass was identified in the anterior maxilla. This was associated with lysis of the alveolar bone and the roots of the incisors and there were nodular proliferations affecting the nasal septum and conchae. There was no response to chemotherapy and so the horse was humanely destroyed. Based on morphological, immunohistochemical and ultrastructural findings the mass was classified as a malignant glomus tumour with multifocal vascular spaces and additional neuroendocrine d...
Boehart S, Arndt G, Rindermann G, Gmachl M, Carstanjen B.To obtain morphometric values for the superficial digital flexor tendon, deep digital flexor tendon, accessory ligament of the deep digital flexor muscle, and suspensory ligament in the palmar metacarpal region of Icelandic Horses. Methods: 50 nonlame Icelandic Horses in training. Methods: Horses included 2 stallions, 30 geldings, and 18 mares from 4 to 20 years of age with a body mass index from 149.1 to 250.11 kg/m2. Transverse ultrasonographic images were obtained with an 8- to 10-MHz linear transducer and a standoff pad. In both forelimbs, the cross-sectional area, circumference, dorsopalm...
Herbrecht V, Waldern NM, Mikkelsen SE, Kjaer M, Dittmann MT, Wiestner T, Weishaupt MA.In order to improve the four-beat-rhythm and forelimb action of the tölt in Icelandic horses (ICE), special shoeing techniques are applied particularly in the front hooves by increasing hoof length and height, or by adding weight to the distal limbs. Although regulations limit dorsal hoof wall length (LDHW) in competition ICE, their shoeing often deviates from a biomechanically optimal distal limb conformation. This study aimed to qualitatively and quantitatively describe current shoeing practices of ICE in competition. Moreover, the influence of LDHW on the occurrence of deviations from a st...
Henselek Y, Fischer J, Schloegl C.The ability to understand the relation between quantities has been documented in a wide range of species. Such quantity discrimination competences are commonly demonstrated by a choice of the larger quantity or numerosity in a two-choice task. However, despite their overall success, many subjects commit a surprisingly large number of errors even in simple discriminations such as 1 vs. 3. Recently, it had been suggested that this is a result of the testing procedure. When monkeys could choose between different quantities of edible rewards, they showed low-level success. If, however, they chose ...
Jensen RB, Brokner C, Knudsen KE, Tauson AH.Four Icelandic (ICE) and four Danish Warmblood (DW) horses were used in a crossover study with two treatments to investigate the effect of breed and the effect of stage of maturity of haylage on the apparent total tract digestibility (ATTD) of a diet consisting of sugar beet pulp, black oats and haylage early or late cut. Fibre was analysed as crude fibre (CF), acid detergent fibre (ADF), neutral detergent fibre (NDF) and dietary fibre (DF = non-starch polysaccharides (NSP) plus lignin). In haylage all analysed fibre fractions increased with advancing stage of maturity, with the cell wall comp...
Söder J, Bröjer JT, Nostell KE.Systemic hypertension is a prominent feature in humans with metabolic syndrome (MS) and this is partly caused by an enhanced endothelin-1 (ET-1) mediated vasoconstriction. There are indications that systemic hypertension might be a feature in equine metabolic syndrome (EMS) but if ET-1 is involved in the development of hypertension in horses is not known. Increased levels of cortisol have also been found in humans with MS but there are no reports of this in horses. Before blood pressure, plasma ET-1 and serum cortisol can be evaluated in horses with EMS, it is necessary to investigate the inte...
Björnsdóttir S, Arnason T, Lord P.A survival analysis was used to compare the culling rate of Icelandic horses due to the presence of radiographic and clinical signs of bone spavin. A follow-up study of 508 horses from a survey five years earlier was performed. In the original survey 46% of the horses had radiographic signs of bone spavin (RS) and/or lameness after flexion test of the tarsus. The horse owners were interviewed by telephone. The owners were asked if the horses were still used for riding and if not, they were regarded as culled. The owners were then asked when and why the horses were culled. During the 5 years, 9...
Luthersson N, Ýr Þorgrímsdóttir Ú, Harris PA, Parkins T, Bennet ED.To investigate equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) in Icelandic horses moving from pasture into training. 81 horses (median age, 3 years; interquartile range, 1 year) from 10 farms representing 4 different Icelandic regions. Initial gastroscopy was undertaken within 2 weeks of moving from pasture into a training establishment. A total of 71 horses underwent endoscopic examination again 8 weeks later. Various management and behavioral factors were assessed through face-to-face questionnaires with the owners or trainers. Multivariable logistic regre...
