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Summary Intestinal hyperammonaemia in horses is a syndrome putatively caused by increased intestinal production and/or absorption of ammonia that clinically manifests as severe neurological abnormalities often in conjunction with signs of gastrointestinal dysfunction but without evidence of hepatic compromise. Ingestion of Black Locust (Robinia pseudoacacia) is a novel primary condition that may predispose to development of the syndrome as described in this issue. Treatment of the condition is symptomatic and aimed at decreasing blood ammonium concentrations by reducing further production and absorption, reducing brain oedema and preventing self-inflicted trauma. Prognosis for survival is guarded, particularly in cases with severe gastrointestinal lesions, and is influenced by the ability to control clinical signs.

Summary Reasons for performing study: Sporadic measurement of serum triglycerides in depressed and inappetant clinically ill horses revealed severe hypertriglyceridaemia without visible evidence of lipaemia on several occasions, leading to the inclusion of serum triglyceride concentrations in the routine serum biochemistry evaluation of our hospital. Since then, more cases have been identified and treated for hypertriglyceridaemia, raising questions about the prevalence, predisposing factors and significance of these findings. Hypotheses: 1) Severe hypertriglyceridaemia without visible opacity of the serum occurs more commonly in clinically ill and inappetant horses than previously described and 2) appropriate treatment using i.v. dextrose and/or partial parenteral nutrition would decrease serum triglycerides to normal limits and might result in improved appetite and attitude of the patient. Methods: The laboratory computer database from 2000 and 2001 was searched for increased serum triglycerides (>5.65 mmol/l) in any horse breed, ponies and miniature breeds excluded. Data analysed included subject details, diagnosis, clinical and laboratory parameters, treatment, response to treatment and outcome. Results: Severe hypertriglyceridaemia was identified in 13 horses, with serum triglyceride concentrations 6.17–18.29 mmol/l, while none showed visible lipaemia. All horses had clinical and laboratory findings consistent with systemic inflammatory response syndrome and all but one had an increased serum creatinine concentration. Treatment with i.v. dextrose and/or partial parenteral nutrition resulted in decrease of the serum triglycerides to normal limits. Conclusions: Severe hypertriglyceridaemia occurs in inappetant and clinically ill horses without evidence of serum opacity more commonly than previously described. The presence of systemic inflammatory response syndrome might predispose horses to hypertriglyceridaemia, while the increased creatinine concentration might be a predisposing factor or result of the condition. Horses identified in our study readily responded to treatment and appetite and attitude improved coincident with decrease of the serum triglycerides to normal limits. Potential relevance: Hypertriglyceridaemia could perpetuate inappetance and depression in clinically ill horses and potentially predispose to fatty infiltration of the liver and other organ systems.

Summary Reasons for performing study: Few reports exist in the veterinary medical literature describing clinical and pathological findings resembling conditions described as (ALI) and acute respiratory distress syndrome (ARDS) in man. Objectives: To document history, clinical, laboratory and diagnostic findings, treatment and outcome of foals age 1–12 months diagnosed with ALI/ARDS at a referral hospital. Methods: Medical records, including radiographic, cytological, microbiological, serological and post mortem findings, were reviewed in a retrospective manner to identify foals with acute onset of respiratory distress, a partial pressure of arterial oxygen (PaO2) to fraction of oxygen in inspired gases (FiO2) ratio of ≤300 mmHg, pulmonary infiltrates on thoracic radiographs or post mortem findings consistent with ALI/ARDS. Results: Fifteen foals age 1.5–8 months were included in the study. Seven foals had previously been treated for respiratory disease, and all foals developed acute respiratory distress < 48 h prior to presentation. Findings on presentation included tachycardia and tachypnoea in all foals, with fever recorded in 8 cases. Eight cases met the criteria for ALI and 7 for ARDS. Radiographic findings demonstrated diffuse bronchointerstitial pattern with focal to coalescing alveolar radiopacities. An aetiological agent was identified in foals ante mortem (n = 6) and post mortem (n = 4). All foals were treated with intranasal oxygen and antimicrobial drugs; 13 received corticosteroids. Nine patients survived, 4 died due to respiratory failure and 2 were subjected to euthanasia in a moribund state. Follow-up was available for 7 foals; all performed as well as age mates or siblings, and one was racing successfully. Conclusions: A condition closely meeting the human criteria for ALI/ARDS exists in foals age 1–12 months and may be identical to previously described acute bronchointerstitial pneumonia in young horses. Potential relevance: ALI/ARDS should be suspected in foals with acute severe respiratory distress and hypoxaemia that is minimally responsive to intranasal oxygen therapy. Treatment with systemic corticosteroids, intranasal oxygen and antimicrobials may be beneficial in foals with clinical signs compatible with ALI/ARDS.

