Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Guarda F, Rattazzi C.The authors describe pathologic and histopathologic findings of three cardiac aneurysms in horses, two of which in the left ventricle and one in the right ventricle. The aneurysms were always associated with multiple foci of myocardiac fibrosis. A hypothesis concerning histogenesis of the lesion is formulated.
Imhof U.In 1968 a skeleton of a horse was found in Kiesen (Switzerland). This discovery could be dated by radiocarbon method: According to that this 13 years old gelding with a withers-height of 135 to 140 cm must have lived during the first third of the 17th century. Apparently it died by an accident. The bones are fully documented with pictures and scales and the findings described and discussed in detail.
Furuoka H, Mizushima M, Miyazawa K, Matsui T.We report the pathological findings of the skeletal muscle and peripheral nerves from a male 14-months-old thoroughbred horse showing idiopathic knuckling. The affected animal, when in staining position, presented knuckling at the fetlock joint of both forelegs, and dragged both fore- and hindlegs when attempting forward movement. The skeletal muscles demonstrated neurogenic atrophy characterized by the scattering of single angular fibers, groups consisting of five to ten angular fibers, and multiple fascicles of atrophic and hypertrophic fibers. The severity of changes tended to be a distal g...
Bathe AP.Three horses with an apparent neurological disorder resulting from nettle rash showed signs of ataxia, distress and muscle weakness, and two of them had urticaria. In each case the condition resolved within four hours, with no long term problems or recurrence.
Barr AR, Wotton SF, Dow SM, Waterman AE, Goodship AE, Duance VC.The effects of osteochondral defect location and post-operative walking exercise on structural repair and recovery of joint function were examined in the midcarpal joints of ponies. Functional recovery was monitored by measuring ground reaction forces using a force plate. Structural repair was evaluated histologically and by measuring the total collagen and uronic acid content and relative proportions of Type I and II collagen in the repair tissue. Central defects tended to cause a more marked functional disturbance but were repaired with fibrocartilage rather than fibrous tissue in 3 out of 6...
Rohner K, Demuth D.We report cases of adverse reactions, some of which serious, of four frequently used therapeutic substances in several animal species. In order to avoid similar cases we discuss special measures or alternative therapies.
Weaver SC, Hagenbaugh A, Bellew LA, Gousset L, Mallampalli V, Holland JJ, Scott TW.Evolution of viruses in the eastern equine encephalomyelitis (EEE) complex was studied by analyzing RNA sequences and oligonucleotide fingerprints from isolates representing the North and South American antigenic varieties. By using homologous sequences of Venezuelan equine encephalomyelitis virus as an outgroup, phylogenetic trees revealed three main EEE virus monophyletic groups. A North American variety group included all isolates from North America and the Caribbean. One South American variety group included isolates from the Amazon basin in Brazil and Peru, while the other included strain...
Peters SE, Wakefield AE, Whitwell KE, Hopkin JM.Genetically distinct forms of Pneumocystis carinii infect several mammalian hosts. We report the amplification of P. carinii DNA from samples of two infected thoroughbred foal lungs by using primers designed from the sequence of a P. carinii mitochondrial rRNA gene; these primers also prime the amplification of P. carinii DNA from other hosts. The nucleotide sequence of part of the mitochondrial rRNA gene amplified from P. carinii infecting one of the foals was determined and found to be distinct from that of published rat-, rabbit-, ferret-, and human-derived P. carinii sequences.
Donofrio JC, Coonrod JD, Chambers TM.Influenza A is a common respiratory infection of horses, and rapid diagnosis is important for its detection and control. Sensitive detection of influenza currently requires viral culture and is not always feasible. The polymerase chain reaction (PCR) was used to detect DNA produced by reverse transcription of equine influenza in stored nasal secretions, vaccines, and allantoic fluids. Primers directed at a target of 212 bp on conserved segment 7 (matrix gene) of human influenza A/Bangkok/1/79(H3N2) produced amplification products of appropriate size with influenza A/Equine/Prague/1/56 (H7N7), ...
