Male Horses Research Articles

Expression of 11β‐Hydroxysteroid Dehydrogenase Type 1 and Glucocorticoid Receptors in Reproductive Tissue of Male Horses at Different Stages of Sexual Maturity

Glucocorticoids (GCs) as mediators of the stress response may affect Leydig cell function by inhibiting either luteinizing hormone receptor expression or testosterone biosynthesis. The isozymes 11β-hydroxysteroid dehydrogenase (11βHSD) 1 and 11βHSD2 control the intracellular cortisol levels. Little is known about the effects of stress on fertility in the equine. The objective of the present study was to determine the presence and cellular localization of glucocorticoid receptors (GCR) and glucocorticoid-metabolizing enzymes (11βHSD1 and 11βHSD2) in equine epididymal and testicular tissue with special regard to sexual maturation. Testicular and epididymal tissue was collected from 21 healthy stallions, and four age groups were designed: pre-pubertal, young, mature and older horses. Immunohistochemistry (IHC) analysis and quantitative real-time PCR (qRT-PCR) were used. Pre-pubertal horses showed higher testicular gene expression of 11βHSD1, 11βHSD2 and GCR than horses of all other groups (p < 0.05). A positive intranuclear immunoreaction for GCR was seen in epithelial cells of caput, corpus and cauda epididymidis and in Leydig cells. Significant differences (p < 0.05) between age groups occurred. The number of Leydig cells staining positive for GCR was highest in immature stallions (p < 0.05). The enzyme 11βHSD1 was localized in epithelial cells of the caput and corpus epididymidis and in Leydig cells. As determined by enzyme assay, nicotinamide adenine dinucleotide (NAD)-dependant dehydrogenase (oxidation) activity was not detected in testicular tissue from immature stallions but in all other age groups (n = 3 per group). Results of this study suggest a contribution of GCs to maturation of male reproductive tissue in horses. In mature stallions, expression of 11βHSD enzymes and the oxidative 11βHSD activity in Leydig cells and epididymal basal and principal cells suggest a protective role on these tissues contributing to physiological intracellular glucocorticoid concentrations.

Prevalence and persistence of Taylorella asinigenitalis in male donkeys

This study was undertaken to investigate the prevalence of Taylorella asinigenitalis in a subset of the donkey population of Michigan and in other equids on farms on which the organism was identified. Other aims were to further characterize the carrier state in terms of persistence and preferred sites of colonization of T. asinigenitalis in the male donkey as well as determine the genotype of any isolates of the organism. Initial testing of 43 donkeys and 1 mule turned up 4 (9.3%) donkeys culture positive for T. asinigenitalis. The 4 culture-positive donkeys resided on 2 farms accommodating a collective total of 89 equids, of which 23 (25.8%) were confirmed positive for T. asinigenitalis. The positive equid population on the 2 farms comprised 14 (67%) of 21 gelded donkeys, 8 (36.4%) of 22 intact male donkeys, and 1 (25%) of 4 gelded horses. T. asinigenitalis was not isolated from 27 female donkeys, 11 female horses, 2 female mules, 1 male horse, or 1 male mule resident on these premises. Isolations of the bacterium were obtained from a number of male donkeys whenever they were sampled over a span of 33 months; preferential sites of isolation were the urethral fossa (fossa glandis), dorsal diverticulum of the urethral sinus, and terminal urethra. Isolates of T. asinigenitalis from the 23 culture-positive equids comprised 2 genotypes, one identical to the type strain isolated in California in 1997, and the other identical to 2 strains isolated from donkey jacks in Kentucky in 1998.

