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.
Mobarak MS, Ryan MF.Light, scanning, and transmission electron microscopy were employed to provide further data on the putative origins of the immunogenic secretory-excretory product (ESP) of Strongylus vulgaris (Looss 1900). The sharply delineated but superficial attachment to the equine caecum by the mouth leaves behind an oval area devoid of epithelial cells. Attachment does not extend deeply enough to reach the muscularis mucosa layer of the equine intestine. The progressive digestion of the ingested plug of tissue (epithelial cells, blood cells and mucous) was visualized. The coelomocytes, floating cells and...
Julliand V, de Vaux A, Millet L, Fonty G.Detection and quantification of cellulolytic bacteria with oligonucleotide probes showed that Ruminococcus flavefaciens was the predominant species in the pony and donkey cecum. Fibrobacter succinogenes and Ruminococcus albus were present at low levels. Four isolates, morphologically resembling R. flavefaciens, differed from ruminal strains by their carbohydrate utilization and their end products of cellobiose fermentation.
Adams AP, Santschi EM, Mellencamp MA.A silver chloride-coated nylon wound dressing (Ag-WD) was evaluated in vitro for antimicrobial activity against five common equine wound pathogens. Methods: Bacterial susceptibility study. Methods: Equine wound pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus equi subspecies zooepidemicus, and Staphylococcus aureus. Methods: An inoculum of each pathogen was incubated directly with Ag-WD and quantitated after 24 to 48 hours of incubation. To determine if bactericidal activity of Ag-WD was contact dependent, an inoculum of E. coli and Staphylococcus aureu...
Akimenko ZA, Ofitserov VI, Shaprov VV, Iastrebov SI.Homogeneous (according to PAGE) capsid and surface viral proteins were isolated from concentrated purified suspensions of tick-borne encephalitis and Venezuelan equine encephalomyelitis viruses by one-stage reversed-phase HPLC. The amino acid composition and the sequences of their N-terminal parts were determined.
van 't Klooster AT, Hallebeek JM, Beynen AC.The diet of horses should cover the energy and nutrient requirements of these animals. The desired composition of the ration depends on its digestion in the equine gastrointestinal tract. Nutritional problems or diseases caused by incorrect composition of the ration or by incorrect feeding should be prevented. The digestion of carbohydrates, fats, and proteins in the different parts of the gastrointestinal tract is described. In addition, the recently introduced net energy and digestible protein evaluation systems for feeds, and the energy and protein requirements of horses are presented.
Oxburgh L, Hagström A.In this paper we describe the development of a nested RT-PCR assay for the rapid diagnosis and characterisation of influenza virus directly from clinical specimens. Viral RNA is extracted from nasal swabs by the guanidine thiocyanate extraction method, and subsequently reverse transcribed. The complementary DNA is then used as template in a nested PCR reaction. Primers designed for use in this assay are specific for three templates; (1) the nucleoprotein (NP) gene, (2) the haemagglutinin gene of the H7N7 equine influenza virus (A1), and (3) the haemagglutinin gene of the H3N8 equine influenza ...
Marshall DE, Gower DB, Silver M, Fowden A, Houghton E.Equine umbilicus was cannulated in utero and a series of cord plasma samples removed for analysis. After steroid extraction and derivatisation, gas chromatographic-mass spectrometric (GC-MS) analysis demonstrated large differences in steroid content between the plasma samples obtained from the umbilical artery and vein, the blood supplies leading to and from the placental surface, respectively. 3Beta-hydroxy-5,7-androstadien-17-one, dehydroepiandrosterone, pregnenolone, 3beta-hydroxy-5alpha-pregnan-20-one, 5-pregnene-3beta,20beta-diol and 5beta-pregnane-3beta,20beta-diol were identified as maj...
Meyers SA, Rosenberger AE.Sperm hyaluronidase has been implicated in sperm penetration of the extracellular matrix of the cumulus oophorus and may play a crucial role in gamete interaction and fertility in mammals. The objectives of this study were to characterize the enzyme activity of equine sperm hyaluronidase and to investigate its cellular distribution. Zymography of stallion sperm plasma membrane extracts was used to identify hyaluronidase activity in protein bands. Affinity-purified polyclonal IgG raised against equine sperm hyaluronidase was used to label fresh and capacitated stallion sperm, followed by indire...
