Veterinary care in horses encompasses the medical and preventive measures taken to maintain and improve the health and well-being of equine patients. It includes a wide range of practices such as routine health examinations, vaccinations, dental care, parasite control, and management of injuries and diseases. Veterinary care also involves diagnostic procedures, surgical interventions, and therapeutic treatments tailored to the specific needs of horses. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of equine veterinary care, including advancements in diagnostic techniques, treatment protocols, and health management strategies to support the well-being and performance of horses.
Squires EL, Cook NL.This article describes in detail the procedures for collection of equine oocytes using a transvaginal ultrasound probe. Success in obtaining oocytes from humans, bovines, and horses are presented. The effect of repeated follicular aspiration of both cattle and horses is reviewed.
Keegan KG, Wilson DA, Lattimer JC, Twardock AR, Ellersieck MR.To evaluate distribution and intensity of 99mTc-methylene diphosphonate (99mTc-MDP) uptake in the navicular area in horses with forelimb lameness isolated to the palmar aspect of the foot. Methods: Prospective, case-controlled study. Methods: 7 horses with clinical signs of navicular syndrome and 7 control horses. Methods: Palmar view, soft tissue-phase scintigraphic images of the foot were obtained between 7 and 12 minutes after injection of 120 to 170 mCi of 99mTc-MDP. Lateral and palmar view, bone-phase images were obtained at 30 minutes and 1, 2, and 4 hours after injection. Palmar views w...
Squires EL.Twinning is a major cause of abortion in mares. Although early management of twins is quite successful, twins that remain after 40 days are difficult to manage. This article reviews the current knowledge of the use of transvaginal ultrasound probe for elimination of twins. Several techniques are presented, as well as discussion on the best time during gestation for this technique to be used.
Zierz J, Wintzer HJ.To judge acute processes of pain objectively the results are told of a determination of adrenaline and noradrenaline in the plasma of 30 horses suffering from pain. Besides a scheme basing on an awarding of points is developed to ascertain changes of physiological and ethological parameters caused by pain. These results in changes of behaviour are compared to results determined by laboratory experiments. Concerning pain of medium and high level a relation to the concentration of catecholamines is noticed. Therefore the total of certain clinical observations is suitable for graduating acute pai...
Soma LR, Uboh CE, Rudy JA, Smith MS.To examine, in horses, the disposition and excretion of the active metabolite 6-methoxy-2-naphthylacetic acid (6MNA) of the nonsteroidal anti-inflammatory prodrug nabumetone. Methods: Pharmacokinetic analysis of 6MNA after oral administration of nabumetone and IV administration of 6MNA. Methods: Using a crossover design, 5 horses were orally administered 3.7 mg of nabumetone/kg of body weight. After a 3-week washout period, 4 horses were administered 2.5 mg of 6MNA/kg, IV. Results: Absorption of nabumetone from the gastrointestinal tract and its metabolism to 6MNA had a median appearance half-...
Gamble HR, Gajadhar AA, Solomon MB.Twelve horses were infected with various doses of Trichinella spiralis and then tested for infection using direct (artificial digestion) and indirect (enzyme immunoassay) methods. Horses became infected in a dose-dependent manner. Larvae accumulated preferentially in the tongue, followed by the masseter, neck, supraspinatus, trapezius, and diaphragm. At lower infection levels, the tongue harbored several times more parasites than were found in other tissues. The sensitivity of artificial digestion methods for detecting infections was directly related to sample size. One-gram samples were not r...
Graham JK.This article describes some of the basic methodology for conducting stallion semen evaluations. Not all of these assays will likely be conducted on every semen sample collected. Routine evaluations should include determination of semen volume, sperm concentration, and an estimation of the percentage of progressively motile sperm, at a minimum. Other assays can be used if a seminal problem is discerned at the beginning of the breeding season or after a stallion has recovered from an illness or injury. Additionally, laboratory assays are particularly important to conduct on cryopreserved spermat...
