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.
MacDonald MH, Pascoe JR, Stover SM, Meagher DM.The authors examined factors influencing survival in 140 horses that recovered from anesthesia after small intestinal resection between 1968 and 1986, using Kaplan-Meier estimated survival curves and the Cox proportional hazards regression model. Seventy-two horses (51%) died during the initial postoperative period, 19 horses (14%) died after discharge from the hospital, 33 horses (24%) were alive, and 16 horses (11%) were classified as censored. Mean age at surgery was 8 years. Horses 15 years of age or older, Arabians and Stallions, were overrepresented in the hospital population. The most c...
Merkt H, Klug E.In the Federal Republic of Germany a lethal accident occurred recently during the semen collection from a stallion and it would be advisable to observe the safety rules of which there are three sections: hobbeling and if necessary twitching of the mare, security in the manner in which the stallion is led, precautions to be observed by the operator.
Heath RB, Steffey EP, Thurmon JC, Wertz EM, Meagher DM, Hyyppa T, Van Slyke GL.Sequelae of routine orotracheal intubation under clinical conditions were characterised in 38 healthy horses presented at three veterinary medical teaching hospitals. Four of these were necropsied and their tissues studied histologically. To minimise variation, 30 mm id cuffed silicone endotracheal tubes or Cole cuffless tubes were used in all patients. Fibreoptic endoscopic examination of upper respiratory and tracheal areas was accomplished pre-intubation, immediately post extubation and after 24 h. Endoscopy revealed that intubation was associated with laryngeal and/or tracheal lesions in a...
Ostblom L, Lund C, Melsen F.Twelve horses suffering from navicular bone disease were examined in a prospective, controlled histomorphometric study for six months. The objective was to compare the histology of navicular bones from untreated animals to those treated with the egg-bar shoeing technique. These data were compared to similar sections from three normal animals. The current investigation provided quantitative support to previous findings concerning clinical improvement. Detailed histology, changes in bone morphometry and pathophysiological reactions are discussed.
Winder NC, Pellegrini A, von Fellenberg R.A peroxidase antiperoxidase technique was used to identify alpha 2-macroglobulin in formalin-fixed sections of normal equine lung and liver and in tissue sections and bronchoalveolar lavage fluid from horses with various lung diseases. Equine peripheral blood leucocytes and bronchoalveolar lavage samples from clinically normal horses were negative for alpha 2-macroglobulin. It was concluded that liver and pulmonary macrophages may be potential sources of alpha 2-macroglobulin. Although alpha 2-macroglobulin may play a role in various chronic bronchointerstitial pneumonias of the horse, it is d...
Høie S, Fossum K.An agar diffusion method using microtiter plates was used to detect antibodies to the DNases produced by Staphylococcus aureus, S. intermedius, and S. hyicus. Antibodies to DNase from S. aureus were demonstrated in most of the sera from the species investigated, except dogs, only 11% of whose sera were positive. Positive titers to S. intermedius DNase were found in 84% of deg sera, 61% of Icelandic pony sera, 41% of pig sera, 21% of human sera, and 20% of cow sera but in only 2 and 4% of goat and sheep sera, respectively. Although antibodies to DNase from S. hyicus were not found in sera from ...
Clark ES, Moore JN.Lateral cecal arterial blood flow, carotid arterial pressure, heart rate, and mechanical activity in the duodenum, right ventral colon, cecal body, and cecal apex were measured in 6 conscious healthy horses for 60 minutes during and for 120 minutes after IV infusion of 0.9% NaCl solution (control) or fenoldopam. There were no significant changes in these measurements during or after infusion of 0.9% NaCl (saline) solution. Fenoldopam, a selective dopamine-1 receptor agonist, was administered in saline solution at dosages of 0.01, 0.05, and 0.1 micrograms/kg/min. Intravenous infusion of fenoldo...
