Retraining of Racehorses (RoR) has launched new welfare guidelines including updated recommendations on horse to rider weight ratios.The charity recommends that the combined weight of a rider and tack carried by an ex-racehorse should not exceed 17% of the horses bodyweight, based on the horse having a healthy body condition score of 3 out of 5.A horse to rider weight ratio of 20% is the absolute maximum limit.Practically, this means for a typical 500kg Thoroughbred, the rider and gear combined should weigh no more than 85kg to maintain optimal welfare, with 100kg as the absolute upper boundary, said a spokesperson for the RoR.The charity warned that exceeding these guidelines could lead to muscle fatigue, poor posture, lameness and behavioural problems, including a reluctance from the horse to be tacked up or mounted.These issues not only compromise a horses comfort and wellbeing, but can also affect safety and performance, they said.Culture of compassionThe 17% guideline has been in place since 2016. However, it has not previously been actively enforced and so the RoR is taking a more flexible and educational stance this year.The charity said that it acknowledged the sensitivity of the subject around rider weight, but emphasised that this is a supportive, non-judgemental approach, with the aim of raising awareness and offering practical advice to help former racehorses stay healthy and happy in their future ridden careers.RoR advises that riders weigh themselves whilst wearing full riding kit and that they regularly monitor their horses condition, making it a standard part of care alongside saddle fitting, routine vaccinations and regular teeth checks.Welfare remains paramountEquine insurance company Agria has committed to a three-year partnership to help RoR deliver welfare-first practices across its programmes.The welfare of the horse underpins everything we do at RoR. With more ex-racehorses than ever taking part in our competitions and events, its essential that their welfare remains paramount, said managing director David Catlow.These new rules and resources are designed to support owners in delivering the highest standards of care, while reinforcing a culture of compassion, responsibility and continuous learning.Agria CEO Vicki Wentworth added: Supporting RoR in these objectives could not feel more natural to Agria finding ways to support horse welfare, and helping horses and riders to enjoy their happiest lives together, is very much in our DNA.We recommend the new initiatives being launches by RoR and know they will bring widespread benefits.Welfare stewarding teamFollowing successful trials, a new welfare stewarding team will have a consistent presence at major RoR competitions, including next weeks The Jockey Club RoR National Championship at Aintree Racecourse (1924 August 2025).Stewards will be easily recognisable in co-branded RoR and Agria tabards and will offer advice, signpost support, and recognise competitors who demonstrate exemplary care and horsemanship.RoR is also rolling out a programme of educational content covering key welfare topics such as rider/horse weight ratios, care in extreme temperatures, nutrition, and foot care, all tailored to the needs of former racehorses and their owners.The updated welfare rules are available to download now. Printed copies will also be provided at major events.Main image of ex-racehorse Mr Buckle Your Horse Library/Aimi ClarkRelated contentHow much weight can a horse carry?This is how to tell if a horse is lameRoR updates its eligibility criteriaTop tips for hacking an ex-racehorseThe post Ex-racehorses shouldnt carry more than 17% of their bodyweight, says RoR appeared first on Your Horse.