Recurrent airway obstruction (RAO) in mature horses is characterized by reversible airway obstruction and neutrophilic inflammation; there is also functional activation of circulating platelets and neutrophils. This study was undertaken to determine if changes in activation marker expression and heterotypic aggregate formation can be used as an indicator of this increased functional responsiveness. In vitro conditions for flow cytometric measurement of CD13, CD41/61 and CD62P expression on activated cells and heterotypic aggregate formation were established. Values were then compared before and after antigen challenge of RAO and healthy horses. Platelet adhesion to serum-coated plastic was measured as a functional marker of platelet activation. In vitro activation resulted in increased expression of neutrophil CD13 and platelet CD41/61 and CD62P. Activation of both cell types caused a significant increase in neutrophil–platelet aggregates. In horses with RAO, but not controls, there was a significant increase in the percentage of CD13 positive neutrophils at 10 h and 24 h and in the mean fluorescence intensity at 10 h. This was accompanied at 24 h by an increased mean platelet side scatter and thrombin-stimulated platelet adhesion. In conclusion, CD13 expression can be used as an indicator of equine neutrophil activation both in vitro and in vivo . Equine platelet activation in vitro can be detected by measuring CD41/61 or CD62P expression, and PAF-activated platelets and neutrophils form aggregates. However, despite evidence of circulating platelet activation, neither a change in expression of platelet activation markers, nor heterotypic aggregate aggregate formation could be detected.

Summary The priority in treating the equine patient with acute diarrhoea is to stabilise the haemodynamic aberrations secondary to the fluid and electrolyte losses. Once this has been initiated and the patient is stabilised ancillary treatments may be beneficial. Besides the well established effects of NSAIDs and polymixin B on systemic inflammation, recent studies suggest that the use of DTOS to bind bacterial toxins and Saccharomyces boulardii to reduce the severity and duration of diarrhoea may be beneficial. The justification for using probiotic products is scant. There is no evidence to suggest that systemic use of antimicrobials benefits equine patients with colitis, with the exception of metronidazole in cases of clostridial diarrhoea. In light of their potentially detrimental effects, their use can, in the opinion of the authors, not be advocated. Better understanding of the pathways of systemic inflammation and more selective anti-inflammatory drugs may be of great benefit in the future.

Diarrhoea is a common problem affecting fools of all ages. Common non-infectious causes of mild to moderate diarrhoea include foal heat diarrhoea and nutritionally induced diarrhoea. Clinical signs often resolve spontaneously without or with only minimal treatment. Gastroduodenal ulceration rarely presents as diarrhoea and resolves once the underlying cause is corrected. Neonatal fools may suffer from hypoxicischoemic enteropothy and necrotising enterocolitis; both are associated with severe, often multi-systemic disease and require intensive medical therapy. Long established infectious causes of foal diarrhoea include rotavirus, Salmonella spp. and Cryptosporidium. Diagnosis can be established using commercially available assays, consecutive faecal cultures or PCR and acid fast faecal staining, respectively. Recent evidence suggests that Clostridium difficile and perfringens may be part of the normal gastrointestinal flora of equine neonates, but can also be associated with cases of mild to severe, and even fatal diarrhoea. Due to their occurrence in normal and diseased animals, diagnosis is difficult and further investigations are required to document their role in foal diarrhoea. Correction of fluid, electrolyte and acid-base abnormalities is the most important treatment of diarrhoea regardless of the underlying aetiology and, depending on age and physiological status, systemic antimicrobials and nutritional support. Although controlled clinical trials are lacking, there is some limited evidence suggesting that treatment with metronidozole, di-tri-octahedral smectite and Saccharomyces boulardii may be beneficial in foals suffering from clostridial diarrhoea. infectious agents affecting older fools include small strongyles and Lawsonia intracellularis, both more recently recognized pathogen causing weight loss, severe hypoproteinoemia and mild to severe diarrhoea. While diagnosis of cyathostomiasis is difficult to establish intra vitam, L. intracellularis may be diagnosed by serology or identification of the organism by faecal PCR. Treatment consists of larvicidal doses of fenbendozole and systemic antimicrobials with excellent intracellular penetration, respectively.