Merkt H.A stallion got fatal injuries by kicks of a maiden mare because a so called "panic hook" untied spontaneously. The use of such hooks to secure mares during mating should therefore not be recommended.
Squires EL.Equine oocytes obtained either by transvaginal ultrasound-guided follicular aspiration or from slaughterhouse ovaries can be matured in vitro. This generally requires culture in TCM-199 containing serum and hormones for 30 to 36 hours. With this protocol, approximately 50% to 60% of the oocytes are at metaphase-II at the end of the culture period. At least some of these oocytes appear viable based on production of fertilized eggs either through in vitro fertilization or fertilization in vivo of a recipient mare. The success of producing equine embryos in vitro is still extremely low. More than...
Brinsko SP.Poor fertility has been associated with hormonal imbalances in the stallion. The primary cause of this imbalance is unknown, but it may be related to abnormal gonadotropin secretion. Secretion of GnRH from the hypothalamus causes the release of LH and FSH from the anterior pituitary and these gonadotropins help maintain adequate steroid levels so that normal spermatogenesis can occur. Hypogonadotropic hypogonadism has not been documented in the stallion; however, GnRH therapy has improved the fertility of a limited number of horses. Downregulation of the HPT axis readily occurs in most other s...
Topper MJ, Prasse KW, Morris MJ, Duncan A, Crowe NA.To adapt and characterize a human ELISA kit to quantify thrombin-antithrombin III (TAT) complexes in horses, and to evaluate TAT as a marker for hypercoagulation in horses. Methods: 29 clinically normal horses used as controls, and 4 ill horses used to evaluate assay for known causes of hypercoagulation. Methods: A commercially available human sandwich-type ELISA kit with 2 antibodies against human thrombin and antithrombin III that bind selectively to their corresponding TAT antigenic sites was used. Equine TAT standards were made from purified equine thrombin and antithrombin III. Proteins d...
Schumacher J, Ford TS, Brumbaugh GW, Honnas CM.Full-thickness, circular, cutaneous wounds (4 cm diameter) were created on metacarpi and metatarsi of 5 horses. On day 6, all 4 wounds on each horse received a stored autogenous split-thickness sheet graft. Grafts were obtained from the horse's ventrolateral thorax with a pneumatic dermatome at the time the cutaneous wounds were created. Grafts were coapted to the granulation bed of 2 wounds of each horse with fibrin glue. Grafts were coapted to the cutaneous margin of all 4 wounds of each horse with cyanoacrylate glue. Bandages were changed daily until the study ended at 14 d. When the bandag...
Graham JK.The main advantage to using frozen semen in any breeding program is faster genetic gain for the inherited trait desired. Milk production of dairy cows doubled (from 26,000 to 52,000 kg of milk/cow per year) between 1950 and 1980, because the dairy industry was using semen only from bulls with the greatest genetic potential for milk production. This genetic gain could have been achieved without the use of frozen semen; however, the time required to achieve that same genetic progress would have been lengthened exceedingly. Fertility rates using frozen stallion spermatozoa are not equal to that o...
Each year, traumatic brain injury (TBI) is associated with 52,000 deaths and accounts for one third of all injury deaths in the United States; in addition approximately 80,000 persons who survive TBI incur some loss of function, residual disability, and increased medical-care needs because of these injuries. Major causes of TBI are motor-vehicle crashes, falls, assaults, and sports and recreational activities. During 1992-1993 in Oklahoma, horseback riding was the leading cause of sports-related TBI. To further characterize horseback-riding-associated TBIs, the Oklahoma State Department of Hea...
Hanson RR, Schumacher J, Humburg J, Dunkerley SC.To evaluate clinical and laboratory findings for horses treated medically for ileal impactions. Methods: Retrospective case series. Methods: 10 horses with primary ileal impaction that were treated successfully with medical treatment alone. Methods: Medical records were reviewed for all horses with naturally developing ileal impaction seen at our hospital between 1990 and 1994. Results: Transrectal palpation revealed an impaction in the midabdominal area in all horses. Generalized distention of the small intestine was evident in 6 horses, whereas 4 horses were examined early in the course of t...
