6 Best Fiber Supplements for Dogs in 2026

iHeartDogs is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no extra cost to you. Fiber does not get enough credit when it comes to dog health. It keeps digestion moving, firms up loose stools, and feeds the good bacteria in your dog’s gut. Some dogs need more fiber because of anal gland issues, weight management, or sensitive stomachs. Others just do better with a little extra roughage in their diet. Whatever the reason, picking the right supplement makes a real difference. We looked at the top-selling fiber supplements and narrowed it down to six that actually deliver. Here’s what stood out. Best Fiber Supplements for Dogs in 2026 #1 – Fiber for Dogs Psyllium Seed Husk Powder Psyllium husk is one of the most trusted fiber sources out there, and this powder makes it easy to add to your dog’s meals. It absorbs water in the gut, which helps firm up loose stools and keep things regular. Dogs dealing with constipation or runny poop often see improvement within a few days. The powder mixes into wet or dry food without much fuss. No artificial flavors, no fillers. Just straight psyllium that does what it’s supposed to do. Best For: Dogs wit...