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.
Vacek JR, Ford TS, Honnas CM.Communications between the femoropatellar, medial femorotibial, and lateral femorotibial joints were studied, using fresh equine cadaver specimens. A total of 90 specimens from 45 horses were used. Horses were randomly assigned to 3 groups with 15 horses/group. Each group was assigned an injection site (femoropatellar joint, medial femorotibial joint, or lateral femorotibial joint), and red latex was injected into the respective location of each joint in each group. Immediately after injection, the joints were flexed and extended 100 times. The stifles were frozen in slight flexion, then cut i...
Zaugg JL, Lane VM.We evaluated the efficacy of buparvaquone in eliminating infection with Babesia equi of European origin in carrier horses and in splenectomized horses with experimentally induced acute infection. When administered at the rate of 5 mg/kg of body weight, IV, 4 times at 48-hour intervals, buparvaquone prompted rapid abatement of parasitemia. However, secondary and tertiary recrudescent parasitemias invariably returned with establishment of the carrier state. Buparvaquone, at the dosage evaluated, had transitory therapeutic efficacy against acute B equi infection in splenectomized horses, but was ...
Proudman CJ, Edwards GB.A centrifugation/flotation technique for the identification of equine tapeworm eggs is described. It was validated by using faeces samples from 80 horses of known tapeworm status, and had a sensitivity of 61 per cent and a specificity of 98 per cent. The exclusion of false negative results in animals with less than 20 tapeworms increased the sensitivity to 92 per cent. No significant correlation was found between the number of eggs observed and the number of tapeworms present in the horses.
Watson TD, Murphy D, Love S.The background, clinical signs, blood biochemistry and management of 18 cases of equine hyperlipaemia are described. Eleven of the animals were Shetland ponies, four were Welsh mountain ponies or their crosses, one was a fell pony and two were riding ponies of mixed breeding. Their average age was nine years. Fourteen of the cases were mares, of which nine were in foal and two were lactating; the remainder were geldings. Underlying or concurrent diseases were identified in only six animals, but in one other animal the hyperlipaemia appeared to have been precipitated by stress, and in another b...
Dahlgren LA, DeBowes RM, Gift LJ, Veatch JK.Heterotopic salivary tissue was diagnosed in a 7-month-old Quarter Horse colt with a history of a draining wound in the left temporal region from time of birth. Surgical excision of the tract was performed for diagnosis and treatment. Histologically, tissues were compatible with a mixed-type salivary gland, most likely of parotid salivary gland origin. Complete resolution of the drainage was achieved after surgical removal of the ectopic tissue.
Chaffin MK, Schumacher J, Hooper N.A 5-month-old male Quarter Horse was examined because of multicentric, granulomatous, cutaneous lesions of the dorsum and prepuce. The cutaneous lesions were excised, and sodium iodide was administered orally for 2 weeks. Multicentric cutaneous pythiosis was diagnosed by histologic examination and immunoperoxidase staining of excised tissues. By 3 months after surgery, all lesions had healed.
Knottenbelt DC, Harrison LJ, Peacock PJ.Three foals under four weeks old and two under six months old with a history of oesophageal obstruction, had oesophageal strictures of different characters in the rostral cervical oesophagus. One case, which was complicated by severe inhalation pneumonia, was euthanased without any treatment and in another initial treatment by bougienage under general anaesthesia was attempted without success. The four surviving cases were provided with progressively firmer and coarser food, starting with liquid only, over a period of three to four weeks. The treatment is recommended in the early stages of str...
Geor RJ, Becker RL, Kanara EW, Hovda LR, Sweeney WH, Winter TF, Rorick JK, Ruth GR, Hope E, Murphy MJ.Fever, limb edema, and laminitis were observed in horses 18 to 36 hours after they consumed hoary alyssum (Berteroa incana) under field and experimental conditions. Clinical signs were not observed in all horses that had ingested the plant. Diagnosis in the field cases was limited to observation of clinical signs and evidence of plant ingestion in hay or on pasture. In most cases, clinical remission was observed 2 to 4 days after empirical treatment, removal of the plant source, or both.
