Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Hinshaw VS, Naeve CW, Webster RG, Douglas A, Skehel JJ, Bryans J.Influenza outbreaks involving viruses of the H3N8 subtype (equine 2) often occur in vaccinated horses. For this reason, a series of influenza viruses of the H3N8 subtype were examined to determine if antigenic variation could be detected in isolates during the period 1963-81. Antigenic analyses with post-infection ferret sera and monoclonal antibodies showed that the haemagglutinins of recent isolates were antigenically distinguishable from the prototype A/eq/Miami/1/63 and that antigenically distinguishable groups of equine 2 viruses co-circulate in the horse population. Based on these studie...
Studdert MJ.DNA was prepared from 43 equine herpesvirus type 1 (EHV 1) isolates, 11 of which were from horses with respiratory disease, 22 from aborted equine foetuses, and 10 from foals that died perinatally. The restriction endonuclease DNA fingerprints of 10 of the 11 respiratory isolates, known with certainty to have been recovered from horses with respiratory disease, were entirely different from all but 3 of the 32 foetal or perinatal foal isolates. The exceptional respiratory isolate, EHV 1 Army 183, had a foetal (F) strain fingerprint but this virus cannot be said with certainty to have been isola...
Mishra PC, Leach DH.The venous organisation of the dermal lamellae of the equine hoof wall of 18 pairs of forelimb hooves from clinically healthy horses was studied using plastic vascular corrosion casts, and scanning electron microscopic and histological techniques. A consistent pattern of venous organisation was observed in the dermal lamella of the toe, quarter and heel regions. The lamellar corium had an extensive interconnecting capillary network which drained into axially located veins of the primary dermal lamella. Many of the capillaries had a proximodistal orientation and most of those located at the int...
Heyneman RA.The subcellular distribution of the superoxide-forming enzyme in horse polymorphonuclear leukocytes was investigated. After activation of the cells with sodium oleate, a relatively stable and NAD(P)H-dependent oxygen consumption and superoxide production was found in association with the plasma membranes. The pH dependence displayed an optimum near neutrality. The apparent Km values were 38 x 10(-6) mol/l for NADPH and 1,560 x 10(-6) mol/l for NADH, suggesting that NADPH is the physiological donor. The rates of oxygen uptake, O2- production, and NADP consumption were consistent with the stoich...
Drudge JH, Lyons ET, Swerczek TW, Tolliver SC.Cambendazole (CBZ) treatments (20 mg/kg) given at 8-week intervals were used for parasite control in a breeding band of ponies (n = 33 to 43) during the period July 1974 to August 1978. Pre- and posttreatment worm egg counts on feces were used to evaluate efficacy of treatments after every 2nd treatment interval by monitoring changes in strongyle egg counts. Initially, effective reductions (expressed as 92% to 96% fewer worm eggs) were lessened to 70% by the 9th treatment (18 months) and to 28% by the 12th treatment, and thereafter, they fluctuated between 0% and 38%. Critical tests on animals...
Pellegrini A, Zweifel HR, von Fellenberg R.Several publications have described in the past properties of partly purified horse alpha 2-macroglobulin (alpha 2M) which are strikingly different from the human alpha 2M. Horse alpha 2M was therefore isolated to purity by classical procedures, i.e. affinity chromatography, ion exchange chromatography and gel filtration, and its properties are compared with those of its human counterpart. The molecular weight of the native protein and its subunits, the isoelectrofocusing pattern and the change in electrophoretic mobility caused by interaction with protease were similar to those of human alpha...
Braend M, Clegg JB, Storset A.In a breeding experiment a stallion of the native Norwegian Trotter breed with an abnormal Hb haplotype (N) and with the Hb type BI/N, sired 6 offspring. The abnormal haplotype controls one α-chain only, having lysine at position 60 and phenylalanine at position 24. Three of the offspring received the N haplotype from the sire and the BII haplotype from the dam, whereas the other 3 offspring received BI from the sire. The BII/N horses have two Hb components after alkaline electrophoresis or isoelectric focusing with the ratio between the fast and the slow band (anodal, cathodal) being approxi...
Bailey E.The linkage group formed by the ELA and A blood group system in horses was studied in American Standardbred horses. The distance between the ELA locus and the A blood group locus was measured as 1.61 centimorgans, observing only the haplotypes contributed by the sires. Strong linkage disequilibrium was found in pacing Standardbred horses for ELA-W1 with Aa, ELA-W5 with Ab and ELA-W10 with Ab. Linkage disequilibrium was apparent at both the population and family level. Among trotting Standardbred horses, linkage disequilibrium was found for ELA-W1 with Aa and for ELA-W10 with Ab. It was not pos...
