Pressure algometry for assessment of abdominal wall sensitivity in horses after ventral midline coeliotomy.

OBJECTIVE: To assess the clinical course of abdominal wall sensitivity after ventral midline coeliotomy in horses by determining mechanical nociceptive thresholds (MNTs) during hospitalization, and to determine the inter-observer reliability of pressure algometry on the abdominal wall. STUDY DESIGN: Observational, cohort study. SAMPLE POPULATION: A total of 13 horses presenting with signs of abdominal pain/colic undergoing ventral midline coeliotomy and 10 healthy horses without an abdominal incision. METHODS: Measurements were performed on days 1, 3, 5, 7 and 9 postoperatively using a pressure algometer. Measurement sites were marked left and right, abaxial to the abdominal incision. Cranial to the incision, two control points were marked. Measurements were made by one observer, blinded to the recorded MNT values. To determine inter-observer reliability, five horses (surgical group n = 2; nonsurgical group n = 3) were measured by two observers in a randomized order. RESULTS: Mean MNT values on days 5 and 7 were 9.61 Ncm-2 and 10.14 Ncm-2 in the operated group (p = 0.009 ; p = 0.005) respectively versus 13.00 Ncm-2 on day 1. Wound-associated points showed lower values than control points (p = 0.002). The nonsurgical group did not show a difference between control points and wound-associated points (p = 0.06). No significant differences were found between the surgical and the nonsurgical groups at the wound-associated points on any days measured. The inter-observer reliability was low (intraclass correlation coefficient of 0.26; Cronbach's alpha of 0.27). CONCLUSION: Operated animals showed a reduction in MNT values on days 5 and 7 when compared with day 1 and lower values for the wound-associated points when compared with the control points. Inter-observer reliability was low. Pressure algometry could be a useful tool for assessing wound sensitivity after ventral midline coeliotomy in horses, which may improve pain management postoperatively.

Monitoring equine head-related pain with the Equine Utrecht University scale for facial assessment of pain (EQUUS-FAP).

This study validates a recently described pain scale, the Equine Utrecht University scale for facial assessment of pain (EQUUS-FAP), in horses with acute or postoperative pain originating from the head, including dental pain, ocular pain, or trauma to the skull. This cohort study of 23 horses with head-related pain and 23 normal, healthy controls revealed significant differences in EQUUS-FAP scores between control horses and horses with acute or postoperative pain (P <0.001). Moreover, pain scores after surgery decreased significantly over time (P <0.001). The scale showed good inter-observer reliability (intra-class correlation coefficient = 0.92), sensitivity (80%), specificity (78%), and positive (80%) and negative predictive values (78%).

Early detection of West Nile virus in France: quantitative assessment of syndromic surveillance system using nervous signs in horses.

West Nile virus (WNV) is a growing public health concern in Europe and there is a need to develop more efficient early detection systems. Nervous signs in horses are considered to be an early indicator of WNV and, using them in a syndromic surveillance system, might be relevant. In our study, we assessed whether or not data collected by the passive French surveillance system for the surveillance of equine diseases can be used routinely for the detection of WNV. We tested several pre-processing methods and detection algorithms based on regression. We evaluated system performances using simulated and authentic data and compared them to those of the surveillance system currently in place. Our results show that the current detection algorithm provided similar performances to those tested using simulated and real data. However, regression models can be easily and better adapted to surveillance objectives. The detection performances obtained were compatible with the early detection of WNV outbreaks in France (i.e. sensitivity 98%, specificity >94%, timeliness 2·5 weeks and around four false alarms per year) but further work is needed to determine the most suitable alarm threshold for WNV surveillance in France using cost-efficiency analysis.

Systematic pain assessment in horses.

Accurate recognition and quantification of pain in horses is imperative for adequate pain management. The past decade has seen a much needed surge in formal development of systematic pain assessment tools for the objective monitoring of pain in equine patients. This narrative review describes parameters that can be used to detect pain in horses, provides an overview of the various pain scales developed (visual analogue scales, simple descriptive scales, numerical rating scales, time budget analysis, composite pain scales and grimace scales), and highlights their strengths and weaknesses for potential clinical implementation. The available literature on the use of each pain assessment tool in specific equine pain states (laminitis, lameness, acute synovitis, post-castration, acute colic and post-abdominal surgery) is discussed, including any problems with sensitivity, reliability or scale validation as well as translation of results to other clinical pain states. The review considers future development and further refinement of currently available equine pain scoring systems.

