Miniature Horses primarily differ from horses in size, conformation, and certain physiological traits. Miniature Horses are bred to retain the characteristics of full-sized horses on a smaller scale, typically measuring less than 34–38 inches in height at the withers, depending on the registry. In contrast, horses encompass a wide range of breeds and sizes, generally standing over 14.2 hands (58 inches) tall. While both Miniature Horses and horses share similar anatomical and physiological features, their size differences can influence aspects such as metabolism, health care needs, and management practices. This page compiles peer-reviewed research studies and scholarly articles that explore the genetics, health considerations, and management practices associated with Miniature Horses and horses, highlighting both their similarities and distinctions.
Bustamante-Filho IC, Rosa AP, Van der Linden LS, Pederzolli CD, Neves AP, Dutra-Filho CS, Jobim MI, Mattos RC.The use of stallion semen collected from cauda epididymis for AI has increased due to the new protocols available for cryopreservation. Preserving the genetic material from valuable males that suffer sudden death or other events that prematurely end the stallion's reproductive life is an important strategy for Stud breeding management. While protecting spermatozoa from oxidative stress and infectious agents, the epididymis promotes the enhancement of sperm cell morphology and changes in membrane protein profile, increasing its fertility potential. The epididymal fluid must be a balanced redox ...
Ghosh S, Qu Z, Das PJ, Fang E, Juras R, Cothran EG, McDonell S, Kenney DG, Lear TL, Adelson DL, Chowdhary BP, Raudsepp T.We constructed a 400K WG tiling oligoarray for the horse and applied it for the discovery of copy number variations (CNVs) in 38 normal horses of 16 diverse breeds, and the Przewalski horse. Probes on the array represented 18,763 autosomal and X-linked genes, and intergenic, sub-telomeric and chrY sequences. We identified 258 CNV regions (CNVRs) across all autosomes, chrX and chrUn, but not in chrY. CNVs comprised 1.3% of the horse genome with chr12 being most enriched. American Miniature horses had the highest and American Quarter Horses the lowest number of CNVs in relation to Thoroughbred r...
Fielding CL, Higgins JK, Higgins JC, McIntosh S, Scott E, Giannitti F, Mete A, Pusterla N.Equine coronavirus (ECoV) is associated with clinical disease in adult horses. Outbreaks are associated with a low case fatality rate and a small number of animals with signs of encephalopathic disease are described. Objective: The aim of this study is to describe the epidemiological and clinical features of two outbreaks of ECoV infection that were associated with an high case fatality rate. Methods: 14 miniature horses and 1 miniature donkey testing fecal positive for ECoV from two related disease outbreaks. Methods: Retrospective study describing the epidemiological findings, clinicopatholo...
Pozor MA, Zambrano G, Roser J, Hess R, Runyon S, Runcan E, Thomas BF, Dymock D, Macpherson ML, Troedsson MH, Kelleman A.The objective of this study was to evaluate acute endocrine effects as well as histological changes in testicular parenchyma induced by the contraceptive compound RTI-4587-073(l). Six miniature stallions were used in this experiment. The treatment group (n = 3) received one oral dose of 12.5 mg/kg of RTI-4587-073(l), and the control group (n = 3) received placebo only. The stallions' baseline parameters (semen, testicular dimensions, endocrine values) were collected and recorded for 5 weeks before treatment and for 6 weeks after treatment. Multiple blood samples were collected for endoc...
Khosravi AR, Nikaein D, Sharifzadeh A, Gharagozlou F.This study was carried out in order to isolate and identify the normal conjunctival fungal flora from Caspian miniature, Thoroughbred, Turkmen and Persian Arab breeds in Tehran, Iran. Methods: A total of seventy-two adult healthy horses were studied. Ocular samples were collected from right and left eyes by using sterile cotton swabs; samples were cultured on Sabouraud dextrose agar and incubated at 30°C for 7-10 days. Molds and yeasts were identified using macro and micro-morphological and physiological characteristics. Conclusions: Number of fungal colonies per eye varied between 0 and 123 ...