Svalastoga E, Nielsen K.The histopathological changes in the synovial membrane of bursa podotrochlearis are described in horses with navicular disease. The changes are compared to the histopathological findings in synovial membrane of arthrotic pastern joints in horses and of arthrotic hips in man. A high degree of concordance is demonstrated and this suggests that navicular disease is an arthrotic disease.
Svalastoga E, Smith M.The subchondral bone pressure in the navicular bone of horses with navicular disease is compared with corresponding pressures in normal horses. An increased intraosseous pressure and a lengthened pressure drop time was demonstrated in patients with navicular disease, which indicates the existence of a venous stasis. Compared with similar investigations in humans with arthrosis it is concluded that navicular disease is a condition resembling arthrosis. The classical clinical symptoms are explained as an expression of resting pains. Treatments are suggested which theoretically can render the pat...
Ostlund C, Pero RW, Olsson B.1. The reproducibility of blood pressure determinations on 103 male horses gave an average coefficient of variation of 5.0%. 2. Different parameters affecting the methodology of blood pressure measurements were separately analysed; i.e. size of specimen, size of cuff in relationship to tail circumference and temperature of the environment. 3. A strong positive linear correlation between age and blood pressure in the horse was established for two breeds with widely varying genetic background--Swedish Warmbloods and Arabians.
Pascoe RR.Within a group of 130 mares which, in the event, carried twin pregnancies, 29 (22.3 per cent) produced their twins following diagnosis of a single palpable follicle at service and a single pregnancy 42 days later. The whole group of 130 twin-pregnant mares gave birth to only 17 live foals (13 per cent). Breeding results for the following season were available for 102 of these mares, when 38 (37 per cent) produced live foals. Thus over the two seasons an average 23 per cent of this group produced live foals. In a second group, comprising 70 mares, twin pregnancy had been diagnosed in all of the...
Vonderfecht SL, Bowling AT, Cohen M.A congenital and probably hereditary neurological defect has been identified in the intestinal tract of six foals produced from the breeding of overo (a type of spotting pattern) horses. The foals had white hair and pink skin with the exception of occasional pigmented foci about the muzzle, ventral abdomen, and hindquarters. The foals appeared normal at birth, but within a few hours developed symptoms of colic. At necropsy, the only significant finding was a narrow, pale segment of large intestine. This abnormality either was confined to the small colon and rectum or involved the entire colon ...
Foster NM, Barber TL, Walton TE.Venezuelan equine encephalomyelitis (VEE) TC-84 vaccinal virus, from 10-1. quantities of infected duck embryo fibroblast cell culture fluids, was isolated by combined continuous-flow centrifugation with isopycnic banding in sucrose. Most of the recovered infectivity and hemagglutinating activity were in a single band at a buoyant density (rho) of 1.2. About 90% of the total input protein (450-520 mg) was removed with the effluent, whereas most of the remaining 10% also banded at a rho of 1.2. Infectivity was inactivated with formalin at a final concentration of 0.05% at 37 degrees C for 24 hr....
Leach D, Oliphant L.Incidental to studies of keratinization of the equine hoof wall, annular gap junctions were found in the stratum spinosum of the intertubular horn of the stratum medium. Adjacent cells of the stratum spinosum showed extensive gap junctions, and often local invaginations of one cell into another were bound by gap junctions. It is proposed that these invaginations become detached from the cell surface to form the annular gap junctions. Formation of annular gap junctions may be a means of disposing of plasma membrane in response to changes in cell volume or shape occurring in keratinization. Inte...
Timoney PJ, Dillon PB, Geraghty VP, McArdle JF.Aspects of experimental transmission of the causal bacterium of contagious equine metritis (CEM) to albino Swiss mice were investigated. Whereas infection was established in the majority of female mice, the organism was recovered from only a limited number of male mice after challenge. No clinical evidence of infection was observed in the experimental mice. There was only one instance of presumptive venereal transmission of the CEM bacterium. One third of infected females conceived and had normal litters.