O'Donohue DD, Smith FH, Strickland KL.A two part survey was carried out in Irish Thoroughbred horses in 1988 and 1989 to establish the incidence and prevalence of developmental skeletal problems, particularly possible manifestations of developmental orthopaedic disease (DOD). Survey One was a retrospective study based on a questionnaire involving the foal crops of 46 stud farms for 3 successive seasons; the 1711 animals initially documented represented 10.46% of Irish foal registrations. The second survey involved repeated monitoring of the 1988 foal crop from birth to 18 months of age on 17 stud farms. The 248 foals initially exa...
Ekfalck A, Rodriguez H, Obel N.LAMINITIS after abdominal surgery is a well known
complication that may occur after the horse has recovered from
colic (McIlwraith and Turner 1987). We had the opportunity to
examine a horse with post-surgical laminitis with a peracute
course whose early death made it possible to gain material from
the acute stage for histopathological investigations. We consider
that our observations may be of some value for colleagues
interested in the pathogenesis of laminitis.
Ball MA, Weldon AD.A 5-year-old Appaloosa gelding was presented with a history of intermittent multiple joint swelling, weight loss, and anemia. Physical examination and clinical pathology revealed a grade IV/VI holodiastolic murmur, louder on the left, and a marked hyperproteinemia. Echocardiography of the heart demonstrated a large vegetative lesion on one of the aortic valve cusps. Blood cultures did not elucidate the causative organism, and the disease was refractory to empiric antibiotic therapy. The horse was euthanized after approximately 2 months of therapy.
Logas D, Kunkle G, Calderwood-Mays M, Frank L.An 8-year-old gelding, with a 1-year history of intense pruritus only after exercise, was diagnosed as having cholinergic pruritus. Provocative testing, using exercise and hot-water baths to increase core body temperature, assisted in the diagnosis. Cholinergic pruritus in human beings is a variant of the more common syndrome, cholinergic urticaria, which is characterized by intense pruritus and pinpoint urticaria. With cholinergic pruritus, intense itching results without urticaria. Specific diagnostic laboratory tests have not been developed.
Perkins NR, Robertson JT, Colon LA.A 15-year-old Standard-bred mare was examined because of signs of abdominal discomfort in late gestation. Palpation per rectum revealed tight broad ligaments above and below the uterus, with the right broad ligament running across the top of the uterine body down toward the left, ventral side of the abdomen. A diagnosis of counterclockwise uterine torsion was made and surgical correction was approached via a left, flank laparotomy with the horse standing. The uterus was repositioned and a uterine tear encompassing 180 degrees of the uterine surface was found in the lateral, uterine body just c...
van Muiswinkel K.Based on three clinical cases, the history and the clinical and radiological aspects of osteochondrosis in horses are discussed. The prognosis, therapy and consequences with regard to athletic soundness and use for breeding are described.
Weaver JC, Stover SM, O'Brien TR.The sites of bony attachment of the tendons, ligaments, and fibrous portion of the joint capsules of the equine metacarpophalangeal (fetlock) joint region were determined by gross dissection. These sites were transposed to standard radiographic views of the fetlock joint to yield illustrations that can be used as an aid in the diagnosis of soft tissue pathology from radiographs. Evidence of direct attachment of the common digital extensor tendon to the proximal phalanx was not found. Branches of the superficial digital flexor tendon were found to insert only on the middle phalanx. The recently...
Sinha AK, Rose RJ, Pozgaj I, Hoh JF.The histochemical ATPase method for muscle fibre typing was first described by Brooke and Kaiser in 1970. However, problems have been found with the subdivision of type II fibres using this technique. To determine whether indirect myosin immunocytochemistry using anti-slow (5-4D), anti-fast (1A10) and anti-fast red (5-2B) monoclonal antibodies with cross reactivity for type I, II and IIa fibres, respectively, in a number of species, could identify three fibre types in equine skeletal muscle, data on fibre type composition and fibre size obtained using the two different techniques were compared...
Sweeney CR, Humber KA, Roby KA.Tracheobronchial aspirates obtained from 66 healthy Thoroughbred racehorses in training at the same track were examined. Twenty-seven percent of the horses had greater than 20% neutrophils in the aspirate. Eosinophils, mast cells, giant cells, and Curschmann's spirals of mucus were observed in 94, 83, 65, and 42% of the horses, respectively. Hemosiderophages were observed in 86% of the horses, half of which had previous confirmation of exercise-induced pulmonary hemorrhage. Although fungal elements were seen in 70% of the horses, bacteria were detected in only 3% of the horses. The authors con...
