Which animals are hindgut fermenters?

• A. Cows and Sheep
• B. Birds and Fish
• C. Horses and Rabbits
• D. Dogs and Cats

Answer: (C)

Hindgut fermentation happens in the hindgut—the cecum and colon—after the stomach, where microbes break down fibrous plant material to extract nutrients like volatile fatty acids. This pattern is typical of non-ruminant herbivores, with horses and rabbits being classic examples. In horses, a large cecum hosts the microbial community that ferments cellulose from forage, while rabbits rely on the hindgut for fiber digestion, complemented by caecotrophy to reclaim nutrients.

This differs from foregut fermentation, as seen in cows and sheep, where fermentation occurs in the forestomach (rumen, reticulum, omasum) before digestion in the stomach. Birds and fish don’t rely on hindgut fermentation as their primary digestive strategy, and dogs and cats, with simple stomachs, don’t use hindgut fermentation as their main means of extracting nutrients from fibrous plant material.

So, the animals that are hindgut fermenters are horses and rabbits.