Eletrocardiografia computadorizada em cavalos Puro Sangue Lusitano submetidos a exercício físico

Foram estudados 24 cavalos atletas hígidos, machos, adultos, da raça Puro Sangue Lusitano, submetidos a esforço físico de trote e galope de rotina do animal, com o objetivo de avaliar a configuração do traçado do eletrocardiograma (ECG) em repouso, mediante eletrocardiografia computadorizada, bem como os efeitos do exercício físico sobre os parâmetros clínicos e eletrocardiográficos destes animais. Foram avaliados exame físico e ritmo cardíaco antes e imediatamente após o exercício físico, assim como as distintas configurações de ondas p e complexos QRS, obtidas ao ECG de repouso. Após o treinamento, ocorreram taquicardia e taquipneia. O ritmo predominante no repouso foi o sinusal e, após o exercício, a taquicardia sinusal. Na morfologia das ondas, encontraram-se quatro configurações distintas para a onda p, e seis para o complexo QRS. Dentre as arritmias cardíacas em repouso, houve uma ocorrência de bloqueio atrioventricular de segundo grau, que desapareceu após exercício. Conclui-se que o traçado do ECG computadorizado de cavalos atletas Puro Sangue Lusitano revela distintas morfologias de ondas p e complexos QRS e baixa ocorrência de arritmias.

Local Anesthesia and Hydro‐Distension to Facilitate Cystic Calculus Removal in Horses

To report a technique for improving surgical access to the bladder for removal of cystic calculi in male horses. Retrospective case series. Geldings (8) with cystic calculi. After catheterization of the bladder through the penis, 100 mL 2% lidocaine hydrochloride solution was instilled. After 10 minutes, the bladder was distended with sterile, warmed Hartmann's solution to a pressure of ≈ 40 cm H(2) O, using gravity feed. This was left in place until abdominal access was gained at surgery, then the fluid siphoned off via the catheter. Calculi were 3-11 cm in diameter (median, 6 cm). Bladder capacity ranged from 1.4 to 2.5 L (median, 1.8 L). Exteriorization time from placing a hand in the abdomen to having the bladder in a surgically accessible position was <5 minutes. The described technique facilitates exteriorization of the bladder for removal of cystic calculi.

Endoscopic‐Assisted Electrohydraulic Shockwave Lithotripsy in Standing Sedated Horses

To report use of transendoscopic electrohydraulic shockwave lithotripsy for fragmentation of urinary calculi in horses. Case series. Male horses (n = 21). Fragmentation of cystic calculi (median, 6 cm diameter; range, 4-11 cm diameter) was achieved by transurethral endoscopy in standing sedated horses using an electrohydraulic shockwave fiber introduced through the biopsy channel of an endoscope. The fiber was advanced until it contacted the calculus. Repeated activation of the fiber was used to disrupt the calculus into fragments <1 cm diameter. Visibility within the bladder was maintained by repeated lavage with saline solution. Complete calculus removal was achieved in 20 horses (95%) with mean total surgical time of 168.6 minutes (range, 45-450). In the 20 horses with single calculi, 1-6 sessions were required to completely fragment the calculus. Except for 1 horse, in which perineal urethrotomy was eventually performed for complete fragment removal, fragments calculi were excreted via the urethra. Postoperative complications included hematuria because of severe mucosal erosion (n = 2), dysuria because of a trapped urethral fragment (2), small amount of urinary debris (1). One horse was euthanatized because of bladder rupture. Complete clearance of calculi and urinary debris was confirmed endoscopically 20 (3-45) days after the last session. Telephone follow-up (mean, 18.8 months; range, 7-24 months) revealed that horses had returned to previous activity levels without recurrence of clinical signs. Transendoscopic electrohydraulic lithotripsy appears to be an effective method for fragmentation of low-density calcium carbonate cystic calculi in male horses.