Dart AJ, Snyder JR.A 14-month-old Arabian colt was admitted for treatment of an articular fracture of the supraglenoid tubercle of the right forelimb. Successful repair was achieved by use of three 5.5-mm cortical screws placed in lag fashion across the fracture line. In other reports of supraglenoid tubercle fractures in horses, investigators have preferred conservative management or surgical removal of the fragment, because of limited success with internal fixation. Use of three 5.5-mm screws placed in lag fashion may offer an alternative method of treatment in selected cases of supraglenoid tubercle fractures...
Adeyefa CA.The precipitin response of the mitogen produced by Strongylus vulgaris arterial larvae was investigated. IgG (T) from the sera of horses naturally infected with S. vulgaris adults and arterial larvae recognised the presence of two antigenic components of the mitogenic fractions. The results obtained seem to confirm that these antigens are immunogenic in stimulating the production of increased levels of IgG(T) in infected animals, and showed that the procedures could be used as immunological tools in the diagnosis of S. vulgaris infection.
Vice JD, Shoemaker RS, Cho DY.A 2-year old Thoroughbred filly was examined for a 1-month history of persistent nasal discharge. Contrast radiography revealed a circumscribed mass within the right maxillary sinus which extended to the frontal sinus and ethmoid labyrinth. A discrete attachment of the mass to the ethmoid labyrinth was identified at surgery. Surgical removal of the mass eliminated the nasal discharge. On gross examination, the external structure of the mass was similar to a turbinate with a thin bony wall covered by a smooth mucosal membrane. The internal structure of the lesion had a lining membrane with mult...
Doxey DL, Pogson DM, Milne EM, Gilmour JS, Chisholm HK.Damage to the neurons of selected autonomic ganglia was quantified in relation to the severity of the clinical signs shown in acute, subacute and chronic cases of dysautonomia (grass sickness). No connection between the clinical severity of acute or subacute dysautonomia and the amount of neuronal damage in the superior cervical, stellate and coeliaco-mesenteric ganglia could be demonstrated. However, a higher proportion of normal neurons were found in chronic cases. Jejunal submucosal neuronal damage was correlated with clinical severity but further work is required to confirm this finding an...
Marquardt J, Heymer J, Heinz H, Deegen E, Adolf GR, Leibold W.Interferon is known to induce antiviral mechanisms and to exert immunoregulatory capacities on various cell types. The antiviral capacity of recombinant equine interferon-beta 1 (rEqIFN-beta 1) is most sensitively monitored by indirect quantitation of multiplication of vesicular stomatitis virus (VSV) in blood cells of horses. As few as 0.5 pg rEqIFN-beta 1/ml can be assessed by means of 90% reduction of VSV-replication in whole blood (w.b.) as well as in isolated mononuclear blood cells (MNC) in spite of individual variations. The immunoregulatory influence of 20-50 pg rEqIFN-beta 1/ml is suf...
Allen WR, Bracher V.During a 5-year period 65 Pony and 20 Thoroughbred pregnant mares were subjected to videoendoscopic hysteroscopy from 10 to 266 days of gestation. The aims of these examinations were to 1) observe foetal and placental development in vivo (60 Pony and 10 Thoroughbred mares); 2) eliminate one of unicornuate twin conceptuses (9 Thoroughbred mares); 3) recover embryonic foetal and placental tissues non-surgically for experimental purposes (47 Pony mares); 4) induce focal separation of the placenta in late gestation as an experimental model of placentitis (5 pony mares and 1 Thoroughbred mare). It ...
Kim EJ, Kim BH, Yang S, Choi EJ, Shin YJ, Song JY, Shin YK.In this study, antibody responses after equine influenza vaccination were investigated among 1,098 horses in Korea using the hemagglutination inhibition (HI) assay. The equine influenza viruses, A/equine/South Africa/4/03 (H3N8) and A/equine/Wildeshausen/1/08 (H3N8), were used as antigens in the HI assay. The mean seropositive rates were 91.7% (geometric mean antibody levels (GMT), 56.8) and 93.6% (GMT, 105.2) for A/equine/South Africa/4/03 and A/equine/Wildeshausen/1/08, respectively. Yearlings and two-year-olds in training exhibited lower positive rates (68.1% (GMT, 14) and 61.7% (GMT, 11.9)...