McCarthy PH.A detailed description is given of the methods to locate and palpate a subcutaneous part of the zygomatic branch of the auriculopalpebral nerve in 9 out of 10 adult horses examined. This permits the exact placing of local anaesthetic along the nerve branch at the described site, resulting in the akinesis of the m orbicularis oculi and the elimination of the blink reflex. This facilitates ophthalmologic examination and possible treatment of some eye conditions.
Boersema JH, Eysker M, Maas J, van der Aar WM.The reappearance of strongyle eggs in faeces after treatment with ivermectin or pyrantel embonate was investigated in 22 foals, 36 yearlings, and 45 adult horses on five Dutch horse farms. The results confirmed earlier studies which showed an egg reappearance period of 9 and 6 weeks after ivermectin and pyrantel treatment, respectively. There were no differences between the egg reappearance periods of foals, yearlings, and adult horses. The mean egg counts of the yearlings were, however, consistently higher than the mean egg counts of the adult horses and foals in both ivermectin- and pyrantel...
Lopes-Pereira CM, Harun M, Schmidtova D, Timane I, Mabasso M, Otto F, Bogin E.Adapting the concept of "bed-side" patient analysis, the Boehringer-Mannheim Reflotron was evaluated for its possible use in veterinary medicine under outdoor-field conditions. Horse blood was analysed with the Cobas Bio analyzer, and indoor and outdoor analyses were also performed with the Reflotron. All values showed close agreement with no significant differences. Good correlation coefficients (r values around 0.9000) were also seen between all methods used. The Reflotron was operated under outdoor-field conditions by using, whenever available, an on-farm electricity source, or a gas operat...
Rebecca PH, Linda P.Although the number of small-scale farms is increasing in North America and Europe, few studies have been conducted to better understand environmental management in this sector. We investigate this issue by examining environmental management on horse farms from both the perspective of the "expert" extension educator and horse farm operator. We conducted a Delphi survey and follow-up interviews with extension educators in Indiana and Kentucky. We also conducted interviews and farm assessments with 15 horse farm operators in the two states. Our results suggest a disconnection between the percept...
Trim CM.Complications following the use of the cuffless large animal endotracheal tube during general anesthesia in 2 horses are reported. One horse developed laryngeal edema during recovery. The edema was treated successfully with dexamethasone, but severe laryngeal trauma was confirmed 24 hours later at necropsy. The second horse had a swollen tongue and had difficulty eating for 3 days after anesthesia. The condition resolved without treatment. this report is a reminder of the potential damage which can occur from endotracheal intubation.
Trostle SS, Hendrickson DA.Suture sinuses formed in 3 horses following closure of ventral midline incisions with size-2 polypropylene. Suture sinuses healed after the suture material was removed. Suture sinus formation following closure with polypropylene may be related to the suture material's mechanical, rather than its chemical, properties. If polypropylene is used to close the linea alba in horses, the amount of tissue incorporated in the suture loops, suture tension, and knot volume should be minimized to decrease the risk of suture sinus formation.
Junge HK, Glaus T, Matos JN, Meira C, Schwarz A, Hoey S, Dennler M, Schwarzwald CC, Mitchell KJ.In a 1-day old filly with a loud heart murmur, transthoracic echocardiography revealed right ventricular hypertrophy associated with severe pulmonary valvular stenosis and a transvalvular pressure gradient (between right ventricle and pulmonary artery) of 125 mmHg. Computed tomographic angiography confirmed the finding, with no evidence of other relevant concurrent abnormalities. Balloon valvuloplasty was performed using a single balloon technique. The foal recovered well from anaesthesia. Following the procedure, the right ventricle-pulmonary artery transvalvular gradient decreased to 38 mm...
