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.
Ryan C, Giguère S, Hagen J, Hartnett C, Kalyuzhny AE.Peripheral blood mononuclear cells (PBMCs) were obtained from 6 foals <1 week of age, 6 foals between 3 and 4 months of age, and 10 adult horses. PBMCs were stimulated with concanavalin A (ConA) or calcium ionomycin-phorbol myristate acetate (CaI-PMA) and the frequency of interferon IFN-gamma and IL-4 secreting cells was measured using an equine-specific ELISPOT assay. The number of IFN-gamma secreting cells was significantly lower in both groups of foals than in adult horses regardless of the mitogen used for stimulation. The number of IFN-gamma secreting cells was significantly higher in ...
Francisco I, Arias M, Cortiñas FJ, Francisco R, Mochales E, Sánchez JA, Uriarte J, Suárez JL, Morrondo P, Sánchez-Andrade R, Díez-Baños P....Two groups of autochthonous Pura Raza Galega (PRG) horses, one comprising 483 animals under a silvopasturing regime, and the other comprising 72 PRG horses managed in farms, were used to analyse the effect of silvopasture on infection by endoparasites. Results were considered according to the age and the sex of the horses. Faecal samples were individually collected from each animal and analysed by the coprological flotation, sedimentation and migration techniques. Coprocultures were also done to identify the main strongylid genera affecting the horses. Eggs from the gastrointestinal nematoda P...
Cappelli K, Felicetti M, Capomaccio S, Pieramati C, Silvestrelli M, Verini-Supplizi A.The stress response is a critical factor in the training of equine athletes; it is important for performance and for protection of the animal against physio-pathological disorders.In this study, the molecular mechanisms involved in the response to acute and strenuous exercise were investigated using peripheral blood mononuclear cells (PBMCs). Results: Quantitative real-time PCR (qRT-PCR) was used to detect modifications in transcription levels of the genes for matrix metalloproteinase-1 (MMP-1) and interleukin 8 (IL-8), which were derived from previous genome-wide expression analysis. Signific...
Weaver MP, Shaw DJ, Munaiwa G, Fitzpatrick DP, Bellenger CR.The objectives of this study were to topographically map pressure distribution across the palmar surface of the navicular bone in response to forces applied by the deep digital flexor tendon (DDFT), and evaluate the effect of raising the heels in vitro . A rig was constructed to hold an equine cadaver limb and apply controlled pressure to the navicular bone from the DDFT. Pressure-sensitive paper was used to quantify and map the resultant pressure. Changes in response to heel wedges (5 degrees and 10 degrees ) were recorded. The areas subject to maximum pressure from the DDFT were: the central...
Schauvliege S, van Loon G, De Clercq D, Devisscher L, Deprez P, Gasthuys F.To examine the influence of direct current shock application in anaesthetized horses with atrial fibrillation (AF) and to study the effects of cardioversion to sinus rhythm (SR). Methods: Prospective clinical study. Methods: Eight horses successfully treated for AF (transvenous electrical cardioversion after amiodarone pre-treatment). Methods: Cardioversion catheters and a pacing catheter were placed under sedation [detomidine 10 microg kg(-1) intravenously (IV)]. After additional sedation (5-10 microg kg(-1) detomidine, 0.1 mg kg(-1) methadone IV), anaesthesia was induced with ketamine, 2.2 m...
Leclere M, Lavoie JP, Dunn M, Bédard C.Thrombelastography (TEG) is used to evaluate the viscoelastic properties of blood during clotting and provides a global assessment of hemostasis and clot lysis. TEG analysis initiated with recombinant human tissue factor (TF) has not been evaluated in clinically healthy horses. Objective: The purpose of this study was to determine whether TEG results are affected by the time elapsed between sampling and analysis (storage time) of equine blood samples and to establish a preliminary equine reference interval for a modified TEG assay, using recombinant human TF to initiate coagulation. Methods: C...
