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.
Darien BJ, Belknap J, Nietfeld J.Two horses with cerebrospinal nematodiasis (Micronema deletrix) had signs similar to those of other neurologic diseases resulting from parasitic (fly larvae, protozoa, or other helminths) migration through the central nervous system (CNS). In one horse (horse 1), a 13-year-old Paso Fino stallion, the cerebrospinal fluid (CSF) was slightly xanthochromic (1+), with a pleocytosis (25 nucleated cells/microliter) and a normal protein level (69 mg/dl). A CSF differential cell count showed 15% neutrophils, 56% lymphocytes, 22% macrophages, 5% eosinophils, and 2% basophils. In the other horse (horse 2...
Morse CC, Richardson DW.An unusually large, pedunculated (20 cm long) mass arising the gastric pylorus which produced complete obstruction of the proximal duodenum and severe gastric distension was found in a 13-year old castrated male Arabian horse. The histological diagnosis was gastric hyperplastic polyp, which has not been reported previously in the horse. The clinico-pathological findings in this horse are compared with hyperplastic (inflammatory) gastric polyps of man.
Bertone AL, Jones RL, McIlwraith CW.The tarsocrural joints of 11 horses were inoculated with 1.2 to 2.16 x 10(6) viable Staphylococcus aureus organisms susceptible to a trimethoprim-sulfadiazine (TMP-SDZ) combination with minimal inhibitory concentration (MIC) of 0.25 micrograms of TMP/ml and 4.75 micrograms of SDZ/ml. Antimicrobial treatment consisted of oral administration of a TMP-SDZ combination--30 mg/kg of body weight given once daily (group-1 horses) or 60 mg/kg given as 30 mg/kg every 12 hours (group-2 horses). Paired serum and synovial fluid samples were obtained before intra-articular inoculation with the S aureus, aft...
Godsey MS, Amoo F, Yuill TM, Defoliart GR.A serologic survey and experimental virus transmission studies were done to assess the role of domestic animals as amplifier hosts of La Crosse (LACV) and Jamestown Canyon (JCV) viruses. Serum from 319 cows, 88 dogs, 122 equines, 47 swine, 10 goats, and 4 cats were tested for neutralizing antibody to LACV, JCV, trivittatus (TVTV), and snowshoe hare (SSHV) viruses. Antibody prevalences of LACV, TVTV, and SSHV were less than 10% in all species. Antibody to JCV was detected in all species except cats. Prevalence ranged from 10% in goats and swine to 29% in dogs. No age-associated trends in JCV pr...
Manohar M.The present study was carried out 1) to compare blood flow in the costal and crural regions of the equine diaphragm during quiet breathing at rest and during graded exercise and 2) to determine the fraction of cardiac output needed to perfuse the diaphragm during near-maximal exercise. By the use of radionuclide-labeled 15-micron-diam microspheres injected into the left atrium, diaphragmatic and intercostal muscle blood flow was studied in 10 healthy ponies at rest and during three levels of exercise (moderate: 12 mph, heavy: 15 mph, and near-maximal: 19-20 mph) performed on a treadmill. At re...
McLaughlin BG, McLaughlin PS.Samples of equine vitreous humor were analyzed for urea nitrogen, creatinine, sodium, chloride, phosphorus, calcium, potassium, and magnesium concentrations. Fresh vitreous chemical concentrations were compared to corresponding serum concentrations and expressed as a vitreous to serum ratio. The effects of postmortem time and temperature on the stability of the chemical concentrations were determined by incubation of the samples at 4 degrees C, and 20 degrees C and 37 degrees C for 6, 12, 24, or 48 h. Chemical concentrations were generally more stable at lower temperatures and shorter incubati...
Bristol DG, Cullen J.Six animals were used to compare simple interrupted, simple continuous, and stapled techniques for end-to-end rotated small colon anastomoses. Three ponies were evaluated three days after surgery for adhesion formation and luminal diameter at each anastomosis site. Two ponies and one horse were evaluated 14 days after surgery for adhesion formation. All anastomosis sites were examined histologically for alignment of tissue planes, and evidence of inflammation. No single technique was superior in all areas examined. While only three of the nine anastomoses had mild fibrinous adhesions at three ...