Barker WH, Wright IM.Accurate description of the calcaneal insertions of the superficial digital flexor tendon (SDFT) is lacking and inconsistent. The aim of this study was to undertake morphologic and morphometic evaluations of these structures to assist in elucidating their functional and pathogenic roles in displacement of the SDFT from the calcaneal tuber. Methods: Dissections were performed on 10 normal cadaveric hindlimbs. The anatomy was photographed to allow measurements at repeatable locations and differences in SDFT dimensions at the various locations were compared using a paired student t-test. Results:...
Riley CB, Cruz AM, Bailey JV, Barber SM, Fretz PB.Many uncomplicated umbilical hernias have been managed successfully in foals by the application of a hernia clamp. Isolated reports of complications following clamp application have led some authors to suggest that it is an unsuitable method of treatment. Little information has been published comparing the complication rates associated with the use of hernia clamps and herniorrhaphy in the treatment of umbilical hernias. The purpose of this retrospective study was to report the characteristics of clinical cases of umbilical hernia and to compare the complication rates following these 2 treatme...
Carter BG, Schneider RK, Hardy J, Bramlage LR, Bertone AL.Fractures of the humerus were diagnosed in horses at The Ohio State University Veterinary Teaching Hospital. Twenty-four horses (44.4%) were destroyed after radiographic assessment (mean age of 5.0 years). Surgical treatment was elected in 13 horses (24.1%, mean age of 0.42 years). Conservative management, consisting of prolonged stall rest, was chosen for 17 horses (31.5%, mean age of 2.2 years). In the surgically treated group, 3 foals (23.1%) all less than 2 months of age at the time of fracture and treated with intramedullary stack pinning, survived and became athletically sound. After con...
Brugmans F, Deegen E.To determine the efficacy of laparoscopic surgical techniques for repair of rectal lacerations in horses. Methods: Experimental study. Methods: Thirty-two segments of equine bowel placed in an equine pelvitrainer, 8 equine cadavers, and 3 normal horses. Methods: In experiment 1, 3 laparoscopic intestinal-repair techniques were evaluated in an equine pelvitrainer: suturing with needle holders, with an automatic suture device, and stapling with a hernia stapler. In experiment 2, descending colon lacerations were sutured laparoscopically using needle holders in a pelvitrainer and in equine cadave...
Beelitz P, Gothe R.In this epidemiological study 127 horses from five breeding farms in Upper Bavaria were included. The horses were coproscopically examined in intervals of four weeks over a 16-month period. Since 1992 in all farms regular prophylactic treatments with anthelmintics have been carried out. In 127 horses at least five species were established, such as Parascaris equorum, Anoplocephala perfoliata, Gasterophilus intestinalis and small strongyles, whose third stage larvae were characterized by eight or twelve intestinal cells. Infections with small strongyles occurred most frequently, followed by G. ...
Magnarelli LA, Van Andel AE, Ijdo JW, Heimer R, Fikrig E.To diagnose granulocytic ehrlichiosis in horses, compare results of indirect fluorescent antibody (IFA) staining procedures with those of immunoblot analysis, and compare serologic test findings with polymerase chain reaction (PCR) results. Methods: 69 horses with high rectal temperatures (> or = 39 C) and lethargy, anorexia, or limb edema. Methods: 43 convalescent serum samples obtained from 38 horses 2 to 18 weeks after onset of illness were analyzed by use of immunoblot procedures and IFA staining methods, using the NCH-1 or BDS ehrlichial strains. Blood samples from 69 acutely ill horse...
Noguera Cender A, Mählman K, Lischer CJ.To describe and evaluate an alternative technique for tenoscopic resection of the manica flexoria (MF). Methods: Descriptive study. Methods: Equine cadaver forelimbs and hind limbs (n = 36). Methods: Three surgeons varying in experience resected the MF in 12 limbs. The procedure was divided into six steps, including resection of the lateral/medial borders of the MF with a hook knife and resection of the proximal border with a micro scalpel. Outcomes compared between surgeons included completeness of resection, appearance of the margins of resection, appearance of the resected MF, collateral da...