Equine neonates may suffer from a variety of diseases; perinatal asphyxia syndrome (PAS) and neonatal sepsis are particular severe, often life-threatening diseases that have the potential to affect homoeostasis of many organ systems. Regardless of the underlying disease process, some general principles apply to the treatment of any critically ill neonatal foal. Maintenance of a normal fluid, electrolyte and acid-base balance as well as cardiovascular and pulmonary function to ensure adequate perfusion and oxygen delivery to peripheral organs is one of the most important aspects of supportive care. Hypovolcemia and dehydration are addressed by administration of boluses of a balanced electrolyte solution while maintenance fluid requirements are best met using a hypotonic solution with a low sodium and a higher potassium content, If fluid therapy alone does not improve peripheral perfusion, use of inotropes and vasopressors may be indicated. Hypoxaemia can be combated by intranasal oxygen insufflation, pharmacological stimulation of the respiratory centre or mechanical ventilation. Blood transfusions may be necessary to improve the oxygen carrying capacity in certain patients. Enteral or parenteral nutrition also constitute an essential part of the treatment plan. With adequate supportive care even critically ill equine neonates can survive and develop into normal fools.

Background: As veterinary medicine has become more sophisticated, with greater numbers of veterinary patients receiving intensive care, more patients with an acute respiratory distress (ARDS)-like syndrome have been recognized. Methods: A consensus definition meeting was held for the purpose of developing veterinary-specific definitions for acute lung injury (ALI) and ARDS. Results/conclusions: Three clinically based definitions for acute lung injury and acute respiratory distress-like syndromes occurring in veterinary patients were described. Neonatal equine respiratory distress syndrome (NERDS) was defined separately due to the specific requirement for primary developmental surfactant dysfunction and lack of an inflammatory component. Five diagnostic criteria categories were established for Veterinary ALI/ARDS (Vet ALI/ARDS) with 4 required and a fifth highly recommended criteria. A strong consensus was reached that onset of respiratory distress must have been acute and that known risk factors must be present. Additional criteria included evidence of pulmonary capillary leak with no evidence of increased pulmonary capillary pressure, evidence of inefficient gas exchange and, finally, evidence of inflammation. Some features of ALI/ARDS in the neonatal horse were recognized as unique, therefore, equine neonatal ALI/ARDS (EqNALI/EqNARDS) was similarly defined but with a graded gas exchange inefficiency table to allow for normal developmental changes in gas exchange. Use of these definitions in planning prospective studies of these problems in veterinary patients should allow for more direct comparisons of studies and clinical trials, with a larger goal of improving outcome in veterinary patients.

BACKGROUND: Information about treatment protocols, adverse effects and outcomes with intrapleural recombinant tissue plasminogen activator (rTPA) use in horses with fibrinous pleuropneumonia is limited.HYPOTHESIS/OBJECTIVES: Describe factors that contribute to clinical response and survival of horses treated with rTPA intrapleurally.ANIMALS: Horses with bacterial pneumonia and fibrinous pleural effusion diagnosed by ultrasonography, that were treated with rTPA intrapleurally.METHODS: Retrospective multicenter case series from 2007-2012. Signalment, history, clinical and laboratory evaluation, treatment, and outcome obtained from medical records. Regression analysis used to identify associations between treatments and outcomes.RESULTS: Thirty three hemithoraces were treated in 25 horses, with 55 separate treatments. Recombinant tissue plasminogen activator (375-20,000 μg/hemithorax) was administered 1-4 times. Sonographically visible reduction in fibrin mat thickness, loculations, fluid depth, or some combination of these was seen in 32/49 (65%) treatments. Response to at least 1 treatment was seen in 17/20 (85%) horses with sonographic follow-up evaluation after every treatment. Earlier onset of rTPA treatment associated with increased survival odds. No association was found between cumulative rTPA dose or number of rTPA doses and survival, development of complications, duration of hospitalization or total charges. Clinical evidence of hypocoagulability or bleeding was not observed. Eighteen horses (72%) survived to discharge.CONCLUSIONS AND CLINICAL IMPORTANCE: Treatment with rTPA appeared safe and resulted in variable changes in fibrin quantity and organization within the pleural space. Recombinant tissue plasminogen activator could be a useful adjunct to standard treatment of fibrinous pleuropneumonia, but optimal case selection and dosing regimen remain to be elucidated.

