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Topic:Clinical Pathology

Clinical pathology in horses involves the study and analysis of biological samples to diagnose and monitor diseases and health conditions. This discipline encompasses various laboratory tests and procedures that assess the physiological and biochemical status of equines. Common analyses include hematology, biochemistry, urinalysis, and cytology, each providing insights into different aspects of equine health. Hematology evaluates blood components, such as red and white blood cells and platelets, to identify conditions like anemia or infection. Biochemistry tests measure enzymes, electrolytes, and metabolites to assess organ function and metabolic status. Urinalysis examines urine samples for indicators of renal function and systemic diseases. Cytology involves the microscopic examination of cells from tissues or fluids to detect abnormalities. This page aggregates peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and diagnostic value of clinical pathology in equine medicine.
Preliminary investigation of concurrent administration of phenylbutazone and romifidine in healthy horses.
Veterinary anaesthesia and analgesia    August 13, 2011   Volume 38, Issue 5 505-509 doi: 10.1111/j.1467-2995.2011.00642.x
Kruger K, Stegmann GF, Becker PJ.To characterize the cardiorespiratory and electrocardiographic effects of the combined administration of phenylbutazone and romifidine. Methods: Prospective four-period, four-treatment, blinded, randomized, crossover trial. Methods: Five, healthy, mixed breed horses. Methods: Prior to treatment administration, a catheter was introduced into the intra-thoracic cranial vena cava via the jugular vein and a subcutaneously located carotid artery was catheterised. All treatments were administered intravenously (IV) and consisted of saline placebo (PLC), phenylbutazone (PBZ, 4.4 mg kg(-1) ) romifidin...
Lateral ridge augmentation using an equine flex bone block infused with recombinant human platelet-derived growth factor BB: a clinical and histologic study.
The International journal of periodontics & restorative dentistry    August 13, 2011   Volume 31, Issue 4 383-388 
De Angelis N, Scivetti M.This paper reports on a patient who underwent horizontal ridge augmentation using recombinant human platelet-derived growth factor BB (rhPDGF-BB) in combination with a collagenate equine block. Ninety days after the first surgery, 8 mm of new bone was noted on a computed tomography scan, and three 5-mm implants were placed. Histology, performed using confocal laser scanning microscopy, showed a large amount of newly formed bone well characterized with osteon and resorption lacunae, which demonstrated the intense bone remodeling. This study supports the use of rhPDGF-BB in combination with allo...
Ultrasound-guided cervical centesis to obtain cerebrospinal fluid in the standing horse. Pease A, Behan A, Bohart G.Horses with intracranial lesions and severe ataxia are not good anesthesia candidates; however, only one method to obtain cerebrospinal fluid (CSF) from the cervical region in a standing horse has been reported. This method is not performed routinely due to the difficulty for sample acquisition. Our hypothesis is that standing cervical centesis can be performed in horses without complication. Ultrasound-guided centesis of the CSF between C1 and C2 in 11 clinically normal horses and two horses with neurologic signs were performed. Horses were sedated and ultrasound was used to identify the suba...
The value of radiographic screening for metallic particles in the equine foot and size of related artifacts on low-field MRI. Urraca del Junco CI, Shaw DJ, Weaver MP, Schwarz T.Magnetic susceptibility artifacts as a result of metal debris from shoeing are a common problem in magnetic resonance imaging of the equine foot. Our purpose was to determine the suitability of radiography as a screening tool for the presence and location of metallic particles in the equine foot and to predict the size of the resultant magnetic susceptibility artifact. Radiography had 100% sensitivity for detection of metal particles > or = 1 mm diameter. Metal particles of known diameter were placed within the hoof wall of 22 cadaver feet and scanned with a low-field strength MR imaging un...
Review of seven cases of granulosa cell tumour of the equine ovary.
The Veterinary record    August 10, 2011   Volume 169, Issue 10 251 doi: 10.1136/vr.d4635
Crabtree J.This paper reviews the equine granulosa cell tumour (GCT) and describes the clinicopathological features, treatment and outcome in seven cases of GCT in mares. Mares were presented with unilateral ovarian enlargement during the 2007 to 2010 breeding seasons. The mean (sd) age of the mares was 11.7 (5.96) years. Three mares were multiparous barren, three were nulliparous and one was primigravida. Behaviour at presentation was 57 per cent anoestrus, 28 per cent with stallion-like behaviour and 14 per cent with persistent oestrus. All mares had unilateral ovarian enlargement. Six non-pregnant mar...