Prostatic Masses in Geldings: Two Cases

Prostatic masses were detected in two geldings that were presented to our referral hospital for evaluation of dysuria. The masses were detected during transrectal palpation and ultrasonography of the prostate gland and were further evaluated using urethral endoscopy. A 10-year-old gelding underwent intraurethral debulking of the prostatic mass. Histopathological diagnosis was prostatic cystadenoma. The mass regrew within 9 months, and the horse was euthanized due to deteriorating clinical control of urinary continence. In another case, a 12-year-old gelding was scheduled for transurethral debulking; however, the owners decided against treatment and the horse was euthanized due to progression of clinical disease. Postmortem examination revealed the prostate to be nearly completely obliterated by the mass. Histopathological diagnosis was adenocarcinoma incorporated into a spindle cell population of unknown histogenesis. To our knowledge, these represent the first reported cases of equine prostatic cystadenoma and adenocarcinoma. In both horses, referring complaint was dysuria, and identification of the prostatic mass was made on palpation and ultrasonographic examination per rectum. Treatment options for prostatic masses in horses are limited because of the difficulty of obtaining prostatic tissue via biopsy, the surgical inaccessibility of the gland, and the apparent low incidence of occurrence. We have subsequently identified prostatic masses in two additional geldings, both also presenting for dysuria. However, the exact nature of these two apparent prostatic masses has not been definitively diagnosed with histopathological examinations to date. The prostate should be evaluated in male horses presenting for dysuria.

A Survey of Pet-and Non-Pet-Owning Swedish Adolescents: Demographic Differences and Health Issues

ABSTRACTThe aim of this study was to describe the prevalence of pet ownership in adolescents in Sweden and establish whether any gender, age or health-related differences exist between those who own pets and those who do not. In addition, the study aimed to explore the relationships between species of pet, age, gender, and other socio-demographic variables and the perceived importance of pets. Three age groups (13–14 years-old, 15–16 years-old, and 17–18 years-old) of adolescents, resident in a single county in Sweden, were surveyed using the questionnaire “Liv och Hälsa Ung” (“Youth Life and Health”). A total of 8,709 respondents were included in the analysis (pet owners = 5,793; non-pet owners = 2,916). Associations between importance of the pet and demographic variables and general self-rated health were investigated using logistic regression analysis. The prevalence of pet owners in the sample was 65%, and the most common types of pets were, in descending order of popularity, cats, dogs, rodents, fish/reptiles, and horses. Most of the pet owners said their pets were very or quite important to them, for the three age groups (73.1–88.6%). In general, pets were more important for the female respondents. Importance was dependent on type of pet, with male and female dog owners and female horse owners rating their pets as more important than the owners of other species of pet. Respondents who did not own a pet were more physically active than their pet- owning peers. Pet owners with the best self-rated health also attributed the greatest importance to their pet. However, adolescents with pets reported more psychological problems and somatic health aspects than those who did not own pets. This finding calls for further studies to be conducted, with designs allowing causal conclusions to be drawn.

Morphological Observation of a Horseshoe (fused) Kidney and its Vascular Pattern in a Horse

The present study describes the anatomical and microscopic features of a horseshoe kidney that was found in a 7-year-old male horse. The specimen consisted of two kidneys joined at their caudal poles by an isthmus composed of renal parenchyma and situated caudal to the caudal mesenteric artery. Six main renal arteries arose from the aorta and the external iliac arteries and ramified into 21 branches before entering the kidney. A hypoplastic and ectopic left testis, located in the inguinal canal, was observed as an associated anomaly.