Beetson SA, Hilbert BJ, Mills JN.The effectiveness of the glutaraldehyde coagulation test (GCT) in detecting failure to acquire colostral immunoglobulin in neonatal foals was investigated. This was achieved by comparing and correlating results from the GCT with those obtained by single radial immunodiffusion (SRID) of equine IgG. The GCT was found to be a practical, inexpensive, semiquantitative test with a high specificity and sensitivity at critical IgG levels.
Geiser DR, Walker RD.The pathophysiology and histopathology of thermal burns in large animals is very similar to that in humans. Burns are classified as first degree, superficial and deep second degree, third degree, and fourth degree, depending upon the depth of thermal injury. Most severe burns will produce a local and a systemic response--both of which must be properly treated to increase the patient's chances for survival. The systemic response is mainly characterized by hypovolemia, fluid and electrolyte loss, protein loss, pulmonary edema, increased caloric requirements, and depressed immune responses. The l...
Byers SW, Dowsett KF, Glover TD.Three stallions were bled each hour for 25 h at 28-day intervals throughout 1 year. Testosterone levels were pulsatile. Pulse frequency and pulse amplitude were higher in the summer months than at other times (P less than 0.01). The number of testosterone pulses also varied throughout the day, with the greatest frequency occurring in the afternoon (14.00-17.00 h) and at night (22.00-01.00 h). Mean testosterone levels were highest in the summer (P less than 0.01) but showed a secondary, smaller increase in the autumn. Semen characteristics were assessed from measurements of 222 stallions. Semen...
Orsini JA, Dikes N, Ruggles A, Charlton C, Perry R.Esophageal obstruction of 1 week's duration in a gelding was diagnosed by contrast radiography and esophagoscopy. A food bolus was found at the junction of the caudal thoracic portion of the esophagus and the cardia. A gastrotomy was performed through a cranial abdominal incision and a phytobezoar was manually broken down and removed. The gelding was started on complete pellet food and water on the fifth day after surgery. The horse remained clinically normal more than 1 year after surgery.
Trump M, Kircher PR, Fürst A.Two fillies with hindlimb lameness and a tentative diagnosis of a pelvic fracture involving the acetabulum were examined using computed tomography (CT). The use of CT for these two cases revealed the exact course of the fractures and fissures, as well as the size and position of fragments, thus allowing for definitive diagnosis.
Smith WN.A system using a suitably sized flotation tank has been developed to reduce the weight that horses and cattle place upon their legs after undergoing surgery to their limbs. The system overcomes the need for the patient to lie down for long periods, thus preventing decubitus. The system is well tolerated with few side effects; after prolonged flotation alopecia may occur on those parts of the patient which remain continuously immersed in water. The method is now commonly referred to as the 'Queensland Sling'.
Wilson SJ, Ward MP.Hendra virus (HeV), a potentially fatal zoonotic disease spread by flying foxes, to date has always infected humans via a spillover event from equine HeV infection. In a theoretical case study, we compared the impacts of two different HeV prevention strategies - vaccination and flying fox roost removal - using a recently developed framework that considers different stakeholder group perspectives. The perspectives of the four selected stakeholder groups regarding intangibles were inferred from public discussions and coverage in the media. For all stakeholder groups, the option to vaccinate hors...
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...
Smyth GB.A 4-year-old Quarter horse gelding presented with a swelling in the soft tissues over the junction of the body and ramus of the left mandible. Radiography showed a well circumscribed lytic area within the mandible surrounded by sclerosis unassociated with any tooth. Aspiration of the lesion yielded pus. The abscess cavity was opened, curetted and lavaged. A Penrose drain was placed in the abscess cavity for 10 days. Bacteriological culture of the exudate and soft tissues from the abscess produced a few colonies of Staphylococcus intermedius. Histopathology showed chronic pyogenic infection. Th...
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...