Sutherland RJ, Cambridge H, Bolton JR.A four-year-old Standardbred gelding presented with a 3.5 year history of intermittent epistaxis and spontaneous submucosal petechiae and ecchymoses in the nares and the mouth. Routine haematological and biochemical examinations were unremarkable. A thrombocytopathy was suspected when activated partial thromboplastin time, one stage prothrombin time, plasma fibrinogen and the platelet count were all normal. The patient's platelets failed to aggregate with serotonin, adenosine diphosphate, collagen (at 20 micrograms/ml) or the endoperoxide analogue U46619. Very high levels of collagen (100 micr...
Bello TR.A controlled test was performed to titrate the anthelmintic dosage of dienbendazole in 24 mixed-breed ponies naturally infected with Strongylus vulgaris, S edentatus, and small strongyle species, as determined by parasitic egg and larval counts in feces. Comparison of results of treatment was made among 3 dienbendazole dosages--2.5, 5, and 10 mg/kg of body weight--and a gum (excipient) mixture given by nasogastric intubation. All ponies were euthanatized and necropsied at 7 or 8 days after treatment. Trichostrongylus axei, Habronema muscae, S vulgaris, S edentatus, small strongyles, and Oxyuri...
Rijkenhuizen AB, Németh F, Dik KJ, Goedegebuure SA.A macroscopic, arteriographic and histological study of the development and the arterial anatomy of the navicular bone of 33 foetuses and 55 young horses is described. After 125 days of gestation the blood supply consists of two routes: one situated in the superficial layer of the fibrocartilage and the other similar to the blood supply of the navicular bone of the normal mature horse. After 270 days gestation, the blood vessels in the fibrocartilage gradually regressed and retracted until they have disappeared at six months after birth. At two months after birth the first macroscopic thinning...
Eysker M, Boersema JH, Kooyman FN.The effect of three albendazole treatments at 5-week intervals, beginning at turnout in April, on cyathostome infections in Shetland ponies was compared with the effect of sequential treatments with albendazole, oxfendazole and oxibendazole. The results showed a substantial reduction in faecal egg output after the first albendazole treatment. Since faecal egg counts remained very low, no estimation of the effect of the second treatment was possible. The third treatment with albendazole and oxibendazole was followed by an increase in faecal egg counts to values of greater than 100 eggs g-1 with...
Bayly WM, Hodgson DR, Schulz DA, Dempsey JA, Gollnick PD.The effects of exercise intensity and duration on blood gases in thoroughbred horses were studied to characterize the apparent exercise-induced failure in pulmonary gas exchange that occurs in these animals. In response to 2 min of exercise, arterial CO2 tension (PaCO2) decreased in mild and moderate exercise, returned to normocapnic levels in moderate to heavy exercise, and rose 5-10 Torr above resting values during very heavy exercise when CO2 production (VCO2) exceeded 20 times the resting value, and mixed venous CO2 tension approximated 140 Torr. Exercise-induced hypoxemia occurred at the ...
Collatos C, Reef VB, Richardson DW.An abscess of the external umbilical remnant and umbilical vein remnant was diagnosed in a 16-month-old colt, using ultrasonography. Because of the colt's size, primary closure of the surgical incision after umbilical cord resection was not complete. Vertical mattress stainless steel sutures and stents were used, and healing was by second intention. Intervening gas-filled viscera made it impossible to visualize ultrasonographically the bladder of umbilical artery remnants in a colt of this age.
Goetz TE, Holland CJ, Dawson JE, Ristic M, Skibbe K, Keegan KG, Johnson PJ, Schaeffer DJ, Baker GJ.The seroprevalence and seasonal trend of antibody titers against equine monocytic ehrlichiosis (Potomac horse fever) were determined in apparently healthy horses in selected areas of Illinois in 1986. Sera from 1,367 horses (6 months to 29 years old) were evaluated for the presence of antibodies against Ehrlichia risticii with indirect immunofluorescence. The majority (88%) of the horses were Thoroughbred or Standardbred racehorses. The number of horses with antibodies against E risticii was 229/1,367 (16.75%). The titers in these horses ranged from 1:10 to 1:640. As the year progressed, the n...