Runcan EE, Pozor MA, Zambrano GL, Benson S, Macpherson ML.The acrosome is a highly specialised region of the spermatozoon that is essential for fertilisation. Defects or dysfunction of this structure have been associated with fertility problems in man and various domestic species including stallions. Current methods of evaluating the acrosome of stallion spermatozoa are time consuming and require specialised equipment, which is cost prohibitive to the average practitioner. Objective: To evaluate 2 conventional stains (Dip Quick and Spermac) and determine their usefulness in assessing acrosome integrity in stallions as compared with specific acrosomal...
Nauwelaerts S, Aerts P, Clayton H.Spontaneous transitions from anti-phase to in-phase manual coordination are explained in the Haken model that describes the two preferred states as stable regions that work as attractors in a stability landscape. Switching between states coincides with a temporary loss of stability. Coordination variability is believed to be indicative of such a loss of stability. In this study, the hypothesis was tested that an increase in variability in the angle profiles of the joints responsible for the transition will precede the transition. A full gait analysis of four miniature horses transitioning from...
Pozor MA, Macpherson ML, McDonnell SM, Nollin M, Roser JF, Love C, Runyon S, Thomas BF, Troedsson MH.The objective of this study was to determine whether an indenopyridine derivative RTI-4587-073(l) was a good candidate for male contraception in horses. We hypothesized that a single administration of RTI-4587-073(l) causes significant suppression of testicular function in stallions without affecting sexual behavior. Three Miniature horse stallions received a single dose of 12.5 mg/kg RTI-4587-073(l) orally (group "treated"), whereas three other Miniature horse stallions received placebo only (group "control"). Semen was collected and evaluated from all stallions twice a week for three baselin...
Nauwelaerts S, Aerts P, Clayton H.Gaits can be defined based upon specific interlimb coordination patterns characteristic of a limited range of speeds, with one or more defining variables changing discontinuously at a transition. With changing speed, horses perform a repertoire of gaits (walk, trot, canter and gallop), with transitions between them. Knowledge of the series of kinematic events necessary to realize a gait is essential for understanding the proximate mechanisms as well as the control underlying gait transitions. We studied the kinematics of the actual transition from trot to canter in miniature horses. The kinema...
Lee CD, Maxwell LK.In most species, large variations in body size necessitate dose adjustments based on an allometric function of body weight. Despite the substantial disparity in body size between miniature horses and light-breed horses, there are no studies investigating appropriate dosing of any veterinary drug in miniature horses. The purpose of this study was to determine whether miniature horses should receive a different dosage of flunixin meglumine than that used typically in light-breed horses. A standard dose of flunixin meglumine was administered intravenously to eight horses of each breed, and three-...
Gandini M, Iotti B, Nervo T.While in cattle emergency and elective Caesarean sec-tions are commonly performed in the field, either with the animal recumbent or standing (Newman 2008), in the horse there are very few reports of field Caesarean sections (Gillespie 1962; Graff 1963; Leibrecht and Watt 1964; Cohen 1975), and all required general anaesthesia. It is therefore considered a procedure to be performed in a hospital setting. Furthermore, while the second stage of labour lasts as long as 6 h, it lasts only 20 min in horse, which, together with the fact that mares usually need to be transported to the hospital, makes...
Dunkel B, Kapff JE, Naylor RJ, Boston R.Clinical impression suggested that pony and miniature breeds (collectively referred to as ponies) presenting to a referral hospital for investigation of gastrointestinal disease had higher blood lactate concentrations on admission than large breed horses. Objective: The study tested the hypothesis that ponies with gastrointestinal disease had higher blood lactate concentrations on admission than large breed horses with similar disease severity. Methods: Retrospective case-control study. Methods: Medical records from September 2006 to July 2011 were reviewed for ponies with a primary presenting...
McCormick JD, Valdez R, Rakestraw PC, Varner DD, Blanchard TL, Cavinder CA, Sudderth AK, Kiser A, Love CC.Management decisions on unilateral orchiectomy are often influenced by the potential for post operative return to successful breeding. The effects of 2 surgical methods (first intention [FI] vs. second intention [SI] incision healing) for unilateral orchiectomy on resulting semen quality and scrotal temperature were evaluated. Objective: To evaluate the effects of 2 surgical unilateral orchiectomy techniques on scrotal healing, size of the remaining testis and post operative sperm quality. Methods: Unilateral orchiectomy was performed on mature Miniature Horse stallions. Semen was collected pr...