Gottschalk RD, van den Berg SS.Bilateral ovariectomy was performed in 11 mares and unilateral ovariectomy in 2 mares. The horses were standing and sedated for surgery. After appropriate preparation a laparoscope was inserted into the abdomen through the paralumbar fossa and the ovary was identified and anaesthetised with local anaesthetic via a custom-built needle. The ovary was then withdrawn from the abdomen through a separate flank incision and removed. The abdomen was not distended with gas before surgery. This method proved to be minimally invasive, rapid and effective.
Röcken M, Fürst A, Kummer M, Mosel G, Tschanz T, Lischer CJ.To report use of transendoscopic electrohydraulic shockwave lithotripsy for fragmentation of urinary calculi in horses. Methods: Case series. Methods: Male horses (n = 21). Methods: Fragmentation of cystic calculi (median, 6 cm diameter; range, 4-11 cm diameter) was achieved by transurethral endoscopy in standing sedated horses using an electrohydraulic shockwave fiber introduced through the biopsy channel of an endoscope. The fiber was advanced until it contacted the calculus. Repeated activation of the fiber was used to disrupt the calculus into fragments <1 cm diameter. Visibility within...
Joyce J, Baxter GM, Sarrafian TL, Stashak TS, Trotter G, Frisbie D.To determine the clinical applications, short and long-term survival, and complications of using transfixation pin casts for treatment of comminuted phalangeal fractures in adult horses. Methods: Retrospective case series. Methods: 20 horses. Methods: Medical records were reviewed to obtain information regarding signalment, fracture location, treatment methods, complications, and short-term survival (discharge from hospital). Long-term follow-up information was obtained via contact with owners or trainers. Results: 12 fractures were in a hind limb, and 8 were in a forelimb. Fourteen fractures ...
Chevalier JM, Pearson GB.The objective of this study was to report clinical outcomes of horses with naturally occurring full-thickness skin lacerations treated with an amorphous silicate dressing. We hypothesized that wounds treated with an amorphous silicate dressing would have minimal complications and lesion resolution without formation of exuberant granulation tissue. 11 client-owned horses. Clinical records of 11 horses with distal limb wounds treated with an amorphous silicate dressing were collected from participating veterinarians across the US. Wound healing progression was monitored by the veterinarian and o...
Moeller BC, Sams RA, Guinjab-Cagmat J, Szabo NJ, Colahan P, Stanley SD.Testosterone is an anabolic androgenic steroid (AAS) that is endogenously produced by both male and female horses that also has the potential for abuse when administered exogenously to race horses. To recommend appropriate withdrawal guidelines so that veterinarians can discontinue therapeutic use prior to competition, the pharmacokinetics and elimination of testosterone were investigated. An aqueous testosterone suspension was administered intramuscularly in the neck of Thoroughbred horses (n = 20). The disposition of testosterone from this formulation was characterized by an initial, rapid a...
Costello J, Firshman AM, Brown JC, Maher M, Tadros EM.A 16-year-old American Paint Horse gelding was presented for evaluation of weight loss and high serum thyroid hormone concentrations resulting from a functional thyroid adenoma. The horse showed no response to a thyrotropin-releasing hormone (TRH) stimulation test. Clinical signs resolved following surgical removal of the adenoma. . Un cheval American Paint Horse hongre âgé de 16 ans fut présenté pour évaluation à la suite d’une perte de poids et d’une concentration sérique élevée d’hormone thyroïdienne résultant d’un adénome thyroïdien fonctionnel. Le cheval ne démontrai...
Mirck MH, van Meurs GK.Seven foals naturally infected with Strongyloides westeri were injected intramuscularly with ivermectin at a dosage rate of 200 mcg per kg body weight. No adverse effects to treatment were observed. Weekly faecal egg counts showed a greater than 99 per cent reduction of S. westeri egg output compared with 7 untreated foals during the 21 days following treatment.
