Why Is My Cat’s Poop Moldy?

Have you noticed white or fuzzy growth on your cat's poop? It's not pleasant, but there is usually a simple explanation.

Mold grows on cat poop after it leaves the body, when it sits in the litter box, especially in warm, humid conditions. Fresh poop that already looks coated may have mucus on it, and white specks may be tapeworm segments. Both are worth a vet check.

Reasons Why A Cat’s Poop Would Be Moldy

Here are the most likely explanations.

It Has Been Sitting Too Long:

Feces are moist and full of bacteria and food residue, so mold can grow on them within a day or two. This is the most common reason for moldy-looking poop.

Cornell's Feline Health Center recommends scooping clumping litter daily and washing the box regularly. Regular scooping also keeps your cat happy to use the box.

Mucus on Fresh Poop:

If the poop looks coated or slimy as soon as your cat passes it, the film may be mucus rather than mold. A little mucus can be normal, but frequent mucus often points to colon irritation.

The Merck Veterinary Manual lists diarrhea with mucus as a possible sign of roundworms. Diet changes, food intolerance and inflammation can also cause it.

White Specks or Segments:

Small white, rice-like pieces on fresh poop or around your cat's rear can be tapeworm segments. Merck notes that tapeworms are diagnosed by finding segments or eggs in the feces.

Change in Diet:

If your cat recently started eating a new type of food or changed brands, the switch can cause soft stool or mucus. Diet doesn't cause mold, but soft, wet stool can grow mold faster if it is left in the box.

How Can I Prevent My Cat’s Moldy Poop?

Scoop the litter box at least once a day, and keep it in a dry, well-ventilated spot.

If you change your cat's food, do it gradually over about a week. Make sure fresh water is always available.

See your vet if you see mucus often, worm segments, blood, diarrhea, or if your cat is straining, losing weight or acting unwell. Bring a fresh stool sample if you can.

Sources

• Feline Behavior Problems: House Soiling, Cornell Feline Health Center
• Gastrointestinal Parasites of Cats, Merck Veterinary Manual