Monitoring of equine health in Denmark: a survey of the attitudes and concerns of potential database participants.

At present Denmark has no central database holding records of equine health and disease. Nor have attitudes to the establishment of a national database, and the concerns it raises, been investigated in a systematic way. The objective of the present study was to assess the attitudes and concerns of potential database stakeholders. Attitudes to participation, and the location, financing and management of the proposed database, together with any concerns it raises, were investigated in a questionnaire study of 13 potential stakeholder groups in Denmark (in total, 1581 questionnaire recipients and 717 respondents): equine veterinarians, researchers, veterinary students, animal welfare organization representatives, horse owners, trainers, farriers, representatives from authorities, ordinary citizens, and representatives of laboratories, and insurance, medical equipment and pharmaceutical companies. Proportions were calculated for pre-categorised responses, and supplementary attitudes were extracted from qualitative responses. Eighty-six percent of respondents stated a positive interest in providing data for the database; the percentage for veterinarians was 90%. Data contribution was regarded as feasible by many of the stakeholder groups; this willingness to provide data, however, depended on the implementation of a very user-friendly system. Requirements included an electronic, simple, and time-efficient data reporting system. Most respondents felt the database should be financed via horse owners through mandatory contributions linked to each horse. Disagreement appeared to arise over data ownership, accessibility, and location. These and other issues need further elaboration in order to find a solution that is acceptable for all stakeholders. It may be advisable to collect and store data in more than one database.

Monitoring of equine health in Denmark: the importance, purpose, research areas and content of a future database.

The plentiful data on Danish horses are currently neither organized nor easily accessible, impeding register-based epidemiological studies on Danish horses. A common database could be beneficial. In principle, databases can contain a wealth of information, but no single database can serve every purpose. Hence the establishment of a Danish equine health database should be preceded by careful consideration of its purpose and content, and stakeholder attitudes should be investigated. The objectives of the present study were to identify stakeholder attitudes to the importance, purpose, research areas and content of a health database for horses in Denmark. A cross-sectional study was conducted with 13 horse-related stakeholder groups in Denmark. The groups surveyed included equine veterinarians, researchers, veterinary students, representatives from animal welfare organizations, horse owners, trainers, farriers, authority representatives, ordinary citizens, and representatives from laboratories, insurance companies, medical equipment companies and pharmaceutical companies. Supplementary attitudes were inferred from qualitative responses. The overall response rate for all stakeholder groups was 45%. Stakeholder group-specific response rates were 27-80%. Sixty-eight percent of questionnaire respondents thought a national equine health database was important. Most respondents wanted the database to contribute to improved horse health and welfare, to be used for research into durability and disease heritability, and to serve as a basis for health declarations for individual horses. The generally preferred purpose of the database was thus that it should focus on horse health and welfare rather than on performance or food safety, and that it should be able to function both at a population and an individual horse level. In conclusion, there is a positive attitude to the establishment of a health database for Danish horses. These results could enrich further reflection on the establishment of a Danish equine health database and prove useful to institutions abroad considering establishing similar databases.

Autologous biologic treatment for equine musculoskeletal injuries: platelet-rich plasma and IL-1 receptor antagonist protein.

Autologous biologic therapies such as platelet-rich plasma and autologous conditioned serum are in widespread clinical use to treat musculoskeletal pathology in horses. These substances exert a therapeutic effect through the provision of either anabolic or anti-catabolic factors, or a combination of both. This article discusses the history, experimental and clinical literature, and currently accepted preparation and usage strategies for both platelet-rich plasma and autologous conditioned serum.

Colic after swimming exercise in racehorses: an investigation of incidence, management, surgical findings and outcome.