Edwards GB, Proudman CJ.A retrospective study of 75 cases of pedunculated lipoma obstruction (PLO) of the intestine was conducted. Age, breed and sex distributions were compared to the non-PLO colic population. Horses in the PLO group were significantly older than in the non-PLO colic group (P < 0.001). A significant increase in risk of PLO was associated with geldings (O.R. 2.32) and with ponies (O.R. 3.75). Of the 75 PLO cases analysed, 69 were strangulating, 70 involved small intestine and 5 involved small colon. Cases of strangulation obstruction tended to have lipomas originating distant to the mesenteric border...
Quiñones Mateu ME, Finol HJ, Sucre LE, Torres SH.Skeletal muscle biopsy specimens were taken from 10 male horses naturally infected with Trypanosoma evansi and from 10 uninfected males. An indirect fluorescent antibody test was used to provide a rapid and reliable indication of infection. Histological, histochemical and transmission electron microscopical techniques were used to examine skeletal muscle. The ultrastructural features in muscle fibres were those usually seen in autoimmune disease, namely fibre and capillary necrosis and mononuclear cell infiltration, consisting of macrophages. Changes in fibre-type percentages did not occur in ...
Möstl E.In the pregnant mare two different groups of oestrogens are produced by the placenta. The precursor of "classical" oestrogens (oestrone, oestradiol-17 beta and oestradiol-17 alpha) is dehydroepiandrosterone which originates from the fetal gonads. The ring B unsaturated oestrogens (equilin and equilenin and their derivatives) derive from farnesyl pyrophosphate by a pathway not involving cholesterol.
Bonass WA, Hudson WA, Elton DM, Killington RA, Halliburton IW.Restriction enzyme digests of DNA from 22 unselected isolates of EHV-1 were analysed by hybridization with cloned DNA fragments covering the genome. In addition to a small amount of inter-strain variation, heterogeneity within strains was observed, caused by loss of specific restriction endonuclease sites in the DNA of a proportion of the virus particles of any one stock. Fifteen strains demonstrated the same intra-strain variation involving loss of the BamHI L-M site which was shown to lie within coding sequence for the large subunit of ribonucleotide reductase. This particular mutation may t...
Ramsay WN.The non-haem iron concentration was estimated in post-mortem liver samples from 51 horses (age range 1-25 years). Two were normal and 49 had been suffering from conditions that were not expected to have had long-term effects on iron metabolism. Muscle samples (splenius and biceps femoris) from 23 of these horses were also analysed. There was a highly significant age-related increase in the non-haem iron concentration in the liver (r = 0.635, p < 0.001), but not in the muscles, in which the iron concentration was much lower than in the liver.
Roser JF, McCue PM, Hoye E.An overnight double antibody RIA, employing a rabbit antiserum raised to bovine 31 kDa inhibin (rAs-#1989, NICHD) and purified bovine 31 kDa inhibin (bINH-I-90/1, NICHD) as trace and standard, was validated to measure immunoreactive inhibin (iINH) concentrations in equine peripheral plasma, follicular fluid (FF), ovarian vein (OV) plasma, testicular tissue extracts (TTE) and testicular vein (TV) plasma. The dynamic relationship of iINH and follicle stimulating hormone (FSH) was investigated during the estrous cycle of the mare and the annual reproductive cycle of the stallion. In the RIA, para...
Xiao L, Herd RP.Diarrhoea is one of the most important diseases of foals and
7040% are affected within the first 6 months of life (Palmer
1985). Although the cause is multifactorial and changes in the
physiology and nutrition of foals are sometimes responsible,
diarrhoea is frequently the result of infection by enteropathogens
such as bacteria, viruses and nematodes (Palmer 1985; Tzipori
1985). There is increasing evidence that Cryptosporidium
infection can also cause diarrhoea in foals (Austin et a/. 1990;
Kim 1990).
Cryptosporidiosis in horses is caused by Cryptosporidium
parvum, a coccidial paras...
Gardner DG.Previously published cases of ameloblastoma in the horse are reviewed in detail for their acceptability as examples of that tumor; an additional one is described. So far, this rare equine lesion has been shown to have two histologic patterns. The first consists of islands and sheets of epithelium that exhibit the basal cell characteristics of ameloblastoma; the central cells comprise stellate reticulum. The second exhibits these basal cell features less markedly and the central cells are spindle-shaped and closely packed. The biologic behavior of the equine ameloblastoma is thought to be the s...
van Nieuwstadt RA, Kalsbeek HC.In a horse with chronic unilateral nasal discharge guttural pouch mycosis caused by Aspergillus fumigatus was diagnosed. A percutaneous indwelling catheter was surgically installed in the left guttural pouch. Initial treatment with a povidone iodine solution proved to be unsatisfactory. Treatment was continued by administering enilconazole by ways of an indwelling through-the-nose-catheter. The latter treatment resulted in complete recovery.