Gibson KT, McIlwraith CW, Park RD, Norrdin RW.Medial patellar desmotomy was performed on one (treated) hindlimb, and a sham operation on the other (control) hindlimb, of 12 normal horses. The horses were examined for lameness before medial patellar desmotomy and at months 1, 2, and 3. The femoropatellar joints were examined radiographically and arthroscopically at month 3. All horses were lame on the treated limb at months 1, 2, or 3. Radiographic changes, including fragment formation at the distal aspect of the patella and bone production at the attachment of the middle patellar ligament on the patella, were present in 11 horses at month...
Sosnicki AA, Lutz GJ, Rome LC, Goble DO.Until now, there has been no reliable method for histochemical determination of fiber types of single skinned muscle fibers. The major problem arises from the fact that most histochemical techniques use cross-sections of a large group of fibers and compare a given fiber with those surrounding it. This is not possible with a single skinned fiber which has been separated from a bundle to be used for mechanical analysis. A further problem is that the skinning procedure itself may alter the staining pattern. We have developed a procedure by which multiple cross-sections of single skinned fibers ca...
Ott EA, Asquith RL.Forty-six Thoroughbred and Quarter Horse yearlings were used in two experiments to evaluate the effect of mineral supplementation on growth and skeletal development. In the first experiment, concentrate and bermuda-grass hay diets providing 2.82 Mcal DE/kg (estimated), 13.0% CP, .62% Ca and .43% P on a DM basis were supplemented with trace minerals (TM) by adding 0, .5 or 1.0% TM premix to the concentrate. The TM content of the three diets (concentrate and hay) in mg/kg DM were: Fe 150, 162 and 176; Mn 56, 60 and 64; Zn 36, 53 and 69; and Cu 7, 8 and 11 for the low, medium and high TM levels, ...
Estrada R, Gutiérrez JM, Alvarado J, Robles A, Avila C, González N.The development of antibody response against phospholipase A2 activity of Bothrops asper venom was studied in a group of adult and healthy horses used in the production of the polyvalent antivenom at the Instituto Clodomiro Picado. Simultaneously, the general condition of the animals during the immunization schedule was also studied. There was a great individual variability in the immune response, although most of the horses studied reached the highest neutralizing titer after injection of doses of venom of 30 mg and 50 mg. On the other hand, in horses that had been previously immunized and we...
Rijkenhuizen AB, Németh F, Dik KJ, Goedegebuure SA.A macroscopical, arteriographical and histological study was made of the arterial supply of the navicular bones of horses with clinical and/or radiographic signs of navicular disease. Based on the clinical and radiological findings the navicular bones of 40 Warmblood horses are divided into four different groups. In the pattern of the arteriogram obvious changes are noticed: an imbalance and a distal to proximal shift between the distal and proximal arterial supply occur, indicating a reduction of the distal blood supply with a compensatory reaction of the proximal, medial and lateral supply. ...
Ducharme NG, Pascoe PJ, Lumsden JH, Ducharme GR.In order to determine which variables are useful in identifying horses with abdominal pain requiring surgery, data were analysed from 219 horses presented at one veterinary teaching hospital. Using multiple stepwise discriminant analysis with a recursive partitioning algorithm, we obtained a decision tree that identifies surgical and non-surgical patients. The prevalence of surgical patients was 79 per cent in this population. The sensitivity, specificity, and positive and negative predictive values of this decision tree were 99 per cent, 55 per cent, 90 per cent and 99 per cent respectively. ...