The incidence of colic following swimming exercise (SC) in a racehorse population examined over 3 years was 0.08%. Following 167,977 swims, 136 cases were reported. Colic resolved spontaneously in 2 horses, medically in 129 or surgically in 5. In a separate study, 21 horses were subject to exploratory laparotomy for SC. Findings included non-strangulating displacements in 7 horses, strangulating displacements in 7, a combination of non-strangulating and strangulating displacements in 1, prominent gaseous intestinal distension in 5 and no abnormalities in 1 horse. A poor response to analgesia prompted surgery in all cases. Rectal palpation and/or abdominal ultrasound was performed in 16 of 21 cases and abnormalities were found in 14 of these. Of the 21 surgical cases, 20 (95.2%) survived to discharge and 18 (90%) raced postoperatively.

Quantitative assessment of increased sensitivity of chronic laminitic horses to hoof tester evoked pain.

REASONS FOR PERFORMING STUDY: To evaluate quantitative sensory testing (QST) of the feet of laminitic horses using a power-assisted hoof tester. HYPOTHESIS: Hoof Compression Thresholds (HCTs) can be measured reliably and are consistently lower in horses with chronic laminitis than in normal horses. METHODS: HCTs of chronic laminitic (n=7) and normal horses (n=7) were repeatedly measured using a hydraulically powered and feedback controlled hoof tester. Data from 2 tests, at 3 sites in both forefeet, during 3 sessions were collected and statistically analysed using linear mixed models. RESULTS: The mean±s.e. HCT for the laminitic horses was 29.6±3.5 kg/cm2 and for horses in the normal group was 59.8±4.3 kg/cm2. Residual variance was the largest of the error components and was greater (P<0.001) for the normal horses; none of the other components significantly differed between the 2 groups. Averaging of HCTs from each foot could produce a test with intraclass correlation coefficients of 0.83 for the normal group and 0.87 for the laminitic group, with an estimated sensitivity of 0.94 and a specificity of 0.93. This test would permit detection with 80% power and 95% confidence of a reduction of over 40% in the difference in mean HCTs between laminitic and normal horses following effective treatment provided that the experimental groups are of 9 or more horses. CONCLUSIONS: HCTs can be safely and reliably measured experimentally using this hoof tester. The level of variability found indicates that, under these conditions, treatments may need to produce at least a 40% improvement to be detected. Simplification of the hoof tester, training of the horse and repeated testing may permit the method to be used clinically to detect changes in the HCTs of individual laminitic horses but these potential improvements will require further investigation. POTENTIAL RELEVANCE: Measurement of HCTs can provide an additional means for assessing the effectiveness of treatments for alleviation of chronic equine laminitis.

Ultrasonographic assessment of laryngohyoid position as a predictor of dorsal displacement of the soft palate in horses.

Dorsal displacement of the soft palate is an important cause of poor performance in racehorses, yet its etiology is not fully understood. Diagnosis requires treadmill videoendoscopy, which is not widely available. The relationship of the larynx, the hyoid apparatus, and the remainder of the skull may be important in predisposing horses to dorsal displacement of the soft palate. We hypothesized that this relationship could be accurately assessed in unsedated horses through ultrasonographic examination. Fifty-six racehorses presented for evaluation of poor performance were subjected to treadmill videoendoscopy and resting ultrasonography. Using ultrasound-assisted percutaneous measures of laryngo-hyoid position, the relationship between selected anatomic structures and the occurrence of dorsal displacement of the soft palate was evaluated. A significant relationship was found between the depth of the basihyoid bone at rest and the occurrence of dorsal displacement of the soft palate at exercise (P = 0.03). Other measures of laryngohyoid position were not found to be associated with dorsal displacement of the soft palate. Thus, there is an association between the occurrence of dorsal displacement of the soft palate at exercise and the resting position of the basihyoid bone, whereby on average a more ventral location of the basihyoid bone is present in horses with dorsal displacement of the soft palate. The pathophysiologic implications of this finding are not fully understood but, based on our findings, ultrasound examination is of value in assisting in the diagnosis of dorsal displacement of the soft palate.

Objective radiographic assessment of abdominal sand accumulation in horses.