Smith P, Samuelson D, Brooks D.The anterior vasculature of the pony eye was examined by the corrosion cast method. The anterior segment of the pony eye has a vascular pattern which is similar but distinct from that of other mammalian species. Large iridal veins collateralized directly with the anterior vortex venous system. The intrascleral plexus was present but formed a fine, radially oriented, extensive network. This contrasted to the circumferential larger-diameter intrascleral plexus noted in dogs and the canal of Schlemm present in primates. The intrascleral plexus only drained posteriorly in the pony as compared to t...
Grosenbaugh DA, Amoss MS, Hood DM, Morgan SJ, Williams JD.Epidermal growth factor (EGF) receptor binding kinetics and EGF-mediated stimulation of DNA synthesis and cellular proliferation were studied in cultured vascular smooth muscle cells (VSMC) from the equine thoracic aorta. Binding studies, using murine 125I-labeled EGF, indicate the presence of a single class of high-affinity binding sites (apparent KD = 2.8 X 10(-11) M), with an estimated maximal binding capacity of 5,800 sites/cell. EGF stimulated [3H]thymidine uptake in confluent quiescent monolayers in a dose-dependent fashion, half-maximal stimulation occurring at 7.5 X 10(-11) M. Likewise...
Manohar M.1. Left ventricular (LV) myocardial O2 extraction was studied in five healthy ponies which had catheters implanted in the great cardiac vein and main pulmonary artery 15-30 days before the study. The abdominal aorta was percutaneously catheterized to sample arterial blood. 2. In addition, phasic LV and aortic pressures, LV dP/dtmax and rate-pressure product were also studied; dP/dtmax is the maximal rate of rise of the left ventricular pressure during the isovolumic phase, and is considered an index of myocardial contractility. Measurements were made at rest (control) and during adenosine infu...
Buergelt CD, Green SL, Mayhew IG, Wilson JH, Merritt AM.The clinical, bacteriologic and pathologic findings of three adult horses suffering from avian tuberculosis are presented. Chronic weight loss and hypoproteinemia were pertinent clinical abnormalities in all three horses. Gross pathologic lesions were characterized by chronic enterocolitis with mesenteric lymphadenopathy in two horses and hepatic granulomas in the third horse. The microscopic diagnoses were chronic, non-caseating granulomatous enterocolitis, and necrotizing, non-mineralizing granulomatous hepatitis, respectively. All three horses had granulomatous lymphadenitis of mesenteric l...
Sweeney CR, Hall J, Fisher JR, Leary HJ, Soma LR, Spencer PA.The efficacy of water vapor-saturated air as a treatment for horses with exercise-induced pulmonary hemorrhage (EIPH) was studied. Horses selected for study (n = 14) had grade 1 or greater hemorrhage in the trachea after a minimum of 4 breezes between 0.8 and 1 km, as determined by endoscopy. Nine horses were treated with water vapor-saturated air; 5 horses were not treated. When the mean and maximal EIPH scores from the pretreatment period were compared with the mean and maximal EIPH scores from the treatment period in both treated and nontreated groups, there was no significant difference be...
Mitema ES, Sangiah S, Martin T.Monensin is extremely toxic to some domestic animals, like the equine species, if they ingest poultry or cattle rations containing the drug. From a treatment standpoint, no specific compounds are known to alleviate or interact with monensin. Effects of some cardiovascular drugs which antagonize calcium influx in cardioskeletal and smooth muscles were evaluated in mice receiving varying lethal doses (80, 100, 120 or 140 mg/kg ip). Calcium channel blockers (verapamil, diltiazem and lidocaine), a calmodulin antagonist (chlorpromazine), adrenergic receptor blockers (yohimbine, tolazoline and propr...
Bertone JJ, Jones RL, Curtis CR.The accuracy of an immunoglobulin (Ig) G test kit for the semiquantitative measurement of IgG concentration was evaluated with serum from 88 foals. Failure of passive transfer (IgG less than 400 mg/dl) was correctly identified in each of 34 samples, and partial failure of passive transfer (400 less than or equal to IgG less than 800 mg/dl) was correctly identified in each of nine samples. Evidence of adequate passive transfer (IgG greater than or equal to 800 mg/dl) was detected in 44 of 45 samples. One sample with 800 mg/dl or more of IgG was incorrectly classified as a partial failure of pas...
Oliveira-Neto MP, Pirmez C, Rangel E, Schubach A, Grimaldi Júnior G.From July 1984 to September 1986, 105 cases of American cutaneous leishmaniasis were studied in a locality closely situated to an urbanized area of the city of Rio de Janeiro, Brazil. Settlement in this area was established at least 20 years ago but the first cases were noted six months prior to the beginning of this study. Cases were almost exclusively cutaneous and ulcerated, with one to six months of evolution. Montenegro's skin tests were positive in all cases and anti-Leishmania antibodies were detected by indirect immunofluorescence test in 74.3% of the patients. Parasites were demonstra...
