Digestive enzyme complex
Lactase
Lactase is the enzyme that digests lactose, the sugar in milk, at the lining of the small intestine.
Also known as: β-galactosidase, beta-galactosidase, lactose-digesting enzyme
What it is
Where it’s found
In dogs, lactase sits in the mucous membrane of the small intestine. A 1965 study of intestinal enzymes in dogs found lactase activity was highest in the youngest pups and fell during the first weeks of life to its lowest levels in adult dogs — the same pattern reported in rats, rabbits, cows and pigs. Sucrase and maltase, the enzymes for other sugars, showed the opposite pattern and were highest in adults.[1]
| Enzyme | Sugar it digests | Young pups | Adult dogs |
|---|---|---|---|
| Lactase | Lactose | Highest | Lowest |
| Sucrase | Sucrose | Low | Highest |
| Maltase | Maltose | Low | Highest |
Why it’s used in dog supplements
Supplementary lactase is familiar from human use, where lactase tablets are taken alongside lactose-containing foods; the response to them varies considerably from person to person.[2]
In a canine blend, lactase is the enzyme family that acts on lactose — the sugar whose digestion is highest in young pups and lower in adult dogs.[1]
On the DIGEST+ label
The label lists six enzymes in the Digestive Enzyme Complex, 150 mg in total, derived from natural plant sources. The label states that total for the complex as a whole; it does not give a separate amount for each enzyme, so we don’t either. Lactase is the last of the six listed on the DIGEST+ label.
- Amylase
- Bromelain
- Protease
- Lipase
- Cellulase
- Lactase
Questions people ask
Do adult dogs still produce lactase?
Yes, but less. A study of intestinal enzymes in dogs found lactase activity was highest in very young pups and decreased to its lowest levels in adult dogs.
What happens to lactose that is not digested?
Lactose that is not broken down and absorbed in the small intestine is fermented by gut bacteria further along the digestive tract.
How much lactase is in DIGEST+?
The label gives 150 mg in total for the six-enzyme Digestive Enzyme Complex, without a separate amount for lactase.
Work out your exact supply
The calculator on the product page takes your dog’s weight band and how many dogs you have, then shows the daily dose, how long a bottle lasts and a sensible refill rhythm.
Sources
- Intestinal Disaccharidase and Alkaline Phosphatase Activity in the Dog — Proceedings of the Society for Experimental Biology and Medicine. Checked 2026-10-15.
- Effects of Prebiotic and Probiotic Supplementation on Lactase Deficiency and Lactose Intolerance: A Systematic Review of Controlled Trials — Nutrients. Checked 2026-10-15.
Updated