Vissani MA, Becerra ML, Olguín Perglione C, Tordoya MS, Miño S, Barrandeguy M.Infection with Equid Herpesvirus type 1 (EHV-1) leads to respiratory disease, abortion, and neurological disorders in horses. Molecular epidemiology studies have demonstrated that a single nucleotide polymorphism (A(2254)/G(2254)) in the genome region of the open reading frame 30 (ORF30), which results in an amino acid variation (N(752)/D(752)) of the EHV-1 DNA polymerase, is significantly associated with the neuropathogenic potential of naturally occurring strains. In order to estimate the prevalence of the EHV-1 neuropathogenic genotype in our country, we analyzed the ORF30 genome region of ...
Kumar S, Kanwar S, Bansal V, Sehgal R.Diphtheria toxin has the capacity to block protein synthesis in cultured mammalian cells, and thus causing cell death. This capacity of diphtheria toxin was utilized for in-vitro neutralization test to determine antibody titer, using Vero cells, which have been found to be susceptible to diphtheria toxin. In the present study, a Vero cell assay was standardized and validated for potency estimation of diphtheria antitoxin serum (DATS). The results obtained by Vero cell assay were compared with in-vivo biological assay. High degree of correlation (+0.98) was found between in-vivo biological assa...
Zhang N, Ding S, Kolbanovskiy A, Shastry A, Kuzmin VA, Bolton JL, Patel DJ, Broyde S, Geacintov NE.The equine estrogens equilin (EQ) and equilenin (EN) are the active components in the widely prescribed hormone replacement therapy formulation Premarin. Metabolic activation of EQ and EN generates the catechol 4-hydroxyequilenin (4-OHEN) that autoxidizes to the reactive o-quinone form in aerated aqueous solutions. The o-quinones react predominantly with C, and to a lesser extent with A and G, to form premutagenic cyclic covalent DNA adducts in vitro and in vivo. To obtain insights into the structural properties of these biologically important DNA lesions, we have synthesized site-specifically...
Choi YH, Harding HD, Hartman DL, Obermiller AD, Kurosaka S, McLaughlin KJ, Hinrichs K.The reported patterns of trophectodermal expression of POU5F1 protein in blastocysts vary among species, and are possibly related to the differences in placental growth and function. This study investigated the pattern of embryonic POU5F1 expression in the horse, a species with delayed placental formation. Immature equine oocytes expressed POU5F1 protein in the cytoplasm and nucleus. Staining for POU5F1 protein in in vitro-produced (IVP) embryos decreased to day 5 of culture, then the nuclear staining increased to day 7. IVP day-7 to -11 blastocysts showed POU5F1 staining in nuclei throughout ...
Florindo HF, Pandit S, Gonçalves LM, Videira M, Alpar O, Almeida AJ.Strangles is an infectious disease caused by Streptococcus equi subspecies equi that affects the upper respiratory tract of the Equidae. The control of this disease seems to be dependent on its earlier detection and prevention, but prolonged animal protection without development of strong and severe side effects has not yet been achieved. Convalescent horses exhibit a protective immune response, mainly against SeM (58 kDa), an antiphagocytic and opsonogenic S. equi M-like protein, known as the major protective antigen against strangles. Purified recombinant SeM and S. equi protein extract-entr...
Choi YH, Hartman DL, Fissore RA, Bedford-Guaus SJ, Hinrichs K.We evaluated the effect of different activation methods on blastocyst development after equine nuclear transfer. All activation treatments were followed by incubation in 2 mM 6-dimethylaminopurine for 4 h. In Experiment 1, reconstructed oocytes were injected with sperm extract for 0.1, 0.2, 0.4, 0.8, or 1.6 sec using a FemtoJet injection device, then treated with ionomycin. The blastocyst rate (9.8%) for 0.1-sec injection was significantly higher than that for 0.2 sec (0%) or 0.8 sec (1.4%). In Experiment 2, injection of murine PLCzeta cRNA before or after ionomycin treatment did not increase ...
