Ponies are members of the Equidae family and share many physiological and anatomical characteristics, yet they are distinguished by several key differences. Ponies are generally smaller in stature, with a height at the withers of 14.2 hands (58 inches) or less, while horses exceed this height. In addition to size, ponies often exhibit a stockier build, thicker manes, tails, and coats, and a greater bone density compared to horses. These differences can influence their suitability for various tasks and environments. This topic encompasses a collection of peer-reviewed research studies and scholarly articles that explore the genetic, phenotypic, and behavioral distinctions between ponies and horses, as well as their implications for breeding, management, and performance in equine disciplines.
Gardner RB, Hart KA, Stokol T, Divers TJ, Flaminio MJ.A 5-week-old Fell Pony colt was examined for fever, lethargy, and anemia. The colt had been lethargic for 1 week before examination, had continued to nurse, had a temperature of 104°F (40°C), and was treated with ceftiofur (5 mg/kg IM q12h). Approximately 36 hours before examination, the colt developed watery diarrhea. Blood work performed by the referring veterinarian on the day of admission revealed a PCV of 10%.
Coombs DK, Patton T, Kohler AK, Soboll G, Breathnach C, Townsend HG, Lunn DP.Protecting equids against equine herpesvirus-1 (EHV-1) infection remains an elusive goal. Repeated infection with EHV-1 leads to protective immunity against clinical respiratory disease, and a study was conducted to measure the regulatory cytokine response (IFN-gamma and IL-4) in repeatedly infected immune ponies compared to non-immune ponies. Two groups of four ponies were established. Group 1 ponies had previously been infected on two occasions, and most recently 7 months before this study. Group 2 ponies had no history no vaccination or challenge infection prior to this study. Both groups w...
Jelìnek F, Faldyna M, Jasurkova-Mikutova G.Five days after birth of a viable Fell pony filly, yellow watery diarrhoea appeared without any signs of systemic disease. Four days later the diarrhoea ceased. On 11th day, the animal showed apathy, and a few days later, the foal was very lethargic, suffered from muscular weakness and severe watery diarrhoea that reappeared. The illness did not respond to therapy. At the age of 21 days the filly spontaneously died under symptoms of intestinal colic and pneumonia. Haematological examinations revealed lower numbers of erythrocytes as well as non-selective lymphopenia. Phagocytic activity was sl...
Wettstein D, Moens Y, Jaeggin-Schmucker N, Böhm SH, Rothen HU, Mosing M, Kästner SB, Schatzmann U.To evaluate pulmonary and cardiovascular effects of a recruitment maneuver (RM) combined with positive end-expiratory pressure (PEEP) during total intravenous anesthesia in ponies. Methods: 6 healthy adult Shetland ponies. Methods: After premedication with detomidine (10 microg/kg, IV), anesthesia was induced with climazolam (0.06 mg/kg, IV) and ketamine (2.2 mg/kg, IV) and maintained with a constant rate infusion of detomidine (0.024 mg/kg/h), climazolam (0.036 mg/kg/h), and ketamine (2.4 mg/kg/h). The RM was preceded by an incremental PEEP titration and followed by a decremental PEEP titrati...
Bosch G, van Duijkeren E, Bergwerff AA, Rijkenhuizen AB, Ensink JM.Ceftiofur concentrations in an infected and uninfected environment were compared and the efficacy of locally administered ceftiofur was evaluated in an experimental infection with Staphylococcus aureus in tissue cages. Eight ponies had tissue cages (TCs) implanted s.c. on each side of the neck. Into one of the cages 150 mg of ceftiofur was administered and fluid samples were taken to determine ceftiofur concentrations. After 1 week the other TC was infected with S. aureus and subsequently treated with 150 mg ceftiofur administered locally into the TC once daily for 21 days. Samples of fluid we...
van der Meulen K, Caij B, Pensaert M, Nauwynck H.In vitro studies demonstrated that most equine herpesvirus 1 (EHV-1)-infected peripheral blood mononuclear cells (PBMC) do not expose viral envelope proteins on their surface. This protects them against antibody-dependent lysis. We examined whether viral envelope proteins are also undetectable on infected PBMC during cell-associated viremia. Further, surface expression of major histocompatibility complex (MHC)-I was examined, since MHC-I assists in making infected cells recognizable for cytotoxic T-lymphocytes (CTL). Four ponies, previously exposed to EHV, and two ponies that had no contact wi...