Easley JT, Freeman DE.To describe successful surgical treatment of bilateral mucocele in an American Miniature horse using a single bone flap to approach right and left paranasal sinuses simultaneously. Methods: Clinical report. Methods: A castrated 6-year-old American Miniature Horse with a bilateral mucocele of the paranasal sinuses. Methods: A single bilateral frontonasal sinus flap was used in a standing procedure to access the left and right conchofrontal sinuses simultaneously to remove the mucous contents and to establish permanent drainage into the nasal cavities. Results: The novel procedure used in this h...
Petersen JL, Mickelson JR, Rendahl AK, Valberg SJ, Andersson LS, Axelsson J, Bailey E, Bannasch D, Binns MM, Borges AS, Brama P, da Câmara Machado A....Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an F(ST)-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of selection in both the Paint and Quarter Horse. Gene sequencing and histological analysis of gluteal muscle...
Makvandi-Nejad S, Hoffman GE, Allen JJ, Chu E, Gu E, Chandler AM, Loredo AI, Bellone RR, Mezey JG, Brooks SA, Sutter NB.Horse body size varies greatly due to intense selection within each breed. American Miniatures are less than one meter tall at the withers while Shires and Percherons can exceed two meters. The genetic basis for this variation is not known. We hypothesize that the breed population structure of the horse should simplify efforts to identify genes controlling size. In support of this, here we show with genome-wide association scans (GWAS) that genetic variation at just four loci can explain the great majority of horse size variation. Unlike humans, which are naturally reproducing and possess many...
Tee SY, Feary DJ.A 9-year-old Miniature Horse gelding infested with ticks (Ixodes holocyclus) was presented with flaccid motor paralysis causing recumbency. Neurological examination and other diagnostic tests did not identify an alternative aetiology, leading to a presumptive diagnosis of tick paralysis. The gelding was treated with tick antiserum and intensive supportive care. He made a gradual recovery over the 48 h following presentation and was discharged without further complications. This case report describes in detail the clinical signs and successful treatment of a Miniature Horse with flaccid paral...
Pozor MA, Muehlhaus J, King A, Macpherson ML, Troedsson MH, Bailey CS.The objective was to investigate the effects of pentoxifylline (PTX) on testicular perfusion and sperm production in stallions. In a preliminary study, six mature Miniature horse stallions were given 0, 8.5, or 17.0 mg/kg of PTX orally, twice daily, for 3 d. Total Arterial Blood Flow Rate (TABFR) was higher (P < 0.05) in all treated versus control stallions during and after treatment. Two months later (during the fall and winter), the same stallions received either 0 or 17 mg/kg of PTX orally, twice daily for 60 d. Resistance and pulsatility indices (RI and PI, respectively) decreased in PT...
Sandmeyer LS, Bellone RR, Archer S, Bauer BS, Nelson J, Forsyth G, Grahn BH. To determine if congenital stationary night blindness (CSNB) exists in the Miniature Horse in association with leopard complex spotting patterns (LP), and to investigate if CSNB in the Miniature Horse is associated with three single nucleotide polymorphisms (SNPs) in the region of TRPM1 that are highly associated with CSNB and LP in Appaloosas. Methods: Three groups of Miniature Horses were studied based on coat patterns suggestive of LP/LP (n=3), LP/lp (n=4), and lp/lp genotype (n=4). Methods: Horses were categorized based on phenotype as well as pedigree analysis as LP/LP, LP/lp,...
