Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Oikawa MA, Kamada M, Yoshihara T, Kaneko M, Yoshikawa T.To elucidate the current status of foal diseases in Japan, clinico-pathological analysis was conducted on 237 foal autopsy cases. As a result, bacterial infection was identified as an important cause of foal death. Most of the bacteria isolated from these cases were ubiquitous, opportunistic, environmental organisms, known to be non-pathogenic to mature animals. Most of cases with bacterial infection were diagnosed as having hypogammaglobulinemia, i.e., failure of passive transfer. In addition, the mean weight of thymuses in foals affected by bacterial infection tended to be lower than that of...
Pearson RA, Merritt JB.Four donkeys and four ponies maintained in climate rooms, were provided with meadow hay or barley straw supplemented with minerals and vitamins ad libitum. Both diets were given to all animals for periods of 21 days. Measurements were made during the last seven days following single doses of two non-absorbable markers (Cr-fibre and Co-EDTA). After six weeks the donkeys repeated the trial, walking 14 km and ascending 260 m five days per week. At rest ponies ate more than donkeys, however the donkeys showed a higher digestibility of dry matter (DM), organic matter (OM) and acid detergent fibre (...
Scott JS, Berney CE, Derksen FJ, Robinson NE.Pulmonary function measurements were made in control ponies and in ponies with recurrent obstructive pulmonary disease (principals) during clinical remission and during an attack of acute airway obstruction. The ponies were given beta-adrenergic antagonists and agonists to determine the role of beta receptors in recurrent obstructive pulmonary disease, and to determine the subtypes of beta receptors mediating bronchodilation in ponies. Aerosol administration of the beta antagonists, propranolol (beta 1 and beta 2), atenolol (beta 1), and butoxamine (beta 2) decreased dynamic compliance (Cdyn) ...
Henninger RW, Bramlage LR, Schneider RK, Gabel AA.Case records of 25 horses with transverse fractures of the proximal sesamoid bone were reviewed to evaluate the success of treatment. All fractures were repaired by use of lag screw fixation and an autogenous cancellous bone graft because the fracture fragments were considered too large for surgical removal and reconstruction of the suspensory apparatus was necessary. Radiography was performed in all cases, and the fractures were classified into 3 types: (1) proximal midbody fractures, which included all fractures in the proximal aspect of the sesamoid bone that resulted in fragments involving...
Doxey DL, Milne EM, Gilmour JS, Pogson DM.An attempt has been made to assess the diagnostic value of clinical features seen at initial examination of horses with grass sickness, colic cases and cases submitted as possible grass sickness but diagnosed subsequently as some other condition. There appears to be no single pathognomonic sign for grass sickness. A range of signs has been associated with grass sickness but these are of value only when related to the length of illness and the history. Biochemical tests related to intestinal tissue damage, stress and dehydration were evaluated and most were found to be of value in diagnosing ac...
Dart AJ, Snyder JR, Julian D, Hinds DM.The microvascular circulation of the cecum was studied in 15 adult horses, using microangiography and light microscopy combined with gross studies and scanning electron microscopy of vascular replicas. After heparinization, the horses were euthanatized and the cecum was transected at the cecocolic junction. Blood was flushed free of the circulation with isotonic NaCl and the cecal lumen was slightly distended. In 6 horses, the vascular system was injected with a modified radiopaque medium and evaluated radiographically. Sections evaluated radiographically were also prepared for histologic exam...
Steffey EP, Willits N, Wong P, Hildebrand SV, Wheat JD, Meagher DM, Hodgson D, Pascoe JR, Heath RB, Dunlop C.Fifty-eight foals were divided into two groups for study of aspects of the clinical anesthetic management of foals and to characterize effects of halothane (n = 30) and isoflurane (n = 28) in foals. There were no significant differences (P greater than 0.05) in the demographics of the two groups. Results of hemograms and biochemical analysis of venous blood samples before and after anesthesia were either not influenced or only mildly (clinically unimportant) affected by either agent. Like adult horses, foals have an increased PaCO2 when anesthetized with inhaled anesthetics. We could detect no...
Elliott AR, Steffey EP, Jarvis KA, Marshall BE.The hypoxic pulmonary vasoconstrictor response to unilateral hypoxia was analyzed in pentobarbital anesthetized dogs (n = 5), miniature swine (n = 5), and ponies (n = 5). The left and right lungs (LL, RL) were separately ventilated with the LL exposed to inspired oxygen concentrations (CIO2) of 100%, 12%, 8% or 4%, while the RL always received a CIO2 = 100%. Pulmonary blood flow distribution was measured using 15 microns radioactive microspheres. LL PAO2, and percent pulmonary blood flow diversion (%FD) were calculated at each CIO2. At CIO2 of 4% there were significant differences (P greater t...
