Pay attention to diet form and digestive supplements to help keep your senior horse’s belly happy.
With advances in preventative health care over the last 50 years, the ole grey mare is not only older, but she’s also healthier. However, age inevitably takes a toll including on the digestive system. Targeted digestive supplements can help.
Senior horses may face several challenges in digesting their food. Natural wear and overaggressive dentistry can lead to loss of the enamel ridges on their chewing surfaces. There is also a change in the angle of the chewing surface (Curve of Spee) which reduces the force of chewing. Although not investigated in horses, aging can result in decrease in stomach acid production and pancreatic digestive enzyme activity. Older horses also often have reduced numbers and diversity of microorganisms in their intestinal tract.
When chewing is an issue, switching the diet to one based on hay cubes/pellets and/or a complete feed, fed thoroughly moistened or even as a “soup,” is highly beneficial. Adding psyllium to every meal improves ease of swallowing and is also prebiotic. You can leave hay available to keep the horse busy unless choke is a problem, but don’t count on it to supply significant calories.
Older research suggested horses needed special levels of protein and some minerals as they aged but later studies have disproven this. It is now believed those early findings were due to parasite damage since the work was done before the appearance of effective over-the-counter de-wormers.
Support from digestive enzymes can help with small intestinal absorption of nutrients to assist in weight and muscle maintenance. Bacterial and yeast fermentation products are rich sources of digestive enzymes as well as growth factors for beneficial organisms.
Research has shown older horses can be as effective at fermenting food in their hind gut as their younger counterparts are. However, we also know the number and diversity of organisms is reduced, making the older horse more sensitive to changes, including in hay.
The best probiotics are a blend of bacterial strains and yeast. The number of live organisms is extremely important. One colony forming unit (CFU) = one live organism. You need to think in terms of tens of billions of CFUs to have an effect. Fermentative organisms also benefit from a supply of easily fermented soluble fiber. Psyllium is ideal for this, and food choices containing soy hulls and beet pulp. Flaxseed contains good levels of soluble fiber.
Deworming is also an issue. Older horses are often more susceptible to parasites and can even harbor worms not normally seen in adults, like roundworms. They should be dewormed at least twice a year with ivermectin or moxidectin with one of those containing praziquantel for tapeworms. Do fresh fecal checks for parasite eggs at least twice a year on this schedule, three months after deworming. If parasites are not well controlled, a more frequent deworming schedule will be needed.
The senior horse may need special attention to diet form and digestive supplements, but there’s no reason they can’t remain in good flesh. If you see a dramatic weight loss, especially if sudden, consult your veterinarian.