Purpose Chemical burns with calcium containing corrosives as well as irrigation with phosphate buffer solutions after eye burns bear the risk of corneal calcification. The aim of this study was to evaluate the correlation between the occurrence of corneal calcification after chemical injuries and the usage of phosphate buffer containing local therapeutics. Methods We reviewed the data of 179 patients who have been treated in the University Eye Clinic Aachen, Germany, between 1941 and 2000. Only when the corrosive did not contain calcium and when the initial irrigating solution did not contain phosphate buffer, respectively, were patients included in the study. The cases were analyse, if the patient was treated with phosphate buffer containing eye drops/ointment during the first 7 days of hospitalization or as an out-patient, and if corneal calcification was visible by slit-lamp examination during the follow-up. Statistical analysis was performed using Fischer's exact test. Results 152 eyes were included. From 63 eyes treated with phosphate buffer containing eye drops, 31 eyes (49%) developed corneal calcification. From 89 eyes treated without phosphate buffer containing eye drops, only 23 eyes (26%) developed corneal calcification. The two-sided p-value of Fischer's exact test is 0.0036. Conclusion During follow-up after chemical eye burns, eye drops containing phosphate buffer double the risk of corneal calcification. We recommend avoiding these agents in order to prevent the burned cornea from additional opacity. Substances containing phosphate buffer are listed in this article.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are characterized by acute, uncontrolled interstitial and alveolar inflammation secondary to a pulmonary or systemic insult. Endothelial and epithelial damage increases alveolo-capillary permeability leading to protein-rich alveolar edema. Clinical manifestations include severe hypoxemia minimally responsive to oxygen therapy, decreased total lung compliance, and increased airway resistance. Foals present with acute onset of severe respiratory distress. In most cases the initial insult can be attributed to an underlying bacterial, or rarely, viral pneumonia. Laboratory findings include severe hypoxemia, hypo- or hypercapnia, leukocytosis, and hyperfibrinogenemia. Radiographic findings vary from heavy interstitial to coalescing alveolar patterns. Treatment consists of intranasal oxygen supplementation, anti-inflammatories, and antimicrobials if underlying bacterial infection is suspected. Based on limited available reports in foals, prognosis is guarded, but even severe cases can survive and return to athletic function.

Objective—To create a mathematical model to assist in early prediction of the probability of discharge in hospitalized foals ≤ 7 days old. Study Design—Prospective study. Animals—1,073 foals. Procedures—Medical records from 910 hospitalized foals ≤ 7 days old for which outcome was recorded as died or discharged alive were reviewed. Thirty-four variables including historical information, physical examination findings, and laboratory results were examined for association with survival. Variables associated with being discharged alive were entered into a multivariable logistic regression model. Accuracy of the model was validated prospectively on data from 163 foals. Results—Factors in the final model included age group, ability to stand, presence of a suckle reflex, WBC count, serum creatinine concentration, and anion gap. Sensitivity and specificity of the model to predict live discharge were 92% and 74%, respectively, in the retrospective population and 90% and 46%, respectively, in the prospective population. Accuracy of an equine clinician's initial prediction of the foal being discharged alive was 83%, and accuracy of the model's prediction was 81%. Combining the clinician's prediction of probability of live discharge with that of the model significantly increased (median increase, 12%) the accuracy of the prediction for foals that were discharged and nonsignificantly decreased (median decrease, 9%) the accuracy of the predication for nonsurvivors. Conclusions and Clinical Relevance—Combining the clinician's initial predication of the probability of a foal being discharged alive with that of the model appeared to provide a more precise early estimate of the probability of live discharge for hospitalized foals.

