To help an underweight chicken, find out why she is thin, then feed her a complete poultry feed at the right protein level plus a few high-energy extras. Food alone will not fix a hen that is thin because of worms, mites, illness or bullying.
First, confirm she is really underweight
Pick the bird up and feel her breast. On a healthy chicken the keel (breastbone) is covered by firm, rounded muscle on both sides. If the keel feels like a sharp blade and the breast muscle is sunken, she is underweight. Weigh her and write the number down, then weigh again once a week so you can see whether the plan is working.
Common reasons a chicken loses weight
- Internal parasites. Worms and coccidiosis are among the most common causes of a thin bird that still seems to eat.
- External parasites. Lice and mites feed on the bird and stress her, especially at night.
- Bullying. Lower-ranking hens can be chased away from the feeder and never get enough.
- Wrong feed. Scratch grains, kitchen scraps or the wrong life-stage feed can leave a hen short on protein and minerals.
- Molting or heavy laying. Both burn a lot of protein and energy.
- Illness. A crop problem, respiratory infection, reproductive disease or a serious flock illness can cause steady weight loss.
If she is also lethargic, has diarrhea, a swollen belly, a crop that stays full or labored breathing, call a vet who treats poultry. Do not give any wormer or other medicine without veterinary advice, because dosing and egg withdrawal times matter.
What to feed an underweight chicken
- A complete feed that fits her age. Adult laying hens do well on a layer feed with roughly 16 to 18 percent protein. Young birds need a starter or grower feed. Check the bag for the life stage and make sure the feed is fresh and dry.
- Easy access. Set up a second feeder and waterer away from the flock, or house her in a small pen next to the flock so she can still see them. Chickens stressed by isolation often stop eating, so keep her in sight of her flockmates.
- Protein-rich extras in small amounts. Scrambled or hard-boiled egg, dried mealworms and a little cooked fish or lean cooked poultry all help rebuild muscle.
- Energy-dense extras. A spoonful of black oil sunflower seeds or cooked oats adds calories. Keep treats to about 10 percent of what she eats, otherwise she will fill up on snacks and skip the balanced feed.
- Moistened feed. Mixing crumbles or pellets with a little water makes them easier to eat, especially if she is weak. Throw out leftovers within a few hours so they do not spoil. You can read more in our guide to soaking chicken feed.
- Clean water. A hen that is not drinking will not eat well either.
What not to feed
- Avocado, chocolate, raw or dried beans, and anything moldy or rotten.
- Large amounts of bread or other filler, which fill her up without adding much nutrition.
- Extra calcium supplements for hens that are not laying, since too much can harm the kidneys.
Garlic is sometimes suggested as a natural dewormer. There is no reliable evidence that it clears a worm burden, so do not rely on it. A fecal test through a vet is the dependable way to know whether she needs treatment.
Check the rest of the flock and coop
If one bird is thin, look at the others. Check for lice and mites around the vent and under the wings, make sure there is enough feeder space for every bird, and keep the coop dry and clean. To understand what a good ration contains, see what is in commercial chicken feed and the difference between pellet and crumble feed.
Bottom line
Find the cause, switch her to a complete feed that matches her age, add small amounts of protein and fat, and weigh her every week. Most birds that are simply under-fed or bullied bounce back in a few weeks. A bird that keeps losing weight despite good feeding needs a vet.
This article is general information and not veterinary advice. If your chicken is losing weight or seems sick, talk to a veterinarian.