Neutrophilic myeloperoxidase index and mean light absorbance in neonatal septic and nonseptic foals.
Veterinary clinical pathology    August 9, 2011   Volume 40, Issue 3 340-344 doi: 10.1111/j.1939-165X.2011.00343.x
Piviani M, Segura D, Monreal L, Bach-Raich E, Mesalles M, Pastor J.Two neutrophilic indices reported by the ADVIA 120 Hematology Analyzer, neutrophilic myeloperoxidase index (MPXI), and mean light absorbance (neutrophil X mean [NXM]) have been proposed as indicators of systemic inflammatory disease in horses and of neutrophil activation in coronary ischemic syndromes in people. Objective: The aim of this study was to evaluate NXM and MPXI in healthy, sick nonseptic, and sick septic foals to determine whether conditions likely associated with neutrophil activation result in decreases in these variables. Methods: In this retrospective study, CBC data from 61 ne...
The clinical presentation and surgical treatment of verrucous dermatitis lesions in a draught horse.
Veterinary dermatology    August 9, 2011   Volume 23, Issue 1 71-e17 doi: 10.1111/j.1365-3164.2011.00997.x
Poore LA, Else RW, Licka TL.Verrucous pastern dermatitis is a progressive inflammatory skin disease commonly involving the palmar or plantar aspects of the pasterns of horses. There are no reports of successful surgical treatment for multifocal circumscribed verrucous masses in the chronic stages of verrucous pastern dermatitis. A combination of sharp dissection and electrocautery was used to resect numerous multifocal circumscribed verrucous masses from the distal hindlimb of an 11-year-old gelding draught horse. There was no evidence of significant regrowth or complications at a 24 month postoperative examination.
Effect of general anesthesia on plasma cardiac troponin I concentrations in healthy horses.
Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology    August 6, 2011   Volume 13, Issue 3 163-169 doi: 10.1016/j.jvc.2011.04.005
Slack J, Boston R, Driessen B, Reef V.To evaluate the effect of general anesthesia on plasma cTnI concentrations in horses. Methods: Thirty-two horses undergoing general anesthesia and either elective surgery or MRI without surgery were prospectively studied. Twenty-nine horses (22 surgical, 7 imaging) completed the study. Plasma cTnI concentrations were determined prior to anesthesia and at 6, 12 and 24 h following discontinuation of the inhalant anesthetic. Results: All horses had cTnI values within the reference range at all time points. Six horses (21%) developed detectable cTnI 6 or 12 h following anesthesia. Risk factors f...
Clinical comparison between a continuous Lembert pattern wrapped in a carboxymethylcellulose and hyaluronate membrane with an interrupted Lembert pattern for one-layer jejunojejunostomy in horses.
Equine veterinary journal    August 5, 2011   Volume 43, Issue 6 708-713 doi: 10.1111/j.2042-3306.2010.00340.x
Freeman DE, Schaeffer DJ.Although experimental studies have demonstrated differences in performance between methods for handsewn jejunojejunostomy in horses, information on clinical results after different methods of anastomosis are rare. Objective: A continuous Lembert pattern wrapped in a carboxymethylcellulose and hyaluronate membrane would perform better than an interrupted Lembert pattern for jejunojejunostomy in horses. Methods: Data was reviewed on 32 horses that underwent jejunojejunostomy from 1993-2002. Kaplan-Meier analyses and rates for post operative colic and death were used to compare outcomes after an ...
Equine amnionitis and fetal loss: mare abortion following experimental exposure to Processionary caterpillars (Ochrogaster lunifer).
Equine veterinary journal    August 5, 2011   Volume 44, Issue 3 282-288 doi: 10.1111/j.2042-3306.2011.00424.x
Cawdell-Smith AJ, Todhunter KH, Anderson ST, Perkins NR, Bryden WL.In Australia, there have been recent reports of unusual abortions in mid- to late-gestation mares. These were clinically distinct from other recognised causes of pregnancy loss and the term 'equine amnionitis and fetal loss' (EAFL) was adopted to describe this syndrome. Initial investigations concluded that possible causal factors included the presence on affected stud farms of Processionary caterpillars (Ochrogaster lunifer). Objective: To determine if exposure of pregnant mares to Processionary caterpillars or their shed exoskeletons can induce EAFL. Methods: Processionary caterpillars and t...