Clinical impression suggests that some gastrointestinal lesions are more common in certain horse types. The study tested the hypothesis that relative prevalence of acute gastrointestinal lesions differs between equid types. In a retrospective caseâ€"control study, records (2010â€"2015) were reviewed for equids with acute gastrointestinal disease. Signalment, details of gastrointestinal lesions and diagnoses were recorded. Animals were categorised as miniature type, pony, Arabian, light breed or draft type. Exclusion criteria were no recorded breed/size/diagnosis, age less than one year and donkeys. Using binary logistic regression the influence of type, sex and age on lesion location, nature and diagnoses were investigated. 575 animals (33 miniature types, 136 ponies, 335 light breed types, 17 Arabians and 54 draft types) were included. Using light breed types as reference, ponies (including miniatures) had decreased odds of colon displacements (OR 0.11; 95 per cent CI 0.05 to 0.24; P0.001) and ponies alone had increased odds of strangulation of the small intestine by lipomas (OR 2.3; 95 per cent CI 1.3 to 4.1; P=0.004). Miniature types had decreased odds of strangulating small intestinal lesions (OR 0.1; 95 per cent CI 0.01 to 0.83; P=0.033) and draft types had increased odds of caecal conditions (OR 9.0; 95 per cent CI 2.3 to 34.8; P0.001). In conclusion, equid type influences development of gastrointestinal lesions.

A retrospective questionnaire-based survey was used to determine the perceived efficacy of Newmarket bloodroot ointment in treating equine sarcoids. In 49 horses with 74 sarcoids, 64 sarcoids responded either completely (n = 49) or partially (n = 15) while 10 did not respond or worsened. Sarcoids < 2 cm responded better to treatment (P < 0.001) than did larger sarcoids.

To discuss controversies surrounding antimicrobial use in critically ill horses.PubMed searches from 1970-present for terms including, but not limited to: "horse," "foal," "antimicrobial," "prophylaxis," "infection," "surgery," "sepsis," and "antimicrobial resistance."Increasing bacterial antimicrobial resistance has changed first-line antimicrobial choices and prompted shortening of the duration of prophylactic and therapeutic treatment. The need to decrease bacterial resistance development to critically important antimicrobials has been highlighted.Veterinary medicine has followed a similar trend but often without a high-level evidence. Common dilemmas include diseases in which the theoretically most effective drug is a reserved antimicrobial, the inability to differentiate infectious from noninfectious disease, the duration and necessity of prophylactic antimicrobials and use of antimicrobials in primary gastrointestinal disease. These problems are illustrated using examples of purulent infections, neonatal sepsis, colic surgery, and treatment of colitis. Although enrofloxacin, cephalosporins, and doxycycline, in contrast to gentamicin, reach therapeutic concentrations within the lungs of healthy horses, the first two should not be used as first line treatment due to their reserved status. Due to the high risk of bacterial sepsis, antimicrobial treatment remains indispensable in compromised neonatal foals but shortening the length of antimicrobial treatment might be prudent. One prospective randomized study demonstrated no difference between 3 and 5 days of perioperative antimicrobial treatment in colic surgery but shorter durations were not evaluated. High-level evidence to recommend antimicrobial treatment of adult horses with undifferentiated diarrhea does not exist.Few evidence-based recommendations can be made. Commonly used antimicrobial combinations remain the mainstay for treating purulent infections. Antimicrobial treatment for compromised foals should not extend beyond recovery. Continuation of prophylactic antimicrobials3 days is likely unnecessary after colic surgery; shorter durations might be equally effective. Antimicrobial prophylaxis in adult horses with diarrhea is unlikely to be beneficial.