Jokisalo JM, Corley KT.RECOVER was created to optimize survival of small animal patients from cardiopulmonary arrest. Several findings from this study are applicable to cardiopulmonary resuscitation in the neonatal foal. In particular, chest compressions should be a priority with no pauses and a "push hard, push fast" approach. The importance of ventilation is minimized with short, infrequent breaths at a rate of 10 to 20 per minute recommended.
Wheeldon EB, Greig WA.The history, clinical signs and post mortem findings in a case of Globidium leuckarti infection in a horse with chronic diarrhoea are described. The limited literature concerning this infection is reviewed, with particular reference to pathogenicity.
Barr B.Diarrhoea is a common problem in the neonatal and suckling foal. In certain circumstances supplemental nutrition is necessary depending on the age of foal, severity of diarrhoea and presence of other systemic manifestations. Nutritional supplementation can be provided either enterally or parenterally. Enteral nutrition is superior to parenteral nutrition because it is the most natural and physiologically sound means to provide nutritional support. Parenteral nutrition may be warranted if the foal is unable to receive or tolerate enteral nutrition. Dextrose alone or with amino acids and lipids ...
Sullins KE, McIlwraith CW.Transverse or oblique midshaft tibial osteotomies were created in 11 foals. The osteotomies were repaired during the same procedure using external skeletal fixation in either full splint or 3-dimensional (3-D) tent configurations. Four of the six foals receiving the full splint fixator recovered to full soundness; two were euthanized because of complications. The foals receiving the 3-D tent configuration would not bear weight on the limbs and consequently suffered significant secondary fracture disease. These foals were euthanized for humane reasons before the scheduled termination of the pro...
Park RD.A complete radiographic examination of the equine foot consists of properly exposed, processed, and positioned radiographs. For radiographic interpretation, in addition to knowing radiographic signs of disease, a knowledge of normal radiographic anatomy and possible insignificant anatomic variations is necessary.
Cooley AJ, Reinhard MK, Gross TL, Fadok VA, Levy M.Widespread cutaneous papules in a yearling Standardbred filly were attributed by light and electron microscopic examination to molluscum contagiosum. Concomitant granulomatous enteritis, suspected clinically due to protein-losing enteropathy, was verified histopathologically. An associated altered altered immune response is suggested as the reason for the widespread poxvirus infection.
Perryman LE.Primary immunodeficiency disorders are genetically determined failures of immune defense that increase susceptibility to infectious agents. This article reviews the salient features of equine primary immunodeficiency disorders, summarizes the molecular mechanisms of each disorder, and updates information that facilitates diagnosis and management of affected horses. The central theme is to encourage clinicians to ask, "I wonder if this horse has an underlying primary immunodeficiency disorder?" when caring for horses suffering from chronic and recurring infections and responding poorly to stand...
Sigel CW, Byars TD, Divers TJ, Murch O, DeAngelis D.Two fasted and 2 fed horses were dosed orally with a combined trimethoprim and sulfadiazine paste formulation at a dose of 35 mg (1:5 combined active ingredients)/kg. Serum concentrations of each drug were determined periodically for 3 consecutive days for the 4 horses. The extent and rate of absorption for trimethoprim were variable, but peak serum concentrations occurred generally within 3 hours; sulfadiazine absorption was slower, reaching peak concentrations by 6 hours. Fasting did not have a consistent effect on the serum concentration profiles for either drug. Both drugs achieved serum c...
Gross DK, Stover SM, Hill AE, Gardner IA.To describe forelimb horseshoe characteristics of horses racing on dirt surfaces and determine whether these characteristics vary with region of California, season, horse characteristics, and race-related factors. Methods: 5,730 Thoroughbred racehorses. Methods: From June 17, 2000, to June 16, 2001, the characteristics of 1 forelimb horseshoe of horses that raced on dirt surfaces at 5 major racetracks in California were recorded. These characteristics included shoe type; toe grab height; and presence of a rim, pad, and heel traction devices (jar caulks, heel stickers, heel blocks, and special ...