In vivo studies involving horses refer to research conducted within living organisms to understand various biological processes, disease mechanisms, and therapeutic interventions in equine species. These studies provide insights into the physiological and pathological responses of horses under natural conditions. In vivo research encompasses a range of investigations, including pharmacokinetics, disease modeling, and the evaluation of treatment efficacy. It often involves the use of controlled environments to simulate real-life scenarios while observing the effects of specific variables on equine health. This page gathers peer-reviewed research articles and scholarly studies that explore the methodologies, findings, and implications of in vivo research in horses, contributing to the advancement of equine science and veterinary medicine.
Treffers HP, Heidelberger M, Freund J.1. Two horses were injected subcutaneously with alum-precipitated rabbit serum albumin. 2. The resulting antibody resembled diphtheria antitoxin and anti-egg albumin in the horse in giving a sharp zone of flocculation with antigen, in being water-soluble, in reactivity toward an anti-antibody rabbit serum, and in its electrophoretic properties. 3. The effect of continued immunization, and of variation in volume and temperature on the reactivity of the antibody are discussed. 4. Intravenous injection of the same antigen into horses did not give rise to detectable amounts of antibody of the same...
Olitsky PK, Cox HR, Syverton JT.We have studied certain properties, additional to those previously described (3), of the virus of vesicular stomatitis of horses, and of the characteristic biological reactions of the virus of equine encephalomyelitis. It has been found that the virus of stomatitis, ordinarily dermotropic, can acquire neurotropism and the neurotropic encephalomyelitis virus can, in turn, be rendered dermotropic in its action. The neurotropism in both instances is associated with definite, although not pronounced, viscerotropism. Both viruses can bring about a similar infection in the white mouse, rat, guinea p...
Woods AC, Chesney AM.A filterable agent has been obtained from the humors and tissues of the eyes of horses suffering from active periodic ophthalmia. The intra-vitreous injection of this filtrate produced in normal horses the same clinical and pathological picture observed in the natural disease. This filtrate injected into rabbits produced a different clinical picture, but the essential pathological lesions closely resembled those found in horses. After passage of the filterable agent through six generations of rabbits, it again produced the clinical and pathological picture of the natural disease when injected ...
Reimann HA.It is conceivable that a change from the virulent, non-phagocytable S form of Pneumococcus to the avirulent phagocytable R form may take place in pneumococcus disease, but the experiments here reported do not settle the question whether or not this is an important factor in determining the outcome in natural infection. It has been shown experimentally that the degradation from the S form to the R form actually does take place in cultures of Pneumococcus growing in agar subcutaneously embedded in guinea pigs, in agar enclosed in vials subcutaneously embedded in rabbits, and spontaneously in the...
Wadsworth AB, Kirkbride MB.Horses immunized to Type I pneumococci developed serum, 0.1 cc. of which protected against 0.5 cc. of a virulent culture, 0.000001 cc. of which killed mice in less than 40 hours. Protective tests of serum from horses immunized to Type II organisms varied, 0.1 cc. protecting, however, in certain instances against 0.1 and 0.01 cc. of virulent homologous culture. Types I and II sera obtained in our experiments with culture sediment and whole culture did not vary markedly for a given type and corresponded closely in their protective titer with samples of sera received from The Rockefeller Institut...
Mares were inseminated with motile spermatozoa suspended in 30-150 microliters Tyrode's medium directly onto the uterotubal papilla at the anterior tip of the uterine horn, ipsilateral to the ovary containing a dominant preovulatory follicle of > or = 35 mm in diameter, by means of a fine gamete intrafallopian transfer (GIFT) catheter passed through the working channel of a strobed light videoendoscope. Insemination of 10, 8, 25, 14, 11 and 10 mares with, respectively, 10.0, 5.0, 1.0, 0.5, 0.1 or 0.001 x 10(6) motile spermatozoa resulted in conception rates of, respectively, 60, 75, 64, 29,...
Eight mares with third-degree rectovestibular lacerations were treated by a two-stage surgical technique. The rectovestibular shelf was corrected with three parallel 'circular' continuous suture rows distributed along the longitudinal axis of the vagina, and the perineal body was reconstructed with three divergent simple continuous rows. Primary healing of the first-stage surgery occurred in all the mares. Seven of the mares completed the two-stage surgery and primary healing occurred in all of them. One of them returned to endurance racing competition and one was lost to follow-up. The other ...
