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Source Focus SR (Senior) — Health (Targeted micronutrition for the older horse, built on the legendary SOURCE kelp…)

Source Focus SR (Senior)

Targeted micronutrition for the older horse, built on the legendary SOURCE kelp formula.

Got a senior horse who needs nutritional support tailored to their aging body's gaps?

Reviewed by Ann Pruitt, InfoHorse.com · Updated May 2026
Source Focus SR senior horse supplement nutrition label panel showing guaranteed analysis and ingredients
Source Focus SR senior horse supplement nutrition label panel showing guaranteed analysis and ingredients

An aging horse does not stop needing good nutrition, it simply stops absorbing it as easily. Source Focus SR (Senior) by SOURCE, INC. is built for exactly that stage of life, when the gut works a little harder, weight is tougher to hold, and the coat that used to gleam starts to look tired. Focus SR layers targeted senior support on top of the kelp-based SOURCE micronutrients that have anchored this company's formulas for half a century.

Open bucket of Source Focus SR senior horse micronutrient supplement showing the fine seaweed-based powder inside
Open bucket of Source Focus SR senior horse micronutrient supplement showing the fine seaweed-based powder inside

Why do senior horses need a different supplement?

As horses age, metabolic efficiency declines. The same hay and grain that kept a horse in bloom at twelve may leave that horse thin, dull, and run-down at twenty-two. Focus SR answers that shift with a dense, broad-spectrum formula: essential omega fatty acids for skin and coat, antioxidants to help counter the wear of aging, beneficial microbes and a nutritional yeast culture to support hindgut digestion, chelated minerals in a form the older gut can actually use, and digestive enzymes to help break feed down. It is senior-specific nutrition designed to do the work an aging body no longer does on its own.

Sealed bucket of Source Focus SR senior horse micronutrient supplement from SOURCE, INC.
Sealed bucket of Source Focus SR senior horse micronutrient supplement from SOURCE, INC.

What makes the SOURCE kelp formula different?

The heart of Focus SR is the same thing that has set SOURCE apart since 1975: micronutrients drawn from specially harvested and processed seaweed. Rather than mega-dosing a single vitamin, the formula delivers a deep, balanced spectrum of naturally occurring minerals and trace elements in organic, bioavailable form, the way nature packages them. SOURCE was founded by Susan Domizi in North Branford, Connecticut, after her own event horse battled chronic hoof and weight trouble; her research into marine micronutrition turned that horse around and became a company. SOURCE was the first equine supplement to carry an unconditional money-back guarantee and is a founding member of the NASC. That heritage is what the senior horse is eating in every scoop of Focus SR.

How do you feed Source Focus SR?

Feeding is simple and consistent with the rest of the SOURCE line. Mix one level measure, about 1.5 oz (42 g), into the daily feed of a 1,000 lb horse, adjusting up or down for body weight. The guaranteed analysis per serving includes 16% crude protein, 10% crude fat, 4.5% linolenic acid, 3,700 ppm zinc, 750 mg vitamin C, and naturally occurring iodine from the seaweed base. Focus SR is offered in a 3.5 lb size, roughly a 37-day supply, and a 25 lb size that lasts about eight months, so owners can match the package to one horse or a barn full of seniors.

Detail view of the large Source Focus SR bucket label for senior horse micronutrient supplementation
Detail view of the large Source Focus SR bucket label for senior horse micronutrient supplementation
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The Solution Section (FAQ)
What is Source Focus SR (Senior)?

Focus SR (Senior) by SOURCE, INC. is a daily micronutrient supplement formulated for the aging horse. It combines essential omega fatty acids, antioxidants, vitamins, beneficial microbes, a nutritional yeast culture, chelated minerals, and digestive enzymes with the company's signature kelp-based SOURCE micronutrients.

What does Focus SR do for an older horse?

It is designed to support the senior horse where age takes its toll: coat and skin condition through omega fatty acids, digestion through beneficial microbes, yeast culture, and enzymes, and overall trace-mineral status through a broad, bioavailable micronutrient spectrum. The goal is to help an older horse hold condition and vitality as natural metabolic efficiency declines.

How much Focus SR do I feed per day?

The standard serving is one level measure, about 1.5 oz (42 g), mixed into feed each day for a 1,000 lb horse. Adjust the amount up or down based on the individual horse's body weight.

What are the kelp-based SOURCE micronutrients?

They are micronutrients and trace minerals derived from specially harvested and processed seaweed. Instead of mega-dosing one nutrient, SOURCE delivers a deep, balanced range of naturally occurring minerals and trace elements in organic, bioavailable form, which is the foundation underneath every Focus formula.

What is the guaranteed analysis of Focus SR?

Per 1.5 oz serving, Focus SR provides 16% crude protein, 10% crude fat, 4.5% linolenic acid, 3,700 ppm (157 mg) zinc, 750 mg vitamin C, and 9 mg of naturally occurring iodine from the seaweed base.

What sizes does Focus SR come in?

Focus SR is available in a 3.5 lb size, approximately a 37-day supply, and a 25 lb size, approximately an eight-month supply. Owners can choose the smaller package for a single horse or the larger one for ongoing, multi-horse feeding.

How is Focus SR different from regular SOURCE?

Focus SR starts with the same legendary SOURCE micronutrients but adds a senior-targeted layer, omega fatty acids, antioxidants, vitamins, microbes, yeast culture, chelated minerals, and enzymes, formulated specifically for the declining metabolic efficiency of the older horse.

Who makes Focus SR and what is the company's background?

Focus SR is made by SOURCE, INC. of North Branford, Connecticut, founded in 1975 by Susan Domizi after marine micronutrition transformed her own struggling event horse. SOURCE was the first equine supplement to offer an unconditional money-back guarantee and is a founding member of the National Animal Supplement Council (NASC).

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Ann Pruitt
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InfoHorse.com