Marly-Voquer C, Schwarzwald CC, Bettschart-Wolfensberger R.Five horses were presented for treatment of atrial fibrillation by transvenous electrical cardioversion (TVEC). A dexmedetomidine infusion was administered for sedation during positioning of the cardioversion catheters, and continued during general anesthesia. Shocks were applied until return to sinus rhythm. Dexmedetomidine infusion provided excellent conditions for TVEC catheter placement and procedure. Utilisation d’une perfusion continue de dexmedetomidine lors de cardioversion électrique transveineuse chez le cheval: une série de cas. Cinq chevaux présentant une fibrillation atriale ...
Parente EJ, Russau AL, Birks EK.Mild lameness is considered a performance-limiting problem that may escape detection until it worsens, and is considered the primary reason for reduced racing performance. The kinematics changes associated with a lame horse at the trot have been demonstrated previously, but the metabolic cost of these alterations in their gait have not been demonstrated. Six fit Thoroughbred horses with an established VO2max participated in 4 trials using a randomised cross-over design study, separated by 10-14 days. The horses were tested with one of 4 trial conditions: lead forelimb lameness (LL); off-lead f...
Evans JW, Roser JF, Mikuckis GM.Human chorionic gonadotrophin (hCG) can be used to study horse luteinizing hormone (LH) receptors in stallion testicular tissue. hCG was more stable than horse LH during radioiodination when compared by their abilities to bind to testicular receptor sites. During incubation, neither hormone lost binding activity at 4 degrees C. Horse LH lost binding activity during incubation at 25 degrees C and both hormones lost binding activity at 37 degrees C. Both hormones bound to the same receptor sites which are specific for the hormones. The receptor sites were not degraded when incubated at 4 degrees...
Crane SA, Ziemer EL, Sweeney CR.Thirty-eight tracheobronchial aspirates (TBA) were collected from twenty 1 to 6-month-old foals, which were free of clinical signs of respiratory tract or other infectious disease. We collected TBA from 9 of the foals 3 times when they were approximately 8, 16, and 24 weeks old. Aspirates were examined cytologically after staining with modified Wright-Giemsa, Gram, toluidine blue, and prussian blue stains. Aerobic bacterial culturing was performed on all aspirates. Of the 20 initial TBA, 4 (20%) were normal cytologically on the basis of previously defined criteria for TBA from clinically norma...
Craig TM.Internal parasites of horses are ubiquitous but that does not suppose that the level of infection does not vary with climatic conditions. Climate determines the limits of where a parasite species can survive the external environment and weather determines the transmission pattern within the climatic bounds [Levine, N.D., 1963. Adv. Vet. Sci. 8, 215-261]. Arid areas have a more limited exposure potential to important parasites but the level of exposure can nonetheless lead to disease. It must be remembered that, even in arid areas, it does rain and irrigation, overflow from water troughs, dew d...
Jacob RJ.Preliminary experiments have revealed that several laboratory and wild-type strains of the equine herpesvirus (EHV) triad were temperature-sensitive for growth when assayed at 39 degrees C. The efficiencies of plating (EOP) observed were 10(-2) for both EHV 1 and 2, and 1 X 10(-6) for EHV 3. The EOPs were determined by plaque assays which compared titrations at 34 degrees C and 39 degrees C on equine fetal dermal fibroblast cells. Growth yield experiments, assayed at 34 degrees C, reflected those EOP's, but did not indicate any difference in yields when infected cultures were incubated at 34 d...
Eberhardt C, Schwarzwald CC.In horses, persistent atrial dysfunction is a prognostic indicator of recurrence of atrial fibrillation (AF). The objective of this study was to quantify left atrial (LA) contractile function in Warmblood horses after successful cardioversion of AF to sinus rhythm, using standard two-dimensional echocardiography (2DE) and two-dimensional speckle tracking (2DST) analyses, and to provide proof-of-concept for use of 2DST to detect LA contractile dysfunction in horses. Methods: Nineteen Warmblood horses with AF and successful transvenous electrical cardioversion (TVEC) or medical cardioversion usi...
Plummer CE, Kallberg ME, Ollivier FJ, Barrie KP, Brooks DE.To describe and evaluate a surgical technique utilized for the therapy of deep corneal stromal abscesses (DSA) in horses. The DSA is excised and replaced with a partial thickness corneal lamellar allograft. Methods: A retrospective clinical study describing the indications for the surgical technique utilized and the outcomes of this procedure in 10 eyes of 10 horses. Results: Each affected eye had a discrete DSA within the posterior stroma. An initial partial thickness semicircular corneal incision was made at the limbus, followed by anterior stromal lamellar dissection over the lesion. After ...