Yasui T, Tsukise A, Fukui K, Kuwahara Y, Meyer W.The distribution of complex glycoconjugates and antimicrobial substances in the ceruminous glands of the horse (Equus przewalskii f. dom., type: pony) was studied using carbohydrate histochemical and immunohistochemical methods. The epithelial cells and luminal secretion of these glands exhibited considerable amounts of glycoconjugates with various saccharide residues, such as alpha-D-mannose, alpha-L-fucose, beta-D-galactose, beta-N-acetyl-D-glucosamine and sialic acid, including O-acetylated sialic acid. Several sugars (alpha-D-mannose, alpha-L-fucose, and beta-D-galactose) were also detecta...
Valentine BA, Cooper BJ.Muscle samples were obtained at necropsy from 225 horses and ponies 1 year of age or older. Samples were processed in routine manner and were stained with hematoxylin and eosin and with periodic acid-Schiff for glycogen. Sections were examined for abnormal glycogen content and amylase-resistant complex polysaccharide and for chronic myopathic change (excessive fiber size variation, increase in number of internal nuclei). A total of 101 horses and ponies with lesions of polysaccharide storage myopathy were identified. Age of affected horses ranged from one to 30 years, with a mean of 14.7 years...
Paillot R, Ellis SA, Daly JM, Audonnet JC, Minke JM, Davis-Poynter N, Hannant D, Kydd JH.Equine herpesvirus-1 (EHV-1) is a ubiquitous pathogen of horses, which continues to cause respiratory and neurological disease and abortion, despite the widespread use of vaccines. Cell mediated immunity (CMI) is thought to play a major role in protection against infection with EHV-1. The aim of this study was to characterise the virus-specific CMI response in ponies vaccinated with vP1014, a vaccinia-based construct (NYVAC) coding for the immediate early gene (gene 64) of EHV-1. This gene product is a CTL target protein for an equine MHC class I allele expressed on the A3 haplotype. EHV-prime...
Gehlen H, Ohnesorge B.To describe removal of guttural pouch chondroids through a laser fenestrated mesial septum in a pony with an obstructed pharyngeal ostium of the left guttural pouch. Methods: Case report. Methods: Pony. Methods: Transendoscopic laser neodymium:yttrium aluminum garnet (Nd:YAG) fenestration of the mesial guttural pouch septum was made by contact method (bare fiber, 15-25 W, exposure time 4 seconds). Dissected tissue was removed by transendoscopic monopolar electrosurgery (loop electrode, cutting blade) and multiple chondroids of varying size were removed from the left guttural pouch through the ...
Morais J, Oom MM, Malta-Vacas J, Luís C.The present study intends to survey the genetic variability of an endangered semiferal Portuguese native pony breed, the Garrano. Thirteen microsatellite markers were examined in 277 animals born in 1998, belonging to eight subpopulations corresponding to eight northern Portuguese geographic regions. Mean heterozygosity (H(o)) in the Garrano breed was 0.732, ranging from 0.531 to 0.857 across subpopulations. Allelic frequencies and diversity differed significantly between regions, suggesting the existence of genetic differentiation within the breed confirmed by the population differentiation e...
Lansdowne JL, Kerr CL, Bouré LP, Pearce SG.To determine the relationship between epidural cranial migration and injectate volume of an isotonic solution containing dye in laterally recumbent foal cadavers and evaluate the cranial migration and dermatome analgesia of an epidural dye solution during conditions of laparoscopy in foals. Methods: 19 foal cadavers and 8 pony foals. Methods: Foal cadavers received an epidural injection of dye solution (0.05, 0.1, 0.15, or 0.2 mL/kg) containing 1.2 mg of new methylene blue (NMB)/mL of saline (0.9% NaCl) solution. Length of the dye column and number of intervertebral spaces cranial and caudal t...
Escala J, Gatherer ME, Voûte L, Love S.Altered intestinal permeability is implicated in the pathogenesis of diverse equine medical conditions including alimentary laminitis and protein-losing enteropathies associated with parasitic infection. The aims of this study were to assess the feasibility of applying the 51Cr-EDTA absorption test for the assessment of intestinal permeability in the horse, and to apply this test in horses with experimentally induced alterations in gastrointestinal function. Four healthy ponies were administered 36 MBq of 51Cr-EDTA via naso-gastric tube, and urine samples were collected into polythene bags str...
Murrell JC, White KL, Johnson CB, Taylor PM, Doherty TJ, Waterman-Pearson AE.To record the electroencephalographic changes during castration in ponies anaesthetized with halothane and given intravenous (IV) lidocaine by infusion. The hypothesis tested was that in ponies, IV lidocaine is antinociceptive and would therefore obtund EEG changes during castration. Methods: Ten Welsh mountain ponies referred to the Department of Clinical Veterinary Medicine, Cambridge for castration under general anaesthesia. Methods: Following pre-anaesthetic medication with intramuscular acepromazine (0.02 mg kg(-1)) anaesthesia was induced with IV guaiphenesin (60 mg kg(-1)) and thiopenta...