Successful Clinical Management of Temporary Blindness In A Horse: A Case Report

Abstrac: Treatment of progressive blindness of both the eyes was attempted in field condition in horse. In this study, a case of equine was presented and since there was constraint of proper diagnosis and treatment, how the case was successfully managed in field condition was projected. After a careful examination, the treatment protocol included Injections of streptopencillin 2.5 g daily twice intramuscularly along with multivitamin injection Hivit daily once for one week and Inj. Melonex was given 10 ml intramuscularly daily for one week was given. The topical and systemic anti-inflammatory medications i.e. Genticyn- HC drops locally and betnesol eye ointment 0.1% w/w (Glaxo) was used 2-3 times a day. With this we could successfully treat the case within a week period. Keyword: Leopard; Immobilization; Xylazine-ketamine; Atepamezole I. Introduction: Uveitis is an immune-mediated disease. Impairment of the normal blood-aqueous barrier in the iris and ciliary body vasculature owing to inflammation is the underlying cause of the clinical signs (Kern, 1987). Uveitis unfortunately is often misdiagnosed as something less severe or in some cases it is totally ignored. It is important that uveitis be diagnosed correctly because lack of or incorrect treatment can have serious consequences (Nelson, 1995). Case presentation: A male horse of age six yrs was brought to veterinary hospital Deorania District Bareilly, with the history of development of progressive blindness of both the eyes. There was no associated history of trauma or accident. Rectal temperature was found to be 103 0 F and the heart rate was 45 per minute. It was reported that the horse was not taking feed properly for the past one week. Due to the limited facilities available in the field only the animal’s faecal examination could be done which was found to be negative for any parasitic ova. II. Clinical examination and treatment On examination of eye carefully it was found that animal had blepherospasms, epiphora, corneal edema, and fibrin clots in the anterior chamber with miosis. Which are the typical signs of acute uveitis. The animal was carefully examined for the reflexes. It was found that animal was having his bilateral vision compromised. The pupillary reflex was found to be present but the animal was unable to walk straight due to blindness. Injections of streptopencillin 2.5 g daily twice was administered intramuscularly along with multivitamin injection Hivit daily once for one week and Inj. melonex was given 10 ml intramuscularly daily for one week. Although diagnosis of the causative agent in this case could not be made due to inadequate facilities but the fact that acute uveitis may be caused due to leptospira infection, which is one of the most common ocular diseases in horses characterized by episodes of active inflammation followed by varying periods of quiescence led us to take a decision on treating the case symptomatically. The topical and systemic anti-inflammatory medications i.e. Genticyn- HC drops locally and betnesol eye ointment 0.1% w/w (Glaxo) was used 2-3 times a day. Injections of meloxicam 15 ml intravenously was given for one week had solved the problem of pain and inflammation and also the corneal edema. Atropine ointment was also used locally which paralyses the iris sphincter and cilliary body musculature. These effects reduce the muscle spasms but along with it a regular history of the defecation was taken to monitor the gut motility which is affected by atropine applied topically also. Injection dexamethasone 10 ml (4mg/ ml) was also given initially for a period of four days intramuscularly. Amazingly it was found that the animal slowly recovered from the compromised vision and started to have a near normal vision within a week period. The treatment was continued for a period of one more week after a gap of another four days.

Linfoma multicêntrico em cavalo: relato de caso

Relatively hemolymphatic tumors are uncommon in horses, but the lymphoma is the most frequent being reported from the early neonatal animals until advanced age. Lymphoma in horses is a disease which differs between animals including clinical signs, illness course, laboratory and pathologic findings. Clinical signs vary depending on tumor location, but the most common are depression, progressive weight loss and lymphadenopathy, may be associated with ventral edema, respiratory distress, fever, anemia, mild colic and diarrhea. Lymphomas are anatomically classified in generalized or multicentric, alimentary or intestinal, mediastinal or thymic and cutaneous. Paraneoplastic syndromes can occur and is usually performed euthanasia by the weakness of the animal. This study is a case report of a male horse sent to the Department of Large Animal Veterinary Hospital of Federal University of Parana with a history and signs of pneumonia, anorexia and progressive weight loss. On physical examination, clinical changes such as tachycardia, tachypnea, lymphadenopathy, submandibular and pre-scapular lymph nodes and ventral edema were present. The blood profile showed hyperfibrinogenemia, neutrophilia and lymphopenia. Abnormal lymph node aspiration biopsy was inconclusive, but suggestive of lymphoma. The animal died 13 days after hospitalization for illnes worsening and necropsy was realized. Later, with the necropsy and histopathological findings, diagnosis of multicentric lymphoma was confirmed.