Harrison LJ, May SA, Richardson JD, Mills G, Dixon P.Four horses with an incomplete fracture of a hindlimb longbone were examined. In two, the tibia had been fractured by external trauma. In the other two horses proximal metatarsal 3 had fractured during normal activity. The diagnoses were made radiographically and the horses were treated conservatively by box rest. The fractures healed satisfactorily and the horses became sound.
Wichtel JJ, Whitlock RH.Botulism was believed to be the cause of progressive symmetric myasthenia in 8 horses on a farm in North Carolina. One horse was found dead, 6 were euthanatized after becoming recumbent, and 1 affected horse recovered. Cecal and colonic contents of 2 horses were determined to contain Clostridium botulinum spores. Alfalfa hay that was fed to the horses contained spores and toxin.
Clabough DL, Roberts MC, Robertson I.Esophageal stenosis was diagnosed in a 7-day-old Thoroughbred foal referred for evaluation of bilateral milky nasal discharge. Double-contrast radiography revealed concentric narrowing of the esophagus at the level of the fifth rib, overlying the base of the heart. Lateral displacement of the esophagus was not apparent. X-ray computed tomography of the cranial portion of the thorax confirmed normal cardiac and great vessel anatomy, ruling out vascular ring anomaly. A nasogastric tube was placed, extending past the stenosis and into the stomach, and the foal was fed mares' milk via this tube. O...
Desideri A, Stefanini S, Polizio F, Petruzzelli R, Chiancone E.Apoferritin has been selectively labeled with a maleimide nitroxide derivative at Cys-126, located in the hydrophilic 3-fold channels. Titration of this derivative with Fe(II), which gives rise to the initial Fe(III)-apoferritin complex, produces, at low metal-to-protein ratios, a decrease of the intensity of the label EPR signal due to the occurrence of a magnetic dipolar interaction. A label-metal distance ranging between 8-12 A can be estimated from titrations performed with VO(IV), which is known to bind in the 3-fold channels, and likewise produces a decrease in the label EPR signal. The ...
Baxter GM, Moore JN, Budsberg SC.An open radial fracture in an adult horse (450 kg) was repaired by internal fixation, using two 18-hole 4.5-mm broad dynamic compression plates and 5.5- and 4.5-mm bone screws. The fracture healed completely, but when evaluated 9 months after surgery, the horse was lame on the fractured limb at a trot. Local infiltration of anesthesia along the distal half of the bone plates greatly ameliorated the lameness, suggesting that the plates were irritating the soft tissues and extensor tendons along the cranial and lateral aspects of the antebrachium. Both bone plates were removed simultaneously wit...
Kannegieter NJ, Ryan N.The case record, and subsequent racing performance, of 110 horses that had undergone arthroscopic surgery of the carpus, were reviewed. Of these, 87% resumed racing, with 43% able to win at least one race, after surgery. Horses with chip fractures from the distal radius had the best prognosis, while horses with sagittal fractures of the third carpal bone had the poorest. The performance of horses with bilateral lesions was similar to those with unilateral lesions. It was concluded that arthroscopic surgery was a suitable technique for the diagnosis and treatment of carpal lesions in the horse....
Wassall DA, Gregory RJ, Phipps LP.The detection of antibodies against Trypanosoma equiperdum in 689 equid sera was compared by enzyme-linked immunosorbent assay (ELISA), the complement fixation test (CFT) and an indirect immunofluorescent test (IIF). CFT was the least sensitive technique, susceptible to anti-complementary factors and the most technically demanding. IIF was more sensitive, but was only suitable for testing limited numbers of samples. In this study, ELISA was the most sensitive test, the least labour intensive and lends itself to a considerable degree of automation. It is suggested that ELISA would be relatively...
Gasthuys F, de Moor A, Parmentier D.The influence of different rates of dopamine and dobutamine on the cardiovascular depression during a standard halothane anesthesia was studied in dorsally recumbent ventilated ponies. Haemodynamic and respiratory responses were investigated by means of cardiac output (CO) determination (thermodilution technique), mean systemic (MAP) and pulmonary artery pressure (MPAP) (direct intravascular method) and arterial blood analysis (blood gases and packed cell volume). An important cardiopulmonary depression characterized by decreases (55% of the standing values) in CO, cardiac index (CI), MAP, MPA...