Murray RC, Gaughan EM, Debowes RM, Huston LC, Cooper VL, Welsh T.A 4-month Arabian filly presented for abdominal pain of 30 hours duration was found to have tachycardia, tachypnea, congested mucous membranes and gross abdominal distension. Further examination disclosed gastric reflux and small intestinal distension. Dehydration, prerenal azotemia, electrolyte abnormalities and metabolic alkalemia were observed. There was a progressive nonresponse to analgesic medication and deterioration in the foal's physiologic condition consistent with a small intestinal strangulating obstruction. Surgical exploration was declined. Necropsy examination revealed incarcera...
Sugiura T, Nakamura H.The zinc content in platelets from rabbits, humans and horses was determined, and the levels of zinc were found to be significantly higher (3 micrograms/10(10) cells) than those in other peripheral blood cells. About 70% of the zinc in the supernatants of platelet lysates could be detected. From the results of gel filtration analysis, the zinc in platelet lysates was found to be bound with a low-molecular-weight protein (MW 6,000-8,000) detected as metallothionein (MT) on the basis of antigenic properties determined by enzyme-linked immunoassay and immunoblotting analysis using monoclonal anti...
Morris EA, Treadwell BV.The effect of interleukin 1 (IL-1) on equine articular cartilage was investigated, using a cartilage explant culture system. Measurement of [35S]O4 incorporation revealed synthesis of matrix proteoglycan by cartilage to be decreased 45, 59.7, and 37.5% after 1, 3, and 5 days, respectively, in culture in the presence of 5 U of IL-1/ml. There was no change in proteoglycan degradation as determined by measurement of [35S]O4 release into the culture medium. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of cartilage-conditioned medium indicated that exposure of cartilage to IL-1 caused ...
Bayly WM, Slocombe RF, Weidner JP, Schott HC, Hodgson DR.The influences of facial airflow, exercise and wearing a facemask on gas exchange and upper airway (Pu), transpulmonary (PTP) and transdiaphragmatic (PTD) pressures were investigated in 6 horses performing an incremental exercise test on an inclined (10%) treadmill. The test consisted of a 2 min walk followed by two 2 min exercise bouts at intensities which produced 40% and 80% of maximal oxygen consumption. Horses performed the test 4 times, once for each of 4 protocols, which involved not wearing a facemask (A), wearing a mask with either no biased flow through it (B), with an expiratory bia...
Willis P, Caudle AB, Fayrer-Hosken RA.Transmission electron microscopy (TEM) was used to evaluate the fine structure of equine oocytes cultured in vitro. Oocytes obtained by follicular aspiration were cultured for either zero or 15 hr. After treatment oocytes were processed either by light microscopy (nuclear evaluation) or TEM (cytoplasmic evaluation). Those oocytes cultured for 15 hr were incubated in modified TCM 199 with 15% (v/v) mare serum (day of ovulation) at 39 +/- 0.2 degree C. Evaluation using TEM revealed that cortical granules were present in all oocytes. However, zero-time oocytes contained few cortical granules, and...
Wilkins PA, Dewan-Mix S.The efficacy intravenous plasma to transfer passive immunity to clinically healthy colostrum-deprived and clinically ill foals with failure of passive transfer was investigated. Efficacy of transfer was evaluated by the elevation of serum IgG per gram of IgG administered as a function of body weight. Colostrum deprived healthy foals had a significantly greater increase in serum IgG than did clinically ill foals with failure of passive transfer. Knowledge of the IgG content of plasma to be administered and the health status of a foal with failure of passive transfer should allow more accurate p...