Lundin C, Sullins KE, White NA, Clem MF, Debowes RM, Pfeiffer CA.Twenty-two foals were divided into groups of intestinal distension and intestinal ischaemia as methods to induce peritoneal adhesions. In the first group, the lumen of a segment of distal small intestine was occluded without extramural vascular compromise and distended with lactated Ringer's solution to a constant pressure of 25 cm H2O for 2 h within the abdomen. The ischaemic group underwent 70 mins total vascular occlusion of identical segments of bowel. Serosal biopsies were obtained before and after each experimental procedure and following 60 mins of reperfusion. Similar biopsies were har...
Baxter GM, Broome TE, Moore JN.One hundred thirteen of 172 horses (66%) undergoing exploratory celiotomy for a small intestinal lesion survived 4 or more days after surgery. Intra-abdominal adhesions causing clinical problems requiring additional surgery or euthanasia were documented in 25 horses (22.1%). Problems developed in significantly more males than females. The most common initial small bowel lesion was ileal impaction (12 horses); 21 horses underwent small intestinal resection or bypass. However, there was no significant difference in the incidence of intra-abdominal adhesions between horses that underwent intestin...
Sweeney CR, Sweeney RW, Benson CE.Results of bacteriologic culture of specimens obtained from 14 horses with pneumonia and from 15 horses that were clinically healthy (nonpneumonia group) were compared. Specimens were obtained by use of an endoscopic guarded tracheal swabbing method and percutaneous tracheal aspiration. The percentage of agreement between the 2 tracheal specimens for the horses of the pneumonia group was 79% for aerobic isolates and 100% for anaerobic isolates. The percentage of agreement between results of the 2 tracheal specimens for horses of the nonpneumonia group was 80% for aerobic organisms and 93% for ...
Sangiah S, MacAllister CC, Amouzadeh HR.The basal gastric pH and free acid contents from five young adult healthy horses were determined at one hour intervals for eight hours. The basal gastric pH and free acid contents varied from 1.63 +/- 0.06 to 1.97 +/- 0.11 and 26.42 +/- 4.14 to 17.92 +/- 5.28 mmol litre-1, respectively. Misoprostol, a methylester analogue of prostaglandin (5 micrograms kg-1, orally) produced a time-dependent increase in the basal gastric pH to above 3.5 (P less than 0.05) at three, four and five hours after administration with a concomitant reduction of 80 to 90 per cent in the basal gastric free acid contents...
Smith JE, Erickson HH, Debowes RM, Clark M.Five horses were exercised at 10m/sec at a 3 degree incline for 2 mins. Packed cell volume, erythrocyte count, haemoglobin concentration, mean corpuscular volume, plasma protein, total white cell count and lymphocytes increased significantly in blood samples taken after exercise, compared with those taken before exercise; but mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration decreased. Erythrocytes were more resistant to osmotic stress after exercise, but their shape and degree of deformity were unaffected by exercise.
Ayliffe TR, Allen WE.PREVIOUS studies have shown that instillation of sodium benzylpenicillin into the uterine lumen of ponies in small volumes is followed by peak plasma concentrations of the antibiotic in 10to 15 mins (Allen 1978; Allen and Clarke 1978). However, the assumption that the circulating penicillin is absorbed only through the endometrium is questionable because Allen, Kessy and Noakes (1979) concluded that the intrauterine instillation of phenolsulphonphthalein was followed by absorption of the dye from the peritoneal cavity, after passage along the uterine tubes.
The present investigation was carri...
Mansell SE, Behnke MC.The nematode Onchocerca cervicalis is the most common causative agent of equine onchocerciasis; this condition is characterised by pruritus and dermatitis and is a differential diagnosis for insect bite hypersensitivity. Onchocerciasis is currently presumed of minor importance within the UK, however prevalence may increase if macrocyclic lactone use declines amid concerns about anthelmintic resistance in gastrointestinal nematodes. This survey aimed to establish O. cervicalis awareness and knowledge levels amongst UK equine veterinarians and to determine approximate numbers of UK horses affect...
