Congenital portosystemic shunts in foals are rare and only a small number of cases have been described. Detailed description of the course of the shunt is lacking in earlier reports. This is the first detailed description of a computed tomography angiography (CTA) displaying an extra-hepatic splenocaval shunt. A 1-month old colt showing increasing signs of dullness, ataxia, circling, lip-smacking and coordination problems was presented. Hyperammonemia was detected and abdominal CTA revealed an extra-hepatic portocaval shunt. During surgery, ligation of the abnormal vessel could not be achieved, and the foal was euthanized because of complications during surgery. CTA provided a detailed overview of portal vasculature. If a portosystemic shunt is suspected in a foal, CTA can be used to confirm the diagnosis and for surgical planning.

Equine squamous gastric disease (ESGD) is common in horses and poses a serious welfare problem. Several risk factors have been identified and ESGD is routinely treated with omeprazole. Fourteen mares, previously used as embryo recipients and diagnosed with ESGD, were selected. Horses were confined to individual stalls, exercised once daily, and fed ad libitum hay, 1 kg of a low starch compound complementary feed and a mineral supplement. Half of the horses received a compound containing hydrolysed collagen (supplement) and the other half did not (control). At the start of the study, ESGD scores were 3.57 and 3.36 for the supplement and control group, respectively. After 4 weeks, the ESGD grades were significantly reduced in both groups (1.89 and 1.43, respectively, p < 0.01), and healing (ESGD < 2) occurred in 7 out of 14 horses. No treatment effect was observed (p = 0.75), and it was concluded that the change in husbandry overshadowed any potential effect of the compound. Severe ESGD can improve, and even heal, with the provision of a diet of ad libitum forage and a small amount of a compound complementary feed, without the use of omeprazole. A predictable daily routine, with a limited number of dedicated caretakers, may have contributed to the improvement of gastric health.

Inflammatory bowel disease (IBD) is a chronic disease characterized by different cell infiltrates in the intestine. The aims of this study were to report the clinical and clinicopathological findings in horses with histological changes compatible with IBD in the duodenum. Further, the clinical progression of IBD and survival were investigated. Patient records were reviewed for horses in which histological evidence of IBD was found in duodenal biopsies collected during endoscopy. The histological changes were classified as mild, moderate or severe and the predominant infiltrating cell type was recorded. Clinical improvement was assessed by the owner via a questionnaire at 6 weeks after biopsy, along with survival after one year. In total, 149 horses were included, and the most common clinical signs were weight loss, reduced performance and pain during abdominal palpation. Most horses showed partial malabsorption during an oral glucose absorption test, and the horses with severe IBD had lower serum protein concentrations. Lymphoplasmacytic enteritis was the most common type of IBD (78.5% of cases), while in six horses neutrophilic infiltration of the duodenum was present. Overall, 71% of the cases had improved clinically after six weeks, mostly following treatment with corticosteroids. The results of a second biopsy were a poor predictor of improvement, and the horses that improved after 6 weeks were more likely to be alive after one year.

Hydrolysed collagen is used as a supplement for horses with osteoarthritis, hoof horn growth problems, and gastric ulcers. To determine the oral availability of a specific hydrolysed collagen supplement and the appropriate dose, six Warmblood mares were fed two different concentrations of the supplement: 100 g HC (C_H), 50 g HC (C_L), and a control of 0 g HC (C_N) during one week in a randomised cross-over design. On day 7, 14 and 21, blood sampling for amino acid (AA) analysis was performed, just prior to feeding the supplement (t = 0) and every hour after feeding for 8 h (t = 1–8). Statistical analysis revealed differences in mean plasma AA concentrations between the CH and CN doses for alanine, arginine, glutamine, glycine, proline, serine and hydroxyproline. Similarly, statistical differences were observed between the CL and CN doses for arginine, glycine, proline and hydroxyproline. This study demonstrated the availability of amino acids from the supplemented hydrolysed collagen. Although clinical efficacy was not evaluated in this study, a dose of 100 g HC once daily resulted in higher plasma concentrations, which remained detectable for at least 24 h, suggesting greater clinical relevance.

Equine Gastric Ulcer Syndrome (EGUS) and Inflammatory Bowel Disease (IBD) are common in adult horses, yet the underlying mechanisms and therapeutic responses remain poorly understood due to the lack of physiologically relevant in vitro models. Here, we report on the establishment and molecular/functional validation of equine gastric and intestinal organoids derived from fresh and cryopreserved biopsy material. Using an adaptation of technique 2. described by Tsai et al. (2018), we successfully cultured three-dimensional (3D)organoids and from the gastric pylorus and multiple other intestinal segments that could be maintained for multiple passages and differentiated into two-dimensional (2D) monolayers. Organoids recapitulated the architecture and cellular heterogeneity of native tissue, expressing stem-cell (SOX9), proliferative (PCNA), and secretory (MUC-2, UEA-1) markers, as well as tight-junction proteins (OCCLUDIN, ZO-1). Transepithelial electrical resistance (TEER) measurements confirmed the formation of different functional epithelial barriers across multiple intestinal regions. This work demonstrates that equine gastrointestinal organoids can be generated from minimal biopsy material, following cryopreservation at the time of collection at slaughterhouse, opening opportunities to develop organoid cultures from clinically relevant biopsy-sized material, thereby reducing the reliance on experimental horse studies and advancing translational 3R-based research.