Plummer CE, Ramsey DT.To determine the incidence of ocular abnormalities in miniature horses. Methods: Descriptive study. Methods: Fifty-three miniature horses. Methods: Ophthalmic examinations were performed using diffuse and focal illumination, slit-lamp biomicroscopy and indirect ophthalmoscopy. Coat color, mane and tail color, age and gender were recorded with results of ophthalmic examination. Results: Ocular abnormalities detected most frequently consisted of cysts arising from the posterior iris, ciliary body, and peripheral retina, curvilinear streaks of retinal pigmented epithelium extending from the perip...
van de Goor LH, van Haeringen WA, Lenstra JA.As a consequence of the close integration of horses into human society, equine DNA analysis has become relevant for forensic purposes. However, the information content of the equine Short Tandem Repeat (STR) loci commonly used for the identification or paternity testing has so far not been fully characterized. Population studies were performed for 17 polymorphic STR loci (AHT4, AHT5, ASB2, ASB17, ASB23, CA425, HMS1, HMS2, HMS3, HMS6, HMS7, HTG4, HTG6, HTG7, HTG10, LEX3 and VHL20) including 8641 horses representing 35 populations. The power of parental exclusion, polymorphic information content...
McKenzie HC.Hyperlipidemia is the presence of elevated lipid concentrations in the blood and is associated with periods of negative energy balance and physiologic stress. In increased concentrations, circulating lipids typically occur in the triglyceride form, which may interfere with numerous normal physiologic functions, particularly by reducing insulin sensitivity. Although the hyperlipidemia risk is greatest in ponies, miniature horses, and donkeys, all equids are at risk if they are in a situation involving negative energy balance. The sedentary lifestyle of many modern horses and the frequent feedin...
Stover KK, Williams SH.In mammals, chewing cycle duration (CCD) increases with various measures of size, scaling with body mass(0.13-0.28) and jaw length(0.55). Proposed explanations for these scaling relationships include the allometry of body size, basal metabolic rate and tooth size, on the one hand, and pendular mechanics treating the jaw as a gravity-driven pendulum, on the other. Little is known, however, about the relationship between CCD and size within species. Recent research in dogs demonstrates altogether different scaling exponents and weaker correlations. This research suggests that breed-specific grow...
Brooks SA, Makvandi-Nejad S, Chu E, Allen JJ, Streeter C, Gu E, McCleery B, Murphy BA, Bellone R, Sutter NB.Horses, like many domesticated species, have been selected for broad variation in skeletal size. This variation is not only an interesting model of rapid evolutionary change during domestication, but is also directly applicable to the horse industry. Breeders select for complex traits like body size and skeletal conformation to improve marketability, function, soundness and performance in the show ring. Using a well-defined set of 35 measurements, we have identified and quantified skeletal variation in the horse species. We collected measurements from 1215 horses representing 65 breeds of dive...
Beeler-Marfisi J, Gallastegui Menoyo A, Beck A, König J, Hewson J, Bienzle D.Gelatinous marrow transformation, or serous atrophy of bone marrow fat, has been noted in livestock, laboratory animals, and wildlife in association with an inadequate plane of nutrition, inanition, or intoxication. This is a report of gelatinous marrow transformation and hematopoietic marrow atrophy in a 5-year-old miniature horse stallion. The horse had oral malformations leading to poor food assimilation and emaciation. A bone marrow biopsy obtained to investigate persistent anemia and leukopenia showed hematopoietic atrophy and replacement of fat with a granular extracellular substance, wh...
Cozens ER.A 4-year-old miniature horse experienced intermittent episodes of pyrexia, lethargy, and purulent vaginal discharge following dsytocia. Vaginal endoscopy and transrectal ultrasonography revealed a blind-ending vaginal cavity and distended uterus. Surgical treatment was declined and the mare was euthanized. Post-mortem examination confirmed the diagnosis of pyometra and vaginal adhesions. Un cheval miniature âgé de 4 ans a vécu des épisodes intermittents de pyréxie, de léthargie et de pertes vaginales purulentes après la dystocie. Une endoscopie vaginale et une échographie transrectale...
Paryani MR, Gilanpour H.The Caspian miniature horse is one of the rare small breeds in the north of Iran. In the present study, the position of the heart and its valves were determined topographically in 4 miniature horses. We found that Caspian miniature horses have general similarities, with certain topographical variability, with other horses.