Waldern NM, Wiestner T, Ramseier LC, Weishaupt MA.To compare gait mechanics and limb loading in Icelandic horses tölting and trotting at equal speeds and estimate their impact on orthopedic health. Methods: 12 orthopedically normal Icelandic horses. PROCEDURES Kinetic and kinematic gait variables were simultaneously recorded as each horse was ridden at a tölt and trot on an instrumented treadmill at 3.4 m/s and 3.9 m/s. Differences between gaits were tested via 1-factor repeated-measures ANOVA. Results: Horses had a higher stride rate and lower stride impulses at a tölt than at a trot. For forelimbs at a tölt, shorter relative stance dura...
Harðardóttir H, Murison PJ, Blissitt K, Olason S, Clutton RE.Ketamine at 2.2 mg/kg given i.v. is often used to induce anaesthesia for surgical procedures in horses under field conditions. Commonly, additional doses are needed to complete the surgery. We hypothesised that surgical conditions would be improved when 5 mg/kg of ketamine was used to induce anaesthesia, while induction and recovery qualities would not differ from those when 2.2 mg/kg ketamine was used. Objective: To compare the anaesthetic effects of two ketamine doses (5 and 2.2 mg/kg) during field anaesthesia for castration of horses. Methods: Prospective, randomised, blinded, clinical stud...
Hesselholt M.By means of isoimmunizations and heteroimmunizations 10 equine blood typing reagents were isolated. The specific antibodies were complete agglutinins, which were used in the direct agglutination test in saline medium. The reagents were designated A2, C, D, E, G, H, I, K, Da1, and Da2 reagent. Da1 and Da2 are preliminary designations. The data obtained from blood typing of a family material and a population material of Icelandic horses showed that the occurrence of each blood type factor is controlled by a single, dominant gene. The family data tended to show that the blood factors under invest...
Albertsdóttir E, Arnason T, Eriksson S, Sigurdsson A, Fikse WF.The genetic evaluation of Icelandic horses is currently based on results from breeding field tests of riding ability and conformation. The effect of integrating competition traits and/or test status into the genetic evaluation was studied concerning estimation bias, predictive ability, accuracy, correlations between breeding values and ranking of sires. Breeding field test data included 19 954 records from horses assessed in 11 countries during 1994-2008. Competition data included 44 160 records from 7687 horses competing in Iceland and Sweden in 1998-2008. Test status was defined as attendanc...
Sigurdsson SF, Olstad K, Ley CJ, Björnsdóttir S, Griffiths DJ, Fjordbakk CT.Osteochondrosis occurs due to failure of the blood supply to growth cartilage. Osteochondrosis lesions have been identified in small tarsal bones and suggested to cause distal tarsal osteoarthritis; however, it has not been determined whether distal tarsal osteochondrosis lesions were the result of vascular failure. Objective: To perform post-mortem arterial perfusion and micro-computed tomography (CT) of the central (CTB) and third tarsal bones (TIII) of fetuses and foals up to 5 months old, to describe tarsal development and any lesions detected. Methods: Descriptive, nonconsecutive case se...
Althaus H, Müller N, Busato A, Mellor PS, Torsteinsdottir S, Marti E.Insect bite dermal hypersensitivity (IBH) is an allergic dermatitis of horses caused by bites of Culicoides spp. and sometimes Simulium spp. The aim of the investigation presented here was to identify allergens causing IBH. A cDNA library expressing recombinant Culicoides nubeculosus proteins was screened using affinity-purified serum from an IBH-affected horse. Screening of the library resulted in identification of one immunoreactive clone. The sequence of the cDNA insert was determined and revealed a 600 bp insert with an open reading frame coding for a 78 amino acid long protein, called rCu...
Waldern NM, Wiestner T, Ramseier LC, Amport C, Weishaupt MA.Tölt is a symmetric four-beat gait with a speed range extending into that of trot and canter. Specific shoeing methods, such as unnaturally high and long hooves, are used to enforce individual gait predisposition. The aim of this study was to assess the consequences of this shoeing style on loading and movement of the limbs at walk, tölt and trot, and at different velocities. Simultaneous kinetic and kinematic gait analysis was carried out at walk (1.4m/s) and at two tölting and trotting speeds (3.3m/s and 3.9 m/s) on an instrumented treadmill. Thirteen sound Icelandic horses were first mea...