Dell'Aquila ME, De Felici M, Massari S, Maritato F, Minoia P.In vitro fertilization (IVF) has had poor success in the horse, a situation related to low rates of sperm penetration through the zona pellucida (ZP). Zona pellucida hardening (ZPH) is seen in mouse and rat oocytes cultured in serum-free medium. The hardened ZP is refractory to sperm penetration. Fetuin, a component of fetal calf serum, inhibits ZPH and allows normal fertilization rates in oocytes cultured in the absence of serum. We evaluated whether fetuin is present in horse serum and follicular fluid (FF) and whether fetuin could inhibit ZPH in equine oocytes matured in vitro, thus increas...
Rees WA, Harkins JD, Lu M, Holland RE, Lehner AF, Tobin T, Chambers TM.To determine pharmacokinetics of single and multiple doses of rimantadine hydrochloride in horses and to evaluate prophylactic efficacy of rimantadine in influenza virus-infected horses. Methods: 5 clinically normal horses and 8 horses seronegative to influenza A. Methods: Horses were given rimantadine (7 mg/kg of body weight, i.v., once; 15 mg/kg, p.o., once; 30 mg/kg, p.o., once; and 30 mg/kg, p.o., q 12 h for 4 days) to determine disposition kinetics. Efficacy in induced infections was determined in horses seronegative to influenza virus A2. Rimantadine was administered (30 mg/kg, p.o., q 1...
Hong CB, Van Meter PW, Latimer CL.A malignant rhabdoid tumour was diagnosed in the orbit of a 2-year-old Thoroughbred filly. The neoplasm, which was very aggressive, was present in nearly every part of the ocular and periocular structures and had spread to the lymph nodes of the head and neck, the salivary glands and the subcutaneous tissues around the eye. The neoplasm was composed of polygonal cells with abundant eosinophilic cytoplasm. Many cells had a large, vesiculate, indented nucleus and contained a paranuclear globular inclusion. Ultrastructurally, the inclusions were seen to consist of whorls of intermediate filaments...
Balasuriya UB, Snijder EJ, van Dinten LC, Heidner HW, Wilson WD, Hedges JF, Hullinger PJ, MacLachlan NJ.Virus derived from an infectious cDNA clone of equine arteritis virus (EAV030H) was intranasally inoculated into two stallions, neither of which subsequently developed clinical manifestations of equine viral arteritis (EVA). Virus was isolated from nasal swabs and mononuclear cells collected from both stallions =14 days p.i. and from the semen of one stallion only at 7 days p.i. Similarly, viral RNA was detected by RT nested-PCR in nasal swabs and mononuclear cells for =14 days p.i. and at 7 days p.i. in the semen of the one stallion. Both stallions seroconverted to EAV by 10 days p.i. and...
Lunn DP, Soboll G, Schram BR, Quass J, McGregor MW, Drape RJ, Macklin MD, McCabe DE, Swain WF, Olsen CW.Equine influenza virus infection remains one of the most important infectious diseases of the horse, yet current vaccines offer only limited protection. The equine immune response to natural influenza virus infection results in long-term protective immunity, and is characterized by mucosal IgA and serum IgGa and IgGb antibody responses. DNA vaccination offers a radical alternative to conventional vaccines, with the potential to generate the same protective immune responses seen following viral infection. Antigen-specific antibody isotype responses in serum and mucosal secretions were studied i...
Christley RM, Hodgson DR, Rose RJ, Reid SW, Hodgson JL.Cytological and bacteriological results from tracheal fluid samples obtained endoscopically using a telescoping, plugged catheter (TPC) were compared with results from samples collected by percutaneous transtracheal aspiration (PTA). The TPC technique and PTA were performed in random order on 9 healthy Standardbred geldings. Three weeks later the procedures were performed on the same horses in the reverse order. The presence of oropharyngeal contamination was determined by quantitative bacteriology and quantification of squamous epithelial cells (SEC)/ml sample. The relative numbers of macroph...
Parlevliet JM, Colenbrander B.In the selection procedure to acquire a breeding licence, 3-year-old Dutch Warmblood stallions have to undergo a breeding soundness test It is questioned whether this evaluation is predictive of the stallion's fertility results in the first breeding season. Therefore, semen parameters at the beginning of their first breeding season were evaluated and correlated to nonreturn at first cycle and foaling rate of mares bred by stallions (n = 13). The total number of mares inseminated with chilled semen from those stallions was 1055. Semen parameters were recorded on 2 ejaculates, collected 1 h apar...