Abdelkader SV, Gudding R, Nordstoga K.Serum activities of gamma-glutamyl transferase (GGT), alkaline phosphatase (AP), aspartate aminotransferase (AST), and concentrations of total bilirubin and total bile acids were screened during a 5 year period in 27 horses used for production of hyperimmune serum. The horses investigated were regularly immunized with live cultures of the endotoxin-releasing bacteria Escherichia coli or Pasteurella multocida, the individual animals having undergone such treatment for periods varying from 2 weeks to 10 years. In a majority of the horses, GGT-activity had increased within 6 to 7 years of first h...
O'Callaghan MW.There is increasing demand on equine practitioners to provide confirmation of their diagnoses. For obscure lameness and for many of the more difficult locomotory problems presented in referral hospitals, the question to be answered is not only how to make the most accurate diagnosis but also how to document the findings so that there is less doubt in the mind of the client. This article describes a quasi algorithmic approach to choosing the best combinations of the increasingly sophisticated imaging methods available for evaluation of orthopedic disease.
Chapman MR, Klei TR, French DD.A critical trial was performed with five ponies 6-9 months of age and raised on a horse farm with demonstrated benzimidazole-resistant cyathostomes. Eleven species of cyathostomes were recovered, seven of which had resistance to thiabendazole. Degrees of resistance varied among ponies and from species to species. Resistant species were Cyathostomum coronatum, Cyathostomum catinatum, Cylicostephanus minutus, Cylicostephanus calicatus, Cylicostephanus longibursatus, Cylicostephanus goldi and Cylicocylus nassatus. This is the first study identifying resistant cyathostome species in the Gulf Coast...
Clayton HM.Time magnification in motion photography allows the observation of events in the stride cycle that normally are beyond the resolution of the human eye. Quantitative analysis goes a stage further by measuring the stride in terms of timing, distance, and angular variables. Motion analysis is a good technique for detecting left-right asymmetries of gait, and the nature of the asymmetries has some value in locating the site of a lameness. Repeated analyses of the same horse allow an objective assessment of the effects of local anesthesia, surgical treatment, or medication. It is anticipated that t...
Röcken H, Wenz C.A unilateral malformation of the eye of a thoroughbred foal is described. The specific form of the tiny lens we named, "lenticulus". It is correlated with a maximal unchangeable mydriasis. The bulb shows physiological size. A brown-black pigmented mass inhibited (internal) inspection and examination of the middle and rear part of the eye. Special emphasis is laid on the insecure behaviour of the foal. A connection with an iridocyclochoroiditis, which was treated in the mare about a year ago, and the pathological changes in the eye of the foal is not evident.
Dieckmann M, Deegen E.Twelve horses with clinical symptoms of a gastric disorder were studied by gastroscopy. Symptoms of gastric disorders were periprandial colic, bruxism, ructus and reflux. Preliminary to gastroscopy the horses were fasted for 24 h. Access to water was not restricted. The gastroscopy could be conducted easily using a fiberscope 2.5 m in length and 11 mm in outer diameter. While ulcers were present in the squamous fundus of all horses only one horse showed ulceration of the glandular fundus. Solitary ulcers near the margo plicatus were found in horses with mild clinical symptoms. In contrast, dif...
Gardner SY, Reef VB, Spencer PA.Medical records of 46 horses with jugular vein thrombophlebitis that were evaluated ultrasonographically were reviewed. The ultrasonographic appearance of the thrombus within the jugular vein was classified as noncavitating if it had uniform low to medium amplitude echoes, or as cavitating if it was heterogenous with anechoic to hypoechoic areas representing fluid or necrotic areas within the thrombus, and/or hyperechoic areas representing gas. Signs of pain on palpation of the affected vein (P less than 0.001), heat over the vein (P = 0.001), and swelling of the vein (P less than 0.05) were s...
The Journal of parasitologyFebruary 24, 2001
Volume 86, Issue 6 1366-1368 doi: 10.1645/0022-3395(2000)086[1366:ARAPDP]2.0.CO;2
Spencer JA, Witherow AK, Blagburn BL.Neospora caninum is a recently described coccidial parasite that was first isolated from a dog in 1988 and has subsequently been shown to infect a wide range of mammals. Neospora hughesi, a new species of this genus, has recently been isolated from the spinal cord of horses showing clinical signs of equine protozoal myeloencephalitis. The random amplified polymorphic DNA polymerase chain reaction technique is capable of differentiating between N. caninum and N. hughesi.