Benbarek H, Deby-Dupont G, Deby C, Serteyn D.The capacity of the two cytokines TNF-alpha and IL-1beta to directly stimulate the oxidative activity of polymorphonuclear neutrophils remains debated. The purpose of this study was to verify if a direct stimulation of equine neutrophils by TNF-alpha and IL-1beta was possible. Equine neutrophils were isolated from blood by discontinuous density gradient centrifugation. The cell viability after isolation was >98%. The neutrophils were used at 1.25 x 10(6) cells by assay, immediately after isolation. The oxidative activity of neutrophils was measured by luminol- or lucigenin-enhanced chemilumine...
Nout-Lomas YS, Page KM, Kang HG, Aanstoos ME, Greene HM.There is poor agreement between observers of equine neurological gait abnormalities using the modified Mayhew grading scale. Objective: To stimulate a dose-dependent ataxia in horses through xylazine administration and identify quantifiable relevant gait parameters. Methods: Balanced, randomised, 2-way crossover design. Methods: Eight horses were assessed before and after administration of xylazine (low dose and high dose). Gait analyses performed before and after xylazine administration included: 1) kinematic data collected on an equine high-speed treadmill (flat and 10% decline) and from acc...
Sannajust K, Spriet M, Anishchenko S, Beylin D.Maximal standardized uptake values (SUV ) are commonly used for the interpretation of PET studies. Limited information regarding the SUV of F-NaF PET in horses is currently available in the literature. The goals of this retrospective secondary analysis study were to provide reference values for F-NaF SUV in the equine distal extremity and assess the effect of attenuation correction. Nonattenuation corrected (NAC) and CT-based attenuation corrected (CTAC) SUV were obtained from 19 feet and 19 fetlocks. Twenty regions of interest (ROIs) were defined for the foot and 22 for the fetlock. Areas p...
Abraham M, Reef VB, Sweeney RW, Navas de Solís C.Ultrasonographic appearance of the gastrointestinal (GI) tract of equine neonates has not been completely described. Objective: To describe (1) sonographic characteristics of the GI segments in normal nonsedated equine neonates, (2) intra- and interobserver variation in wall thickness, and (3) the sonographic appearance of asymptomatic intussusceptions, and (4) to compare age and sonographic findings of foals with and without asymptomatic intussusceptions. Methods: Eighteen healthy Standardbred foals ≤5 days of age. Methods: Prospective, cross-sectional blinded study. Gastrointestinal sonogr...
Murray MJ, Grodinsky C, Cowles RR, Hawkins WL, Forfa RJ, Luba NK.Gastroendoscopic examinations were conducted on thirty-two 2- to 60-day-old Thoroughbred foals on 5 breeding farms. Repeat gastroendoscopic examinations were performed 35 to 135 days after the initial examination, with the age of foals ranging from 39 to 190 days. On initial endoscopic examination, lesions consisting of ulcers and/or erosions were most prevalent in the stratified squamous epithelial mucosa adjacent to the margo plicatus along the greater curvature of the stomach (15 of 32 foals), and were observed much less frequently at other sites within the stomach. In addition to ulcers an...
Diesterbeck U, Distl O.Navicular disease or podotrochlosis has long been known to cause forelimb lameness in horses. It had been proposed that the development of podotrochlosis has similarities to the human osteoarthritis (OA) complex. Alterations of the navicular bone can be made visible early in life only on the basis of radiographs. Reports on the prevalences of navicular disease indicate that radiological alterations in the navicular bone are present in different warmblood populations at frequencies of between 14.9% and 87.6%. Genetic factors play an important role in the development of the radiological signs. E...
Uhlinger C, Kristula M.Anthelmintic schedules that alternate between drug classes are widely used in horses. However, the results of investigations in which ovine nematode parasites were used have established that alternation of drug classes does not delay the development of drug resistance. This field study was designed to assess the effect of alternation of drug classes on the development of oxibendazole (OBZ) resistance in benzimidazole (BZD)-resistant equine small strongyles. A privately owned herd of horses was used for this study. These animals grazed the same pasture and had been treated with the same anthelm...