Aleman M, Nieto JE, Benak J, Johnson LR.To describe the clinical and laboratory findings, diagnostic features, and outcome of tracheal collapse in American Miniature Horses at a referral institution. Methods: Retrospective case series. Methods: 13 American Miniature Horses with tracheal collapse. Methods: Medical records of American Miniature Horses with tracheal collapse at a referral hospital were reviewed. Data extracted included signalment, history, clinical signs, laboratory data, diagnostic procedures, outcome, and histologic findings. Results: Tracheal collapse was documented in 5.6% of American Miniature Horses admitted to t...
Edwards GB.Diseases of the small colon are numerous and they can affect horses of any age. Diseases can be simple obstructions, nonstrangulating obstructions, strangulating obstructions, and congenital defects. American Miniature Horses appear prone to luminal obstruction with impacted intestinal contents, and some ischemic diseases are more common in postpartum mares. Enterotomy and enterectomy have a high success rate in the small colon, provided the affected portion can be exteriorized. The beginning and terminal portions of the small colon can be involved in many diseases and are not readily accessib...
Bustamante-Filho IC, Rosa AP, Van der Linden LS, Pederzolli CD, Neves AP, Dutra-Filho CS, Jobim MI, Mattos RC.The use of stallion semen collected from cauda epididymis for AI has increased due to the new protocols available for cryopreservation. Preserving the genetic material from valuable males that suffer sudden death or other events that prematurely end the stallion's reproductive life is an important strategy for Stud breeding management. While protecting spermatozoa from oxidative stress and infectious agents, the epididymis promotes the enhancement of sperm cell morphology and changes in membrane protein profile, increasing its fertility potential. The epididymal fluid must be a balanced redox ...
Fox J, Duncan R, Friday P, Klein B, Scarratt W.A 12-month-old American Miniature horse colt was presented to the Virginia Tech Veterinary Teaching Hospital with a 7-month history of progressive ataxia. Physical examination revealed a head intention tremor, base-wide stance, and ataxia. Necropsy findings were confined to the brain. There were bilateral areas of liquefactive necrosis and cavitation corresponding to the dorsal accessory olivary and lateral (accessory) cuneate nuclei. Cerebellar folia of the dorsal vermis were thin. Microscopically, the cerebellar cortex was characterized by patchy areas of Purkinje cell loss with associated v...
Blanchard T, Varner D, Johnson L, Roser J, Hill J, Miller C.The scrota of three Pony stallions and one miniature horse were insulated for 36 h. Plasma testosterone concentrations decreased gradually and were significantly (P < 0.05) lower than pretreatment values at 16, 24, 30, 38 and 44 h after onset of scrotal insulation. Plasma LH and oestradiol concentrations were significantly (P < 0.05) decreased 18 h, and 24 and 26 h, after onset of scrotal insulation, respectively. Plasma FSH concentrations were significantly (P < 0.05) decreased 4 days after the insulation was removed. Decreases in the potential daily sperm output per Pony for early p...
Clegg PD, Dyson SJ, Summerhays GE, Schramme MC.This paper describes the clinical and diagnostic features of 20 cases of scapulohumeral osteoarthritis in Shetland ponies, miniature horses and falabella ponies. The history and clinical signs were similar in all the cases Radiographically they all had consistent changes which consisted predominantly of articular osteophytes and periarticular enthesiophytes. Six of the cases had radiographic evidence of dysplasia of the scapulohumeral joint, although it was uncertain whether this was a primary or a secondary finding. No specific treatment appeared to be advantageous. At follow up, six of the p...
Esdaile E, Kallenberg A, Avila F, Bellone RR.Coat color is a trait of economic significance in horses. Variants in seven genes have been documented to cause white patterning in horses. Of the 34 variants that have been identified in KIT proto-oncogene, receptor tyrosine kinase (), 27 have only been reported in a single individual or family and thus not all are routinely offered for genetic testing. Therefore, to enable proper use of marker-assisted selection, determining breed specificity for these alleles is warranted. Screening 19 unregistered all-white Shetland ponies for 16 white patterning markers identified 14 individuals whose phe...