Gastrointestinal sand accumulation is a common cause of equine colic. Subjective assessment of sand accumulation on abdominal radiographs has been used as a diagnostic aid; however, there is poor correlation between clinical, diagnostic, and surgical findings. The purpose of this study was to develop an objective method of assessing radiographic sand accumulation in order to improve the diagnostic utility of radiography for sand colic. Fifty-one equine abdominal radiographic examinations were reviewed, with approximately half of the imaged patients having a clinical diagnosis of sand colic. Initially, four observers independently reviewed these radiographic studies to subjectively decide whether or not sand accumulation was sufficient to cause colic. Subsequently, an objective scoring system was developed using various radiographic parameters that yielded a score ranging from one to 12 for quantity and apparent density of sand accumulation. Inter- and intraobserver results using the subjective scoring method had significant differences among all observers. Subjective assessment was also deemed to be inaccurate for colic prediction. Using the objective scoring system, there were no significant differences between or within the observers' results. A score of seven out of 12 was found to have an 83% likelihood of being associated with a positive diagnosis of sand colic. The designed objective scoring method creates a more uniform and accurate method to assess the sand accumulation.

Specific causes of morbidity among Swedish horses insured for veterinary care between 1997 and 2000.

The principal aim of this study was to analyse the incidence of disease due to general and more specific causes among over 100,000 horses covered by complete insurance for veterinary care by a Swedish insurance company during 1997 to 2000. The database was used to calculate the rate of cause-specific morbidity in horses of different ages, sexes and breed groups kept in different regions with different human population densities. The joints were the most commonly affected part of the body, followed by unspecified/whole body, the skin and the digestive system. The most common specific diagnosis was fetlock arthritis, followed by lameness of undefined origin, other locomotor problems, traumatic injuries to the skin, arthritis in several joints, and colic. Geldings had the highest rate of at least one disease event in the joints, unspecified/whole body, skeletal or respiratory system, whereas in the other four major systems the difference between the sexes was marginal.

Tracheobronchoscopic assessment of exercise-induced pulmonary hemorrhage in horses.

OBJECTIVE: To determine the interobserver variability of assessment of exercise-induced pulmonary hemorrhage (EIPH) during tracheobronchoscopic examination in horses. ANIMALS: 747 Thoroughbred racehorses. Procedures-850 tracheobronchoscopic examinations were performed within 2 hours of racing for the horses. Examinations were recorded on videotape, and EIPH and its severity were assessed independently by 3 veterinarians. Concordance was determined by calculation of the Cohen weighted kappa statistic and tabulation of scores assigned by each observer. RESULTS: Weighted kappa statistics ranged from 0.75 to 0.80. In 99.4% of observations, all observers agreed or 2 of 3 agreed and the third differed by < or = 1 grade. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that interobserver reliability of tracheobronchoscopic assessment of EIPH in Thoroughbred racehorses is high when the examination is conducted by experienced veterinarians. Concordance among investigators is sufficient to justify use of this grading system for further studies and clinical descriptions of EIPH.

Evaluation of clinical and laboratory variables as prognostic indicators in hospitalised gastrointestinal colic horses.

The present prospective study included 106 horses referred to the Department of Large Animal Sciences, The Norwegian School of Veterinary Science, as non-responders to the initial colic treatment in general practise. In 14 of these cases a required surgical treatment was not performed due to economical or other reasons and were excluded from the study. Clinical and laboratory data were obtained at the arrival in the hospital. The outcome for all analyses was survival/ non-survival. A multivariable logistic regression was performed. The analyses were used in medically (46 horses) and surgically treated cases (46 horses) separately. The same analyses were also run for all 92 horses in a simulated "field" situation, where only clinical variables and D-dimer values were included. The fraction of survivors was 78% in the medical and 48% in the surgical cases. In total 63% of the horses survived. In the final multivariable logistic regression model packed cell volume (PCV) was the only important predictor for medically treated cases, and heart rate and presence of hyperaemic or cyanotic mucous membranes were the predictors in the surgically treated cases as well as in the simulated "field" situation. In conclusion, traditional variables as heart rate, mucous membranes and PCV were the important predictors for the outcome in hospitalised colic cases.

Evaluation of a stochastic Markov-chain model for the development of forelimb injuries in Thoroughbred racehorses.

