Why Your Cat Can’t Gain Weight
📝 Summary
If a cat eats plenty but stays thin, it may be sick or on low-quality food. This guide covers parasites, poor gut absorption, high activity, and cheap kibble—plus what to do if weight keeps dropping.
1 Reasons a Cat Stays Thin
1. Why a cat won’t gain weight
Internal parasites—worms steal nutrients and blood, lowering appetite or causing overeating with malabsorption, plus diarrhea, vomiting and dull coat. Deworm regularly.
Poor gut function—even with big meals, little is absorbed, so the cat stays thin and may have loose stools. Use easily digestible food and probiotics to improve gut flora and absorption.
High activity—kittens are lean and lively, burning lots of calories; if appetite and spirit are normal, slight thinness is fine—many fill out after adulthood.
Low-quality kibble—cheap food is mostly grain with little meat and many additives; cats like it but get too few nutrients to gain weight, and grain is hard to digest. Choose a high-quality, complete kibble.
If measures don’t help and weight keeps falling, see a vet.
2. What if weight keeps dropping
If unsure of the cause, get a check-up for hidden health issues, then treat per the vet. Common causes—parasites and poor nutrition—are avoidable:
Deworm regularly—every 3 months internally, monthly externally, even for indoor cats (owners can carry eggs home).
Use quality kibble—meet nutritional needs; underweight kittens need high-calorie, high-fat food.
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