Bailey SR, Elliott J.Endotoxin has been implicated in the pathophysiology of acute laminitis. The aim of this study was to examine the direct effects of endotoxin on isolated equine digital blood vessels. Equine digital veins (EDV), incubated in Krebs-Henseleit solution containing lipopolysaccharide (LPS) (1 microg/ml) became hyporesponsive to 5-HT after 16 h. Cycloheximide and ibuprofen blocked this effect of LPS and increased the maximum response obtained to 5-HT when compared to control vessels. L-nitroarginine methyl ester (L-NAME) reversed the hyporesponsiveness caused by LPS. Vessels maintained in culture me...
Katwa LC, Johnson PJ, Ganjam VK, Kreeger JM, Messer NT.Biosynthesis of endothelin-1 (ET-1), the most potent endogenous vasoconstrictor yet identified, is increased following myocardial infarction (MI) in man. Pathological events which occur in the connective tissues of the equine hoof during laminitis are similar in some respects, to changes occurring in the myocardial connective tissues following MI in man. The objective of this study was to determine whether ET-1 expression in connective tissues obtained from the hoof of laminitic horses is increased compared with tissues obtained from healthy horses. Expression of ET-1 in connective tissues of ...
Petersen SL, Botes C, Olivier A, Guthrie AJ.Laser therapy is used in many countries, including South Africa, for the treatment of skin wounds. Low level galium aluminium arsenide (GaAlAs) laser was administered to full thickness skin wounds (3 x 3 cm) induced surgically on the dorsal aspect of the metacarpophalangeal joints of 6 crossbred horses in a randomised, blind, controlled study. Treated wounds that received a daily laser dosage of 2 J/cm2 were compared with nontreated control wounds on the opposite leg. There were no wound complications. Both groups of wounds were cleaned daily using tap water. Wound contraction and epithelialis...
Morley PS, Townsend HG, Bogdan JR, Haines DM.To evaluate efficacy of a commercial vaccine for prevention of infectious upper respiratory tract disease (IURD) caused by equine influenza virus. Methods: Double-masked, randomized, controlled field trial. Methods: 462 horses stabled at a Thoroughbred racetrack. Methods: Vaccine or saline solution placebo was administered 4 times in the population at 6-week intervals. The vaccine contained 3 strains of inactivated influenza virus, and inactivated equine herpesvirus type 4. Horses received 1 or 2 doses of vaccine or placebo prior to onset of a natural influenza epidemic, and were examined 5 d/...
Hutchens DE, Paul AJ, DiPietro JA, Lock TF, Jones CJ, Rowley DD, Wallace RW.A controlled test was conducted to assess the efficacy bioequivalence of a single dose of 0.5% fenbendazole (FBZ) top dress pellets to a 10% FBZ suspension formulation (Panacur suspension 10%, Hoechst Roussel Vet). Thirty horses with naturally-acquired parasite infections, in replicates of three, were used. Strongyle egg per gram counts were not significantly different (P>0.1) between groups pretreatment, but FBZ treated groups were significantly different from the control group post-treatment. At necropsy, which occurred seven to nine days post-treatment, two methods of nematode recovery were...
Ramina A, Dalla Valle L, De Mas S, Tisato E, Zuin A, Renier M, Cuteri V, Valente C, Cancellotti FM.The reverse transcriptase polymerase chain reaction (RT-PCR) assay was used to detect Equine Arteritis Virus (EAV) in the semen of 88 horses and 2 donkeys, with neutralising antibodies against EAV, on the basis of the amplification of a 279 bp long fragment located in the viral polymerase gene. The RT-PCR assay revealed the virus at 4 TCID50/ml in cell culture and showed a greater sensitivity (54.4%) than cell culture isolation (33.3%). Moreover, the two samples of donkey semen were found positive. The cDNAs obtained from 14 samples of horse and 2 of donkey semen were sequenced. Comparing the ...
McIlwraith CW.Tearing of the medial palmar intercarpal ligament is described in 45 intercarpal (midcarpal) joints in 42 horses (37 racehorses, 5 non-racehorses). Of the 37 racehorses, there were 20 Quarter Horses, 14 Thoroughbreds and 3 Standardbreds. The patients had been referred for arthroscopic surgery for removal of osteochondral chip fragments that had been diagnosed radiographically or diagnostic arthroscopy of a persistent carpal problem. The problem was unilateral in 39 horses and bilateral in 3. The presenting clinical signs were lameness and/or persistent synovial effusion. In one instance, the p...
