Laminitis: risk factors and outcome in a group of Danish horses

Reasons for performing study: Recent systematic reviews have highlighted the lack of quality information with respect to the epidemiology of equine laminitis. Objectives: To identify in Denmark the risk factors for new (i.e. not believed to have suffered from laminitis previously) cases of laminitis (NL) and to look at the outcome and incidence of repeated episodes of laminitis in these animals as well as those which had previously suffered an episode of laminitis (i.e. chronic cases) over the following 12 months. Methods: Information was obtained from 110 veterinary diagnosed cases of laminitis (69 new and 41 chronic) and 80 control animals (the next non-laminitic horse/pony seen by that participating practice). All animals were followed for up to one year. Univariable and multivariable conditional logistic regression was conducted for the NL case control pairs. Variables were retained within the final multivariable models if the likelihood ratio p-value was < 0.05. Results: There was no association between sex or gender and laminitis. A recent change of grass, being on what was considered high quality grass and being a cold-blooded type, <149cm ( i.e. Shetland, Fell, Welsh, or Dartmoor pony, Icelandic horse, Norwegian fjords, or a mix of these breeds) were all significant risk factors for laminitis. Although cresty neck score (CNS), and body condition Score (BCS), were significantly associated with NL at the univariable screening stage, they were found to be confounders of breed and each other during the multivariable model building process. Other factors such as weight, and estimated starch intake were not found to be significant .Thirty three percent of all the laminitis cases had been humanely destroyed within 12 months of diagnosis, mainly for laminitis associated reasons, compared with only 7.5% of the controls (none for laminitis associated reasons). Conclusions: and potential Relevance: This study confirms the importance of grass turn out and breed on laminitis risk. Horses in work at the time of diagnosis as well as those diagnosed in the winter and spring were more likely to be humanely destroyed within the next 12 months than those not in work or diagnosed in the autumn and summer

Straw as an Alternative to Grass Forage in Horses-Effects on Post-Prandial Metabolic Profile, Energy Intake, Behaviour and Gastric Ulceration

Simple Summary Many leisure horses have low energy requirements and obesity is common. Straw has a low energy content and could be a forage option for these horses. However, a previous study suggested that providing straw as the only forage was associated with an increased risk for gastric ulcers. This study evaluated replacing 50% of the daily forage allowance with a good hygienic quality wheat straw. Six horses were fed both the control diet (grass forage only, CON) and the straw diet (50:50 grass forage and straw, S). Each diet was fed for three weeks and all horses were evaluated on both diets. Diet did not affect the prevalence of gastric ulcers. Feed intake time was longer and daily energy intake lower on diet S, compared to CON. Plasma insulin levels were lower on diet S compared to CON, which could be beneficial for horses with overweight or insulin dysregulation. The results suggest that good hygienic wheat straw provided at 50% of the forage ration does not cause gastric ulcers, but may prolong feeding time and promote a metabolic profile more suitable for overweight horses. Including straw as part of the ration therefore may improve welfare for horses with low energy requirements. Straw's low energy content means it is a roughage option for horses with low energy requirements. Previously, in a field study, straw was associated with an increased risk for gastric ulcers. This study evaluated the effect on gastric ulcers, metabolic profile and behaviour of replacing, in a forage-only ration, 50% of the daily allowance with wheat straw. Six equines were studied in a 2 x 21-day cross-over design. The control diet (CON: 100% grass forage) and the straw diet (S: 50% grass forage and 50% straw [DM basis]) were iso-energetic. Gastroscopy was performed prior to the study and on day 21 and blood samples were collected and behavioural observations were performed. Diet did not affect squamous or glandular gastric ulcer scores (p > 0.05). Feed intake time was longer (p < 0.05) plus energy intake and plasma insulin concentrations were lower on diet S compared to CON (p < 0.0001). Plasma serotonin concentrations tended to be higher on diet S compared to CON (p = 0.05). The results suggest that good hygienic quality wheat straw can be included for up to 50% of the diet without causing gastric ulcers and that it can extend feeding time and promote a metabolic profile more suitable for overweight horses

Effect of moving from being extensively managed out in pasture into training on the incidence of equine gastric ulcer syndrome in Icelandic horses

Objective: To investigate equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) in Icelandic horses moving from pasture into training. Animals: 81 horses (median age, 3 years; interquartile range, 1 year) from 10 farms representing 4 different Icelandic regions. Procedures: Initial gastroscopy was undertaken within 2 weeks of moving from pasture into a training establishment. A total of 71 horses underwent endoscopic examination again 8 weeks later. Various management and behavioral factors were assessed through face-to-face questionnaires with the owners or trainers. Multivariable logistic regression was used to determine factors contributing to any change in ESGD and EGGD severity score during the 8-week training period. Results: Incidence of EGGD and ESGD in this feral population was similar to that found in domesticated horses. ESGD incidence (severity score, ≥ 2; score range, 0 to 4) reduced from an initial 71.6% (58/81) to 25.4% (18/71). On multivariable analysis, sex (ie, being a stallion or a female vs gelding) increased the likelihood of ulcer grade reduction. Being fed preserved forage 3 or more times a day also improved the likelihood of ESGD reduction (odds ratio, 17.95; 95% CI, 1.67 to 193.40; P = .017). Overall, the farm explained 35% of the variance, confirming the importance of management factors. Incidence of EGGD (severity score, ≥ 1; score range, 0 to 2) reduced from 47% (38/81) to 40.8% (29/71) during the same period. No measured variables were associated significantly with EGGD incidence or reduction. Clinical Relevance: Pasture provision (without supplementary feed or forage) does not result automatically in a low incidence of gastric ulcers. Regular provision of preserved forage is a key factor in reducing ESGD incidence

Effect of changing diet on gastric ulceration in exercising horses and ponies after cessation of omeprazole treatment

Diet is an accepted risk factor for equine squamous gastric disease (ESGD), but there is little published evidence for the benefit of dietary change (DC). This study evaluated the effect of DC with or without initial omeprazole medication. Twelve pairs of exercising horses with ESGD Grade 2/4 (EM) and 17 pairs with ESGD Grade ≥3/4 (ES), were monitored. Paired horses had similar management, feeding times, workloads, and initially feed or forage. One of each pair was randomly assigned, postgastroscopy (Scope1), to a specified restricted starch ration; the other remained on their original diet. Omeprazole (4 mg/kg per os SID) was given to all ES pairs for 4 weeks. Gastroscopies were scored, without dietary knowledge, after 4 and 10 weeks (Scopes 2 and 3). Workloads remained similar throughout. McNemar’s tests identified any changes in ESGD grade. Within the EM group, DC had no additional effect. For the ES group remaining on their original diet, there was significant improvement in ESGD grade from Scopes 1 to 2 (P &lt; .001) but a worsening between Scopes 2 and 3 (P = .005), with Scope 3 being no different from Scope 1 (P = .08) reflecting no apparent long-term medication benefit. For the DC group, there was significant improvement in ESGD grade from Scopes 1 to 2 (P &lt; .001) and between Scopes 1 and 3 (P = .003); In addition, there was no significant difference between Scopes 2 and 3 (P = .32). Although limited by the small number of pairs evaluated, this study provides evidence that appropriate DCs can be a beneficial management strategy for ESGD