Puchalski SM, Galuppo LD, Drew CP, Wisner ER.We compared contrast-enhanced computed tomography (CT) and high field magnetic resonance (MR) imaging in a horse with deep digital flexor tendonopathy. Lesions in the distal extremity were documented grossly and histopathologically. In contrast-enhanced CT, the deep digital flexor tendon lesions were markedly contrast enhancing with evidence of angiogenesis in the core and dorsal border lesions. The lesion morphology was clearly delineated on MR imaging, but without contrast media angiogenesis cannot be identified. Gross examination, histopathologic examination, and CD31 immunohistochemistry c...
Koch TG, Thomsen PD, Betts DH.A robust methodology for the isolation of cord blood-derived multipotent mesenchymal stromal cells (CB-MSCs) from fresh umbilical cord blood has not been reported in any species. The objective of this study was to improve the isolation procedure for equine CB-MSCs. Methods: Pre-culture separation of red and white blood cells was done using either PrepaCyte?-EQ medium or Ficoll-Paque? PREMIUM density medium. Regular FBS and MSC-qualified FBS were compared for their ability to support the establishment of putative primary MSC colonies. Conclusions: Our results indicate that PrepaCyte-EQ medium i...
You Y, Uboh CE, Soma LR, Guan F, Li X, Rudy JA, Liu Y, Chen J.An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method for fast-throughput analysis of eight anabolic and androgenic steroids (AAS) in equine plasma is reported. Analytes were recovered by liquid-liquid extraction using methyl tert-butyl ether, separated on a 1.9 microm C(18) reversed-phase column, and analyzed in positive electrospray ionization mode on a triple quadrupole mass spectrometer with selected reaction monitoring (SRM) and full product ion scans. Two SRM ion transitions were monitored for each AAS during screening to obtain highly selective screenin...
Duffy CW, Morrison LJ, Black A, Pinchbeck GL, Christley RM, Schoenefeld A, Tait A, Turner CM, MacLeod A.African animal trypanosomiasis, or Nagana, is a debilitating and economically costly disease with a major impact on animal health in sub-Saharan Africa. Trypanosoma vivax, one of the principal trypanosome species responsible for the disease, infects a wide host range including cattle, goats, horses and donkeys and is transmitted both cyclically by tsetse flies and mechanically by other biting flies, resulting in a distribution covering large swathes of South America and much of sub-Saharan Africa. While there is evidence for mating in some of the related trypanosome species, Trypanosoma brucei...
Sanada Y, Senba H, Mochizuki R, Arakaki H, Gotoh T, Fukumoto S, Nagahata H.To establish a reliable diagnostic measure for equine Anoplocephala perfoliata infection, the impact of deworming was examined in 12 Thoroughbreds to which bithionol (5-10 mg/kg body weight) was administered and feces were examined by the modified Wisconsin method using sucrose solution. One day after the administration, cestode eggs were detected in previously fecal egg-negative 3 horses and increased in the other 9 horses. The optimum time for post-deworming egg detection was examined in following horses: 17 mares were administered bithionol and 10 mares were used as controls. The fecal egg ...
Bowers JR, Slocombe RF.A 4-year-old crossbred, Welsh Mountain Pony gelding was presented with multiple, thick, round, raised, 3 to 8 mm diameter nodular lesions on the medial aspects of both ears. The nodules did not involve the epidermis and were observed to develop over several months. Punch biopsies were taken and histopathological examination returned a diagnosis of auricular chondrosis. Neither auricular chondrosis nor auricular chondritis has been reported in horses, although it has been recorded in cats, dogs, laboratory animals and humans.