Schamhardt HC, Merkens HW, Lammertink JL.Software for analysis of force plate recordings of the horse at normal walk is described. The data of a number of stance phases are averaged to obtain a representative tracing of that horse. The amplitudes of a number of characteristic peaks in the force-time curves are used to compare left and right front limbs and left and right hind limbs. The averaged tracings are plotted, default on the line printer or, via separate program, on a high quality pen plotter. A version of the program applicable for analysis of human force plate recordings, is available.
Costa HM, Silva AV, Guimarães MP.This paper describes some morphological aspects of Cylicocyclus brevicapsulatus (Ihle, 1920) (Nematoda: Cyathostominae) from Equus caballus in Brazil. The worms were studied using an optical microscope (measurements and illustrations) and a scanning electron microscope for a more detailed examination of the external morphology. The buccal capsule is very short, with a very thin wall, and the dorsal gutter is absent. Other morphological aspects are described including measurement of the spicules and gubernaculum.
Sturgeon BP, Milne EM, Smith KC.A 20 x 10 cm, lobulated mass was present in the perianal region of a 4-year-old Dales pony. Histopathology revealed an unencapsulated, loose arrangement of sheets and whorls of narrow mesenchymal cells, situated in the deep dermis. Intervening areas had a myxomatous appearance. The whorls were often arranged around a central structure resembling an axon or a vascular structure. Immunohistochemistry revealed that the elongated mesenchymal cells and central axon-like structures expressed vimentin, S-100, and neuron-specific enolase, but not pancytokeratin, glial fibrillary acid protein, and the ...
Labelle AL, Metzler AG, Wilkie DA.Neoplasia, for which surgical excision is a frequent treatment, is the most common disease of the equine nictitating membrane. There is little long-term follow-up information available to the practitioner regarding the long-term effects of nictitating membrane excision on ocular health. No information is available to compare recurrence of primary neoplasia of the nictitating membrane after excision with local or general anaesthesia. Objective: To evaluate the long-term complications of nictitating membrane resection in horses; recurrence of neoplasia of the nictitating membrane when nictitatin...
Carnevale EM, Squires EL, Maclellan LJ, Alvarenga MA, Scott TJ.In some mares with lesions of the reproductive tract, embryo collection and survival rates are low, or collection of embryos is not feasible. For these mares, oocyte transfer has been proposed as a method to induce pregnancies. In this report, a method for oocyte transfer in mares and results of oocyte transfer performed over 2 breeding seasons, using mares with long histories of subfertility and various reproductive lesions, are described. Human chorionic gonadotropin or an implant containing a gonadotropin-releasing hormone analog was used to initiate follicular and oocyte maturation. Oocyte...
Nottle BF, Tatarniuk DM, Caldwell FJ, Bell CD, Caston SS, Merkatoris PT, Gillen AM, Katzman SA.To describe the presentation, diagnosis, treatment, and outcome for horses with fibro-osseous lesions of the craniofacial complex. Methods: Retrospective multicenter case series. Methods: Thirty horses evaluated for fibro-osseous lesions of the skull from January 1, 2001 through December 31, 2019 in four centers. Methods: Medical records were reviewed for signalment, clinical presentation, histological and diagnostic imaging findings, treatment instituted, and outcome. Long-term outcome information was obtained by owner questionnaire or the medical record. Results: Diagnoses included ossifying...
Dart AJ, Pascoe JR, Snyder JR.Segmental ischemic necrosis of the descending colon associated with discrete tears of the mesocolon were diagnosed in 2 mares following foaling. After foaling, both mares had a slow onset of signs of abdominal pain and gradual deterioration of clinical status. Increases in peritoneal fluid total protein concentration and WBC count and a palpable impaction of the descending colon on examination per rectum were useful diagnostic aids. Surgical intervention was successful in one mare, but not in the other.
Coffman JR, Hammond LS, Garner HE, Thawley DG, Selby LA.A COMMON progression of chronic laminitis is ischaemic
necrosis with secondary infection a frequent complication.