Waelchli RO, Lutz H, Hermann M, Rüegg C, Eggenberger E.Hematologic reference values were established in 18 healthy foals in the first two months of life. Blood samples were collected prior to colostrum consumption and at 30 hours, 1 week, 3, 5, 7 and 9 weeks of age. PCV, Hb and RBC decreased during the first week and RBC, but not PCV and Hb, increased toward the end of the second month. With the exception of the sample at 1 week, the foals had mean RBC values significantly higher than those of controls. Mean MCV and MCH did not change during the first week, but decreased slightly thereafter; all means were smaller than in controls. The numbers of ...
Lebedev SG, Lebedeva LF.A medium containing egg yolk, mare's milk and/or modified PBS was used to culture Day-8 to 8.5 equine blastocysts. Twenty-one variants of the medium containing different concentrations of the 3 components were prepared. Embryos were recovered nonsurgically and placed into the media at 37 degrees C for 24 h. A total of 45 embryos was cultured; of these 7 died in culture and 13 showed inadequate development at the onset, while 25 continued to grow in the media. It was established that embryos grew best in media containing 20 to 60% yolk, 20 to 60% mare's milk and/or 20 to 60% PBS. It was found e...
Serteyn D, Blais D, Abou Madi NA, Coppens P, Mottart E, Philippart C.Ketamine (0.3 mg/kg) administered intravenously to 12 halothane anesthetized horses caused a significant respiratory depression during ten minutes when respiration was spontaneous. Significant hemodynamic effects were not observed except for cardiac index. Clinical application was also discussed. Ketamine (0.3 mg/kg) administered intravenously to 12 halothane anesthetized horses caused a significant respiratory depression during ten minutes when respiration was spontaneous. Significant hemodynamic effects were not observed except for cardiac index. Clinical application was also discussed.
Belford CJ, Lumsden JH.This report is an assessment of clinical chemistry dry reagent methodology for veterinary use. A portable reflectance photometer and dry reagent strips were used to measure canine whole blood hemoglobin, and total bilirubin, glucose, cholesterol, creatinine and urea in canine, bovine, equine and feline sera. Creatine kinase and lactate dehydrogenase were assayed in canine, bovine and equine sera. The following aspects of performance are reported: within run variation determined on canine samples, between run variation using a commercial control, correlations between dry reagent and wet reagent...
Wensley FM, Berryhill EH, Magdesian KG.Lymphoma is the most common hemopoietic neoplasia in horses. Common clinicopathologic abnormalities in equine lymphoma include hyperglobulinemia, hypoalbuminemia, hyperfibrinogenemia, anemia, thrombocytopenia and lymphocytosis. Hypoglobulinemia has been reported in other species with lymphoma, however it has not been well-described in horses. The objectives of this study were to examine the prevalence of hypoglobulinemia in equine lymphoma, and to identify prognosis and clinicopathological abnormalities associated with serum globulin concentrations. Unassigned: Ninety-six horses with lymphoma ...
Frohlich M, Knights K, Springer NL.Differentiating immune-mediated causes from other causes of anemia and thrombocytopenia can be challenging. Flow cytometry can detect surface-associated immunoglobulin (sIg) on red blood cells (RBC) and platelets (PLT) in dogs and horses. Sample storage parameters for ideal assay performance has not been evaluated in horses. The study objective is to identify optimal storage time and temperature of equine whole blood for the detection of RBC-sIg and PLT-sIg via flow cytometry. Both assays were performed on samples at time 0, 4, 24, 48, and 72 h post collection. RBC-sIg samples were stored at ...
Scheffer CJ, Sloett van Oldruitenborgh-Oosterbaan MM.In the horse, it is important to make a reliable ECG recording during exercise as cardiac arrhythmia is one of the possible causes of poor performance. The purpose of the present study was to obtain a satisfactory, standardized method for ECG recording by computer during a standardized treadmill exercise test and to evaluate the procedure both in healthy and in diseased horses. Ten experienced healthy research horses were used to develop and adapt the original method (for humans) of computerized ECG recording with the Cardio Perfect software program and to obtain reference values for heart rat...
Salama SA, Dardiri AH, Awad FI, Soliman AM, Amin MM.African horsesickness virus was isolated from blood samples of street dogs in Aswan Province in Arab Republic of Egypt. Of six isolated "dog strain" African horsesickness viruses, three viruses designated D2, D6 and D10 have been identified as type 9 African horsesickness virus. Methods of isolation, tissue culture adaptation, serological indentification and typing are described. Horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathological signs of African horsesickness. Reisolation of African horsesickness virus type 9 was achieved from ...