Sheppard M, Drysdale SM, Studdert MJ.Physical maps were constructed for the genome of equine adenovirus 1 (EAV1) using the restriction enzymes; DraI, EcoRV, NotI and SfiI. The total size of the EAV1 genome was 34.4 kb estimated by comparison with known DNA standards and the polarity of the fragment order, with respect to the left and right molecular ends, was determined by hybridization with known regions of the human adenovirus 2 (HAV2) genome.
Lindåse S, Johansson H, Månsby M, Bröjer J.The hyperglycaemic clamp has been used for measurement of insulin sensitivity (IS) but not for measurement of β-cell response in the horse. However, the repeatability of this test has not been reported for horses. Objective: To determine the repeatability and reliability of measures for IS and β-cell response to glucose using the hyperglycaemic clamp in horses. Methods: Repeated measures, longitudinal study. Methods: Six healthy Standardbred mares underwent a 120-min hyperglycaemic clamp on two occasions with a 10-day washout period. Indices of repeatability and reliability were calculated f...
Williams GE.To determine whether force-plate evaluation of horses with navicular disease would reveal an abnormal gait that persists despite loss of sensation to the palmar foot region, which may predispose such horses to navicular disease. Methods: 17 clinically normal Thoroughbreds and 8 Thoroughbreds with navicular disease. Methods: Data on ground reaction forces were obtained in trotting horses, using a force plate. Force-time curve variables for clinically normal horses were derived from 4 points at the beginning and 4 points at the end of the vertical and craniocaudal horizontal plots. Principal com...
Hu WG, Chau D, Wong C, Masri SA, Fulton RE, Nagata LP.The genes encoding envelope proteins E1 and E2 of western equine encephalitis virus (WEEV) were respectively cloned into a prokaryotic T7 RNA polymerase-regulated expression vector. The recombinant C-terminal 6xHis-tagged WEEV E1 and E2 were expressed in bacteria as inclusion bodies that were subsequently solubilized with 8M urea, purified by immobilized metal ion affinity chromatography and finally refolded using an arginine system. The purified 6xHis-tagged proteins showed 50kDa bands as revealed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, consistent with the expected size...
Hornyák A, Dénes B, Szeredi L, Dencsö L, Rusvai M.Two monoclonal antibodies against the Bucyrus strain of equine arteritis virus (EAV) were produced, and according to immunoperoxidase reaction following Western blot of electrophoresed EAV structural proteins, they recognized the nucleocapsid (N) protein antigen (14-kDa protein). Besides reacting with the blotted polypeptide, the antibodies of the two clones (designated 1H1 and 4G6) selected from 576 have shown high affinity and specificity to intracellular virus antigen as well. Both antibodies reacted with the representatives of the different subtypes of equine arteritis virus providing a su...
Daunt DA.In conclusion, vigilant supportive care is necessary to prevent morbidity and death in the anesthetized horse. Because some of the equipment and drugs are specialized and the consequences of some postanesthetic complications are severe, availability of those items must be confirmed prior to anesthesia. Proper positioning and padding will help to reduce the incidence of postanesthetic myopathy-neuropathy syndrome in these large patients. Adequate tissue perfusion is important and can be achieved by controlling anesthetic depth, increasing intravascular volume with fluid administration, and by a...
Johnson W, Inamasu J, Yantzer B, Papangelou C, Guiot B.A soft tissue defect is often an unavoidable consequence of various surgical procedures or a result of trauma. Recently, intraoperative use of xenograft as a patch to the soft tissue defect has become popular with various products available in the market. In this study, mechanical properties of the OrthADAPTtrade mark Bioimplants (Pegasus Biologics, Irvine, CA), new xenograft products composed of collagen from equine pericardium, were evaluated individually and against an existing bioimplant product. The OrthADAPTtrade mark Bioimplants have three subtypes which differ in the degree of crosslin...
Steward ML.This article describes the use of the wooden shoe in the treatment of chronic laminitis. The shoe, designed to provide a solid base and full roller motion, offers mechanical advantages and enables reduction and redistribution of forces within the hoof capsule.
Delli-Rocili MM, Cribb NC, Trout DR, Thomason JJ, Valverde A.To compare the effectiveness of a paravertebral nerve block vs local portal blocks for laparoscopic closure of the nephrosplenic space in standing sedated research horses. Methods: Randomized clinical trial. Methods: Twelve horses were randomly allocated to two groups (n = 6 per group), paravertebral block of nerves T , L , and L or local blocks of the three laparoscopic portals. Methods: Horses were sedated with dexmedetomidine (4 μg/kg IV and constant rate infusion [CRI] of 2.5 μg/kg/h) and morphine (50 μg/kg IV and CRI of 30 μg/kg/h). According to group allocation, 20 mL of either lid...