The effects of a novel anti-inflammatory compound (AHI-805) on cyclooxygenase enzymes and the recovery of ischaemia injured equine jejunum ex vivo.
Equine veterinary journal. Supplement    August 4, 2011   Issue 39 106-111 doi: 10.1111/j.2042-3306.2011.00401.x
Marshall JF, Bhatnagar AS, Bowman SG, Morris NN, Skorich DA, Redding CD, Blikslager AT.Flunixin meglumine is used for treatment of equine colic despite evidence of inhibited recovery of mucosal barrier function following small intestinal ischaemic injury. This study aimed to characterise an alternative treatment (AHI-805) for abdominal pain in the horse. Objective: To determine the effect of AHI-805, an aza-thia-benzoazulene derivative, on the cyclooxygenase enzymes and the recovery of mucosal barrier function following ischaemic injury. Methods: Effect of AHI-805 on in vitro COX-1 and COX-2 activity was determined by measuring coagulation-induced thromboxane B(2) (TXB(2)) and l...
Surgical drainage and post operative lavage of large abdominal abscesses in six mature horses.
Equine veterinary journal. Supplement    August 4, 2011   Issue 39 123-127 doi: 10.1111/j.2042-3306.2011.00405.x
Mair TS, Sherlock CE.Six mature horses with large abdominal abscesses (defined as an abscess >15-20 cm in at least one dimension) were treated by surgical drainage and post operative lavage. The abscess was associated with previous intestinal surgery in one horse, and with Streptococcus equi spp. equi infection in the other 5. A Foley catheter was used to drain and lavage the abscess in all cases. The abscess was accessed by a ventral midline laparotomy in 5 cases and by standing flank laparoscopy in one. Two horses were subjected to euthanasia within 7 days due to persistent or recurrent colic. The other 4 hor...
Peritoneal and plasma D-lactate concentrations in horses with colic.
Veterinary surgery : VS    August 4, 2011   Volume 40, Issue 7 817-824 doi: 10.1111/j.1532-950X.2011.00859.x
Yamout SZ, Nieto JE, Beldomenico PM, Dechant JE, leJeune S, Snyder JR.To evaluate the association between peritoneal fluid and plasma d-lactate concentration with variables used in the diagnosis and prognosis of horses with colic. Methods: Clinically healthy horses (n=6) and 90 horses with colic. Methods: Prospective cross-sectional study. Methods: D-lactate concentration was determined in peritoneal fluid and plasma of all horses. Information on other blood and peritoneal fluid variables, signalment, results from the physical examination, outcome, need for surgery, lesion location, and type was retrieved from medical records. Results: Peritoneal D-lactate conce...
Comparison of primary closure of incisional hernias in horses with and without the use of prosthetic mesh support.
Equine veterinary journal. Supplement    August 4, 2011   Issue 39 69-75 doi: 10.1111/j.2042-3306.2011.00377.x
Whitfield-Cargile CM, Rakestraw PC, Hardy J, Cohen ND, Davis BE.Repair of incisional hernias in horses has been described previously; however, this report describes the outcome of primary closure of incisional hernias in a large number of horses and compares these results with those of mesh implantation. Objective: To report the perioperative care, complications and long-term outcome of primary closure of incisional hernias in horses and to compare these results with a second population of horses in which prosthetic mesh was used. Methods: Medical records of horses undergoing an incisional herniorrhaphy between 1998 and 2009 were reviewed. Information obta...
Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): treatments and long-term results of treatments.
Equine veterinary journal    August 4, 2011   Volume 44, Issue 3 272-276 doi: 10.1111/j.2042-3306.2011.00427.x
Dixon PM, Parkin TD, Collins N, Hawkes C, Townsend N, Tremaine WH, Fisher G, Ealey R, Barakzai SZ.There is limited objective information available on the treatment and the long-term response to treatment of the different types of equine sinus disease. Objective: To document the treatments and long-term response to these treatments in 200 cases of equine sinus disease (1997-2009). Methods: The treatments of horses affected with subacute primary sinusitis (n = 52); chronic primary sinusitis (n = 37); dental sinusitis (n = 40); sinus cyst (n = 26); traumatic (n = 13); dental-related oromaxillary fistula (n = 8); sinus neoplasia (n = 10); mycotic sinus disease (n = 7); and intrasinus progressi...
Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): ancillary diagnostic findings and involvement of the various sinus compartments.
Equine veterinary journal    August 4, 2011   Volume 44, Issue 3 267-271 doi: 10.1111/j.2042-3306.2011.00420.x
Dixon PM, Parkin TD, Collins N, Hawkes C, Townsend N, Tremaine WH, Fisher G, Ealey R, Barakzai SZ.There is a lack of objective information on the value of ancillary diagnostic techniques used to investigate equine sinus disease, and also on which sinus compartments are commonly affected in this disorder. Objective: To record the ancillary diagnostic findings used to investigate equine sinus disease and to document which compartments are affected. Methods: The clinical case records of 200 consecutive cases of sinus disease, including subacute (2 months' duration) primary (n = 37); dental (n = 40); traumatic (n = 13); sinus cyst (n = 26); sinus neoplasia (n = 10); dental related oromaxillary...
Mucosal injury and inflammatory cells in response to brief ischaemia and reperfusion in the equine large colon.
Equine veterinary journal. Supplement    August 4, 2011   Issue 39 16-25 doi: 10.1111/j.2042-3306.2011.00415.x
Grosche A, Morton AJ, Graham AS, Valentine JF, Abbott JR, Polyak MM, Freeman DE.Intestinal ischaemia and reperfusion (I/R) can activate inflammatory cells in the equine colon, although effects on different types of inflammatory cells have received little attention. Objective: To assess early mucosal injury, the reaction of mucosal neutrophils, eosinophils, mast cells and macrophages, and cyclooxygenase (COX)-1 and -2 expression in response to I/R in the equine large colon. Methods: Large colon ischaemia was induced for 1 h (1hI) followed by 4 h of reperfusion in 6 horses, and mucosal biopsies were sampled before and after ischaemia, and after 1, 2 and 4 h of reperfusion. ...
Multiple small intestinal pseudodiverticula associated with lymphoma in three horses.
Equine veterinary journal. Supplement    August 4, 2011   Issue 39 128-132 doi: 10.1111/j.2042-3306.2011.00380.x
Mair TS, Pearson GR, Scase TJ.Three mature horses presented with progressive weight loss, inappetence, ventral abdominal oedema and lethargy. Two of the animals had intermittent signs of low grade abdominal pain. At presentation, all 3 had hypoalbuminaemia; 2 had hyperfibrinogenaemia and the other had neutrophilia. An oral glucose tolerance test was performed in 2 cases, both of which demonstrated impaired glucose absorption. One pony treated with corticosteroids failed to improve and developed peritonitis and was subjected to euthanasia after 2 weeks. One pony had small intestinal biopsies obtained via a standing flank la...
Ultrastructural changes in the equine colonic mucosa after ischaemia and reperfusion.
Equine veterinary journal. Supplement    August 4, 2011   Issue 39 8-15 doi: 10.1111/j.2042-3306.2011.00402.x
Grosche A, Morton AJ, Graham AS, Sanchez LC, Blikslager AT, Polyak MM, Freeman DE.Ultrastructural changes in the epithelium can provide information on early changes in barrier properties, repair and inflammation in equine colon after ischaemia and reperfusion (I/R). Objective: To describe the morphology and ultrastructure of the epithelium in equine large colonic mucosa after I/R, and the response of inflammatory cells to injury. Methods: Ischaemia was induced for 1 h followed by 4 h of reperfusion in a 40 cm segment of the pelvic flexure in 6 horses. Mucosal biopsies before and after ischaemia, and after 1, 2 and 4 h of reperfusion were fixed in glutaraldehyde/paraformalde...
Effects of flunixin meglumine on the recovery of ischaemic equine colonic mucosa in vitro.
Equine veterinary journal. Supplement    August 4, 2011   Issue 39 112-116 doi: 10.1111/j.2042-3306.2011.00382.x
Morton AJ, Grosche A, Matyjaszek SA, Polyak MM, Freeman DE.The effects of prostaglandins and nonsteroidal anti-inflammatory drugs (NSAIDs) on repair of equine intestinal mucosa are important since most horses with gastrointestinal diseases are routinely treated with NSAIDs, such as flunixin meglumine (FM), and these drugs can be toxic to equine gastrointestinal mucosa. Objective: Flunixin meglumine would not affect recovery of equine colonic mucosa in vitro, 18 h after a reversible ischaemic injury. Methods: In 14 anaesthetised horses, a segment of pelvic flexure was subjected to 2 h of ischaemia and the horses were allowed to recover for 18 h. Seven ...
