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.
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...
Claes A, Ball BA, Brown JA, Kass PH.To identify risk factors for rectal tears in horses; assess the effect of initiating cause on tear location, size, and distance from anus; and determine short-term survival rate among horses with various grades of rectal tears. Methods: Retrospective case series. Methods: 99 horses. Methods: Medical records for horses with a rectal tear were reviewed, and data including age; sex; breed; cause, location, and size of the tear and its distance from the anus; tear grade; treatment; and outcome (short-term survival [ie, survival to discharge from the hospital] vs non-survival) were recorded. Data f...
Annear MJ, Gemensky-Metzler AJ, Elce YA, Stone SG.A 13-year-old female Miniature Horse was evaluated for progressive unilateral exophthalmia of the left globe of 3 weeks' duration. Results: Results of a physical examination were unremarkable. Ophthalmic examination identified exophthalmus of the left globe with complete resistance to retropulsion and mild blepharoconjunctivitis. Computed tomography revealed a large, space-occupying mass within the left caudal maxillary and left conchofrontal sinuses. The mass extended into the left retrobulbar space and contacted the cribriform plate. Trephination yielded copious amounts of turbid yellow flui...
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...
Ginther OJ, Beg MA, Neves AP, Mattos RC, Petrucci BP, Gastal MO, Gastal EL.Plasma concentrations of FSH, LH, oestradiol and progesterone were studied daily during 12 interovulatory intervals and 21 periovulatory periods in nine Miniature ponies. The peak of the FSH surge that was temporally associated with emergence of the future ovulatory follicle occurred when the follicle was approximately 9 mm, compared with a reported diameter of 13 mm in larger breeds. The ovulatory LH surge involved a slow increase between Days 13 and 18 (ovulation=Day 0; 0.6+/-0.1 ng day(-1)), a minimal increase or a plateau on Days 18 to 21 (0.04+/-0.1 ng day(-1)), and a rapid increase after...
Parth RA, Svalbe LS, Hazard GH, Church S.Two cases of severe scapulohumeral osteoarthritis in Miniature ponies are described, one bilateral and the other unilateral. The condition is thought to occur in miniature breeds as a result of scapulohumeral dysplasia. The presentation in one of the ponies was unusal: it refused to pick up either fore limb, with progression to a uniquely bizarre gait with narrow forelimb placement, an arched back and widely placed hindlimbs camped well forward under the body. The other pony was presented for an acute unilateral non-weight bearing forelimb lameness. Response to analgesia in both cases was poor...
Haupt JL, McAndrews AG, Chaney KP, Labbe KA, Holcombe SJ.It has been suggested that the rate of post operative abdominal adhesions in miniature horses is higher than that for other breeds. However, few reports exist in the veterinary literature describing complications and long-term survival following surgical treatment of colic in these horses. Objective: To determine the prevalence of surgical lesions in miniature horses with acute abdominal disease in terms of clinical signs, surgical management, post operative treatment and complications, as well as short- and long-term survival. Methods: Medical records of 57 American Miniature Horses undergoin...
Hansen M, Knorr C, Hall AJ, Broad TE, Brenig B.The solute carrier family 26, member 2 (SLC26A2) gene belongs to a family of multifunctional anion exchangers. Mutations in the human SLC26A2 gene are associated with autosomal recessively inherited chondrodysplasias. Hence, we postulate that the equine SLC26A2 could be a candidate gene for conformational traits in horses. An equine BAC clone harboring the SLC26A2 gene was isolated. The complete 142,625 bp insert sequence of this clone was determined by transposon sequencing. Together with the SLC26A2 gene the BAC clone contains four genes, i.e. the macrophage colony stimulating factor 1 recep...
Hatfield CL, Riley CB.This report describes previously unreported upper airway abnormalities encountered in a 5-month-old American miniature horse colt presented for elective surgery. Caution should be exercised when administering general anesthesia or heavy sedation to individuals of this breed that present with multiple congenital abnormalities. Conduite à tenir en présence de difficultés respiratoires pendant l’induction de l’anesthésie générale chez un cheval miniature américain atteint de nanisme. Ce rapport décrit des anomalies jamais rapportées des voies respiratoires supérieures d’un cheval ...