Tetens J, Moore RM, Hosgood GL, Eades SC, Keowen ML, Horohov DW.To evaluate systemic effects of i.v. infusion of ATP-MgCl2 subsequent to infusion of a low dose of endotoxin in horses. Methods: 12 adult horses. Methods: Horses were administered endotoxin (lipopolysaccharide [LPS]) or saline (0.9% NaCl) solution i.v., during a 30-minute period. Immediately thereafter, horses in each group were infused i.v. with ATP-MgCl2 or saline solution. Two weeks later, horses were administered the opposite solution (LPS or saline solution), but it was followed by the same infusion as 2 weeks previously (ie, ATP-MgCl2 or saline solution). Cardiopulmonary and clinicopatho...
Laverty S, Pascoe JR, Williams JW, Funk KA.A 10-year-old Appaloosa stallion was referred for evaluation of colic. At admission, the heart rate, capillary refill time, respiratory rate, and rectal temperature were high. Fifteen liters of reflux was obtained by nasogastric intubation. Palpation of an abdominal mass per rectum elicited signs of pain. At exploratory laparotomy, a mass was palpated in the ascending portion of the duodenum. The small intestine ruptured at the site of obstruction during manipulation. The horse was euthanatized. A large cholelith was the cause of the duodenal obstruction. At necropsy, multiple choleliths of va...
Bannai H, Kambayashi Y, Ohta M, Nemoto M, Tsujimura K.To assess the prevalence of equine coronavirus infection in riding horses, virus-neutralizing tests were performed on serum and saliva samples collected at four facilities in Japan. Seropositivity rates ranged from 79.2% to 94.6%, suggesting widespread circulation of the virus in these populations. Antibody prevalence in saliva samples from two facilities that had experienced outbreaks in the previous year (67.6% and 71.4%) was significantly higher than at the other facilities without reported outbreaks (41.7% and 45.2%, P<0.05). The presence of salivary antibodies in a high proportion of h...
Jurek KA, Schoonover MJ, Williams MR, Rudra P.To determine the influence of perfusate volume on synovial fluid amikacin concentrations in the joints of the hind limb after standing saphenous intravenous regional limb perfusion (IVRLP). Methods: Randomized crossover design. Methods: Six adult horses. Methods: Saphenous IVRLP was performed in 6 standing horses with 1 g of amikacin diluted with 0.9% NaCl to volumes of 10 ml, 60 ml, and 120 ml. Samples of synovial fluid from the tarsocrural, metatarsophalangeal, and hind limb distal interphalangeal joints were collected at 15 and 30 min after perfusate administration. Concentrations ...
Patterson-Kane JC, Harrison LR.A 5-month-old male Thoroughbred foal with a history of chronic septic arthritis of the tibiotarsal joint and recent respiratory distress was euthanized and a postmortem examination performed. A giant diverticulum communicating with the lateral aspect of the right atrial cavity of the heart was observed. Histologically, the wall was comprised of myocardial tissue containing cavernous vascular spaces. There was gross and histologic evidence of right-sided heart failure. Congenital right atrial diverticula are rare anomalies in humans and have not previously been reported in foals.
Bertuglia A, Pallante M, Pillon G, Valle D, Pagliara E, Riccio B.This case series describes an alternative surgical technique to obtain reattachment of osteochondritis dissecans (OCD) lesions in the lateral trochlear ridge of the femur (LTRF) as well as the clinical and radiological outcome of treated cases. Four Standardbred yearlings (6 lesions in total) underwent surgical fixation of large OCD defects in the LTRF under arthroscopic guidance. Reattachment of the OCD lesions was obtained using 3.0/3.7 mm headless bio-compression and absorbable poly-l-lactic acid (PLLA) screws, inserted perpendicularly to the cartilage surface through the lesion. All horse...
Al-Khaldi K, Yimer N, Sadiq MB, Firdaus Jesse Bin Abdullah F, Salam Babji A, Al-Bulushi S.Diluents and various biological products have been used in different animal species, with promising outcomes in post-thaw sperm quality. Nevertheless, only a few reports are available for the semen of Arabian horses. Edible bird's nest (EBN) - a product of the salivary secretions of swiftlet species is widely known to have both antioxidant and anti-inflammatory properties. Presently, there is no data available on the role of EBN supplemented in different extenders and its effect on semen quality in stallion semen. Two in vitro experiments were conducted to examine the effects of edible bird's ...