Begg LM, Hughes KJ, Kessell A, Krockenberger MB, Wigney DI, Malik R.A 20-year-old Welsh Mountain Pony (212 kg) mare was initially presented for a chronic cough, fever, weight loss and low grade abdominal pain. She later developed dyspnoea, tachypnoea and exercise intolerance. The presence of multiple masses (up to 17 cm diameter) in the pulmonary parenchyma was established using lateral thoracic radiography and transthoracic ultrasonography. Encapsulated, budding yeasts were observed in smears made from transtracheal washings and needle aspirates of the pulmonary lesions. Cryptococcus gattii (synonym: Cryptococcus neoformans variety gattii; Cryptococcus bacill...
Grogan EH, McDonnell SM.To evaluate behavioral compliance of horses and ponies with simulated intranasal vaccination and assess development of generalized aversion to veterinary manipulations. Methods: Clinical trial. Methods: 28 light horse mares, 3 pony geldings, 2 light horse stallions, and 3 pony stallions that had a history of compliance with veterinary procedures. Methods: Behavioral compliance with 2 intranasal vaccine applicators was assessed. Compliance with standard physical examination procedures was assessed before and after a single experience with either of the applicators or a control manipulation to e...
Meyer C, Guthrie AJ, Stevens KB.Haematological variables and selected serum indices, particularly those affected by changes in renal and hepatic function, were examined in 6 healthy ponies following 4 intramuscular doses of 4 mg/kg imidocarb dipropionate administered every 72 hours. This treatment regime has been reported to sterilise experimental Babesia equi infections in horses and may have value in preventing the spread of this disease during exportation of possible carrier horses to non-endemic countries. Serum bile acids and serum gamma glutamyltransferase activity were measured to evaluate the effect of this treatment...
Cook RF, Cook SJ, Bolin PS, Howe LJ, Zhou W, Montelaro RC, Issel CJ.In the context of DNA vaccines the native equine infectious anemia virus (EIAV)-envelope gene has proven to be an extremely weak immunogen in horses probably because the RNA transcripts are poorly expressed owing to an unusual codon-usage bias, the possession of multiple RNA splice sites and potential adenosine-rich RNA instability elements. To overcome these problems a synthetic version of sequences encoding the EIAV surface unit (SU) envelope glycoprotein was produced (SYNSU) in which the codon-usage bias was modified to conform to that of highly expressed horse and human genes. In transfect...
Atwal OS, McDonell W.The pulmonary intravascular macrophages (PIMs) of equines contain a unique electron-dense surface coat that is predominantly composed of lipoproteins. A single exposure of inhalatory halothane causes mobilization of the surface coat into the endocytotic system of the PIMs, followed by expansion of the Golgi apparatus and its enrichment with acid phosphatase. Simultaneously, the cells of the lymphocytic series show hyperplasia in the form of mitotic changes inside the microvascular compartment of the lung. Halothane is known to cause acute and chronic hepatotoxicity because of its biotransforma...
Thirion-Delalande C, Guillot J, Jensen HE, Crespeau FL, Bernex F.A 6-year-old female pony died after 2 days of prostration. Clinical signs included hyperthermia and abnormal pulmonary auscultation sounds. Necropsy revealed diffuse severe necrohaemorrhagic colitis and splenitis, multiple visceral ecchymoses, petechial haemorrhages in the brain and lungs. Microscopical examination showed acute necrohaemorrhagic colitis, encephalitis, pneumonia and splenitis associated with fibrinoid vasculitis, thrombosis and fungal hyphae within and around vessels. Immunohistologically, concomitant aspergillosis (caused by Aspergillus fumigatus) and mucormycosis (causde by A...
Donaldson MT, McDonnell SM, Schanbacher BJ, Lamb SV, McFarlane D, Beech J.The purpose of this study was to evaluate the variation in plasma adrenocorticotropic hormone (ACTH) concentration and dexamethasone suppression test (DST) results with season, age, and sex in healthy, pony mares (n=15) and pony stallions (n=14) living under semiferal conditions and horse mares (n=10) living at pasture. Plasma ACTH concentrations were measured in September 2002, and in January, May, and September 2003. DSTs were performed in January and September 2003. Plasma ACTH concentrations in September 2002 and September 2003 were similar and were significantly greater than in January an...
McGuigan MP, Walsh TC, Pardoe CH, Day PS, Wilson AM.Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13 degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at t...