Rubilar L, Cabreira A, Giacaman L.Thirteen thoroughbred foals with an adult infection and a presumed immature infection with Fasciola hepatica were treated with 12 mg triclabendazole/kg bodyweight. The absence of eggs from samples of faeces examined at intervals up to 110 days after treatment showed that all the animals were cured. In a second trial the same dose of triclabendazole cured 11 of 12 foals whereas nitroxynil at 7 mg/kg cured only six of 12 foals. No side effects were observed after treatment.
Nixon AJ, Stashak TS.Malalignment of the atlas and axis was seen in 4 horses with an idiopathic form of atlantoaxial subluxation characterized by spinal cord compression on extension. The bone structure and density of the atlas and axis were radiographically normal in 3 of the 4 horses. Clinical signs appeared when the horses were 6 to 30 months old, and 3 of the 4 horses had a history of trauma. Although a congenital anomaly could not be ruled out, the cause was thought to be trauma. The horses were moderately to severely ataxic at the time of examination. Myelography revealed compression of the spinal cord at th...
Adams R, Calderwood-Mays MB, Peyton LC.Three horses were examined for ulcerative pharyngitis, which had been unresponsive to treatment. Biopsy specimens of the pharyngeal lesions were characterized histologically by a mixed population of lymphocytes and histiocytes, suggesting chronic inflammation. Only when biopsy specimens of regional lymph nodes revealed this cell population disrupting the lymph node architecture was the diagnosis of malignant lymphoma made.
Bukowiecki CF, Sanders-Shamis M, Bramlage LR.Medial collateral ligament ruptures in horses are rare and difficult to treat. Conservative treatment usually results in degenerative joint disease that causes permanent lameness. Surgical treatment may be an alternative for salvaging horses for breeding purpose.
Brown CM, Kaneene JB, Walker RD.A survey of 584 veterinarians in equine practice was performed to determine their intramuscular injection techniques and the influence of those techniques on the development of clostridial myositis or cellulitis. Usable responses were obtained from 439 veterinarians (75.2%). Of these, 414 used a new needle and syringe for each injection, 241 swabbed the site with a cleansing/disinfectant agent, and 242 swabbed the top of multidose injection bottles with a similar solution. Only 2 clipped the hair at the injection site. Twenty eight of the respondents reported that at least 1 horse developed a ...
Losonsky JM, Kneller SK.Bilateral metacarpophalangeal radiographs of 100 Standardbreds were examined for visualization and location of nutrient foramina of the proximal phalanx. Foramina were located in the dorsal or palmar cortex or were not visible radiographically. Of 100 horses, 45 had bilaterally symmetrical foramina. Left and right proximal phalangeal foramina were asymmetrical in the remaining 55 horses. Of 200 proximal phalangeal foramina (in 100 horses), 78 were in the dorsal cortex, 61 were in the palmar cortex, and 61 were not visible radiographically. A significant (P = 0.05) effect of age or sex could no...
Orsini JA, Nunamaker DN.A 4-year-old Standardbred stallion sustained a severely comminuted fracture involving the second, third, and fourth metacarpal bones. The fracture was repaired using two 14-hole broad dynamic compression plates positioned at 90 degrees to one another, allowing one plate to protect the other in the bending mode. An autologous cancellous bone graft obtained from the tuber coxae was added at the site of the defect in the mid- to upper third of the third metacarpal bone. Complications associated with the fixation included a Staphylococcus aureus infection 5 months after surgery, laminitis that dev...
King JN, Gerring EL.The Limulus amoebocyte lysate assay was used to test for the presence of endotoxin in 37 clinical cases of equine colic. Positive plasma titres were detected in 10 cases and the presence of endotoxin was significantly correlated with a high heart rate, a high packed cell volume and a poor prognosis. High levels of endotoxin were detected in gut contents taken from several sites in the gastrointestinal tract of normal horses.
Dorn PL, Derse D.Deletion analysis of the equine infectious anemia virus long terminal repeat revealed that sequences responsive to virus-specific transactivation are located within the region spanning the transcriptional start site (-31 to +22). In addition, an active exon of a trans-acting factor (tat) was identified downstream of pol and overlapping env (nucleotides 5264 to 5461). Activation by tat is accompanied by an increase in the steady-state levels of mRNA directed by the equine infectious anemia virus long terminal repeat.