Bracher V, Allen WR.The new generation of videoendoscopes uses an electronic, instead of an optical, system for image transmission. Advantages over conventional fibre-optic endoscopes include increased image quality, handling robustness and direct display of the image on a TV monitor for multiple simultaneous viewing. In the present study, hysteroscopy was performed on 14 normal fertile Welsh Pony and Thoroughbred mares at various times during the annual and ovarian breeding cycles. Oestrus was characterised by an oedematous, relaxed cervix lying on the floor of the vagina, diffuse oedema of the endometrium and t...
Dauparaitė E, Kupčinskas T, Varady M, Petkevičius S.Control of strongyle infections presents a global challenge for horse practitioners due to the development of anthelmintic resistance (AR), however comprehensive information on AR in Lithuania is still lacking. The aim of this study was to assess the current situation of fenbendazole (FBZ) AR in horses at stable level in Lithuania. Results: Faecal samples from 121 horses from six stables were examined using the Mini-FLOTAC method. Of these, 89 horses met the inclusion criteria that included strongyle faecal egg counts (FEC) exceeding 200 eggs per gram (EPG). Faecal egg count reduction tests (F...
Andrews FM, Rosol TJ, Kohn CW, Reed SM, DiBartola SP.Three horses less than or equal to 3 years old were evaluated because of stunted growth, weight loss, anorexia, depression, and lethargy of at least 1 month's duration. A neonatal foal was examined after its death. In each case, gross and microscopic renal lesions were compatible with bilateral renal hypoplasia (ie, cortical hypoplasia with severe medullary hypoplasia). In young horses with renal failure, bilateral renal hypoplasia should be considered in the differential diagnosis, and may represent a congenital lesion.
Tyma JF, Epstein KL.Sinusitis and pneumonia following exploratory celiotomy in horses were studied, evaluating associations between these 2 respiratory complications and selected pre-, peri-, and post-operative variables. The incidence of sinusitis was 2.5% (8/318) and pneumonia 3.5% (11/318). These respiratory complications were associated with peri-operative reflux, longer antimicrobial treatment, and longer hospitalization. . La sinusite et la pneumonie consécutives á une coeliotomie exploratoire chez le cheval ont été étudiées, afin d’évaluer les associations entre ces deux complications respiratoire...
Ardans A, Walters G.Treatment with 3 formulations of cambendazole (paste, pellets, and suspension) was compared with thiabendazole treatment in 181 Quarter Horses (females and intact and altered males) of different ages in 2 experiments. The mean output of strongyle eggs, as measured by eggs per gram of feces (epg), was reduced by at least 95% by the 3 formulations of cambendazole compared with pretreatment epg and epg in simultaneously nonmedicated horses. Eggs of Parascaris equorum were seen in 19 of the younger horses in experiment I. Parascaris eggs were not seen in postmedication fecal samples from 14 horses...
Arana Valencia N, Thompson DL, Southerland CV.Four experiments assessed factors affecting prolactin responses to sulpiride administration in horses. Experiment 1 compared the efficacy of the (-) enantiomer of sulpiride to that of the commonly used (+/-) racemic mixture. Mares were used in an 8 × 8 Latin square to compare the prolactin responses to four doses of levosulpiride to four corresponding doses of the racemic mixture at twice the dose. Responses at each dose indicated equal and similar (P > .1) responses. Experiment 2 compared the efficacy of 1 gram of orally administered racemic sulpiride to 100 mg of intramuscularly injec...
Greet TR.This paper describes the outcome of treatment in 23 horses with an ethmoidal haematoma. In 22 cases a diagnosis could be made by endoscopic means alone but in 1 horse the lesion was confined to the maxillary sinus and a diagnosis was made only at surgery. One horse was destroyed at the owner's request but the other 22 underwent radical excision of the lesion via a facial flap approach under general anaesthesia. Post-operative haemorrhage was controlled by nasal packing with a gauze bandage and this was removed between the 2nd and 4th post-operative day. One horse died from encephalitis the day...