Parkinson TJ, Mogg TD, Dykgraaf S, Collett MG.An aged pony gelding presented with sudden onset of neck pain, depression and ataxia and weakness of the hindlegs, together with longer-term weight loss. Diagnostic procedures failed to isolate the cause of these signs and, despite symptomatic treatment, the animal's condition deteriorated until it required euthanasia. Unassigned: Post mortem examination revealed the presence of multiple splenic and hepatic haemangiosarcomata, with metastases to the lung and dorsal cervical muscles overlying C1 and C2 vertebrae. No lesions were present in the spinal cord, spinal column or brain. Conclusions: T...
Saroglu M, Aktas M, Olgun D, Arun SS.A tumor-like tissue mass of lateral-limbal site in the right eye of a 12-year-old Cob Pony mare was presented for surgical removal. The mass, covering the lateral limbus, bulbar conjunctiva and part of the cornea, was surgically removed, and the corneal defect repaired with a pedicle bulbar conjunctival graft. The mass was inflammatory in nature containing mononuclear cells. No recurrence or complication occurred at 6- and 12-month follow-up examination.
Heidmann P, Tornquist SJ, Qu A, Cebra CK.To determine whether epsilon-aminocaproic acid (EACA) administered IV affects hemostasis and fibrinolysis in clinically normal horses and ponies. Methods: 20 clinically normal adult horses and ponies. Methods: Blood samples were collected 24 hours before (baseline) and 1 and 5 hours after i.v. administration of a low dose (30 mg/kg) or high dose (100 mg/kg) of EACA. Platelet count, fibrinogen concentration, prothrombin time, partial thromboplastin time (PTT), D-dimer concentration, alpha2-antiplasmin activity, and thrombin-antithrombin complex concentration were measured. Values at 1 and 5 hou...
Jongbloets AM, Sloet van Oldruitenborgh-Oosterbaan MM, Meeus PJ, Back W.Equine canker is a chronic, hyperplastic, exudative pododermatitis affecting one or more feet. Although many causes and treatments have been suggested, the cause of the disease is still unknown and most probably multifactorial. Local treatments include radical surgical debridement of the diseased hoof tissue and application of caustic substances, antibiotics, and pressure bandaging. Nevertheless, the number of recurrences is high (45%). This article presents a 3-year-old New Forest pony-cross mare in which all horny structures (frogs, coronets, spurs, chestnuts) of all feet were affected. Bact...
van der Harst MR, Bull S, Laffont CM, Klein WR.The aminoglycoside gentamicin is often used in equine practice. Despite its clinical use, concerns remain regarding the potential toxic side-effects, such as nephrotoxicity, in equine patients, particularly after repeated dosing. The aim of the study was to investigate first in vitro the mechanisms contributing to the renal toxicity of gentamicin and to identify sensitive biomarkers indicating proximal tubule damage. To this end, the kidney-derived cell lines LLC-PKI and MDCK were treated with gentamicin at different concentrations. Toxicity was assessed by measuring the release of gamma-gluta...
Ensink JM, Bosch G, van Duijkeren E.Tissue chambers, implanted subcutaneously in the neck in six ponies, were inoculated with Streptococcus equi subsp. zooepidemicus in order to determine the clinical efficacy of prophylactic administration of trimethoprim/sulfadiazine (TMP/SDZ) against this infection. The TMP/SDZ treatment consisted of one intravenous (i.v.) injection of 5 mg/kg TMP and 25 mg/kg SDZ and the same dose of TMP/SDZ per os (p.o.), both given 3 h before inoculation. The oral dose was then repeated every 12 h for 5 days. TMP/SDZ concentrations in tissue chamber fluid (TCF) were above 10 times MIC at the moment of inoc...
Saville WJ, Dubey JP, Oglesbee MJ, Sofaly CD, Marsh AE, Elitsur E, Vianna MC, Lindsay DS, Reed SM.Sarcocystis neurona and Sarcocystis fayeri infections are common in horses in the Americas. Their antemortem diagnosis is important because the former causes a neurological disorder in horses, whereas the latter is considered nonpathogenic. There is a concern that equine antibodies to S. fayeri might react with S. neurona antigens in diagnostic tests. In this study, 4 ponies without demonstrable serum antibodies to S. neurona by Western immunoblot were used. Three ponies were fed 1 x 10(5) to 1 x 10(7) sporocysts of S. fayeri obtained from dogs that were fed naturally infected horse muscles. A...