McMullen RJ, Gilger BC.To determine ocular dimensions (A- and B-scan ultrasound) and corneal curvature (radius of corneal diameter determined in B-scan ultrasound) in the equine eye and to calculate the appropriate dioptric power for a posterior chamber intraocular lens (IOL) necessary to achieve emmetropia in the eyes of horses undergoing lens extraction. Methods: Fourteen clinically normal adult horses of various breeds. Additionally, for comparison, one American Miniature colt foal, and one 2.5-year-old Shire gelding were examined. Methods: B-scan ultrasound was performed on one eye from each horse. One eye from ...
Rezaian M.Histology of the tongue, including apex, root and body, in four adult Caspian miniature horses was examined. Serial sections with 6 mum thickness were stained with haematoxylin-eosin and Masson trichrome and studied under light microscope. The tongue was covered by stratified squamous epithelium. It was thick and keratinized bearing numerous lingual papillae on the dorsum, mostly filiform with a very fine keratinized thread projecting above the surface and bending backward. The fungiform papillae were sparsely scattered among the filiform papillae and covered with keratinized squamous epitheli...
Christie JL, Hewson CJ, Riley CB, McNiven MA, Dohoo IR, Bate LA.In North America, there are few representative data about the effects of management practices on equine welfare. In a randomized survey of 312 nonracing horses in Prince Edward Island (response rate 68.4%), owners completed a pretested questionnaire and a veterinarian examined each horse. Regression analyses identified factors affecting 2 welfare markers: body condition score (BCS) and stereotypic behavior. Horses' BCSs were high (mean 5.7, on a 9-point scale) and were associated with sex (males had lower BCSs than females; P < 0.001) and examination date (P = 0.052). Prevalences of crib bi...
Couëtil LL, Gallatin LL, Blevins W, Khadra I.A 7-month-old miniature horse was referred for respiratory distress. Tracheal collapse at the level of the thoracic inlet was diagnosed. An intraluminal nitinol stent was placed with endoscopic guidance. Respiratory function was restored immediately after stent placement. The main complication observed during a 14-month follow-up period was growth of granulation tissue through the stent, which was controlled satisfactorily by electrocautery performed during endoscopy with the horse standing. Treatment of tracheal collapse with an intraluminal stent is an effective, practical, and minimally inv...
Tyson R, Graham JP, Colahan PT, Berry CR.An 8-month-old miniature horse filly was presented for evaluation of severe rotational and angular limb deformities of the thoracic and pelvic limbs. On radiographic examination, complete ulnas and fibulas were identified. These findings are consistent with a condition previously described as a form of atavism. The term atavism is used to describe the reappearance of a trait or character that was seen in all earlier evolutionary specimens of a particular species, but has not been seen in recent ancestors. The atavistic traits of complete ulnas and fibulas have previously been described in Wels...
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...
Semevolos SA, Watkins JP, Auer JA.To describe surgical arthrodesis of the scapulohumeral joint and to evaluate its efficacy in reducing morbidity associated with severe shoulder dysfunction in miniature horses. Methods: Retrospective study. Methods: Four miniature horses. Methods: Medical records and radiographs were reviewed for history, physical examination findings, lameness evaluation, radiographic evaluation, surgical techniques, postoperative complications, and outcome. A 10- or 11-hole, 4.5-mm narrow dynamic compression plate and 4.5-mm cortical screws were applied to the cranial surface of the scapula and cranial surfa...
Plummer CE, Ramsey DT, Hauptman JG.To determine corneal thickness, intraocular pressure (IOP), and horizontal and vertical corneal diameter (HCD and VCD) and to obtain axial measurements of the anterior chamber depth (ACD), crystalline lens thickness (CLT), vitreous chamber depth (VtCD), and axial globe length (AGL) in eyes of Miniature Horses. Methods: 41 healthy Miniature Horses. Methods: Ocular component measurements were obtained via ultrasonic pachymetry, applanation tonometry, ultrasound, and by use of a Jameson caliper. Results: Mean IOP and corneal thickness for all eyes were 26.0 mm Hg and 785.6 microm, respectively. T...
Patrick DJ, Kiupel M, Gerber V, Carr EA.A 2-year-old female Miniature Horse that presented with a history of progressive weight loss, depression, and diarrhea was diagnosed at necropsy with a highly malignant abdominal neoplasm involving the left ovary, kidneys, adrenal glands, intestines, and various abdominal and thoracic lymph nodes. Microscopic examination of these masses revealed large pleomorphic cells that stained positive for vimentin and inhibin and negative for epithelial membrane antigen and placental alkaline phosphatase. Ultrastructural examination of the cells revealed a high nucleocytoplasmic ratio and indented euchro...