Muhktar MM, Timoney JF.Streptococcus equi infection in horses is characterised by intense infiltration of lymph nodes by polymorphonuclear leucocytes (PMNs) suggesting a potent chemotactic response to the organism or its products. Equine PMNs were separated using Ficoll-Hypaque medium and used in an assay of chemotaxis under agarose to study the components of S equi involved in this response. Results showed that complement-derived chemotactic factors generated by activation of the alternative complement pathway were important in chemotactic responses to S equi. Both whole bacteria and peptidoglycan preparations were...
Kolm G, Knapp E, Wagner R, Klein D.Interleukin-1beta (IL-1beta) is a primary cytokine of the skin that has a pivotal role in keratinocyte differentiation, epidermal wound healing and host defense. Pathological increase of cutaneous IL-1beta is associated with edema formation, epidermal hyperproliferation and atopic dermatitis in humans. However, in horses the role of cutaneous IL-1beta in edema formation and allergic skin disease has not been characterised so far. Particularly in Culicoides hypersensitivity (CHS), intradermal injection of Culicoides extract may be associated with enhanced transcription of local IL-1beta. To exa...
Alonso Jde M, Rodrigues KA, Yamada AL, Watanabe MJ, Alves AL, Rodrigues CA, Hussni CA.Heparin is routinely administered in postoperative abdominal surgery aiming to prevent adhesions formation; however, there is no consensus indicating its effectiveness. This study evaluated the effect of heparin on peritoneal reactivity after abdominal surgery, through the association between peritoneal fluid features and ultrasonographic and laparoscopic examination. Ten adult horses were used: control group (CG) and treated group (TG). Both groups underwent laparotomy and small colon enterotomy. TG received subcutaneous heparin at 150 IU/kg every 12 hours for 5 days. The animals underwent ...
Vreman S, Wiemer P, Keesler RI.A 10-year-old KWPN (Royal Warmblood Studbook of the Netherlands) gelding was euthanized after developing severe neurological symptoms preceded by severe epistaxis during laser treatment for progressive ethmoid haematoma (PEH) in the right nasal cavity. Postmortem examination of the head revealed a large amount of clotted blood between the right ventral and dorsal conchae in the nasal cavity and acute haemorrhage in the right subarachnoid space. Histologically, there was moderate, acute polioencephalomalacia in the neuropil adjacent to the haemorrhage. The haemorrhages were most likely caused b...
Denoix JM.Equine diagnostic sonography was initially used for the diagnosis and documentation of tendon injuries. Since 1990, this technique, along with radiography, has become an indispensable imaging procedure for the diagnosis of equine joint injuries. Sonography provides precise diagnostic information on the synovial membrane and fluid, the articular cartilage, subchondral bone and joint margins, the ligaments and menisci, and the anatomical structures involved in periarticular swelling or enlargement. Improvements in ultrasound machines and better superficial and deep image resolution allow us to e...
Brama PA, Rijkenhuizen AB, van Swieten HA, Warmerdam EP.The prognosis of aortic-iliac thrombosis (TAI) is usually considered to be poor, although affected horses are reported to have recovered following treatment with sodium gluconate. This paper presents some diagnostic techniques to monitor the development of hypoxemia in the diseased limb and to visualise the extension of the thrombosis into the femoral artery. Also, a surgical technique using a Fogarty thrombectomy catheter for partial or total removal of thrombi to restore blood flow, is described. One horse recovered completely, allowing it to resume its former career, the other horse improve...
Gruys E, Kok HA, Van Der Werff YD.Post-morten examination of a fourteen-year-old mare of the Gelderland breed, which had been treated for severe dyspnoea and had subsequenlty died, revealed the presence of haemothorax, atelectasis of the lung and a metastasized haemangiosarcoma of the left ovary. The haemothorax could have resulted from rupture of one of the metastases.
Dubuc J, Da Silveira EA.A 3-week old Hanoverian foal was presented with bilateral moderate to severe carpal valgus. The deviations were 10 and 14 degrees, respectively for the left and right carpi and orthogonal radiographs of both front limbs highlighted bilateral persistent ulnar remnants. A partial resection of the ulnar remnants and periosteal transection on the disto-lateral aspect of the radius were performed bilaterally under general anesthesia. The valgus deviations began to improve within the first month and the limbs were almost straight (2 degrees for the left and right carpi) 5 1/2 months after surgery. T...