Dyer KR, Duncan ID.The intraneural course of nerve fibres in the equine recurrent laryngeal nerve was investigated by partially ligating the nerve at a proximal site, and 3-8 weeks later, tracing the course and spatial relationships of intact and degenerating fibres along the distal stump. This nerve was chosen because of its great length, the fact that it is a nonbranching motor nerve and because of debate about the course of abductor and adductor nerve fibres in the recurrent laryngeal nerve. Six ponies were used and in each the recurrent nerve was partially ligatured about 20 cm from the larynx, using a fine ...
Fernie DS, Batty I, Walker PD, Platt H, Mackintosh ME, Simpson DJ.The vaccination of four ponies on two occasions with a formolised culture of Haemophilus equigenitalis produced a high circulating antibody titre to the organism in each pony. Three out of four vaccinated and all of three unvaccinated ponies developed typical symptoms of contagious equine metritis (CEM) when subsequently challenged with a vaginal exudate containing H equigenitalis. Similarly, three ponies which had previously been infected with H equigenitalis and which had recovered spontaneously also developed contagious equine metritis when rechallenged with the organism. The clinical and b...
Brault LS, Penedo MC.A putative mutation causative of cerebellar abiotrophy (CA), a genetic defect found almost exclusively in Arabian horses, was recently identified. Objective: To investigate the presence of the CA mutation in breeds other than Arabian and ascertain whether the mutation had been introduced into these breeds by Arabian ancestry. The CA mutation is present in breeds of horses with Arabian ancestry. Methods: Allele-specific PCR was used to genotype 1845 non-Arabian horses for the CA mutation. For those breeds in which at least one carrier was identified, an additional 266 horses were genotyped to d...
Houpt KA, Zahorik DM, Swartzman-Andert JA.The ability of ponies to learn to avoid a relatively novel food associated with illness was tested in three situations: when illness occurred immediately after consuming a feed; when illness occurred 30 min after consuming a feed; and when illness was contingent upon eating one of three feeds offered simultaneously. Apomorphine was used to produce illness. The feeds associated with illness were corn, alfalfa pellets, sweet feed and a complete pelleted feed. The ponies learned to avoid all the fees except the complete feed when apomorphine injection immediately followed consumption of the feed....
Busija DW, Orr JA, Rankin JH, Liang HK, Wagerle LC.The effect of hyperoxia on cerebral blood flow (CBF) was examined in 12 unanesthetized ponies. CBF was determined using radioactive microspheres, 15 micrometer in diam, durijng inspriation of the following gases: 1) room air (control); 2) 40% I2 in N2; and 3) approximately 100% O2 with 2.2-4.5% CO2 added to maintain isocapnia. CBF did not change from control values during either level of hyperoxia. However, cerebrospinal fluid (CSF) carbon dioxide tension (PCO2) increased during 40% O2 (delta 1.0 Torr) and approximately 100% O2 (delta 2.9 Torr). This rise in CSF PCO2, not due to a change in CB...
Glade MJ, Krook L, Schryver HF, Hintz HF.Epiphyseal and articular cartilages were examined in pony foals treated with intramuscular injections of either 0.5 mg dexamethasone per 100 kg bodyweight daily for 3, 8 or 11 months, or 5.0 mg per 100 kg for 11 months, and in horse foals treated with 5.0 mg per 100 kg for 20 weeks. The proximal femoral growth plates exhibited increased spatial separation between chondrocyte columns, narrowed zones of disorganized columnar and hypertrophic cartilage, abnormal penetration of hypertrophic cartilage by metaphyseal capillaries, retained cartilage in the spongiosa, distal terminal plate formation, ...
Slocombe JO, McCraw BM.Trials were conducted in ponies to evaluate the efficacy of pyrantel pamoate (Strongid-T(R)) and two newer anthelmintics not yet commercially available, nitramisole and avermectin B(1)a, against migrating Strongylus vulgaris larvae. Ponies were removed from their mares within 24-48 hr after birth and reared in isolation, worm free. Between six and 14 weeks of age they were infected with 2000 or 2500 infective S. vulgaris larvae. Subsequently, they were monitored daily for clinical signs until the experiment terminated at 28 days postinfection. All ponies showed increased body temperature and r...
Szczepanik MP, Wilkołek PM, Pluta M, Adamek ŁR, Pomorski ZJ.The purpose of this study was to evaluate transepidermal water loss, skin hydration and skin pH in normal ponies. Sixteen ponies of both sexes were examined in the study. Measurements were taken from seven different sites: the neck region, the shoulder, thorax, lumbar, inguinal, lip region and the auricle. In each of the regions transepidermal water loss (TEWL), skin hydration and skin pH were measured. For transepidermal water loss, the lowest values were observed in the lumbar region (9.71g/hm2), while the highest values were observed in the lip region (22.35 g/hm2). In the case of skin hydr...