Park RD, Morgan JP, O'Brien T.The incidence of chip fractures in carpal bones and the distal end of the radius in the horse was determined. The radial carpal bone was involved 50% of the time, with the distal end of the radius and intermediate and 3rd carpal bones being involved less frequently. Nine locations were designated where chip fractures in the carpus occurred most often.
A higher incidence of fractures was noticed from the right carpus, with slab fractures of the 3rd carpal bone being noticed more frequently on the right front limb.
Reef VB.A 10-year-old Quarter Horse mare was referred for evaluation and treatment of a large pectoral skin slough and hemoglobinuria. The skin slough was secondary to Clostridium perfringens cellulitis and associated gas gangrene. Cold hemagglutinin disease was diagnosed and was suspected to be secondary to C perfringens septicemia. The autoimmune hemolytic anemia, severe intravascular hemolysis, and hemoglobinuria were treated with dexamethasone and hydrocortisone. The infection was treated with 20 X 10(6) units of sodium penicillin, IV, 4 times daily, and the wound was debrided. When the mare relap...
Burbidge HM, Kannegieter N, Dickson LR, Goulden BE, Badcoe L.Iohexol, a water soluble non-ionic contrast agent, was evaluated for myelography in the horse. Both 300 and 350 mg iodine/ml iohexol gave diagnostic cervical myelograms. Pathological changes were limited to extradural oedema and an increase in the number of white blood cells and specific gravity in the cerebrospinal fluid two days after myelography. This increase in white blood cells in the cerebrospinal fluid was, however, much less than that recorded by other authors using metrizamide and iopamidol contrast media. These findings indicate that iohexol is a less irritant myelographic contrast ...
Sugar O.Reports of pathologic investigations as to the cause of intermittent claudication in horses were made in France in October, 1831, by veterinarian Jean-François Bouley. Obstructive clots in the femoral arteries were found to be responsible for the muscular changes causing limping. Bouley's work in the horse was used by Charcot in 1858 to understand the mechanism of claudication in the case of a soldier with gunshot wound in whom a traumatic aneurysm, clotting, and ischemia of the legs developed. This was not, however, the first medically reported case of human claudication from vascular occlus...
Valberg SJ, Schultz AE, Finno CJ, Bellone RR, Hughes SS.The prevalence of clinical signs and factors triggering muscle atrophy and rhabdomyolysis associated with an MYH1 mutation in Quarter Horses and related breeds (QH) remain poorly understood. Objective: Determine the prevalence and potential triggers of atrophy and stiffness in horses homozygous reference (N/N), heterozygous (My/N), and homozygous (My/My) for the MYH1 mutation. Methods: Two-hundred seventy-five N/N, 100 My/N, and 10 My/My QH. Methods: A retrospective case-control study using a closed-ended questionnaire completed by clients of the Veterinary Genetics Laboratory at the Universit...
Beck NF, Khalid M, Charles JM, Abbas SK, Care AD.The objective of the present study was to determine whether parathyroid hormone-related peptide (PTHrP) is present in the equine follicular fluid and if so, how it is related to the follicular development in the horse. For this purpose, ovaries were collected from 40 Thoroughbred and Thoroughbred Cross mares at slaughter during the period from February to May. Normal growing follicles were dissected from the ovaries of each mare and their diameters measured. A total of 174 follicles was used in this study. The follicular fluid was aspirated from each follicle and assayed for PTHrP, oestradiol ...
Bryans JT.The immunogenic potency and safety of a chemically inactivated equine herpesvirus 1 vaccine with added adjuvant was evaluated by testing serum-neutralizing and complement-fixation antibody responses of pregnant Thoroughbred mares. The vaccinated population comprised 321 pregnant mares on 7 farms; 3 in Normandy, France; 1 in Kildare, Ireland; and 3 in central Kentucky. The pattern of antibody response to vaccination was found qualitatively and quantitatively similar to that of pregnant mares previously vaccinated and determined by challenge exposure to be immune to abortigenic infection under e...
Nocera I, Aliboni B, Sgorbini M, Gracia-Calvo LA, Conte G, Ben David L, Citi S.Ultrasound (US) is a well-established technique for investigating joint diseases in horses, complementary to radiography. Few studies have been performed on the ultrasonographic aspect of the elbow joint in horses and no reports are available on donkeys. The aim of this study is to describe the ultrasonographic appearance of the elbow joint in healthy donkeys. Descriptive cohort study included 34 elbow joints, which were evaluated in 17 donkeys. Inclusion criteria included no lameness or musculoskeletal diseases in the donkeys. The structures evaluated were the lateral and medial collateral li...