Campbell TM, Studdert MJ, Blackney MH.Some kinetic data on the inactivation of equine herpesvirus type 1 (EHV1) and equine rhinovirus type 1 (ERhV1) by betapropiolactone (BPL) and ultraviolet (UV) irradiation are reported. 0.25% BPL at 37 degrees C for 1 h reduced the titre of EHV1 by greater than 10(3 . 4) and of ERhV1 by greater than 10(4 . 1) TCID50/ml. UV irradiation (334 microW/cm2) produced similar reductions in titre after 2 min. These data were used as a basis for inactivating EHV1 and ERhV1 by the combined action of BPL and UV irradiation. Viruses were exposed to 0.1% BPL for 1 h at 4 degrees C with constant stirring, fol...
Nes N, Lømo OM, Bjerkås I.In 4 female foals of the Norwegian horse breed, "Fjord Horse", congenital arthrogryposis of the limbs are described. The disorder was mainly limited to the hind limbs and associated with polydactylia and partly with brachygnathia superior and cleft palate. The defective foals were paternal halfsisters of 4 normal foals (1 female + 3 males), sired by the stallion "Bingo" 1804, which was phenotypically quite normal. The disorder being lethal, is possibly caused by a sex-limited or a strongly sex-influenced dominant gene.
Heizmann CW, Berchtold MW, Rowlerson AM.The physiological role of the Ca2+-binding protein parvalbumin in skeletal muscle has been investigated by measuring the parvalbumin content by HPLC in a variety of mammalian muscles, including man, and comparing the results with the respective muscle relaxation properties and fiber type compositions. The parvalbumin concentrations were highest in the skeletal muscles of the smallest animal investigated (mouse, gastrocnemius: 4.9 g/kg), which has the highest relaxation speed, and lowest in the larger animals (horse, deep gluteal muscle: less than or equal to 0.001 g/kg) and man (vastus, tricep...
Meyers K, Reed S, Keck M, Clem M, Bayly W.Twenty-three horses with clinical signs of gastrointestinal disease were evaluated once or serially during the course of the disease for the presence or absence of circulating endotoxin-like substances (ET+ or ET-) and whether the horses were negative, positive, or very positive for serum fibrin/fibrinogen degradation products (FDP-, FDP+, or FDP++). In addition, platelet count, activated partial thromboplastin time (APTT), and 1-stage prothrombin time (OSPT) were measured. When examined initially, 5 horses were ET-/FDP-, 8 were ET-/FDP+, 7 were ET+/FDP-, 3 were ET+/FDP+, and none was ET+/FDP+...
Allen WE, Clarke AR.Plasma concentrations of sodium benzylpenicillin following intrauterine infusion were increased by reducing the volume of solution and expelling air from the vagina after infusion. Instillation of 10 per cent Lugol's iodine solution into the uterus before penicillin infusion further increased the absorption rate, although peak plasma levels of penicillin were less than half those which resulted from intramuscular injection of the same dose.
White NA, Moore JN, Douglas M.This paper describes the histological and scanning electron microscopical examinations of the right colic artery of eight ponies. Lesions all had large thrombi surrounding a larva or larvae, with arterial wall thickening. Endothelial shape change, degeneration and loss were present. Fibrin-platelet red blood cell aggregates were present on endothelial surfaces as well as on the surface of thrombi. Damage to the intima appeared to produce the conditions for progressive thrombus formation.
Houpt KA.Some of the techniques that may be used to study social, reproductive, and ingestive behavior in horses are described in this paper. One of the aspects of equine social behavior is the dominance hierarchy or patterns of agonistic behavior. Paired or group feeding from a single food source may be used to determine dominance hierarchies quickly. Focal animal studies of undisturbed groups of horses may also be used; this method takes longer, but may reveal affiliative as well as agonistic relationships among the horses. Reproductive behavior includes flehmen, the functional significance of which ...
Barr AR, Sridhar B, Denny HR.Five horses with long incomplete longitudinal fractures of the third metacarpal bone and three horses with similar fractures of the third metatarsal bone were examined. In three of the metacarpal fractures a long incomplete fissure extended proximomedially, in association with the more common lateral condylar fracture of the third metacarpal bone, and in the other two cases the fracture originated from the medial aspect of the distal articular surface. In the three horses with fractures of the third metatarsal bone the fractures had a consistent spiral configuration.
Capik I, Ledecky V, Mihály M.Abnormalities of dental development such as hypoplasia of cementum, oligodontia, polydontia, enamel hypoplasia, brachygnathia, and prognathia are quite common in the horse. Abnormalities of eruption are less common and often associated with trauma. This case report describes the diagnosis and therapy for pre-eruption displacement of the maxillary left third and fourth premolar teeth resulting from previous facial trauma in a 1.5-year-old filly.