A Case of Ambiguous External Genitalia in a Thoroughbred Male Horse with the 63,XO/64,XY Mosaic Karyotype

A Thoroughbred colt with ambiguous external genitalia was presented for clinical and histological examinations. The colt had a short penis that faced backward between his hind limbs. The measurements of luteinizing hormone, follicle stimulating hormone, testosterone and ir-inhibin showed a tendency to increase gradually from April. Both the sex-determining region of the Y chromosome and amelogenin gene fragments were detected by the PCR method. A cytogenetic analysis revealed the 63,XO/64,XY mosaic karyotype (ratio 83:17). In autopsy, immature symmetrical subcutaneous testes were found in the inguinal regions. The testes and other accessory sex organs were histologically normal. These results add to our knowledge of chromosomal abnormality and information concerning disorders of sex development in the horse.

Comparative ergoespirometric adaptations to a treadmill exercise test in untrained show Andalusian and Arabian horses

Significant differences exist in the respiratory adaptation to exercise in different equine breeds. This research describes the ergoespirometric response to exercise of Andalusian (AN) and Arabian (A) horses, both selected according to morphological criteria. Thirteen untrained male horses (6 AN and 7 A) performed a treadmill exercise test (TET) with a slope of 6%, with workloads starting from 5 m/s and increasing 1 m/s every 3 min until the horses were not able to keep the required velocity. Tidal volume (TV), respiratory rate, minute ventilation (VE), oxygen uptake (VO2), carbon dioxide production, peak oxygen uptake (VO2peak), respiratory exchange ratio (RER), exercise time to fatigue (ETF) and respiratory aerobic threshold (RAT) were determined. AN horses presented higher TV and VE, whereas respiratory rate, VO2 and VCO2 were lower at the same velocities. RER was similar between breeds. ETF was longer in A horses (556.7 ± 66.5 in AN vs. 607.1 ± 71.1 s in A) and no significant differences were found in RAT (5.50 ± 0.50 in AN vs. 5.86 ± 1.07 m/s in A). In summary, despite the more intense ventilatory response to exercise at the same velocity, AN horses had lower VO2. The AN horse develops a more intense ventilatory response to fixed velocities than the A horse and it could be interesting to clarify the role of the locomotion characteristics in this response.

Standing laparoscopic castration in an equine male pseudohermaphrodite

SummaryThis report describes the surgical anatomy and successful removal of the internal gonads in a 6‐year‐old male pseudohermaphrodite Friesian horse by standing laparoscopy. Gonads could not be identified by physical or ultrasonographic examination and bilateral standing flank laparoscopy revealed the presence of intra‐abdominal gonads suspended from the dorsal aspect of the abdominal cavity by 10–15 cm long vascular pedicles. No evidence of female internal genitalia such as a uterus was found and bilateral gonadectomy was performed laparoscopically. Histological analysis of the excised gonads confirmed the diagnosis of male pseudohermaphroditism. Minor cosmetic surgery of the external genitalia to correct urinary misdirection was successfully performed 3 months after laparoscopic castration. Standing flank laparoscopic examination was excellent for identification and surgical removal of internal genitalia. Standing flank laparoscopy should be considered for inspection and removal of internal genitalia in intersex horses.

Bilateral dentigerous cysts (heterotopic polyodontia) in a yearling Standardbred colt

SummaryThis article describes the occurrence of bilateral dentigerous cysts in a 1‐year‐old entire male Standardbred horse. Computer tomography (CT) with a positive contrast CT fistulogram was used to accurately define the anatomy of the cysts preoperatively. Conventional surgical techniques were used to remove the cysts under general anaesthesia. The CT studies were able to precisely define the margins of the cysts and facilitated uncomplicated surgical excision. Follow‐up examination of the animal revealed excellent cosmesis at the surgical site. Histology was used to confirm the diagnosis of bilateral dentigerous cysts. Preoperative CT studies are invaluable to precisely define the anatomical locations of the dental anomalies associated with dentigerous cysts and thereby allow confident and uncomplicated excision. Dentigerous cysts may occur bilaterally in horses.