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.
Gillen A, Mudge M, Caldwell F, Munsterman A, Hanson R, Brawner W, Almond G, Green E, Stephens J, Walz J.The long-term outcomes of external beam radiotherapy for treatment of noncutaneous tumors of the head in horses is unknown. Objective: To report the long-term outcomes for treatment of noncutaneous tumors of the head of horses, and report short and long-term clinical adverse effects. Methods: Thirty-two horses treated in 2 referral hospitals. Methods: In this retrospective study, medical records of horses receiving radiation therapy for noncutaneous tumors between 1999 and 2015 were reviewed. Signalment, tumor type, treatment protocol, tumor control duration, and survival were recorded. Kaplan...
Hill AC, Polak-Vogelzang AA, Angulo AF.Acholeplasma strains were isolated from the nasopharynx of a horse (strain PN525T [T = type strain]) and the feces of a rabbit (strain B1). One clone of strain PN525T and one clone of strain B1 were examined in detail. These clones were indistinguishable from each other and were serologically distinct from the previously described Acholeplasma and Mycoplasma spp. The strains had the following properties: guanine-plus-cytosine content of 31 mol%; sterol was not required for growth, which occurred under both aerobic and anaerobic conditions; glucose was metabolized; and arginine was hydrolyzed. ...
Heath MF, Evans RJ, Poole AW, Hayes LJ, McEvoy RJ, Littler RM.The responses of equine blood platelets in citrated platelet-rich plasma to arachidonic acid, U44069 (prostaglandin endoperoxide analogue), adenosine 5'-diphosphate, platelet-activating factor or collagen were investigated by turbidimetric aggregometry. Pre-treatment of the platelets with aspirin (1 mmol/l) or paracetamol (1.3 mmol/l) abolished shape change and aggregation in response to arachidonic acid; decreased the rate of aggregation in response to collagen, with no separate effect on shape change; had no marked effect on aggregation caused by the other agonists; but in no case transforme...
Trotter GW, Miller D, Parks A, Arden W.Persistent, severe metabolic acidosis complicated the operative and postoperative period in a 4-year-old mare with colic. On the basis of clinical and laboratory findings, a renal tubular disorder was diagnosed. Renal tubular acidosis is rare in horses. In the only report found on the subject, type I renal tubular acidosis was described in 2 horses. Bicarbonate titration studies in our case helped document type II renal tubular acidosis in this mare.
Bauquier J, Stent A, Gibney J, Jerrett I, White J, Tennent-Brown B, Pearce A, Pitt J.Investigation of toxicosis caused by Malva parviflora was required after 4 horses from the same farm developed severe muscle fasciculations, tachycardia, sweating and periods of recumbency leading to death or euthanasia after ingesting the plant. Objective: To describe historical, clinical, clinicopathological and pathological findings of 4 horses with suspected M. parviflora toxicosis. The role of cyclopropene fatty acids (found in M. parviflora) and mechanism for toxicosis are proposed. Methods: Case series. Methods: Historical, physical examination, clinicopathological and pathological find...
Vorster DM, Wang W, Kemp KL, Bamford NJ, Bertin FR.The thyrotropin-releasing hormone (TRH) stimulation test is used to diagnose pituitary pars intermedia dysfunction (PPID) using 10- or 30-min protocols. Imprecise sampling time for the 10-min protocol can lead to misdiagnoses. Objective: To determine the effect of imprecise sampling time for the 30-min protocol of the TRH stimulation test. Methods: In vivo experiment. Methods: Plasma immunoreactive adrenocorticotropin (ACTH) concentrations were measured 9, 10, 11, 29, 30 and 31 min after intravenous administration of 1 mg of TRH in 15 control and 12 PPID horses. Differences in ACTH concent...
Faszer K, Draper D, Green JE, Morris GJ, Grout BW.A Stirling Cycle freezer has been developed as an alternative to conventional liquid nitrogen controlled rate freezers. Horse semen samples were cooled in 0.25 ml straws and 15 ml bags in the Stirling Cycle freezer under laboratory conditions and as a portable device, powered from a car battery. For comparison, straws were frozen in a conventional liquid nitrogen controlled rate freezer. Upon thawing, motility and viability of samples frozen in the Stirling Cycle freezer were not significantly different when compared to samples frozen in the liquid nitrogen freezer. Unlike liquid nitrogen syst...