For 6 years we have performed a complete blood count
(CBC) on all hospitalised horses (at the University of Missouri
Veterinary Hospital) every Monday, Wednesday and Friday.
Preliminary scrutiny of the results indicated that persistent
elevation of the total white blood cell count (WBC) and
neutrophilia was consistent with poor prognosis in horses
affected with laminitis. Because of these considerations we
decided to perform a retrospective examination of the blood
cell d...
Swor TM, Watkins JR, Bahr A, Epstein KL, Honnas CM.Previous olecranon fracture reports contain a small proportion of type 5 fractures, mostly treated with conservative therapy. Objective: To evaluate the clinical details and outcome of type 5 olecranon fractures in a large group of horses treated by tension band plate fixation and to compare results with other treatment methods. Methods: Medical records of 97 cases, including 32 (33%) classified as type 5, were reviewed. Subject details, history, radiographic findings, treatment and follow-up results (2-146 months post operatively) were recorded. Results: Treatment included open reduction and ...
Hughes KJ.Ocular manifestations may develop in many systemic diseases of horses; however, signs may not be observed unless ophthalmological examination is specifically undertaken. Recognition and assessment of ocular lesions in horses with systemic disease is desirable to facilitate diagnosis and determination of treatment options and diagnosis for both the underlying systemic disease and ocular manifestations. The purpose of this article is to review systemic diseases of horses that may have ocular signs as part of the disease process. Systemic diseases are discussed in categories of pathways for devel...
Lyons ET, Drudge JH, Tolliver SC.Critical tests were conducted in 14 naturally infected equids (13 horses and 1 pony) to evaluate the antiparasitic activity of haloxon. Single doses were administered by stomach tube to 3 horses and 1 pony (60 mg/kg of body weight), by addition to the feed of 3 horses (60 mg/kg), and intraorally by powder gun to 7 horses (65 mg/kg). Haloxon was efficacious (99% to 100%) against infections of Parascaris equorum, Oxyuris equi (mature and immature), and Strongylus vulgaris at both dosage levels. Probstmayria vivipara parasites were removed in 1 horse treated at 60 mg/kg by stomach tube and S equi...
Sasaki N, Hobo S, Yoshihara T.This study concerns the establishment of a simple testing method for breath concentration of hydrogen and methane in horses. Twenty-eight healthy thoroughbreds and 24 Arabians were used. Breath samples were collected using one-minute closed circulatory respiration through an aluminum bag filled with 10 liters of pure oxygen, which was mounted on the subjects by means of a face mask. Breath samples obtained, were analyzed by gas chromatography. A significant correlation in both hydrogen and methane levels was observed for samples collected at separate times. These findings confirmed the usefuln...
Mendoza P, d'Anjou MA, Carmel EN, Fournier E, Mai W, Alexander K, Winter MD, Zwingenberger AL, Thrall DE, Theoret C.Understanding radiographic anatomy and the effects of varying patient and radiographic tube positioning on image quality can be a challenge for students. The purposes of this study were to develop and validate a novel technique for creating simulated radiographs using computed tomography (CT) datasets. A DICOM viewer (ORS Visual) plug-in was developed with the ability to move and deform cuboidal volumetric CT datasets, and to produce images simulating the effects of tube-patient-detector distance and angulation. Computed tomographic datasets were acquired from two dogs, one cat, and one horse....
Lang A, Brucker P, Ludwig M, Wrede T, Theunert J, Gasse H.The topographical correlations between certain extracranial and intracranial osseous points of interest (POIs), and their age-related changes, are indispensable to know for a diagnostical or surgical access to intracranial structures; however, they are difficult to assess with conventional devices. In this pilot study, the 3-dimensional coordinates of extra-/intracranial POIs were determined, thus avoiding perspective distortions that used to be intrinsic problems in 2-dimensional morphometry. The data sets were then analysed by creating virtual triangles. The sizes, shapes, and positions of t...