Method to calibrate phase fluctuation in polarization-sensitive swept-source optical coherence tomography.
Journal of biomedical optics    August 3, 2011   Volume 16, Issue 7 070502 doi: 10.1117/1.3597721
Lu Z, Kasaragod DK, Matcher SJ.We present a phase fluctuation calibration method for polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) using continuous polarization modulation. The method uses a low-voltage broadband polarization modulator driven by a synchronized sinusoidal burst waveform rather than an asynchronous waveform, together with the removal of the global phases of the measured Jones matrices by the use of matrix normalization. This makes it possible to average the measured Jones matrices to remove the artifact due to the speckle noise of the signal in the sample without introducing aux...
Equine rhabdomyolysis.
Veterinary pathology    August 1, 2011   Volume 48, Issue 6 E52-E58 doi: 10.1177/0300985811414034
Quist EM, Dougherty JJ, Chaffin MK, Porter BF.A 1.5-year-old Quarter Horse gelding with a history of chronic nasal discharge and leukocytosis presented with signs of increased lethargy and muscular pain. The horse quickly became recumbent and unable to rise and was euthanized due to a poor prognosis. At necropsy, severe bilateral guttural pouch empyema was observed, as well as numerous well-demarcated areas of pallor within the skeletal muscles of all major muscle groups. Polymerase chain reaction testing of the guttural pouch exudate confirmed an infection with Streptococcus equi subsp. equi, and an S. equi-associated immune-mediated rha...
Effects of barefoot trimming on hoof morphology.
Australian veterinary journal    August 1, 2011   Volume 89, Issue 8 305-311 doi: 10.1111/j.1751-0813.2011.00806.x
Clayton HM, Gray S, Kaiser LJ, Bowker RM.To monitor changes in hoof morphology in response to barefoot trimming. Methods: Seven horses were trimmed every 6 weeks according to barefoot trimming principles, which involved levelling the hoof to live sole, lowering the heels, bevelling the toe and rounding the peripheral wall, while leaving the sole, frog and bars intact. A 4-month period was allowed to lower the heels sufficiently to achieve a hoof shape representative of the barefoot trim. This was regarded as the starting point for morphological adaptations in response to maintenance of the trim. Hoof morphology was measured from late...
Laminar chemokine mRNA concentrations in horses with carbohydrate overload-induced laminitis.
Veterinary immunology and immunopathology    July 28, 2011   Volume 144, Issue 1-2 45-51 doi: 10.1016/j.vetimm.2011.07.005
Faleiros RR, Leise BS, Watts M, Johnson PJ, Black SJ, Belknap JK.Chemokines play a vital role in leukocyte activation and emigration that reportedly plays a central role in laminar injury in equine laminitis. The purpose of this study was to evaluate the pattern of laminar chemokine expression in horses in the classical carbohydrate overload (CHO)-model of laminitis. Laminar samples were obtained 24h following water administration in the control group (CON, n=8), and at the onset of fever (≥ 102°F, 12-22 h post CHO, DEV group, n=8) and at the onset of lameness (20-48 h post CHO, LAM group, n=8) in induced horses. Real time quantitative PCR was performed ...
Successful treatment of equine sarcoids with cisplatin electrochemotherapy: a retrospective study of 48 cases.
Equine veterinary journal    July 27, 2011   Volume 44, Issue 2 214-220 doi: 10.1111/j.2042-3306.2011.00425.x
Tamzali Y, Borde L, Rols MP, Golzio M, Lyazrhi F, Teissie J.Sarcoids are the commonest form of equine skin tumour. Several therapeutic measures have been described but none is considered to be universally effective. Electrochemotherapy (ECT) is a new anticancer therapy that utilises electrical field pulses to induce increased cell membrane permeability to antitumour hydrophilic drugs, such as cisplatin. The increased intracellular concentration of the drugs has a significant therapeutic benefit. The procedure has not been previously reported in a large number of horses. Objective: To validate ECT as a novel alternative treatment for equine sarcoids. Me...