Klei TR, Chapman MR, Torbert BJ, McClure JR.An indirect fluorescent antibody assay (IFA) was developed using Strongylus vulgaris third stage larvae (L3) as antigens. Observations using the IFA indicate that a species-specific antibody response to S. vulgaris L3 develops in S. vulgaris-infected ponies and that some surface L3 antigens are shared by adult worms. Sequential antibody levels against S. vulgaris were measured in strongyle-naive and in immune ponies following initial and challenge infections using the IFA and an indirect hemagglutination assay (IHA). Antibody levels measured by IFA increased faster following initial infections...
Cognie J, Freret S, Lansade L, Parias C, Barriere P, Gesbert A, Reigner F, Deleuze S.The impact of very early castration of foals has not yet been studied despite the many positive effects observed in dogs and cats. Objective: The objective of the study was to compare castration at 3 days and 18 months and assess their subsequent morphological and behavioural development. Methods: This was a randomised, blinded clinical study. Methods: Twenty-two Welsh ponies underwent either early (3-day old, EC group, n = 11) or traditional (18-month old, TC group, n = 11) castration. Animals were followed up to 3 years of age. All ponies were castrated using a primary closure techn...
Houpt KA, Wolski TR.The dominance hierarchy of a herd of 10 Thoroughbred mares was determined twice, at an interval of 18 months, using paired feeding tests. Each mare's rank was correlated significantly between the 2 tests. This indicated that the hierarchy within the herd was stable. The offspring of dominant and subordinate mares were also tested for dominance in their own age groups. The offspring of dominant mares tended to be near the top of the hierarchy while those of middle and low ranking mares were not consistently found in the middle or bottom of their own hierarchies. Paired feeding tests were carrie...
Spadavecchia C, Levionnois O, Kronen PW, Leandri M, Spadavecchia L, Schatzmann U.To investigate effects of isoflurane at approximately the minimum alveolar concentration (MAC) on the nociceptive withdrawal reflex (NWR) of the forelimb of ponies as a method for quantifying anesthetic potency. Methods: 7 healthy adult Shetland ponies. Methods: Individual MAC (iMAC) for isoflurane was determined for each pony. Then, effects of isoflurane administered at 0.85, 0.95, and 1.05 iMAC on the NWR were assessed. At each concentration, the NWR threshold was defined electromyographically for the common digital extensor and deltoid muscles by stimulating the digital nerve; additional el...
Fikes LW, Lin HC, Thurmon JC.Xylazine (0.35 mg/kg) or lidocaine (0.35 mg/kg) was injected into the epidural space of six ponies to compare their effectiveness as epidural analgesics. Each pony received both treatments at 1 week intervals with the order of treatments randomized. Xylazine produced analgesia of significantly longer duration (247 +/- 58 minutes) than that produced by an equal dose of lidocaine (135 +/- 22 minutes). Mild transient ataxia of no clinical significance developed in all ponies with both treatments. Spinal cords were removed from two ponies and examined histologically. No discernible pathologic chan...
Kemen MJ, McClain DS, Matthysse JG.Equine infectious anemia virus was transmitted from an acutely ill and an inapparently infected pony to uninfected ponies by the interrupted feeding of horse flies (tabanids). Transmission from acutely ill ponies was not accomplished following: (1) the interrupted feeding of a single horse fly, (2) bites of horse flies that had fed on an acutely affected pony 24 hours earlier, (3) bites of horse flies that had oviposited after feeding on an acutely affected pony, or (4) the inoculation of larval material derived from horse flies that had fed to repletion. It was concluded that horse fly transm...
Smith PJ, Samuelson DA, Brooks DE, Whitley RD.Normal drainage of aqueous humor from the anterior chamber of the equine eye occurred through conventional and unconventional routes. To determine the degree of uveoscleral outflow in the pony, 1- and 3-microns (diam) microspheres were perfused through the anterior chamber for 60 and 90 minutes. Two eyes were treated with pilocarpine before perfusion of spheres to observe any effect on outflow. Presence of spheres was detected by scanning electron microscopy and verified by light microscopy. By 60 minutes of the perfusion, 1- and 3-microns spheres thoroughly infiltrated the anterior uveal trab...
Asplin KE, Patterson-Kane JC, Sillence MN, Pollitt CC, Mc Gowan CM.Ponies with laminitis associated with insulin resistance and hyperinsulinaemia lack systemic and/or intestinal inflammatory signs, suggesting a different pathogenesis potentially reflected in differing histopathology. Objective: To describe the histological appearance and quantify morphological changes in primary and secondary epidermal lamellae (PEL and SEL) of laminitis lesions from ponies with insulin-induced laminitis. Methods: Equine hoof lamellar tissue was obtained from 4 control ponies and 5 ponies with laminitis induced following infusion of insulin (1036 ± 55 µU/ml) while maintai...