Dart AJ, Perkins NR, Dart CM, Jeffcott LB, Canfield P.To evaluate the effect of a non-occlusive dressing incorporated in a 3-layer bandage on second intention healing of wounds of the distal portion of the limb. Methods: Untreated wounds in 33 adult horses used in four studies using the same wound-healing model conducted over 5 years. Methods: Standardised, full-thickness wounds were made in the skin overlying the dorsomedial aspect of the mid-metacarpus; 17 horses were bandaged with a non-occlusive dressing covered by gauze-coated cotton wool that was compressed with adhesive tape; 16 horses were left unbandaged. Wounds were photographed weekly ...
Cheetham J, Pigott JH, Hermanson JW, Campoy L, Soderholm LV, Thorson LM, Ducharme NG.The equine upper airway is highly adapted to provide the extremely high oxygen demand associated with strenuous aerobic exercise in this species. The tongue musculature, innervated by the hypoglossal nerve, plays an important role in airway stability in humans who also have a highly adapted upper airway to allow speech. The role of the hypoglossal nerve in stabilizing the equine upper airway has not been established. Isolated tongues from eight mature horses were dissected to determine the distal anatomy and branching of the equine hypoglossal nerve. Using this information, a peripheral nerve ...
Lopes MS, Diesterbeck U, da Câmara Machado A, Distl O.Navicular disease or podotrochlosis is one of the main causes of progressive forelimb lameness in warmblood horses. The objective of this study was to refine a quantitative trait locus on horse chromosome 2 for radiological alterations in the contour of the navicular bone (RAC) in Hanoverian warmblood horses. Genotyping was performed in 192 Hanoverian warmblood horses from 17 paternal half-sib groups. The marker set was extended to 58 informative microsatellites including nine newly developed microsatellites. QTL for RAC could be delineated at 32.50-43.13 Mb and a further new QTL for RAC could...
Causey RC, Artiushin SC, Crowley IF, Weber JA, Homola AD, Kelley A, Stephenson LA, Opitz HM, Guilmain S, Timoney JF.Attenuated Salmonella enterica serovar Typhimurium MGN707, expressing the SzP protective protein of the MB9 serovar of Streptococcus equi subspecies zooepidemicus (SzP-MB9) was tested for its safety and efficacy as a nebulised intranasal vaccine against streptococcal uterine infections in mares. In a preliminary study, vaccinated mares (n=5) displayed serum, nasal and uterine responses (P<0.05) to S. Typhimurium lipopolysaccharide (St-LPS). Subsequently, vaccinated mares (expressor group, n=7), but not mares vaccinated with the vector only (control group, n=7), displayed significant increas...
Du Toit N, Burden FA, Baedt LG, Shaw DJ, Dixon PM.Equine cheek teeth (CT) diastemata often cause deep periodontal food pocketing and are therefore regarded as a painful dental disorder of equidae. However there appears to be no information available on the size or shape of these diastemata. This post mortem study examined 16 donkey skulls (mean age = 32-years) containing 45 CT diastemata to define the anatomical shape and dimensions of these diastemata, and of the associated periodontal food pockets that occur with this disorder. Diastemata were found to more commonly involve mandibular (56.0%) compared with maxillary CT (44.0%), and 71.0% of...
Bermudez V, Miller RB, Johnson W, Rosendal S, Ruhnke L.The growth of Mycoplasma equigenitalium and Mycoplasma subdolum from specimens collected from the clitoral fossa of each of four Standardbred mares was not diminished by freezing of the specimens in liquid nitrogen (-196 degrees C) for up to 30 days when compared to samples cultured immediately.
McKelvey WA, Owen RR.Case records of 11 horses with acquired torticollis during a 15-year period were reviewed. The cause was established in seven of eight cases and included cervical intervertebral disk protrusion, skull fracture, neurogenic atrophy, and dystrophic myodegeneration. The latter condition was considered to be the most likely cause in the three horses that recovered.
Hooper RN.Necropsy of a 12-year-old Quarter Horse mare revealed a blind-end segment of intestine originating from the antimesenteric border of the ileum. The blind-end segment had looped around and strangulated the ileum and 3.5 m of the jejunum.