OBJECTIVE: To evaluate a Markov-chain model for the development of forelimb injuries in Thoroughbreds and to use the model to determine effects of reducing sprint distance on incidence of metacarpal condylar fracture (CDY) and severe suspensory apparatus injury (SSAI). SAMPLE POPULATION: Weekly exercise and injury data for 122 Thoroughbreds during racing or training. PROCEDURE: Weekly data were used to construct a Markov-chain model with 5 states (uninjured [UNINJ], palpable suspensory apparatus injury [PSAII, SSAI, CDY, and lost to follow-up [LOST]). Transition probabilities between UNINJ and PSAI were estimated as a function of weekly sprint distance by use of linear regression analysis. The model was used to predict distributions of annual CDY and SSAI incidences in southern California racehorses and was validated by using CDY incidence reported by racetrack practitioners. The model was modified by reducing the number of sprint distances that were > 6 furlongs (> 1.20 km) by 20%, and CDY and SSAI incidences were compared with those generated by the baseline model. RESULTS: The model accurately fit development of injuries in the sample population but overestimated development of injuries in the southern California racehorse population. Development of and recovery from PSAI were correlated with distance run at high speeds. Reducing by 20% the number of sprints run at distances > 6 furlongs significantly reduced modeled annual CDY and SSAI incidence by 9%. CONCLUSIONS AND CLINICAL RELEVANCE: Reducing the number of sprints at distances > 6 furlongs, particularly among horses with PSAI, reduces risk of CDY and SSAI.

Calcium regulation by skeletal muscle membranes of horses with recurrent exertional rhabdomyolysis.

OBJECTIVE: To determine whether an alteration in calcium regulation by skeletal muscle sarcoplasmic reticulum, similar to known defects that cause malignant hyperthermia (MH), could be identified in membrane vesicles isolated from the muscles of Thoroughbreds with recurrent exertional rhabdomyolysis (RER). SAMPLE POPULATION: Muscle biopsy specimens from 6 Thoroughbreds with RER and 6 healthy (control) horses. PROCEDURES: RER was diagnosed on the basis of a history of > 3 episodes of exertional rhabdomyolysis confirmed by increases in serum creatine kinase (CK) activity. Skeletal muscle membrane vesicles, prepared by differential centrifugation of muscle tissue homogenates obtained from the horses, were characterized for sarcoplasmic reticulum (SR) activities, including the Ca2+ release rate for the ryanodine receptor-Ca2+ release channel, [3H]ryanodine binding activities, and rate of SR Ca2+-ATPase activity and its activation by Ca2+. RESULTS: Time course of SR Ca2+-induced Ca2+ release and [3H]ryanodine binding to the ryanodine receptor after incubation with varying concentrations of ryanodine, caffeine, and ionized calcium did not differ between muscle membranes obtained from control and RER horses. Furthermore, the maximal rate of SR Ca2+-ATPase activity and its affinity for Ca2+ did not differ between muscle membranes from control horses and horses with RER. CONCLUSIONS AND CLINICAL RELEVANCE: Despite clinical and physiologic similarities between RER and MH, we concluded that RER in Thoroughbreds does not resemble the SR ryanodine receptor defect responsible for MH and may represent a novel defect in muscle excitation-contraction coupling, calcium regulation, or contractility.

[Nutrition of horses: ration calculation and assessment]. / Voeding van paarden: rantsoenberekening en -beoordeling.

In various situations it is desirable to evaluate the diet of horses. Such situations occur when nutrition is considered as the cause of disease or symptoms or and when a diet or diet change raises concern about whether the animal is receiving sufficient nutrients. Ration evaluation consists of translating feed ingredients into nutrients supplied and comparing this with nutrient requirements. The basics of ration evaluation are illustrated by means of four examples of horse diets.

Anesthetic complications in the horse.

The basis for management of all complications is early recognition, preparation, and a problem-solving approach. Some anesthetic complications, such as equipment malfunction and injuries from endotracheal intubation or misplaced drug injections, are common to all animals and can be prevented almost entirely by careful management. Other problems, such as pulmonary dysfunction and cardiovascular depression, seem to occur more often in healthy horses than in healthy members of other domestic species. Postoperative myopathy-neuropathy, sometimes a devastating complication, seems to be peculiar to the horse, and its incidence has been linked to hypotensive inhalant anesthesia. Careful positioning and padding, monitoring of anesthetic depth, and treating of cardiovascular depression may prevent most cases of postanesthetic myopathy. Idiosyncratic drug reactions, such as MH, are entirely unpredictable and can be rapidly fatal unless recognized early and treated vigorously and specifically.