Equine Cushing’s disease, more accurately termed pituitary pars intermedia dysfunction (PPID), and equine metabolic syndrome (EMS) represent two of the most significant endocrine disorders affecting equine patients. These conditions pose complex management challenges that extend beyond initial diagnosis and treatment. This article will explore the role of the equine registered veterinary nurse (RVN) in the treatment and management of horses with PPID and EMS. The learning objectives for this article are as follows:
- To understand the role of the equine RVN in treating cases of PPID and EMS
- To understand how to apply Schedule 3 of the Veterinary Surgeons Act 1966 to the role of the equine RVN
- To help vets to better understand the role of the equine RVN and delegate Schedule 3 tasks confidently
Schedule 3 of the Veterinary Surgeons Act 1966
The Veterinary Surgeons Act 1966 and its subsequent amendments provide the legal framework within which RVNs operate in the United Kingdom. The Schedule 3 Amendment Order (2002) is particularly relevant to equine RVNs managing horses with PPID and EMS, as it outlines the specific procedures that may be carried out by qualified RVNs under veterinary direction.
RVNs are not permitted to diagnose medical conditions or prescribe medications; only veterinary surgeons may carry out these actions. Under Schedule 3, RVNs are permitted to perform a range of procedures which can be useful in the management of endocrine disorders in horses. These include taking blood samples for diagnostic testing (Figure 1), administration of medications and monitoring of vital parameters (BEVA, 2024). In order to perform these actions, the RVN must be directed to do so by the veterinary surgeon in charge of the case. The British Equine Veterinary Association (BEVA) has produced a set of guidelines to help with the interpretation of Schedule 3 with a view to instilling confidence in veterinary surgeons to delegate more procedures to equine RVNs in practice.
This growing caseload, combined with the chronic nature of these conditions, has highlighted the invaluable contribution that equine RVNs can make to patient outcomes
The prevalence of both PPID and EMS has increased significantly in recent years, partly due to improved diagnostic capabilities and greater awareness among horse owners and veterinary professionals. This growing caseload, combined with the chronic nature of these conditions, has highlighted the invaluable contribution that equine RVNs can make to patient outcomes and owner concordance with long-term management protocols.
Pituitary pars intermedia dysfunction (PPID)
PPID is commonly seen in older horses, but it can affect horses as young as 10 years of age. The nerves in the hypothalamus degenerate progressively, causing insufficient amounts of dopamine to be produced. If the pars intermedia in the pituitary gland does not receive enough dopamine, it cannot control the level of hormones it produces. This results in high levels of multiple hormones being produced, including adrenocorticotropic hormone (ACTH) (Gregory and Bett, 2025).
Clinical signs and treatment of PPID
Clinical signs include hirsutism (long, curly coat), lethargy, laminitis, polydipsia, polyuria and, in some cases, recurrent foot abscesses. Diagnostic tests involve taking a blood sample to test ACTH levels. If ACTH results prove inconclusive, a thyrotropin releasing hormone (TRH) stimulation test may be required.
Treatment usually involves the administration of a dopamine agonist, such as pergolide. If the horse has laminitis, this will need to be treated and managed long term. Management changes may be required, such as clipping year-round if the horse has hirsutism and nutritional changes to help put weight on but not induce laminitis. The horse’s immune system may be weakened by PPID, making it more important to keep up to date with vaccinations, dental checks and faecal worm egg counts.
Most of these patients will be treated at home, but an RVN can be involved in owner education about the condition, collecting repeat blood samples, teaching the owner about body condition scoring, pain scoring and medication administration, and assisting with long-term care and support. If laminitis is a factor, RVNs can also obtain diagnostic radiographs for the vet to interpret.
Equine metabolic syndrome (EMS)
EMS is where a combination of insulin dysregulation, obesity and a predisposition to laminitis are evident. It is not known why there is a link between insulin dysregulation and laminitis in EMS (Gregory and Bett, 2025). EMS is seen in younger and middle-aged horses and often seen in native pony breeds, but it can affect any breed.
Clinical signs and treatment of EMS
Clinical signs include regional adiposity (on the crest, shoulders and rump), laminitis, obesity (although this is not always seen), difficulty losing weight and infertility in some mares. Diagnostic tests include an oral sugar test for insulin responses post feeding, insulin tolerance test for tissue insulin sensitivity and/or blood samples for resting insulin concentrations and to rule out PPID (Gregory and Bett, 2025).
Treatment involves many different factors. A controlled diet will be required to help with weight loss and reduce the risk of laminitis. The horse will ideally be managed on a forage-only diet, but if still obese, the forage amount should be weighed out, feeding 1.5 percent of ideal body weight (Frank et al., 2010). Any grazing should be considered when calculating feed amounts. Feed companies can analyse forage to ascertain the percentage of non-structural carbohydrates (NSC) present, or owners can soak the hay to reduce the NSC percentage (Morgan et al., 2015).
RVNs can support the owner with these activities, from calculating the daily feed requirements to showing them how to weigh the feed out. The RVN can also show the owner how to body condition score the horse so that progress can be objectively assessed and reported back to the vet.
One of the most significant contributions of equine RVNs in managing PPID and EMS lies in client education and ongoing support
In the absence of laminitis, an exercise regime should be created to help with weight loss and insulin sensitivity. An exercise programme should be created with the individual horse and owner in mind. The programme should build up to the horse being exercised five times a week, for 30 minutes, with an increase in intensity as fitness improves. Horses with laminitis should not be exercised until the condition has been stabilised. RVNs can assist the vet to create the exercise programme and support the owner to implement it when the horse is discharged.
Treatment for EMS often requires the administration of oral medications such as gliflozins. These are SGLT2 inhibitors which block renal glucose reabsorption. This can help to correct hyperglycaemia and reduce high insulin levels to normal or near-normal levels. Levothyroxine has also been used in the past to improve insulin sensitivity (Frank et al., 2010) and to accelerate weight loss through increasing the metabolic rate, alongside an exercise programme (Durham et al., 2019). The RVN can advise the owner on how best to administer these medications and help them to monitor progress over time.
Client education and support
One of the most significant contributions of equine RVNs in managing PPID and EMS lies in client education and ongoing support. The RVN’s ability to translate complex medical information into practical, understandable guidance for horse owners is invaluable. Educational activities include teaching owners to recognise clinical signs of disease progression or complications, proper techniques for medication administration, and the importance of environmental management in preventing laminitic episodes. RVNs can develop educational materials, organise client education evenings and provide telephone support to address concerns and questions that arise between veterinary visits.
Interdisciplinary collaboration
The complexity of managing horses with PPID and EMS necessitates collaboration among various professionals, including veterinary surgeons, farriers, equine nutritionists and equine physiotherapists. The equine RVN can serve as the central coordinator in this interdisciplinary approach, ensuring communication between team members and continuity of care.
Conclusion
The collaborative approach to managing PPID and EMS, with RVNs working alongside veterinary surgeons and other professionals, represents the future of equine healthcare delivery
The role of the equine RVN in managing horses with PPID and EMS extends far beyond basic nursing care. Working within the framework of Schedule 3 of the Veterinary Surgeons Act 1966, RVNs provide essential diagnostic support, therapeutic intervention, client education and ongoing monitoring, all of which are crucial for the successful long-term management of these complex conditions. The collaborative approach to managing PPID and EMS, with RVNs working alongside veterinary surgeons and other professionals, represents the future of equine healthcare delivery.