A study of patrilineal genetic diversity in Iranian indigenous horse breeds

Autosomal markers and mtDNA have been used in horse phylogenetic studies. These studies display evolutionary events that happened in both sexes or only in females. It is necessary to investigate genetic diversity in Y-specific markers for clarifying contribution of males in horse domestication. The Y chromosome, excluding the pseudoautosomal region, is inherited as a single nonrecombinant unit and, therefore, it warrants that mutational events in patrilines are preserved as single haplotypes. Six Yspecific microsatellites were used to study patrilineal genetic variation in 405 male horses from 8 Iranian native horse breeds, one wild population and an exotic breed. These markers displayed no variation in all populations. The lack of polymorphisms could be as a result of lower contribution of stallions to the gene pools of the domestic horses compared to the mares because a sex bias is towards females due to a special breeding strategy (in which a few selected stallions mate with many mares each), a strong tendency to upgrade many breeds by crossing between champion stallions from particular breeds and mares from different breeds; also due to a bias in the early utilization of male horses as food source, a bias towards stallions in migrations and lack of detailed maps on horse Y chromosome.

The relationship of training milestones with racing success in a population of Standardbred horses in New Zealand

AIM: To investigate the association between attainment of training milestones by 2-year-old horses with racing outcomes in a population of Standardbred racehorses in New Zealand. METHODS: Retrospective records of the 2001/2002-born Standardbred foals were obtained. The three training milestones used were: registered with a trainer, entered in a trial, and competed in a race. The racing outcomes were length of career in years raced and number of race starts, and total earnings. Cox regression analysis was used to assess the association between attainment of the three milestones by 2-year-olds and the number of race starts and years raced. Logistic regression models were used to determine the association between attainment of the milestones by 2-year-olds and the outcomes won and placed in a race. Linear regression was used to model the association between attainment of the milestones by 2-year-olds and annual earnings and total earnings (transformed using Ln (earnings+NZ$100)). RESULTS: Of 3,032 horses in the population, 1,018 (33.6%) registered with a trainer, 609 (20.1%) trialled, and 272 (9.0%) raced as 2-year-olds. Horses that first raced as 2-year-olds had a longer racing career and more race starts than those that that did not race as 2-year-olds (p<0.001); this was also true when starts in the 2-year-olds were omitted from analyses. Horses that were registered with a trainer, trialled or raced as 2-year-olds were more likely to have won or placed in a race than those that did not achieve the milestones as 2-year-olds (p<0.001). Linear regression showed horses that trialled and raced as 2-year-olds had greater total earnings than those that did not, and male horses had a greater total earnings than female horses. CONCLUSION: Only one third the Standardbred racehorses born in 2001/2002 registered with a trainer as 2-year-olds, but the results of this study indicate that horses that began training, trialling, or racing as 2-year-olds had longer and more successful careers than those that did not achieve the milestones as 2-year-olds. Further investigation is required to quantify the management practices of these horses to determine the factors that may be associated with a successful racing career.

Ex vivo spontaneous generation of 19-norandrostenedione and nandrolone detected in equine plasma and urine