Background Reproducible and accurate recognition of presence and severity of ataxia in horses with neurologic disease is important when establishing a diagnosis, assessing response to treatment, and making recommendations that might influence rider safety or a decision for euthanasia. Objectives To determine the reproducibility and validity of the gait assessment component in the neurologic examination of horses. Animals Twenty-five horses referred to the Royal Veterinary College Equine Referral Hospital for neurological assessment (n = 15), purchased (without a history of gait abnormalities) for an unrelated study (n = 5), or donated because of perceived ataxia (n = 5). Methods Utilizing a prospective study design; a group of board-certified medicine (n = 2) and surgery (n = 2) clinicians and residents (n = 2) assessed components of the equine neurologic examination (live and video recorded) and assigned individual and overall neurologic gait deficit grades (0–4). Inter-rater agreement and assessment-reassessment reliability were quantified using intraclass correlation coefficients (ICC). Results The ICCs of the selected components of the neurologic examination ranged from 0 to 0.69. “Backing up” and “recognition of mistakes over obstacle” were the only components with an ICC > 0.6. Assessment-reassessment agreement was poor to fair. The agreement on gait grading was good overall (ICC = 0.74), but poor for grades ≤ 1 (ICC = 0.08) and fair for ataxia grades ≥ 2 (ICC = 0.43). Clinicians with prior knowledge of a possible gait abnormality were more likely to assign a grade higher than the median grade. Conclusion and Clinical Importance Clinicians should be aware of poor agreement even between skilled observers of equine gait abnormalities, especially when the clinical signs are subtle.

A neonatal foal with signs of rectal bleeding was diagnosed with an intraluminal rectal mass and intussusception on surgical exploration of the abdomen. Histologically, the mass consisted of cystic spaces lined by simple columnar epithelium with numerous goblet cells and was surrounded by thin bands of smooth muscle in a myxomatous stroma. Although the mass shared similarities with retrorectal cystic hamartoma (tailgut cyst) and juvenile polyps, described in human medicine, location and histologic findings were not entirely consistent with either condition.

Appropriate durations of perioperative antimicrobial therapy following exploratory coeliotomy in horses are controversial, and with the rising prevalence of multiresistant bacteria there is a strong incentive to use antimicrobials for the shortest time possible. Following exploratory coeliotomies, incisional infections are an important cause of morbidity in horses and could be influenced by the duration of systemic antimicrobial therapy. The aim of this study was to investigate whether 72 hours of perioperative antimicrobial therapy is as effective as 120 hours at preventing the development of postoperative incisional infections. Horses undergoing exploratory coeliotomy at two referral hospitals were assigned randomly into Group 1 (receiving 72 hours of perioperative antimicrobial therapy) and Group 2 (receiving 120 hours of perioperative antimicrobial therapy). Only horses recovering from surgery and surviving for >120 hours were included in the study. Ninety-two horses met the criteria for inclusion in the study, 42 in Group 1 and 50 in Group 2. The overall incisional complication rate was 42.2 per cent, and no significant difference in the number of incisional complications in the two groups was identified. Results of the study suggest that there is no benefit in using 120 hours over 72 hours of perioperative antimicrobial therapy to prevent incisional infections.

Activated platelets can contribute to host defense through release of products with bactericidal actions such as antimicrobial peptides and reactive oxygen species (ROS), as well as by forming heterotypic aggregates with neutrophils and enhancing their antimicrobial properties. Whilst release of vasoactive mediators from equine platelets in response to stimuli including bacterial lipopolysaccharide (LPS) has been documented, neither ROS production, nor the effects of activated platelets on equine neutrophil ROS production, have been reported. This study first sought evidence that activated equine platelets inhibit bacterial growth. Platelet superoxide production in response to stimuli including Escherichia coli -derived LPS and lipoteichoic acid (LTA) from Staphylococcus aureus was then determined. The ability of LPS and LTA to up-regulate platelet P-selectin expression and induce platelet–neutrophil aggregate formation was investigated and the effect of co-incubating activated platelets with neutrophils on superoxide production measured. Growth of E. coli was inhibited in a time-dependent manner, and to a similar extent, by addition of platelet rich plasma (PRP) or platelet poor plasma (PPP) obtained by centrifugation of PRP. Activation of platelets in PRP by addition of thrombin led to a significant increase in the inhibitory action between 0.5 and 2 h. Although phorbol myristate acetate (PMA) caused superoxide production by equine platelets in a protein kinase C-dependent manner, thrombin, platelet activating factor (PAF), LPS, LTA and formyl-methionyl-leucyl phenylalanine (FMLP) were without effect. LPS and LTA did induce platelet activation, measured as an increase in P-selectin expression (% positive cells: 17 ± 3 (un-stimulated); 63 ± 6 (1 μg/ml LPS); 64 ± 6 (1 μg/ml LTA); n = 5) but not platelet superoxide production or heterotypic aggregate formation. Co-incubation of activated platelets with neutrophils did not increase neutrophil superoxide production. This study has demonstrated for the first time that when activated, equine platelets, like those of other species, are capable of releasing ROS that could assist in bacterial killing. However, the findings suggest that neither superoxide production by platelets nor enhancement of production by neutrophils is likely to play a significant role. Nevertheless, as has been reported in man, equine PPP and PRP did inhibit E. coli growth in vitro , and addition of thrombin significantly increased the inhibitory effect of PRP. This suggests that products released from activated platelets could contribute to antimicrobial activity in the horse. The factors in equine plasma and released by activated platelets that are responsible for inhibiting bacterial growth have yet to be determined.