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.
Camacho-Rozo CA, Santos GO, Wenzen DP, Cousseau SB, Wronski JG, Argenta FF, Winter GHZ, Pavarini SP, Mattos RC.This report describes a case of sudden death of a pregnant miniature mare due to an acute ovarian hemorrhage leading to fatal hemoperitoneum. The miniature horse was a 12-year-old female, 60 days pregnant, with a body condition score of 7 (1-9), with a history of obesity and laminitis. Necropsy revealed hemoperitoneum due to an ovarian capsule rupture and hemorrhage after a physiological supplementary ovulation and luteinization. Ovarian rupture after ovulation is uncommon in mares.
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...
Basso RM, Andrade DGA, Alves CEF, Laufer-Amorim R, Borges AS, Oliveira-Filho JP.Dwarfism is a skeletal disorder that causes abnormal growth. In Miniature horses, dwarfism can occur as chondrodysplastic dwarfism, an autosomal recessive disorder associated with five mutations (D1, D2, D3*, D4 and c.6465A > T variant) in the aggrecan (ACAN) gene. The aim of this study was to evaluate the expression of aggrecan (at the gene and protein level) and specific cytokines (IL-1β, IL-6, and TNF-α) in the articular cartilage of Miniature horses with chondrodysplastic dwarfism (D4/c.6465A > T genotype). Metatarsal bone samples from eight dwarf Miniature horses were collected fo...
Hatfield CL, Riley CB.This report describes previously unreported upper airway abnormalities encountered in a 5-month-old American miniature horse colt presented for elective surgery. Caution should be exercised when administering general anesthesia or heavy sedation to individuals of this breed that present with multiple congenital abnormalities. Conduite à tenir en présence de difficultés respiratoires pendant l’induction de l’anesthésie générale chez un cheval miniature américain atteint de nanisme. Ce rapport décrit des anomalies jamais rapportées des voies respiratoires supérieures d’un cheval ...
Semevolos SA, Watkins JP, Auer JA.To describe surgical arthrodesis of the scapulohumeral joint and to evaluate its efficacy in reducing morbidity associated with severe shoulder dysfunction in miniature horses. Methods: Retrospective study. Methods: Four miniature horses. Methods: Medical records and radiographs were reviewed for history, physical examination findings, lameness evaluation, radiographic evaluation, surgical techniques, postoperative complications, and outcome. A 10- or 11-hole, 4.5-mm narrow dynamic compression plate and 4.5-mm cortical screws were applied to the cranial surface of the scapula and cranial surfa...
Hardeman LC, van der Meij BR, Back W, van der Kolk JH, Wijnberg ID.In equine laminitis, the deep digital flexor muscle (DDFM) appears to have increased muscle force, but evidence-based confirmation is lacking. Objective: The purpose of this study was to test if the DDFM of laminitic equines has an increased muscle force detectable by needle electromyography interference pattern analysis (IPA). Methods: The control group included six Royal Dutch Sport horses, three Shetland ponies and one Welsh pony [10 healthy, sound adults weighing 411 ± 217 kg (mean ± SD) and aged 10 ± 5 years]. The laminitic group included three Royal Dutch Sport horses, one Friesian, o...
Cargile JL, MacKay RJ, Dankert JR, Skelley L.Tumor necrosis factor-alpha (TNF) is an important mediator of endotoxin-induced pathologic changes. To help define the role of TNF in equids with endotoxemia, the effects of pretreatment with a murine monoclonal antibody (MAB) against equine TNF were evaluated in Miniature Horses given endotoxin. Five horses were given TNF MAB at a dosage of 1.86 mg/kg of body weight, IV, and 5 were given control MAB. Five minutes later, lipopolysaccharide (LPS; Escherichia coli O55:B5), 0.25 microgram/kg, was given to all horses by bolus IV infusion. Clinical signs of disease were monitored at intervals up to...
Turrentine MA, Sculley PW, Green EM, Johnson GS.Two sibling miniature horses, a male and a female, had a normal 1-stage prothrombin time and a prolonged activated-partial thromboplastin time (APTT). The addition of as little as 5% of a normal equine plasma pool to the plasma samples of both horses shortened their prolonged APTT to within normal limits. Coagulation factor analysis revealed deficiencies in factor XII (12 and 13 U/dl, control population 77 to 128 U/dl), when determined with a feline factor XII-deficient plasma substrate, but normal concentrations (119 and 96 U/dl) when a human factor XII-deficient plasma substrate was used. De...