Kline KE, Moorman VJ.Monitoring activity level has become popular in people and animals. In the horse, these monitors may be helpful for the detection of disease, monitor limb loading after surgery, and assist in rehabilitation. The objective of this study was to evaluate the accuracy of a commercial activity monitor (AM) (FitBit Zip) in horses. In Part 1, four stalled horses had five AMs placed (head, chest, withers, and left forelimb and hindlimbs) with stride length setting of 60.96 cm and were monitored for 24 hours with AM and video. In Part 2, four stalled horses had two AMs placed (left forelimb and hindl...
DeBowes RM.A variety of rectal, perirectal, and coccygeal surgeries can be performed in the standing equine patient if appropriate chemical and physical restraints are available and adequate regional anesthesia can be achieved. Some rectal tears and most rectal prolapses, mass lesions, perirectal abscesses, rectal biopsies, and selected injuries of the tail can be managed without prohibitive difficulty. Severe injuries that compromise the small colon cranial to the peritoneal reflection may require flank laparotomy, midline celiotomy, or humane euthanasia to manage the disease process effectively and app...
McKenzie RK, Gibson IR, Ritmeester A.Three weanling Thoroughbred fillies were presented during autumn with depression, muscle rigidity and, in one case, colic symptoms and cardiovascular shock. Results: All fillies had abnormal physical examinations that included elevated heart rates and respiratory rates coupled with muscle rigidity through the back and rump. Biochemistry revealed markedly elevated creatinine kinase and aspartate aminotransferase which indicated a myopathy. Methods: All three horses were diagnosed with presumptive equine atypical myopathy. The horses received supportive therapy as per the literature available at...
Iacono E, Merlo B, Rizzato G, Mislei B, Govoni N, Tamanini C, Mari G.The aim of the present study was to verify how repeated ovum pick-up (OPU), performed in anestrous and cyclic mares, affect ovarian activity, measured by progesterone (P4) and 17ß-estradiol (E2) plasma levels. Ovum pick-up of all visible follicles was performed every 9 to 12 days, and four sessions were carried out during anestrous (A) and breeding season (BS). The number of aspirated follicles per mare at each session was not significantly different between the two periods (BS: 6.1 ± 2.4; A: 7.5 ± 4.4; P > 0.05), but the mean follicular diameter was significantly higher during BS (16.0 ...
Schoene C, Nedderman AN, Houghton E.Little is known about the metabolism of 17 alpha-alkyl anabolic steroids in horses. In this study, the metabolism of 17 alpha-methyltestosterone is investigated by oral administration of a (1 + 1) mixture of the steroid and its deuteriated analogue. Both compounds were synthesized from dehydroisoandrosterone (DHA), using a Grignard reaction followed by an Oppenauer oxidation. Post-administration urine extracts were analysed by gas chromatography--mass spectrometry (GC-MS) using both electron impact (IE) and chemical ionization (CI). Interpretation of the data was facilitated by observation of ...
Gulevskiĭ AK, Grishchenko VI, Tereshchenko OS, Zagnoĭko VI, Akhremenko AK, Kucherenko SN.The effect of the fraction (1-10 kDa) obtained from the brain of cold-adapted animal (Yakut horse) on Ca2+ transport in sarcolemma vesicles of cardiomyocytes was investigated. It was shown that during insertion of Yakut horse brain fraction into incubation medium at the concentration from 10(-9) M to 3.10(-5) M at Ca2+ transport substrate concentration from 0.1 mM to 1.0 mM, the rate of Ca2+ passive penetration into vesicles slightly increased and at Ca2+ transport substrate concentration 3 mM, which is physiologic, a decrease of rate values was established for all concentrations of the fracti...
Mallem MY, Thuleau A, Noireaud J, Desfontis JC, Gogny M.To investigate the role of superoxide anions in the lipopolysaccharide (LPS)-induced impairment of beta-adrenoceptor-mediated equine digital vein (EDV) vasodilation. Methods: EDVs isolated from forelimbs of 24 healthy adult horses. Methods: Endothelium-intact or endothelium-denuded EDV rings were incubated with or without LPS (10 microg/mL) of Escherichia coli (O55:B5) for 4 hours. Cumulative concentration-relaxation curves resulting from administration of isoprenaline, a nonselective beta-adrenoceptor agonist, or from administration of SR 58611A, a selective beta(3)-adrenoceptor agonist, were...