19-Norandrostenedione (NAED) and nandrolone are anabolic-androgenic steroids (AASs). Nandrolone was regarded solely as a synthetic AAS until the 1980s when trace concentrations of apparently endogenous nandrolone were detected in urine samples obtained from intact male horses (stallions). Since then, its endogenous origin has been reported in boars and bulls; endogenous NAED and nandrolone have been identified in plasma and urine samples collected from stallions. More recently, however, it was suggested that NAED and nandrolone detected in urine samples from stallions are primarily artifacts due to the analytical procedure. The present study was undertaken to determine whether NAED and nandrolone detected in plasma and urine samples collected from stallions are truly endogenous or artifacts from sample processing. To answer this question, fresh plasma and urine samples from ≥8 stallions were analyzed for the two AASs, soon after collection, by liquid chromatography hyphenated to tandem mass spectrometry (LC–MS/MS). NAED and nandrolone were not detected in fresh plasma samples but detected in the same samples post storage. Concentrations of both AASs increased with storage time, and the increases were greater at a higher storage temperature (37 °C versus 4 °C, and ambient temperature versus 4 °C). Although NAED was detected in some fresh stallion urine samples, its concentration (<407 pg/mL) was far lower (<0.4%) than that in the same samples post storage (at ambient temperature for 15 days). Nandrolone was not detected in most of fresh urine samples but detected in the same samples post storage. Based on these results, it is concluded that all NAED and nandrolone detected in stored plasma samples of stallions and most of them in the stored urine samples are not from endogenous origins but spontaneously generated during sample storage, most likely from spontaneous decarboxylation of androstenedione-19-oic acid and testosterone-19-oic acid. To our knowledge, it is the first time that all NAED and nandrolone detected in plasma of stallions and most of them detected in the urine have been shown to be spontaneously generated in vitro during sample storage. This finding would have significant implications with regard to the regulation of the two steroids in horse racing.

Genetic variation in durability of Swedish Warmblood horses using competition results

The aim of the study was to investigate the possibilities of using number of years in competition as a measure of durability in the genetic evaluation of Swedish Warmblood horses. Competition results recorded between 1971 and 2008 in the disciplines dressage, show jumping and eventing were used to estimate genetic parameters for number of years in competition. Only male horses not used in breeding born between 1967 and 1991 were included in the study (17,962 horses). The study showed that horses with placings in more than one discipline at an early age had the longest competition career. This result suggests that these horses are talented for sports and possibly also that there is a positive effect of all-round training of young horses on their durability. For estimation of genetic parameters for number of years in competition different linear mixed animal models were compared. Depending on the model and transformation the heritability for total number of years in competition varied between 0.07 and 0.17. The lower values were obtained when adjustments in the model were made for age at first placing in competition. Higher heritabilities were obtained for competition years in show jumping and lower for eventing. Performance traits scored at young horse tests and as points in competition (lifetime and for young horses) showed positive genetic correlations with total number of years in competition. These results indicate that years in competition represent both the durability of the horses and their talents for performance. It is suggested that number of years in competition may be used for genetic evaluation of durability.

Discovery of lost diversity of paternal horse lineages using ancient DNA

Modern domestic horses display abundant genetic diversity within female-inherited mitochondrial DNA, but practically no sequence diversity on the male-inherited Y chromosome. Several hypotheses have been proposed to explain this discrepancy, but can only be tested through knowledge of the diversity in both the ancestral (pre-domestication) maternal and paternal lineages. As wild horses are practically extinct, ancient DNA studies offer the only means to assess this ancestral diversity. Here we show considerable ancestral diversity in ancient male horses by sequencing 4 kb of Y chromosomal DNA from eight ancient wild horses and one 2,800-year-old domesticated horse. Both ancient and modern domestic horses form a separate branch from the ancient wild horses, with the Przewalski horse at its base. Our methodology establishes the feasibility of re-sequencing long ancient nuclear DNA fragments and demonstrates the power of ancient Y chromosome DNA sequence data to provide insights into the evolutionary history of populations.

Haematuria in two geldings caused by osteochondroma of theos pubis: Case reports and anatomic study of theos pubisin 41 cadaveric pelvises

SummaryExostosis of theos pubiscausing haematuria, and potentially cystorrhexis, in horses has not been described in the literature. In this study, 2 geldings that suffered from exercise‐induced haematuria caused by an osteochondroma of theos pubis, and the assessment of 41 cadaveric pubic bones are reported on. The anatomy of theos pubisis highly variable. The prevalence of exostosis in theos pubisappears to be higher in male horses. Palpation and ultrasonography of the pelvisper rectumand cystoscopy are valuable diagnostic tools. Depending on the extent of changes in the bladder wall, surgical removal of the exostosis should be considered in order to prevent cystorrhexis. In horses that present with haematuria, closer assessment of theos pubisfor the presence of an exostosis is warranted.