The objective of this study was to enhance the in vitro sperm quality and in vivo fertility of frozen-thawed equine semen by the addition of l-carnitine (LC) to post-thawed semen. Different concentrations of LC were added to thawed samples to obtain four treatments control and 0.5, 1 and 2Â mM LC. In the in vitro experiments, sperm motility and kinematics, membrane integrity and intracellular calcium ion concentration ([Ca ] ) were investigated, and the antioxidant bioactivity of LC was assessed by measuring hydrogen peroxide and nitrite concentrations (NO ). The fertility rate was assessed v...
This Opinion piece is offered as a cursory overview of sperm development, function, and transport through the eyes of an equine veterinarian. My professional background is predominantly clinical in nature, but my fascination with sperm function and preservation has led to a fairly sizeable review of the scientific literature over the years in hopes of extracting laboratory findings that have application to my daily activities in the clinical arena. Spermatozoa are quite unique among cellular types with regard to both form and function, and represent the only endogenously derived cell type that...
To document morphologic changes that occur in equine intestinal serosa after experimentally induced ischemia and subsequent reperfusion (jejunum, ascending colon) or after intraluminal distention and decompression (jejunum). Methods: Morphologic effects of ischemia-reperfusion or intraluminal distention-decompression determined on the serosal layer of the equine jejunum. The large colon serosa was evaluated after ischemia-reperfusion injury. Methods: Seven adult horses. Methods: After induction of general anesthesia and ventral median celiotomy, ischemia was created by arteriovenous (AVO) and ...
Fifteen horses harboring naturally acquired, patent Parascaris equorum and Oxyuris equi infections were equally allotted to 3 treatment groups given (1) injectable vehicle; (2) injectable ivermectin at the dose rate of 200 microgram/kg of body weight; and (3) injectable ivermectin at the rate of 300 microgram/kg. All treatments were given IM in the neck. All animals were killed 14 days after treatment and examined for the targeted nematodes. Regardless of dose rate, ivermectin proved 100% effective in the removal of adult O equi and P equorum infections. Levels of immature P equorum were decre...
Yu Y, Wang J, Ruan L, Chen L, Khan MZ, You A, Wang C, Li L, Ren H, Wang T, Liu W.Equid alphaherpesvirus type 8 (EHV-8) is a contagious pathogen that causes reproductive disorders, respiratory diseases, and viral encephalitis in equids, resulting in significant economic losses for the global horse and donkey industries. Currently, there are no approved antiviral drugs or vaccines available for EHV-8 control. In this study, we investigated the antiviral efficacy of celastrol against EHV-8 both in vitro and in vivo. Our results demonstrated that celastrol significantly inhibited EHV-8 infection in Rabbit kidney (RK-13) and equine dermal cells (NBL-6) in a dose-dependent manne...
Rhodin M, Serra Bragança FM, Persson-Sjodin E, Björnsdóttir S, Gunnarsdottir H, Gunnarsson V, Hernlund E, Smit IH.Icelandic horses are valued for their additional gaits, but assessing lameness in this breed can be challenging. Pelvic (P) vertical movement asymmetries, differences (D) in minimum (min)/maximum (max) position, are used to quantify impact (PDmin) and push-off (PDmax) hindlimb lameness during the trot, but no established parameters exist for detecting hindlimb lameness in other gaits. Objective: To evaluate temporal stride parameters and upper-body movement asymmetry after transient hindlimb lameness induction in walk, trot and tölt. Methods: In vivo experiment. Methods: Eleven Icelandic hors...
Vernemmen I, Demeyere M, Van Steenkiste G, Buschmann E, Decloedt A, van Loon G.Ultrasonographic guidance of catheter-based interventions in horses is based primarily on transthoracic echocardiography (TTE). Intracardiac echocardiography (ICE) has the potential to provide detailed imaging of specific cardiac regions. Insight and training in echocardiographic guidance can be acquired using an echocardiography simulator. Objective: Use an echocardiography simulator for horses to determine specific ICE views for catheter-based interventions and validate these in live horses. Methods: Six adult healthy experimental horses. Methods: Observational study. An echocardiographic ph...
Samie KA, Kowalewski MP, Schuler G, Gastal GDA, Bollwein H, Scarlet D.In horses, the mechanisms behind ovarian follicle growth and oocyte maturation remain largely unknown. In other species, oocyte-secreted factors growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) have been related to the acquisition of developmental competence and to interaction with granulosa cells for the regulation of follicle development. This study assessed the expression and localization of GDF9 in the equine ovary, and its possible relationship with granulosa cell function. Results: Using custom-made antibodies, GDF9 protein was localized in oocytes from th...
de Morais CBR, Santiago JM, da Silva AH, Nascimento DBD, de Farias IM, da Silva Dias W, Taran FMP, Lucena JEC.This study aimed to verify whether donkeys of the Nordestino ecotype are more efficient than horses concerning apparent digestibility and gas production of Tifton 85 hay at different maturity stages, using the total feces collection method and the in vitro gas production technique. Four donkeys and four horses were used in a 2 × 2 factorial completely randomized design with two Equidae species and hay at two maturity stages (higher quality "Hay 1″ and lower quality "Hay 2″). No difference (P < 0,05) was found between the Equidae species for apparent nutrient digestibility of the Hay 1....