This report describes a unique case of presumed migration of Parelaphastrongylus tenuis through the spinal cord into the eye of a llama where it survived and matured within the ocular environment. Blindness of the eye was most likely attributable to migration of the parasite through the central nervous tissue.

Reasons for performing study Equine cervical osteoarthritis is a common disease known to contribute to both neck pain and cervical vertebral compressive myelopathy. There are no published studies demonstrating the usefulness of latero-oblique radiography as a diagnostic tool for cervical osteoarthritis. Objectives To determine the sensitivity, specificity and positive and negative predictive values of latero-oblique radiography as a diagnostic tool for cervical articular process joint osteoarthritis. Study design Prospective cadaver study. Methods Latero-oblique radiographs and CT images were collected, and post mortem examinations performed, on 27 cadaver necks from Thoroughbred-type horses of various ages and sexes. Two equine clinicians independently reviewed each set of images for the presence of osteoarthritis. The authors, under the guidance of a veterinary pathologist, reviewed all articular process joints for bony changes indicative of osteoarthritis. Results The prevalence of osteoarthritis identified on CT images was 57.9% (Assessor A) and 23% (Assessor B). The prevalence of lesions identified on post mortem examination was 25.6%. Latero-oblique radiography showed a low sensitivity for identifying osteoarthritis when compared to both CT imaging (6.3–16.1%) and post mortem examination (2.2–4.4%). However, it showed a high specificity when compared to both CT imaging (92.1–97.8%) and post mortem examination (87.2–95.0%). The positive predictive value for identifying osteoarthritis was moderate (40.9–80.0%) when compared to CT imaging and poor (4.2–18.2%) when compared to post mortem examination. The negative predictive value was moderate when compared to both CT imaging (42.9–76.3%) and post mortem examination (78.0–79.8%). Conclusions Latero-oblique radiography has low sensitivity, but high specificity for the detection of cervical osteoarthritis when compared to both CT imaging and post mortem examination. Further investigation comparing the sensitivity, specificity and positive and negative predictive values of latero-oblique radiography vs. laterolateral radiography would determine whether taking latero-oblique radiographs, which can be more difficult to obtain and interpret, is necessary for the diagnosis of cervical osteoarthritis in practice. Ethical animal research: Ethical committee oversight not currently required by this congress: The study was performed on material obtained from an abattoir. Sources of funding: None. Competing interests: None.