Jaussaud P, Guieu D, Bellon C, Barbier B, Lhopital MC, Sechet R, Courtot D, Toutain PL.The pharmacokinetics of tolfenamic acid were studied in five ponies after an intravenous (iv) administration (2 mg/kg bodyweight [bwt]) and in four horses after an oral administration (30 mg/kg bwt) of tolfenamic acid. The plasma levels were determined by high pressure liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). For the iv administration, a three-compartment model was used to represent the plasma concentration-time curve of the drug. The elimination half-life of the compound was 6.1 +/- 1.5 h, the total body clearance was 72.4 +/- 16.7 ml/kg bwt/h and the ste...
Rugh KS, Garner HE, Sprouse RF, Hatfield DG.Systemic arterial hypertension is associated with equine laminitis, a disease precipitated by gross over-ingestion of carbohydrates. We examined the hearts from nine chronically hypertensive (161 +/- 11/99 +/- 6 mmHg) laminitic ponies and nine normotensive (128 +/- 2/76 +/- 3 mmHg) ponies postmortem for signs of left ventricular hypertrophy. The hypertensive ponies had hearts which were significantly larger (7.77 +/- 0.26 g/kg bodyweight (BW) vs. 5.67 +/- 0.22 g/kg BW), as well as increased combined left ventricle and septum weight (4.99 +/- 0.21 g/kg BW vs. 3.67 +/- 0.20 g/kg BW) and left ven...
Johnson CB, Young SS, Taylor PM.The electroencephalogram (EEG) has been used in human clinical anaesthesia as an indicator of cortical activity and as an indicator of the depth of anaesthesia. It would be useful if it provided a reliable indication of the depth of anaesthesia of horses. In this study anaesthesia was induced with thiopentone and maintained with halothane in nine ponies. The end tidal halothane concentration (PE-Hal) was monitored and 20 seconds of EEG were recorded at 0.8 per cent, 1.0 per cent and 1.2 per cent halothane, equivalent to the minimum alveolar concentration (MAC), 1.25 MAC and 1.5 MAC. Each 20 se...
McKelvie J, Foster AP, Cunningham FM, Hamblin AS.Circulating lymphocyte numbers are elevated in horses with the allergic skin disease sweet itch and skin lesions are typified by an infiltrate of eosinophils and mononuclear cells, the latter of which have not been fully characterised. The aim of the present study was to characterise the lymphocyte subpopulations in the circulation and skin of ponies with sweet itch by flow cytometry and a newly developed modified alkaline phosphatase immunohistochemical technique. Sweet itch ponies were found to have significantly greater numbers of circulating CD5+ and CD4+ T-lymphocytes than normal animals....
Giles SL, Harris P, Rands SA, Nicol CJ.Individual animals experience different costs and benefits associated with group living, which may impact on their foraging efficiency in ways not yet well specified. This study investigated associations between social dominance, body condition and interruptions to foraging behaviour in a cross-sectional study of 116 domestic horses and ponies, kept in 20 discrete herds. Social dominance was measured for each individual alongside observations of winter foraging behaviour. During bouts of foraging, the duration, frequency and category (vigilance, movement, social displacements given and receive...
Wodas L, Mackowski M, Borowska A, Puppel K, Kuczynska B, Cieslak J.β-lactoglobulin is one of the most abundant milk whey proteins in many mammal species, including the domestic horse. The aim of this study was to screen for polymorphism in the equine LGB1 and LGB2 gene sequences (all exons, introns, and 5'-flanking region) and to assess potential relationship of particular genotypes with gene expression levels (measured in milk somatic cells) and milk composition traits (protein, fat, lactose, and total β-lactoglobulin content). Direct DNA sequencing analysis was performed for twelve horse breeds: Polish Primitive Horse (PPH), Polish Coldblood Horse (PCH), ...
Firth EC, Klein WR, Nouws JF, Wensing T.Single doses of sodium ampicillin (10 mg/kg) and kanamycin sulfate (5 mg/kg) were administered intramuscularly (i.m.) separately, and then together, to five pony mares. The plasma antibiotic concentration-time curves were constructed. The pharmacokinetic parameters of the antibiotics given separately were not altered by concurrent administration. Four of the five pony mares were then given the i.m. kanamycin/ampicillin combination 4 h after acute synovitis and fever had been induced by injection of lipopolysaccharide into the left intercarpal joint. The plasma concentration-time curves and the...