Siwinska N, Zak A, Baron M, Cylna M, Borowicz H.The aim of this study was to determine the normal location, wall thickness and motility of the right dorsal colon in adult ponies and miniature horses. The abdominal ultrasonography examination was performed in a study group consisting of 23 ponies and miniature horses and in a control group comprising ten Thoroughbred horses. The procedure was performed in unsedated standing animals. The location and the thickness of the right dorsal colonic wall was examined on the right side of the abdomen between the 10th and the 14th intercostal space. The contractility was recorded in the 12th intercosta...
Stover KK, Williams SH.In mammals, chewing cycle duration (CCD) increases with various measures of size, scaling with body mass(0.13-0.28) and jaw length(0.55). Proposed explanations for these scaling relationships include the allometry of body size, basal metabolic rate and tooth size, on the one hand, and pendular mechanics treating the jaw as a gravity-driven pendulum, on the other. Little is known, however, about the relationship between CCD and size within species. Recent research in dogs demonstrates altogether different scaling exponents and weaker correlations. This research suggests that breed-specific grow...
McCormick JD, Valdez R, Rakestraw PC, Varner DD, Blanchard TL, Cavinder CA, Sudderth AK, Kiser A, Love CC.Management decisions on unilateral orchiectomy are often influenced by the potential for post operative return to successful breeding. The effects of 2 surgical methods (first intention [FI] vs. second intention [SI] incision healing) for unilateral orchiectomy on resulting semen quality and scrotal temperature were evaluated. Objective: To evaluate the effects of 2 surgical unilateral orchiectomy techniques on scrotal healing, size of the remaining testis and post operative sperm quality. Methods: Unilateral orchiectomy was performed on mature Miniature Horse stallions. Semen was collected pr...
Gandini M, Iotti B, Nervo T.While in cattle emergency and elective Caesarean sec-tions are commonly performed in the field, either with the animal recumbent or standing (Newman 2008), in the horse there are very few reports of field Caesarean sections (Gillespie 1962; Graff 1963; Leibrecht and Watt 1964; Cohen 1975), and all required general anaesthesia. It is therefore considered a procedure to be performed in a hospital setting. Furthermore, while the second stage of labour lasts as long as 6 h, it lasts only 20 min in horse, which, together with the fact that mares usually need to be transported to the hospital, makes...
Stein L, Sledge D, Smedley R, Kiupel M, Thaiwong T.A 15-y-old Miniature horse mare had a 6-mo history of an ulcerated mass on the right lower eyelid. An incisional biopsy and a subsequent excisional biopsy were submitted to the Michigan State University Veterinary Diagnostic Laboratory for microscopic evaluation. Histologically, the incisional biopsy was composed of sheets of large neoplastic vacuolated polygonal cells. A few regions contained poorly differentiated neoplastic round-to-basaloid cells that rimmed the sheets of highly vacuolated polygonal cells. Both vacuolated and basaloid cells exhibited strong perimembranous and cytoplasmic im...
de Moura Alonso J, de Melo-Neto GB, Dos Santos B, Mogollón García HD, Paim KP, Pinheiro Ferreira JC, Santos Schmidt EM, da Silva ANF, da Cunha GM....This study aimed to evaluate the inflammatory response of miniature horses subjected to open and half-closed orchiectomy by physical examination, blood cell count, peritoneal fluid evaluation, total plasma protein, fibrinogen, and serum amyloid A (SAA) concentrations. Methods: Thirteen male healthy miniature horses were divided into two groups, according to the surgical approach: half-closed technique (HCT) and open technique (OT). The HCT group was subjected to ligation of the spermatic cord followed by its sharp incision, and closure of the vaginal tunic, and the OT group was only submitted ...
Fielding CL, Mayer JR, Dechant JE, Epstein KL, Magdesian KG.Trauma from dog attacks has been associated with mortality rates as high as 23% in some species. However, the prognosis and clinical features of this type of injury have not been described in equids. Objective: To describe survival rate, signalment, clinical features, and biochemical results in equids presented for emergency care after presumed dog attacks. We hypothesized there would be differences between survivors and nonsurvivors. Methods: A total of 28 equids presented for presumed dog attacks from 3 referral centers. Methods: A retrospective study was performed using data from 3 hospital...