Vinijkumthorn R, Prapaiwan N, Chotikaprakal T, Prompiram P, Phaonakrop N, Roytrakul S, Tesena P.Phenylbutazone (PBZ) can potentially induce gastrointestinal ulceration, and early detection of PBZ-induced gastroenteropathy will be useful for the diagnosis, treatment, and prevention of PBZ toxicity. Objective: To identify putative proteins associated with equine gastric ulcer syndrome after clinical dose (4.4 mg/kg) administration of PBZ by proteomic study. Methods: In vivo experiments. Methods: Proteomic analysis using LC-MS/MS compared protein expression in serum and faeces of seven PBZ-treated horses with seven placebo-treated controls, and a novel putative biomarker was validated via...
Wilsher S, Ismer A, Grippo A, Hoogewijs M, Bussade P, Kovacsy S.Different cryoprotectants can influence the ability of embryos to successfully survive vitrification and subsequent warming before transfer. Objective: To compare pregnancy rates for embryos ≤500 μm vitrified, without puncture or aspiration of the blastocoele cavity, with one of three commercial human embryo vitrification kits containing the same penetrating cryoprotectants (DMSO and EG) but varying in their non-penetrating cryoprotectants (NPCPAs; sucrose, trehalose, dextran serum supplement [DSS], and hydroxypropyl cellulose [HPC]). Methods: In vivo experiments. Methods: Embryos (n =â...
Couto G, Grippo A, Ismer A, Hoogewijs M, Pedro B, Vasconcelos L, Santos G, Wilsher S.Vitrified in vitro-produced embryos can be successfully warmed in isotonic media at room temperature (RT; 22°C). However, this protocol has not been reported for in vivo embryos, which are more challenging to vitrify and warm. Study objectives were to see if vitrified in vivo embryos warmed in RT isotonic medium gave equivalent pregnancy rates to stepwise serial dilution warming, and if embryo size influenced the results. One hundred and seventeen embryos were divided into groups by size (G1:≤ 300 μm, n = 59; G2:> 300-400 μm, n = 33; G3:> 400-500 μm, n = ...
Schnelten TA, Kästner SBR, Reineking W, Hewicker-Trautwein M, Sauter P, Neudeck S.To visualize the endothelial glycocalyx in equine intestinal vessels using electron microscopy and immunohistochemistry and to evaluate the impact of induced endotoxemia on its integrity. Unassigned: 6 healthy horses free of gastrointestinal disease were anesthetized with dexmedetomidine, ketamine, and diazepam and mechanically ventilated under isoflurane anesthesia. Jejunal venous tissue samples were collected after perfusion fixation with lanthanum nitrate before and 120 minutes after endotoxemia induced by IV administration of 30 ng·kg-1 Escherichia coli lipopolysaccharide. For transmissio...
Young KAS, Schnabel LV, Gilger BC.Equine ocular disease is common and often challenging to treat using traditional methods. This has led to the development of new therapies. Like human medicine, veterinary medicine is adopting cellular and gene therapy as innovative approaches. Equine ocular disease is a particularly promising area for these techniques. Notably, immune-mediated diseases (such as immune-mediated keratitis and equine recurrent uveitis), ulcerative keratitis, and infectious ocular diseases are of interest. Several ocular gene therapy products are approved for use in humans, and more are currently being researched...
Márquez-Moya A, Carreras-Vico N, Sala-Ayala L, MartÃnez-Bovà R, Cuervo-Arango J.Transvaginal ultrasound-guided follicular aspiration or ovum pick-up (OPU) has become the standard technique for oocyte collection in mares for intracytoplasmic sperm injection (ICSI). Although repeated follicular flushes and wall scraping are commonly used to improve oocyte recovery rate (ORR), the relative contribution of each remains unclear. This study aimed to compare the effects of multiple flushes versus controlled scraping time on ORR in mares. A controlled trial was conducted in two phases: (1) an ex vivo phase using slaughterhouse ovaries (n = 32), and (2) an in vivo phase in c...