Wilmink JM, Nederbragt H, van Weeren PR, Stolk PW, Barneveld A.The contribution of wound contraction to wound closure determines the speed of second intention wound healing and it has been shown that significant differences exist with regard to both contraction and inflammatory response between horses and ponies and between various areas of the body. In this study, the contraction capacity of fibroblasts from limbs and buttocks of 4 Dutch Warmblood horses and 4 Shetland ponies was studied in vitro, in order to determine whether differences in wound contraction are due to differences in the inherent contraction capacity of the fibroblasts or to differences...
Gehlen H, Wulke N, Ertelt A, Nielsen MK, Morelli S, Traversa D, Merle R, Wilson D, Samson-Himmelstjerna GV.All around the world, intestinal helminths constitute one of the most prevalent life-long occurring infections and re-infections affecting all horse age groups. A range of parasite species among strongyles, ascarids, and tapeworms is known to have the potential to cause colic in horses. However, there is a lack of current scientific evidence on the actual relevance of helminth infection levels in the context of colic in horses kept during prevailing epidemiological conditions. Thus, a prospective case-control study on the occurrence of intestinal helminths in a total of 620 mainly adult equine...
Goyache F, Alvarez I, Fernández I, Pérez-Pardal L, Royo LJ, Lorenzo L.Empirical evidence of the usefulness of different molecular-based methods to estimate the effective population size (N(e)) for conservation purposes in endangered livestock populations is reported. The black-coated Asturcón pony pedigree (1,981 individuals) was available. Additionally, a total of 267 Asturcón individuals born in 1998, 2002, and 2008 were typed for 15 microsatellites. These yearly cohorts (cohort(1998, 2002, 2008)) included almost all individuals kept for reproduction at the end of the corresponding foaling season. The genealogical realized N(e) was estimated for each cohort ...
Fagliari JJ, McClenahan D, Evanson OA, Weiss DJ.To determine whether plasma protein concentrations were altered in ponies with alimentary laminitis. Methods: 12 adult ponies. Methods: Acute laminitis was induced in 6 ponies by oral administration of carbohydrate (85% corn starch, 15% wood flour); the other 6 ponies were used as controls. A physical examination was performed and blood samples were collected immediately before and 4, 8, 12, 24, and 28 hours after administration of carbohydrate. Plasma protein concentrations were determined by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Results: 19 plasma proteins rang...
Mohammadi A, Te Moller NCR, Ebrahimi M, Plomp S, Brommer H, van Weeren PR, Mäkelä JTA, Töyräs J, Korhonen RK.In this study, we mapped and quantified changes of proteoglycan (PG) content and biomechanical properties in articular cartilage in which either blunt or sharp grooves had been made, both close to the groove and more remote of it, and at the opposing joint surface (kissing site) in equine carpal joints. In nine adult Shetland ponies, standardized blunt and sharp grooves were surgically made in the radiocarpal and middle carpal joints of a randomly chosen front limb. The contralateral control limb was sham-operated. At 39 weeks after surgery, ponies were euthanized. In 10 regions of interest (...
Kowalczyk L, Steblaj B, Schauvliege S, Schramel JP, Pavlidou K, Savvas I, Duchateau L, Gasthuys F, Moens Y.To compare breathing patterns and transdiaphragmatic pressure during total intravenous (TIVA) and isoflurane anaesthesia in ponies. Methods: Experimental, cross-over study. Methods: Six healthy ponies weighing 286 (233-388) ± 61 kg, age 13 (9-16) ± 3 years. Methods: Following premedication with romifidine [80 μg kg(-1) intravenously (IV)], general anaesthesia was induced with midazolam (0.06 mg kg(-1) IV) and ketamine (2.5 mg kg(-1) IV) and maintained with either isoflurane (Fe'Iso = 1.1%) (T-ISO) or an IV combination of romifidine (120 μg kg(-1) per hour), midazolam (0.09 mg kg(-1) hour(-...
Gossett KA, French DD, Cleghorn B, Church GE.Hypertonic NaHCO3 infusion caused blood volume expansion, increased blood bicarbonate concentration, and delayed the onset of hypophosphatemia in ponies with endotoxemia. However, NaHCO3 infusion did not normalize blood pH, and it increased blood L-lactate concentration, and caused hypokalemia, hypernatremia, and hyperosmolality. The deleterious effects of NaHCO3 infusion in endotoxemia ponies outweighed the beneficial effects. The role of hypertonic NaHCO3 given IV for treatment of endotoxemia in equids must be reevaluated.