Arighi M, Miller CR, Pennock PW.Scapulohumeral arthrodesis was performed successfully as treatment for severe degenerative arthritis in a 62-kg miniature horse. Using an approach similar to that used for a dog, this horse's scapulohumeral joint was opened, the cartilage was removed, and the site was stabilized, using an 11-hole narrow dynamic compression plate. Fusion was uncomplicated. The stallion became a successful pasture-breeding animal.
Nauwelaerts S, Aerts P, Clayton H.Spontaneous transitions from anti-phase to in-phase manual coordination are explained in the Haken model that describes the two preferred states as stable regions that work as attractors in a stability landscape. Switching between states coincides with a temporary loss of stability. Coordination variability is believed to be indicative of such a loss of stability. In this study, the hypothesis was tested that an increase in variability in the angle profiles of the joints responsible for the transition will precede the transition. A full gait analysis of four miniature horses transitioning from...
Gull T, Schmitz DG, Bahr A, Read WK, Walker M.Diagnostic imaging, including computed tomography, of a two-month-old foal with renal failure indicated that its right kidney was probably absent and that its left kidney was abnormal in shape. The foal was stabilised and released, but three days later its clinical signs recurred. Postmortem examination revealed renal hypoplasia and dysplasia, the first reported case of this condition in an American miniature horse.
Gastal EL, Neves AP, Mattos RC, Petrucci BP, Gastal MO, Ginther OJ.Follicular dynamics were studied during 12 interovulatory intervals (IOIs) and 36 preovulatory periods in Miniature mares. The percentage of IOIs with the following follicle events was: ovulatory wave with only one follicle>or=10 mm (55%), diameter deviation similar to previous reports in larger mares (25%) and minor waves emerging before or after the ovulatory wave (55%). Follicle data were compared among Miniature ponies, large ponies and Breton horses (n=12 IOIs per breed). The IOI was longer (P<0.001) in Miniature ponies (23.3+/-0.9 days) and in large ponies (23.9+/-0.5 days) than in...
Peloso JG, Coatney RW, Caron JP, Steficek BA.An obstructive enterolith was diagnosed in an 11-month-old 68-kg miniature horse with a 24-hour history of mild, intermittent colic. Abdominal radiography revealed gas distention of the cecum and the right and left ascending colon, and a radiodense elliptical structure in the area of the left kidney. During exploratory laparotomy, the right dorsal colon was noticed to contain ecchymotic hemorrhage and generalized discoloration in the portion proximal to the location of the enterolith. While exteriorizing the ascending colon, it ruptured caudal to the diaphragmatic flexure in the right dorsal c...
Scheffer CJ, Blaauw G, Dik KJ, Sloet van Oldruitenborgh-Oosterbaan MM.A mini-Shetland stallion was referred with bilateral pruritus localized to the anterior neck. More detailed clinical examination also revealed ataxia, and diagnostic imaging, including pre- and post-contrast computed tomography, revealed an old fracture of C2. Spinal cord compression was diagnosed. The probable causal relation between the fracture, the ataxia, and the localized pruritus seems comparable to the 'contusio cervicalis posterior' in humans, in which spinal cord trauma may cause pruritus in the associated dermatome.
Renaudin CD, Conley AJ.Methods to diagnose and monitor equine pregnancy continue to advance with improved instrumentation enabling the development of novel, non-invasive approaches to assess fetal well-being and viability using ultrasound and endocrine testing. From early embryonic loss to placentitis, that is typically encountered later in gestation, fetal viability and development as well as placental function can be evaluated using two fundamentally different, structural and functional, approaches. Ultrasound provides structural information on embryonic and fetal growth using such parameters as combined thickness...
Ing S.A 22-year-old miniature horse gelding was brought to a veterinary clinic with multiple porcupine quills embedded in the face. One quill had perforated through the left caudoventral cornea but did not extend beyond the anterior chamber. The horse was referred to a specialist clinic for removal of the intraocular quill and subsequent primary surgical repair of the corneal wound. Following aggressive medical treatment, the horse retained vision. Piquants de porc-épic oculaires et faciaux chez un cheval miniature. Un cheval hongre miniature de 22 ans a été amené à une clinique vétérinaire a...