Asano K, Suzuki K, Chiba M, Sera K, Asano R, Sakai T.To investigate the relationships between trace elements concentrations in hair and atrial fibrillation (AF) in horses, concentrations of nineteen trace elements were detected in hair using the particle induced X-ray emission (PIXE) method. The horses were assigned to either control (n=22, no abnormalities) or AF groups (n=5) based on electrocardiograph findings. The mean concentrations of Ca and Zn in the hair of the AF group were significantly higher than those in the control group. The Zn/Cu ratio of the hair in the AF group (29.8 +/- 5.5) was significantly higher than that in the control gr...
Madewell BR, Munn RJ.Abnormal irregularly branched and anastomosing tubules within cisternae of endoplasmic reticulum were observed by transmission electron microscopy in tumour cells comprising connective tissue neoplasms (sarcoids) from three horses and a mule. These tubuloreticular inclusions were also observed in cultured tumour cells from one of these horses examined, but were not detected in fibroblasts (fibrocytes), epidermis, or vascular endothelial cells in skin biopsy specimens from five clinically healthy horses, nor in one additional equine connective tissue neoplasm.
Frost AB, Larsen F, Larsen SW, Østergaard J, Thomsen MH, Stürup S, Andersen PH, Larsen C.To establish a pharmacokinetic model for the model drug, sodium diatrizoate (DTZ), allowing joint disappearance kinetics to be estimated from serum appearance kinetics following intra-articular administration, and to calculate the relative joint exposure after intravenous and intra-articular DTZ administration (F(iv/IA)). Methods: Each of five horses received an aqueous solution of 3.9 mg/kg sodium diatrizoate both intravenously and intra-articularly separated by a one-week wash out period. Serum and synovial samples were collected over 7 h and analyzed for content of model compound using indu...
Machida N, Tanaka Y, Taya K, Nakamura T.A case of congenital ovarian interstitial cell hamartoma in a thoroughbred foal that died of apparent nutritional myopathy (white-muscle disease) 14 h after birth is described. An incidental finding at necropsy was a pale brown, mushroom-shaped, pedunculated mass (6 x 4 x 3 cm) attached to the left ovary. On the cut surface, the mass had a peripheral rim of dense parenchyma (3-5 mm wide), surrounding a pale gelatinous core. Histologically, the mass consisted of a peripheral zone of densely packed large cells that were quite similar, morphologically, to fetal ovarian interstitial cells, and a c...
Ledbetter EC, Irby NL, Schaefer DM.To describe in vivo corneal confocal microscopy of horses with microscopic corneal foreign bodies and to correlate findings with clinical, cytological, and histopathologic evaluations of clinical cases and foreign body morphologies observed in vitro with the confocal microscope. Methods: Five horses with microscopic corneal foreign bodies. Methods: Sedated and anesthetized horses were examined with a modified Heidelberg Retina Tomograph II and Rostock Cornea Module. Confocal microscopy images were compared with images from cytologic and histopathologic corneal samples. To establish microscopic...
Norman WM, Court MH, Greenblatt DJ.To evaluate changes in the pharmacokinetic disposition of diazepam in foals from 4 to 84 days of age. Methods: 4 male and 2 female full-term mixed-breed foals. Methods: Diazepam terminal half-life, volume of distribution, clearance, free fraction, unbound volume of distribution, free clearance, peak desmethyldiazepam concentration, and area under the desmethyldiazepam concentration-time curve were determined after i.v. administration of 0.25 mg of diazepam/kg of body weight to foals at 4, 21, 42, and 84 days of age. Results: Disposition of diazepam was best described using a two-compartment mo...
Branch MV, Murray RC, Dyson SJ, Goodship AE.Osteoarthritis (OA) is a common cause of distal tarsal pain, but disease development is poorly understood. Awareness of normal tarsal structure and function is important in order to understand the pathogenesis of OA. Thickening of the subchondral bone (SCB) plate has been related to the development of OA, but SCB plate patterns in the equine tarsus have not been documented. Objective: There is a repeatable pattern of SCB thickness across the distal tarsal joints, and specifically that thickness would be greatest dorsally and laterally. Methods: Twenty cadaver tarsi were collected from mature h...