Hack Y, Henriksen ML, Pihl TH, Nielsen RK, Dwyer AE, Bellone RR.Equine recurrent uveitis (ERU) is an autoimmune disease defined by inflammation of the uveal tract of the eye. The cause of ERU is thought to be complex, involving both genetic and environmental factors. The purpose of this study was to investigate potential genetic risk factors for ERU in the Icelandic horse. Fifty-six Icelandic horses (11 affected with ERU and 45 controls) living in Denmark and the USA, eight years or older, were included in the study. A case-control GWAS was performed using the GGP Equine 80K array on the Illumina Infinium HD Beadchip using 40 horses. A mixed linear model a...
Gehlen H, Haubold A, Stadler P.The aim of this study was to establish echocardiographic reference values for healthy Icelandic horses. For this purpose cardiologic examinations were performed on 44 healthy trained and untrained Icelandic horses without known cardiologic or pulmonary disease. The atrial diameter of the trained horses were significantly greater than in the untrained horses and the left ventricular free wall diameter was also higher in the trained than in the untrained horses. These findings confirm that the changes of the heart caused by training which have previously been described by other authors in warmbl...
Satoła A, Łuszczyński J, Petrych W, Satoła K.Knowledge of the body weight of horses permits breeders to provide appropriate feeding and care regimen and allows veterinarians to monitor the animals' health. It is not always possible to perform an accurate measurement of the body weight of horses using horse weighbridges, and therefore, new body weight formulas based on biometric measurements are required. The objective of this study is to develop and validate models for estimating body weight in Icelandic foals using machine learning methods. The study was conducted using 312 data records of body measurements on 24 Icelandic foals (12 col...
Strand E, Össurardóttir S, Wettre KB, Fjordbakk CT.To report clinical findings and performance in horses in which alar fold collapse (AFC) had been diagnosed and surgically treated and to assess form and degree of respiratory obstruction. Methods: Retrospective case series. Methods: Twenty-one standardbreds, 2 coldblooded trotter racehorses, 1 thoroughbred, and 1 Icelandic horse. Methods: Alar fold collapse was diagnosed on the basis of continuous abnormal expiratory flutter noise coinciding with filling of the false nostrils during exercise on a high-speed treadmill that was alleviated by suturing the alar folds (AF) temporarily in a dorsal p...
Björnsdóttir S, Agustsdóttir E, Blomström AL, Oström IL, Berndtsson LT, Svansson V, Wensman JJ.In a stable of eight horses in Northern Iceland, six horses presented with clinical signs, such as ataxia and reduced appetite, leading to euthanasia of one severely affected horse. Serological investigations revealed no evidence of active equine herpes virus type 1 infection, a common source of central nervous system disease in horses, nor equine arteritis virus and West Nile virus. Another neurotropic virus, Borna disease virus, was therefore included in the differential diagnosis list. Results: Serological investigations revealed antibodies against Borna disease virus in four of five horses...
Rørvang MV, Nicova K, Yngvesson J.In spite of a highly developed olfactory apparatus of horses, implying a high adaptive value, research on equine olfaction is sparse. Our limited knowledge on equine olfaction poses a risk that horse behavior does not match human expectations, as horses might react fearful when exposed to certain odors, which humans do not consider as frightening. The benefit of acquiring more knowledge of equine olfaction is therefore twofold; (1) it can aid the understanding of horse behavior and hence reduce the risk of dangerous situations, and (2) there may be unexplored potential of using odors in severa...
Delarocque J, Frers F, Huber K, Jung K, Feige K, Warnken T.Insulin dysregulation (ID) is an equine endocrine disorder, which is often accompanied by obesity and various metabolic perturbations. The relationship between weight variations and fluctuations of the insulin response to oral glucose tests (OGT) as well as the metabolic impact of ID have been described previously. The present study seeks to characterize the concomitant metabolic impact of variations in the insulin response and bodyweight during repeated OGTs using a metabolomics approach. Methods: Nineteen Icelandic horses were subjected to five OGTs over one year and their bodyweight, insuli...