Hall NP, Sweeney DM, Holmströem M, Kim W, Wang Y, Donahue KD, Palmer SE, Lambert DH, Bayly WM.To determine whether targeted lesion-specific algorithms developed from data collected with accelerometer-based inertial measurement units worn by racing Thoroughbreds could retrospectively identify horses at high risk of incurring forelimb condylar or proximal sesamoid fractures. Unassigned: Fracture-specific algorithms were generated from July 2021 to December 2024 with accelerometer data from 42,623 races by 15,755 horses, including 54 races by 23 horses that subsequently suffered condylar fractures and 90 races by 31 horses that later sustained proximal sesamoid fractures. Fracture-specifi...
Toddy T, Ledbetter EC, Knickelbein KE.To describe the demographics and treatment outcomes of horses definitively diagnosed with epithelial or stromal immune-mediated keratitis (IMMK) by use of in vivo confocal microscopy (IVCM) and/or histopathology. Unassigned: Medical records of horses presented to the Cornell University Equine Hospital definitively diagnosed with epithelial or stromal IMMK with IVCM and/or histopathology between 2020 and 2024 were reviewed. Patient signalment, affected eye(s), diagnostics, treatments, and outcomes were assessed. Unassigned: 22 horses met the inclusion criteria. The mean age was 16.9 years (SD, ...
Castillo JDCR, Forte L, Elghandour MMMY, Maggiolino A, De Palo P, Ponce-Covarrubias JL, Salem AZM.Parasitic infections remain a major constraint to equine health and performance, and the worldwide rise of anthelmintic resistance is forcing a shift toward integrated parasite management and new complementary tools. Caesalpinia coriaria (Divi-divi) pods are exceptionally rich in tannins and have been proposed as a potential source of antiparasitic phytochemicals. This review summarizes the current evidence on C. coriaria, focusing on its relevance to equine gastrointestinal helminths. Most available data come from in vitro screening against ruminant nematode models (mainly Haemonchus contortu...
Ledbetter EC, Knickelbein KE, Irby NL, Schmidt C.To describe the clinical and in vivo confocal microscopy (IVCM) characteristics of horses with corneal stromal invasive squamous cell carcinoma (CSI-SCC). Methods: Retrospective study of 7 horses with histopathologically confirmed unilateral CSI-SCC. Methods: Horses with corneal CSI-SCC were examined by laser scanning IVCM. Signalment, clinical findings, and histopathology results were compared with IVCM findings. Results: Clinical ocular lesions in all horses included a heavily vascularized, opaque, gray or tan, anterior or midstromal opacity invading the cornea from the limbus. The corneal ...
McKenna KD, Struble SE, Max LNF, Linardi RL, Ortved KF.To quantify platelets, leukocytes, cytokines, and growth factors in ProVet autologous platelet concentrate (APC). We hypothesized that APC would contain significantly increased leukocytes and platelets compared to whole blood and significantly increased concentrations of anti-inflammatory cytokines and growth factors compared to serum. Unassigned: Blood was obtained from 6 horses and processed to produce APC. Leukocyte and platelet concentrations were quantified in whole blood and APC. Cytokines, including interleukin (IL)-1β, IL-4, IL-6, IL-10, tumor necrosis factor-α, and IL-1Ra, and growt...
Rogers CM, Ledbetter EC, Reid AM, Scott EM, Knickelbein KE.Use of photodynamic therapy (PDT) for the treatment of immune-mediated keratitis (IMMK) in horses is becoming common. The safety and morphologic impact on the normal equine cornea have not been investigated, and the mechanism of its efficacy is unknown. Objective: To investigate the morphologic effects and safety of in vivo PDT on healthy equine corneas. Methods: In vivo experiment. Methods: Six university-owned horses underwent unilateral corneal PDT with intrastromal infracyanine green (EmunDo®) and photoactivation with an 810 nm diode laser (500 mW for 2.5 min = 75 Joules). Compl...
Gallacher K, Woolford L, Santos LC, Serpa PBS, Len J, Gilbert RO, Kind KL.Endometrial health is vital for the reproductive efficiency of broodmares and accurate diagnostic testing is crucial for directing the best treatment options and outcomes. Confocal laser endomicroscopy (CLE) is an endoscopic technique for obtaining in-vivo, real-time microscopic imaging of tissues using a fiber optic probe. CLE relies on induced tissue fluorescence and fluorescein sodium, given intravenously, is the contrast agent most used in human medicine. This study aimed to determine the feasibility of CLE for imaging equine endometrium and determine a standard dose of fluorescein sodium ...
