Chicks die for a handful of common reasons, and most of them are preventable once you know what to look for. The most frequent culprits are temperature problems, dehydration, pasty butt, disease, and poor air quality in the brooder. Figuring out which one is affecting your flock usually comes down to the age of the chicks, what their droppings look like, and how they’re behaving.
Temperature Too High or Too Low
Temperature is the single most common killer of young chicks. They can’t regulate their own body heat for the first several weeks of life, so they depend entirely on the brooder setup. Chicks that are too cold will huddle tightly under the heat source, pile on top of each other, and eventually become lethargic and stop eating. Chicks that are too hot will spread to the edges of the brooder, pant with open beaks, and can die from overheating just as quickly.
The target temperatures drop by about 5 degrees each week:
- Week 1: 93 to 95°F
- Week 2: 88 to 90°F
- Week 3: 83 to 85°F
- Week 4: 78 to 80°F
- Week 5: 75°F
- Week 6: 70°F
- After 6 weeks: 50 to 70°F is comfortable
Place your thermometer at chick level, not above the brooder. And watch their behavior more than the thermometer. Chicks that are comfortable will spread out evenly, move around, eat and drink normally, and sleep in relaxed positions. If they’re all crammed into one corner or scattered to the walls, adjust the heat.
Starve-Out in the First Four Days
A newly hatched chick absorbs its yolk sac just before hatching, and that internal reserve provides enough nutrition for roughly four days. During that window, chicks need to learn to eat and drink on their own. If they don’t, they simply run out of energy when the yolk sac is depleted and die. This is called “starve-out,” and it’s especially common in chicks shipped through the mail that arrive stressed and disoriented.
When your chicks first arrive or hatch, dip each one’s beak gently into the waterer so they learn where it is. Tap the feed with your finger to mimic a mother hen pecking at food. Make sure the waterer is shallow enough that they can drink without drowning, and that the feeder is easy to access. If a chick seems weak and isn’t eating by day two, it needs individual attention: try offering water with a dropper and placing it directly next to the feed.
Pasty Butt
Pasty butt is exactly what it sounds like. Droppings dry and harden over the chick’s vent (the opening where waste comes out), eventually sealing it shut. If you don’t catch it, the chick can’t pass waste and will die within a day or two. It’s most common in the first week or two of life.
The usual causes are stress from shipping, temperatures that are too high or too low, and feeding treats or anything other than proper chick starter feed. Check every chick’s rear end at least twice a day for the first two weeks. If you see a buildup of dried droppings, hold the chick’s backside under lukewarm running water until the material softens, then gently work it off without pulling. Pulling can tear the skin. Work quickly in a warm room so the chick doesn’t get chilled, and return it to the brooder immediately.
Coccidiosis
Coccidiosis is a parasitic infection of the intestines and one of the biggest killers of chicks between about 3 and 8 weeks old. The parasites live in soil and droppings, so chicks pick them up from contaminated bedding, especially in warm, moist conditions. Signs include bloody or watery diarrhea, rapid weight loss, ruffled feathers, lethargy, and a sharp drop in feed and water intake. A flock can go from looking fine to having multiple sick birds in just a day or two.
Medicated chick starter feed contains a low dose of a coccidiostat that helps chicks build immunity gradually as they’re exposed. If you’re raising chicks on unmedicated feed, they’ll still develop immunity over time, but they’re more vulnerable to a sudden heavy exposure. During an active outbreak, a medication called amprolium is typically added to the drinking water. Keeping bedding dry and clean is the most effective prevention, since the parasites thrive in wet litter.
Bacterial Infections From the Hatchery
Some infections are passed from the hen to the chick before it even hatches. Pullorum disease, caused by a type of Salmonella, is one of the most serious. The bacteria localizes in the hen’s reproductive tract and infects developing eggs. In one study, about 6.5% of eggs laid by carrier hens tested positive for the bacteria. Adult hens often show no symptoms at all, but in young chicks the disease is acute and causes high mortality.
Chicks with Pullorum disease are typically weak, huddled, and produce white or yellowish diarrhea. Losses tend to spike in the first two weeks. This is more common in chicks from small-scale or free-range flocks that haven’t been tested, and in warmer climates where sanitation is harder to maintain. Reputable hatcheries participate in the National Poultry Improvement Plan, which tests breeding flocks for Pullorum and other diseases. Buying from NPIP-certified sources significantly reduces your risk.
Ammonia and Air Quality
If your brooder smells like ammonia, the air is already harming your chicks. Ammonia builds up from decomposing droppings in the bedding, and young chicks are particularly sensitive because they’re small and close to the ground where ammonia concentrates. Exposure at just 10 parts per million, a level that’s barely noticeable to you, causes excess mucus production and damage to the tiny hair-like structures in chicks’ airways. At 100 ppm, there’s extensive damage to the lining of the trachea. The recommended maximum is 25 ppm, but your goal should be no detectable smell at all.
Clean bedding frequently, ensure the brooder has adequate ventilation (without creating drafts on the chicks), and avoid overcrowding. If you can smell ammonia when you lean down to chick height, it’s time for a full bedding change.
Toxic Bedding Materials
Cedar shavings are a common bedding choice that can be dangerous for young chicks. Cedar contains volatile oils (phenols) that give it that distinctive smell. When the wood is chopped into shavings, more surface area is exposed and those oils release into the air more readily. Young chicks have fragile respiratory systems, and breathing these compounds in an enclosed brooder can cause irritation and respiratory distress. Pine shavings that have been kiln-dried are a safer choice, as the drying process removes most of the volatile compounds. Avoid newspaper (too slippery, can cause leg problems) and sawdust (too fine, chicks eat it).
Vitamin Deficiencies
If your chicks are developing strange neurological symptoms, nutrition could be the problem. A chick deficient in vitamin B1 (thiamine) will develop weakness, have trouble digesting food, and eventually sit on its bent legs with its head tilted back in what’s called a “stargazing” position. Convulsions follow if it’s not corrected.
Vitamin E deficiency causes a different set of problems, including a brain condition that leads to loss of coordination. Affected chicks stumble, fall over, and can’t walk normally. Muscular dystrophy and fluid accumulation under the skin are other signs. This is more likely when feed contains rancid or unstable fats, or when the feed is old and the vitamins have degraded.
The fix for both is straightforward: use fresh, properly stored chick starter feed from a reputable brand, and don’t dilute it with scratch grains, table scraps, or treats during the first several weeks. Commercial chick starter is formulated to provide everything a growing chick needs. Feed that’s been sitting in a hot garage for months may have lost significant vitamin content.
Sorting Out the Problem
The age of the chick and the specific symptoms usually point you toward the cause. Deaths in the first four days with chicks that never seemed to thrive suggest starve-out or a hatchery-transmitted infection. Deaths in weeks two through four with bloody droppings point strongly to coccidiosis. Sudden losses across multiple ages with a strong smell in the brooder indicate an air quality problem. A single chick with a pasted vent is easy to fix if caught early, fatal if missed.
Start with the basics every time: check the temperature at chick level, confirm every bird is eating and drinking, inspect vents for pasting, look at the droppings for blood or unusual color, and get your nose down to their level to check air quality. Most chick losses come from one of these fixable problems, and catching them early makes the difference between losing one chick and losing half your flock.