Rivas LJ, Hinchcliff KW, Robertson JT.Cervical meningomyelocele, spina bifida, and hydrocephalus were diagnosed in a newborn miniature colt that was unable to stand and had a cystic mass in the caudal portion of the dorsal cervical region. Results of physical examination and ultrasonographic imaging of the brain supported the diagnosis of hydrocephalus. Results of radiographic evaluation of the vertebral column were consistent with spina bifida at C5-C6. Fluid aspirated from the cervical mass resembled CSF. Radiography of the cervical region after injection of iohexol into the mass revealed herniation of the spinal cord through a ...
Andrade DGA, Basso RM, Castiglioni MCR, Silva JP, Machado VMV, Laufer-Amorim R, Borges AS, Oliveira-Filho JP.Four causative mutations (D1, D2, D3*, and D4) of chondrodysplastic dwarfism have been described in the equine () gene. Homozygotes for one of these mutations and heterozygotes for any combination of these mutations exhibit the disproportionate dwarfism phenotype. However, no case description of homozygotes for D4 (D4/D4) has been reported in the literature, to our knowledge. We report 2 Miniature horses with the genotype D4/D4 in the gene. Clinically, the 2 dwarfs had a domed head that was large compared to the rest of the body, mandibular prognathism, and short and bowed limbs, mainly in t...
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...
Hazlett M, Stalker M, Lake M, Peregrine A.A miniature horse which died following humane seizure from an Ontario farm was emaciated with serous atrophy of fat. Autopsy revealed hepatic atrophy and moderate periportal fibrosis. Eggs and trematodes seen in the liver were identified as Dicrocoelium dendriticum. This appears to be the first reported case of infection of equids in North America with Dicrocoelium dendriticum. Infection parDicrocoelium dendriticumhépatique chez un cheval miniature. Un cheval miniature qui est mort à la suite d’une saisie humanitaire dans une ferme de l’Ontario était émacié et avait une atrophie sére...
Haupt JL, McAndrews AG, Chaney KP, Labbe KA, Holcombe SJ.It has been suggested that the rate of post operative abdominal adhesions in miniature horses is higher than that for other breeds. However, few reports exist in the veterinary literature describing complications and long-term survival following surgical treatment of colic in these horses. Objective: To determine the prevalence of surgical lesions in miniature horses with acute abdominal disease in terms of clinical signs, surgical management, post operative treatment and complications, as well as short- and long-term survival. Methods: Medical records of 57 American Miniature Horses undergoin...
Sellers RS, Toribio RE, Blomme EA.Idiopathic systemic granulomatous disease, which has been reported in horses, cattle and human beings, is characterized by perivascular granulomatous and lymphoplasmacytic inflammation in many organ systems. Diagnosis is based on the exclusion of possible viral, fungal or bacterial causes. The disease was identified in a miniature pony with widespread lymphoplasmacytic and granulomatous inflammation, special staining techniques having revealed no evidence of any aetiological agent. Skin lesions, which were severe, consisted of hyperkeratosis and serocellular crust formation, with inflammatory ...
Annear MJ, Gemensky-Metzler AJ, Elce YA, Stone SG.A 13-year-old female Miniature Horse was evaluated for progressive unilateral exophthalmia of the left globe of 3 weeks' duration. Results: Results of a physical examination were unremarkable. Ophthalmic examination identified exophthalmus of the left globe with complete resistance to retropulsion and mild blepharoconjunctivitis. Computed tomography revealed a large, space-occupying mass within the left caudal maxillary and left conchofrontal sinuses. The mass extended into the left retrobulbar space and contacted the cribriform plate. Trephination yielded copious amounts of turbid yellow flui...
Iranmanesh M, Sato AF, Tenney W, Brinker EJ, Cortez K, Mazan M.A 1-year-old Miniature Horse filly was presented for chronic lethargy and hyporexia. Elevated liver enzymes, bile acids, and ammonia were noted on bloodwork. The primary differential diagnosis was a portosystemic shunt (PSS). Three-phase computed tomographic angiography findings were consistent with a transhepatic portosystemic shunt. Percutaneous liver biopsy confirmed severe diffuse hepatic changes, most likely due to chronic pyrrolizidine alkaloid toxicosis, and medical management was elected. Based on an extensive literature review, this is the first report of a transhepatic portosystemic ...