Kirkwood NC, Hughes KJ, Stewart AJ.Poor recognition of subtle clinical abnormalities and equivocal ACTH concentrations make early diagnosis of PPID difficult. Progressive clinical findings and corresponding ACTH concentrations in horses transitioning to PPID over time have not been documented. Seven horses with ACTH concentrations equivocal for PPID (utilizing locally derived, seasonally adjusted diagnostic-cut off values (DCOV)) and no clinical signs of PPID were selected. Sequential measurement of basal and thyrotropin-releasing hormone (TRH)-stimulated ACTH concentrations and recording of clinical findings occurred from Octo...
Borisevich IV, Potryvaeva NV, Mel'nikov SA, Evseev AA, Krasnianskiĭ VP, Maksimov VA.Immunoglobulin (Ig) against Marburg fever (MF) has been obtained from the equine serum. In terms of physicochemical and immunobiological properties, the obtained preparation corresponds to the quality of heterologous commercial immunoglobulins. The application of Marburg virus (MV) Ig with a titer of no less than 1:2048 by the emergency prevention scheme 1-2 hours after intraperitoneal inoculation of guinea pigs with MV in a dose of 20-50 LD50 protected 88-100% of the animals from death. MV Ig is recommended for emergency prevention of human MF.
Shokri H.The aim of this study was to investigate the prevalence of Malassezia species from the body skin and external ear canal of healthy horses. The samples were obtained by scraping the skin surface from the nose, groin and dorsum and swabbing from the external ear canal of 163 animals, and then incubated on sabouraud dextrose agar and modified Dixon agar. Malassezia species were isolated from 34.9% of horses. The percentages of Malassezia species were 64.3% for Arab, 35.7% for Persian, 35.4% for Thoroughbred and 27.1% for Turkmen breeds. The greatest abundance of Malassezia species was found in th...
Rudolph W, Remane D, Wissenbach DK, Peters FT.1. Ergopeptine alkaloids like ergovaline and ergotamine are suspected to be associated with fescue toxicosis and ergotism in horses. Information on the metabolism of ergot alkaloids is scarce, especially in horses, but needed for toxicological analysis of these drugs in urine/feces of affected horses. The aim of this study was to investigate the metabolism of ergovaline, ergotamine, ergocristine, and ergocryptine in horses and comparison to humans. 2. Supernatants of alkaloid incubations with equine and human liver S9 fractions were analyzed by reversed-phase liquid-chromatography coupled to h...
Mahmoud AL.From 60 horses showing skin lesions, 42% were positive for fungal infection. Horses less than 2-year old were more susceptible to this infection. Fourteen species belonging to nine genera of keratinophilic and cycloheximide-resistant fungi were recovered from collected specimens. Trichophyton was the dominant genus of which T. equinum was the most common. This species proved to be the main causative agent of ringworm in horses. In addition to dermatophytes, many species of the isolated fungi were keratinophilic. The presence of such fungi on hairs and skin of horses may create an opportunity f...
Leach DH.The future directions of navicular disease research are unclear. Often researchers investigate only one of the multitude of factors likely to be important in understanding the disease. Two exceptions to this is work done by Wright in this issue of EVJ and by MacGregor (1988) who compared a number of the treatment regimens (e.g. rest, warfarin, isoxsuprine, shoeing with egg bars) and found that approximately 75% of the horses improved in their performance. Perhaps this percentage of 'recovered' horses from this disease is what can be realistically expected, as often horses with navicular diseas...
Rawlings CA, Byars TD, Van Noy MK, Bisgard GE.Activated coagulation test (ACT) was performed in 37 adult ponies and 31 adult horses. The mean ACT time of all ponies and horses was 2 minutes 38 seconds, with a standard deviation (SD) of 29 seconds. The ACT was compared with the Lee-White clotting test in heparinized ponies. The correlation of ACT with the Lee-White test was 0.95. Anticoagulation heparinized ponies during prolonged cardiopulmonary bypass was successfully monitored with the ACT. The ACT is simple and reproducible, has a definite end point, and would seem to be an ideal screening test for hemorrhagic diathesis in equine anima...
