Independent Equine Nutritionist
As an registered independent equine nutritionist based in the north of the UK the first half of 2023 has proved a busy time. The number of acute laminitis cases I received in May 2023 exceeded the total number I received in the entirety of 2022. There are multiple possible causes for a horse to develop laminitis, but the shear number of cases being seen is likely to be associated with the elevated grass growth rates in the UK since mid March. As shown in Figure 1, this years grass growth rate in May has been significantly higher than the average growth rates since 2019. While these growth rates are approaching the average for June, with rain forecast for many areas for the first time in weeks, the rate of grass growth is predicted to escalate again.
Grass growth and Laminitis
The association with growing fresh grass and laminitis is linked with the levels of soluble
carbohydrate or sugars in a horses diet.
Young short grass has a higher sugar % per kg dry matter than longer more mature grass. If enough sugar is consumed, be that from short sweeter grass or a higher amount of long course grass eaten quickly, it can exceed the level that an individual horse can healthily withstand. In this situation the painful and life threatening condition of laminitis can develop.
Several factors can effect just how much is too much for an individual horse or pony. The vast majority of laminitis cases involve a horse with a hormonal disorder, such as Equine Metabolic Syndrome, insulin dysfunction or PPID (Cushings). Also overweight or obese horses and ponies are more likely to develop laminitis. With over half the UK equine population being either overweight or obese this years grass growth rates pose a real threat to a significant proportion.
To support horses, especially those at higher risk during rapid grass growth periods it maybe necessary to limit access to grass. This can be achieved by reduced turn out time, reducing the available grazing space, using grazing muzzles, removing them from the grass and offering a lower calorie and sugar content forage such as soaked hay instead. If the horse is overweight or obese it is strongly advisable to implement a weight loss plan, and for all horses to monitor for sings and symptoms, as shown in Figure 2.
If you think your horses maybe suffering from, or at risk of developing laminitis please consult with your vet to devise a treatment or prevention plan. If your horse is overweight please consult with a nutritionist to create a suitable weight-loss programme.
 Chaucheyras-Durand, F., Sacy, A., Karges, K., Apper, E. 2022 Gastro-Intestinal Microbiota in Equines and its role in health and disease: the black box opens. Microorganisms (10) 2517
 Linderberg,F, Krych,L., Kot,W., Fielden, J., Frokiaer,H., van Galen,G., Nielsen,D.S, Hansen,A.K. 2019 Development of the equine gut microbiota. Sci. Rep. (9) 14427
 Quercia,S., Freccero,F., Castagnetti,C., Soverini,M., Turroni,S., Baigi,E., Rampelli,S., Laci,A., Mariella,J., Chinellato, E. 2019. Early colonisation and temporal dynamics of the gut microbial ecosystems in standardbred foals. Equine Vet. J. (51) 231-237
 Husso, A., Jalanka, J., Alipour, M.J., Huhti, P., Kareskoski, M., Pessa-Morikawa, T., Livanainen, A., Niku, M. 2020. The composition of the perinatal intestinal microbiota in horse. Sci. Rep (10) 441
 La Torre, U.D, Henderson, J.D., Furtado, K.L., Pedroja, M, Elenamarie, O.M., Mora,A., Pechanec, M.Y., Maga, E.A., Mienaltowski, M.J. 2019 Utilising the fecal microbiota to understand foal gut transitions from birth to weaning. PLoS ONE (14) e0216211
 Freestone, P., Lyte, M. 2010 Stress and microbial endocrinology: Prospects for ruminant nutrition. Animals (4) 1248-1257
 Lyte, M. 2013 Microbial endocrinology in the microbiome-gut-brain axis: How bacterial production and utilization of neurochemicals influence behaviour. PLoS Pathog (9) e1003726
 Lyte, M. 2011. Probiotics function mechanistically as delivery vehicles for neuroactive compounds: Microbial endocrinology in the design and use of probiotcs. BioEssays News Rev. Mol.Cell. Dev. Biol (33) 547-581
 Mach, N., Ruet, A., Clark, A., Bars-Cortina, D., Ramayo-Caldas, Y., Crisci, E., Pennarun, S., Dhorne-Pollet, S., Foury, A., Moisan, M.P, 2020 Priming for welfare: gut microbiota is associtated with equitation conditions and behaviour in horse athletes. Sci. Rep. (10) 8311
 Perry, E., Cross, T-W.L, Francis, J.M., Holscher, H.D., Clark, S.D., Swanson, K.S. 2018 Effect of Road transport on equine caecal microbiota. J. Equine Vet. Sci (68) 12-20
 Faubladier, C., Chaucheyras0Durand, F., da Veiga, L., Julliand, V. 2013 Effect of transportation on fecal bacterial communities and fermentative activities in horses: Impact of Saccaromyces cervisiae CNCM I-1077 supplementation. J. Anim. Sci. (91) 1736-1744
 Mach, N., Foury, A., Kittelmann, S., Reigner, F., Moroldo, M., Ballester, M., Esquerre, D., Riviere, J., Salle, G., Gerarad, P. 2017 Effects of weaning methods on gut microbiota composition and horse physiology. Front. Physiol (8) 535
 Perricone, V., Sandrini, S., Irshad, N., Comi, M., Lecchi, C., Savoini, G., & Agazzi, A., 2022 The role of yeast saccharomyces cerevisiae in supporting gut health in horses: An updated review on its effects on digestibility and intestinal faecal microbiota. Animals 12, 3475