The effectiveness of rehydrating horses through an old-fashioned method, via the rectum, has been demonstrated in a study in Romania.
Patricia Astelean and her colleagues said dehydration and hydro-electrolytic imbalances were relatively common in animal species, including horses, and can be life-threatening.
In horses, it can be caused by various factors such as painful oral disorders, throat problems, neuropathies, gastroenteritis, gut obstructions, kidney issues, endotoxemia, fever, overheating or strenuous exercise.
“Whatever the cause, dehydration represents a medical emergency. It may easily lead to hypovolemic shock, prerenal kidney insufficiency, inability of core body temperature regulation etc.”
In horses, rehydration can be done orally, intravenously or via the rectum as an enema.
Oral rehydration is convenient, but is recommended for patients with a normal, functional digestive tract.
Intravenous rehydration is common, but may be responsible for infection, hydro-electrolytic disorders, and volume overload if not done properly.
Rehydration via the rectum, by high enema – a process which relies on the rectal mucosa’s permeability to fluids – was commonly employed in the past, but its use is much rarer today.
A high enema can be used in patients who cannot be rehydrated orally, the researchers said.
A high enema had certain benefits when compared to the intravenous route, they suggested. “It does not require sterile solutions and it has lower risk of fluid overload.”
The study team, writing in the veterinary medicine bulletin of the University of Agricultural Sciences and Veterinary Medicine in Cluj-Napoca, described an experiment involving eight non-pregnant mares of pure and crossbred Lipizzaner breeding who were affected mild dehydration.
Their mild dehydration status was established by clinical and laboratory criteria, including hematology and plasma biochemistry.
Each horse was given a high enema of a balanced polyionic solution by using an esophageal tube. The solution contained water, sodium chloride and potassium chloride.
Blood samples were collected before and after fluid therapy, which were analysed to determine a complete blood count and electrolytes measurement, total protein, albumin, and creatinine.
Expectedly, dehydrated animals had blood markers consistent with dehydration, including elevated hematocrit associated with mildly elevated blood protein levels, high sodium levels, and elevated waste products in the blood.
In all cases, the parameters were restored to normal levels in response to the enema, and no side effects or issues were recorded.
“This method,” they said, “may be used in mild dehydrated patients, when the animals refuse or cannot drink water.”
The researchers said it was a reliable therapy, not only when oral therapy was not possible or if no venous route was available for intravenous administration.
They noted there were few studies on the effectiveness of high enemas in severely dehydrated patients, or those affected by hypovolemic shock.
“We are fully aware that our conclusions are limited by a relatively small number of cases. However, they highlight the efficiency of a high enema at least in horses affected by mild dehydration.
“Notably, no injuries or any side effects were recorded. Thus, rehydration by high enema might be considered in cases affected by mild dehydration, any time when voluntary water consumption is not possible.”
The Efficiency of Rectal Fluid Therapy in Moderately Dehydrated Horses
Patricia AȘTELEAN, Eva DIUGAN, Cristian MOLNAR, Orsolya SÁRPATAKI, Răzvan CODEA, Alexandra I. BLIDARU, Adrian POTARNICHE, Ioan MARCUS, Bogdan SEVASTRE
Bulletin UASVM Veterinary Medicine 75(1)/2018 doi:10.15835/buasvmcn-vm:004917
The full study can be downloaded here.