Runcan EE, Pozor MA, Zambrano GL, Benson S, Macpherson ML.The acrosome is a highly specialised region of the spermatozoon that is essential for fertilisation. Defects or dysfunction of this structure have been associated with fertility problems in man and various domestic species including stallions. Current methods of evaluating the acrosome of stallion spermatozoa are time consuming and require specialised equipment, which is cost prohibitive to the average practitioner. Objective: To evaluate 2 conventional stains (Dip Quick and Spermac) and determine their usefulness in assessing acrosome integrity in stallions as compared with specific acrosomal...
Golenz MR, Knight DA, Yvorchuk-St Jean KE.Nasogastric infusion of a human enteral feeding preparation was effective in reversing hyperlipemia in an anorectic miniature horse with an esophageal laceration. The nutrient preparation was delivered every 4 hours by gravity flow through a 12 F enteral feeding tube. Within 48 hours of initiating enteral nutrition, the hyperlipemia had resolved. Signs of intolerance to the preparation were not observed, and further weight loss was prevented. The use of a human enteral formula was a convenient and successful alternative for the treatment of hyperlipemia in the horse.
Every LJ, Hostnik ET, Hostnik LD, Yardley J, Shore-Khirallah AT, Thompson A, Linn SC.Tracheal collapse in horses is reportedly uncommon; however, American Miniature Horses are more commonly affected. There is no description of the tracheal luminal diameter of American Miniature Horses, making early detection of tracheal luminal narrowing difficult. Objective: To 1) describe radiographic tracheal luminal diameter in clinically normal American Miniature Horses, 2) report the prevalence of subclinical tracheal collapse in a population of American Miniature Horses, and 3) use tracheal videofluoroscopy to quantify variation in tracheal luminal diameter throughout the respiratory c...
Aleman M, Nieto JE, Benak J, Johnson LR.To describe the clinical and laboratory findings, diagnostic features, and outcome of tracheal collapse in American Miniature Horses at a referral institution. Methods: Retrospective case series. Methods: 13 American Miniature Horses with tracheal collapse. Methods: Medical records of American Miniature Horses with tracheal collapse at a referral hospital were reviewed. Data extracted included signalment, history, clinical signs, laboratory data, diagnostic procedures, outcome, and histologic findings. Results: Tracheal collapse was documented in 5.6% of American Miniature Horses admitted to t...
Colmer SF, Wulster K, Johnson AL, Levine DG, Underwood C, Watkins TW, Van Eps AW.A 15-year-old Miniature Horse mare with persistently increased plasma calcium (total and ionized) and serum parathyroid hormone concentrations was presented for suspected primary hyperparathyroidism. Ultrasonography of the thyroid region identified an enlarged heterogeneous mass axial to the right thyroid lobe suggestive of an enlarged parathyroid gland, which was further confirmed using sestamibi nuclear scintigraphy and 3-phase computed tomography. Percutaneous ultrasound-guided ethanol ablation of the mass, a method not previously described in the horse, was performed under general anesthes...
Hughes KJ, Dowling BA, Matthews SA, Dart AJ.To report on the outcome of surgical treatment of acute abdominal crises in miniature breed horses. Methods: Retrospective case series of miniature horses presented to the University Veterinary Centre, Camden with an acute abdominal crisis. Methods: Hospital records of all miniature horses that underwent ventral midline laparotomy for acute abdominal crisis between 1997 and 2001 were reviewed. The signalment, history, clinical signs, results of ancillary diagnostic procedures, location and type of intestinal lesion, treatment and outcome were retrieved from each case record. Long-term survival...
Ragle CA, Snyder JR, Meagher DM, Honnas CM.A study of 15 American miniature horses (AMH) that underwent surgical treatment for colic was performed. Information obtained from the medical records included signalment, clinical signs, type and location of gastrointestinal lesion, and postoperative complications. All 15 AMH had intraluminal obstructions, attributable to feed impactions (11 horses), enteroliths (2), and sand (2). The most common location of obstruction was the small colon, which was involved in 9 of the 15 cases. All 15 AMH survived and were discharged from the hospital. Six of the 15 AMH underwent subsequent surgical treatm...