Distal border fragments and shape of the navicular bone: radiological evaluation in lame horses and horses free from lameness.
Equine veterinary journal    July 27, 2011   Volume 44, Issue 3 325-331 doi: 10.1111/j.2042-3306.2011.00429.x
Biggi M, Dyson S.The significance of distal border fragments of the navicular bone is not well understood. There are also no objective data about changes in thickness and proximal/distal extension of the palmar cortex of the navicular bone. Objective: To describe the distribution of distal border fragments and their association with other radiological abnormalities of the navicular bone and describe the shape of the navicular bone in sound horses and horses with foot-related lameness, including navicular pathology. Methods: Sound horses had radiographs acquired as part of a prepurchase examination. Lame horses...
Decreased oxidative phosphorylation and PGAM deficiency in horses suffering from atypical myopathy associated with acquired MADD.
Molecular genetics and metabolism    July 27, 2011   Volume 104, Issue 3 273-278 doi: 10.1016/j.ymgme.2011.07.022
Westermann CM, Dorland L, van Diggelen OP, Schoonderwoerd K, Bierau J, Waterham HR, van der Kolk JH.Earlier research on ten horses suffering from the frequently fatal disorder atypical myopathy showed that MADD (multiple acyl-CoA dehydrogenase deficiency) is the biochemical derangement behind atypical myopathy. From five horses that died as a result of this disease and seven healthy control horses, urine and plasma were collected ante mortem and muscle biopsies were obtained immediately post-mortem (2 patients and 7 control horses), to analyse creatine, purine and carbohydrate metabolism as well as oxidative phosphorylation. In patients, the mean creatine concentration in urine was increased...
Lamellar leukocyte infiltration and involvement of IL-6 during oligofructose-induced equine laminitis development.
Veterinary immunology and immunopathology    July 26, 2011   Volume 144, Issue 1-2 120-128 doi: 10.1016/j.vetimm.2011.07.016
Visser MB, Pollitt CC.Laminitis is known to involve deregulation of proteases and destruction of the lamellar basement membrane with the host inflammatory response also playing a role. Leukocyte infiltration has been well characterized in the black walnut model of laminitis induction, but not in carbohydrate induced models. Increased gene expression of multiple cytokines, including IL-6, has also been implicated in laminitis development. Using real time PCR, immunohistochemistry and zymography methods, we characterize leukocyte infiltration and IL-6 gene expression in oligofructose (OF) induced laminitis. As well, ...
Long-term facial artery catheter implantation for serial arterial blood sampling and invasive arterial blood pressure measurement in horses.
Veterinary journal (London, England : 1997)    July 23, 2011   Volume 192, Issue 3 541-543 doi: 10.1016/j.tvjl.2011.06.031
Dias DP, Teixeira LG, Canola PA, Albernaz RM, Marques JA, Neto JC.The purpose of this investigation was to evaluate surgical catheter implantation in the facial artery of horses and the long-term maintenance of such arteries using heparin and ascorbic acid as filling solution. Nine horses were implanted with a polyurethane catheter. The catheters were flushed with a heparin/ascorbic acid solution every 8h and remained patent for 25 days. Arterial blood samples were collected twice a day, and one exercise test that included serial blood samples and arterial pressure recordings was performed on a treadmill. Polyurethane catheters surgically implanted in the fa...
The effect of treatment with flunixin meglumine at different times relative to hCG administration on ovulation failure and luteal function in mares.
Animal reproduction science    July 23, 2011   Volume 127, Issue 1-2 84-90 doi: 10.1016/j.anireprosci.2011.07.008
Cuervo-Arango J.Flunixin meglumine (FM), a prostaglandin synthetase inhibitor, causes ovulatory failure in the mare. However, the effect of the FM treatment relative to the time of hCG administration on the ovulation failure has not been determined nor has its effect on the luteal function of treated mares. Estrous mares with a follicle ≥32 mm (range of 32-38 mm) were treated with 1.7 mg/kg b.w. of FM iv at zero, 12, 24 and 36 h (n=6), at 24 and 36 h (n=6), at 28 and 36 h (n=6), at 24h (n=6) or at 30 h (n=6) after treatment with 1500 IU hCG. One group received no FM (control, n=6). Progesterone concentratio...