Summary Reason for performing study: Platelet activation occurs in human obstructive airway diseases and in laboratory animal models. However, there is limited evidence that platelets may be involved in equine recurrent airway obstruction (RAO) and other inflammatory diseases. This study investigated whether platelet activation also occurred in RAO. Hypothesis: Platelet function is altered in ponies with active RAO. This alteration can be detected ex vivo by measuring platelet adhesion. Methods: An in vitro platelet adhesion assay measuring acid phosphatase (AcP) activity colorimetrically was adapted for use with equine platelets and responses to selected agonists were established. Platelet adhesion and aggregation was evaluated in vitro on platelets isolated from 6 ponies with RAO before, during and after a 7 h natural antigen challenge. Three ponies with no history of airway disease were also studied. Results: Adhesion of equine platelets to serum coated plastic was detected at concentrations of 10–100 times 109/l. Adhesion increased in response to stimulation with platelet activating factor and thrombin, but not equine interleukin 8. Prior to the antigen challenge, adhesion of nonstimulated platelets was low and increased significantly (P

Objective—To determine the phosphodiesterase (PDE) isoenzymes in equine platelets and evaluate their influence on platelet adhesion. Sample Population—Platelets obtained from healthy New Forest Pony geldings that ranged from 12 to 20 years of age (mean ± SEM, 17.3 ± 1.1 years). Procedures—PDE isoenzyme activity in equine platelets was determined by use of a 2-step radioactive assay. Functional importance of PDE isoenzymes was established by use of selective inhibitors in a colorimetric adhesion assay. Results—PDE1, PDE2, PDE3, and PDE5 and small amounts of PDE4 were found in equine platelets. Inhibition of PDE3 abolished platelet adhesion almost completely, whereas inhibition of PDE4 and PDE5 had little effect. Conclusions and Clinical Relevance—Function of equine platelets can be influenced by inhibition of PDE3. Selective PDE3 inhibitors may be clinically useful to regulate platelet function. They offer the advantage of increased potency with fewer adverse effects, compared with those for nonselective PDE inhibitors.

A nutritional plan should be incorporated into every treatment plan of the critically ill patient. Weight loss and cachexia are the result of prevalence of catabolic processes over anabolic processes in addition to absolute or relative increased demands and decreased food intake.

CHOLESTEROL granulomata – benign choroid plexus masses often detected at equine postmortem examinations – are sometimes associated with central neurological signs (Ivoghli and others 1977, Johnson and others 1993, Jackson and others 1994, King 1997). Antemortem diagnosis was impossible until advent of magnetic resonance imaging (Maulet and others 2008) and CT (Vink-Nooteboom and others 1998, Vanschandevijl and others 2008). These two cases are the first to illustrate diagnosis using standing (unanaesthetised) CT (CT Lightspeed QX/i; GE medical systems) and describe the long-term follow-up of one case, revealing that the prognosis for some cases is fair. Case 1: A 12-year-old Irish Draught cross gelding was presented with a 10-day history of intermittent lethargy and abnormal head carriage. On presentation, episodes of generalised muscle rigidity and ataxia were noticed by the owner; the horse was obtunded with reduced tongue tone and drooping of the lower lip and reluctant to flex or extend the neck and back. Neurological signs had improved following administration of methylprednisolone, penicillin and flunixin meglumine. On presentation to the Royal Veterinary College, the horse was obtunded; menace responses were reduced bilaterally, but pupillary light reflexes were intact. Mild superficial gluteal muscle fasciculations were evident. The horse had an exaggerated guarding response to deep palpation of the neck at C5 to C7. The neuroanatomical localisation suggested forebrain involvement, but based on cervical discomfort on …

Background: Limited research has been undertaken to determine the impact of horse age, sex and number of riders on horse performance in British Eventing (BE) horse trials. Improved understanding of this can aid professionals in planning a competition horse’s career. Objectives: To investigate the impact of age, sex and number of riders on the peak performance of horses at each of the main levels of BE competitions. Methods: The best score from each horse competing in BE horse trials in the years 2008 to 2018 were recorded, principal component and hierarchical cluster analysis was performed. Basic data analysis was used to identify variables associated with particular better-performing clusters of horses. The interplay of the combinatory variables was then used to map out the trends in career trajectory for horses competing at each level of competition in the best and worst performing clusters.Results and conclusions: The peak performance of mares was worse than geldings and stallions at all levels. At Novice to Advanced, stallions did not perform as consistently with multiple riders as geldings. The age at which the best performing groups peaked was similar for mares and geldings in all classes, although stallions peaked at an older age than mares and geldings at Novice and Intermediate level. All horses were a minimum of four years old at the time of competition, as per British Eventing rules. Keywords: equine, competition, show jumping, dressage, training