Bell C, Hnenny L, Torske K.A 5-year-old Hannovarian warmblood gelding was presented for recurrent headshaking exacerbated with exercise. The horse displayed clinical signs of repetitive vertical head movements, face rubbing on the forelimbs and on the ground, repetitive sneezing, and striking the muzzle with his forelimbs. The clinical signs resulted in a horse that could not be ridden and was dangerous. Clinical signs were most persistent in direct sunlight, but occurred with excitement, exercise, or bridling indoors. A diagnosis of equine trigeminal mediated headshaking syndrome was made. Surgical treatment was perfor...
Card C.Morphologic assessment of spermatozoa is one of the most objective measures in a Breeding Soundness Examination of a stallion. There are different systems for morphologic assessment of spermatozoa. The objectives of this article are to review spermatogenesis, describe clinical sample preparation, discuss previous methods of morphologic classification and explain the use of a differential spermiogram. The advantages of the differential spermiogram method of analysis are discussed, along with its use in delineating intrinsic and extrinsic disturbances in spermatogenesis. Case examples of specifi...
Pascoe RR.The epidemiology of dermatomycocis due to Trichophyton equinum var autotrophicum was studied in a number of thoroughbred stables in south-east Queensland. The significant factors in the epidemiology were defined. The infection was readily transmitted, particularly by infected saddle-girths, on which the fungus could survive for 12 months. Mild abrasion from the saddle during work favoured the development of lesions and prolonged the recovery period. A pronounced age and seasonal incidence of the disease was demonstrated as young horses under the age of 3 years were most susceptible, and the ma...
Galera PD, Brooks DE.Keratomycosis in the horse exists in several unique clinical forms. This paper discusses the diagnosis and clinical management of keratomycosis in the horse associated with tear film instability, epithelial keratopathy, subepithelial infiltrates, superficial and deep ulcers, plaques, melting ulcers, descemetoceles, iris prolapse, and stromal abscesses. Prompt diagnosis and aggressive treatment of equine keratomycosis can make a major difference in the maintenance of a cosmetic and visual eye.
Wong CW, Thompson HL, Thong YH, Thornton JR.Bronchoalveolar lavage samples were collected using a fibreoptic endoscope from horses at specified times before and after single bouts of exercise. Lucigenin-dependent phagocytic chemiluminescence was used to assess the effect of exercise on the alveolar macrophage metabolic activity in response to stimulation by opsonised zymosan. A profound suppressive effect on the chemiluminescence production was present throughout the first three days after exercise. However, the cellular composition of lavage fluids was not altered by the exercise. It is suggested that strenuous exercise may jeopardize ...
Sanna G, Pipia AP, Tamponi C, Manca R, Varcasia A, Traversa D, Scala A.Intestinal strongyles (IS) are the most important parasites of equids, due to their high prevalence worldwide, pathogenicity and the spread of drug-resistant populations. Despite the large number of horses bred in Sardinia Island, Italy, no data are available on the efficacy of anthelmintic compounds in the control of horse strongylosis. Therefore the aim of the present study was to evaluate the efficacy of five commercial anthelmintic formulations containing fenbendazole (FBZ), pyrantel (PYR), moxidectin (MOX) and two ivermectin formulations (IVM1 and IVM2) against IS in Sardinia by performin...
Wilks CR, Studdert MJ.The immunological and virological status of 3 foals in respect of equine herpesviruses (EHV) was established and the foals were sequentially infected with EHV2, EHV3 and EHV1. Following experimental infection with EHV2, no clinical signs of disease were observed in any foal. The inoculation of EHV3 into the genital tract resulted in lesions of the mucous membrane and perineal skin that were considered typical of equine coital exanthema. Following intransal inoculation of EHV3 extensive ulceration and pustule formation on the nasal mucosa was observed by day 5 accompanied at day 7 by a profuse,...