Baby chicks are most vulnerable in their first week of life, when their immune systems, digestive systems, and ability to regulate body temperature are all still developing. The most common causes of early death come down to four categories: environment (too hot, too cold, or too humid), dehydration, disease, and digestive problems. The good news is that most of these are preventable once you know what to look for.
Temperature Problems Kill More Chicks Than Anything Else
Chicks cannot regulate their own body temperature for several weeks after hatching. A brooder that’s too cold will chill them, and a brooder that’s too hot can kill them just as fast. The target temperature for week one is 90 to 95°F, measured at chick level (not at the top of the brooder). Each week, you drop it by about 5 degrees until they’re feathered out around 8 to 10 weeks.
Your chicks will tell you if the temperature is wrong. If they’re huddled together in a tight cluster directly under the heat source, they’re too cold. If they’re pressed against the walls of the brooder, as far from the lamp as possible, they’re too hot. Comfortable chicks spread out evenly, moving freely between warmer and cooler zones. Continuous loud peeping, especially a high-pitched, persistent sound rather than the normal chatty chirping, is a distress signal that something in the environment is off.
A common mistake is using a single heat lamp with no cooler area to escape to. Your brooder should be large enough that chicks can move toward or away from the heat. A cold snap overnight or a bulb that burns out while you’re asleep can wipe out an entire group of chicks in hours.
Dehydration Happens Faster Than You’d Expect
A chick can go from healthy to critically dehydrated within a matter of hours, especially in a warm brooder. Signs include sunken eyes, dry or wrinkled skin on the legs, lethargy, labored breathing, and poor balance. If you gently pinch the skin on a chick’s neck and it doesn’t spring back quickly, dehydration is likely. A dehydrated chick’s crop (the small pouch at the base of the throat) will feel empty or contain only dry, hard feed.
Chicks that arrive by mail are particularly at risk because they’ve been in transit without water. When you first place chicks in the brooder, dip each one’s beak into the water so they learn where it is. For a chick that’s already showing signs of dehydration, offer lukewarm water with a teaspoon of sugar per quart to encourage drinking and provide a quick energy boost. Make sure waterers are shallow enough that chicks can’t drown but accessible enough that every chick can reach them without being blocked by stronger birds.
Pasty Butt Can Be Fatal if Missed
Pasty butt is exactly what it sounds like: dried droppings that seal over the vent (the opening just below the tail), preventing the chick from passing waste. Left untreated, it’s fatal. It’s most common in the first 10 days of life, before chicks produce enough of their own digestive enzymes to fully break down feed. Stress from shipping, temperature swings, and the transition from absorbing yolk nutrients inside the egg to digesting solid food all contribute.
Check your chicks’ vents at least twice a day during the first two weeks. If you see a crusty buildup, don’t pull it off. Dried droppings cement to the down and skin, and yanking will tear the tissue. Instead, hold the chick’s rear end under warm (not hot) running water until the mass softens, then gently work it free with a cotton swab in a downward motion. If the mass is really stuck, dab a small amount of vegetable oil on it first to help loosen it. Keep the rest of the chick as dry as possible so it doesn’t get chilled, and return it to the brooder promptly.
Coccidiosis: The Most Common Disease in Young Flocks
Coccidiosis is caused by a microscopic parasite that lives in the gut and destroys the intestinal lining. It spreads through droppings, which means it thrives in damp, dirty bedding. The classic sign is diarrhea, often bloody, along with fluffed feathers, lethargy, and a drop in eating and drinking. It can kill chicks quickly once symptoms appear.
The standard prevention is medicated chick starter feed, which contains amprolium. Amprolium is not an antibiotic. It works by blocking the parasite’s ability to absorb a B vitamin it needs to survive, while leaving the chick unaffected. Michigan State University’s veterinary college recommends feeding medicated starter for the first six weeks of life, then gradually transitioning to non-medicated feed over about 10 days. If you’re raising chicks on non-medicated feed by choice, keep the brooder exceptionally clean and dry, and watch closely for any changes in droppings.
Yolk Sac Infection (Mushy Chick Disease)
Some chicks hatch with bacteria already present inside their bodies. Omphalitis, commonly called mushy chick disease, is an infection of the yolk sac that chicks absorb in the final days before hatching. It’s caused by bacteria entering through the navel or shell during incubation. If you’re hatching your own eggs, contamination can come from dirty incubators, unwashed hands, contaminated egg trays, or eggs that weren’t stored properly before setting.
Affected chicks have a soft, distended abdomen, a foul smell, and an inflamed or discolored area around the navel or vent. They’re typically weak from the start and fail to thrive. Unfortunately, once a chick shows clear signs of omphalitis, the prognosis is poor. Prevention is the real tool here: sanitize your incubator between hatches, handle eggs with clean hands, and discard any eggs with visible cracks or contamination before setting them.
Brooder Pneumonia From Damp Bedding
Aspergillosis, often called brooder pneumonia, is a fungal infection that chicks inhale from moldy bedding or contaminated litter. It typically strikes in the first two weeks of life. The fungus grows in warm, damp environments, which is exactly what a poorly maintained brooder provides. Chicks with brooder pneumonia show difficulty breathing, a faster-than-normal respiratory rate, and what’s sometimes called “silent gasping,” where the chick opens its beak to breathe but makes little or no sound. In severe cases, you may see poor balance or a cloudy film developing over the eyes.
There’s no practical treatment for aspergillosis in chicks. Prevention comes down to bedding management: use dry, clean shavings (pine is standard), avoid cedar, and change the bedding before it gets damp or caked. If you notice a musty or moldy smell in the brooder, change the bedding immediately. Never use litter that’s been stored in a damp barn or that shows any visible mold.
Nutritional Deficiencies That Mimic Disease
If your chicks are on a quality commercial chick starter, nutritional problems are rare. But if you’re mixing your own feed, supplementing heavily with treats, or using feed that’s been stored too long, deficiencies can show up in ways that look alarming. Riboflavin (vitamin B2) deficiency is one of the most recognizable: chicks develop curled toes, leg weakness, limping, and eventually paralysis. This happens because riboflavin is essential for nerve function and bone development during the rapid growth phase. Without enough of it, the protective coating on peripheral nerves breaks down.
The fix is straightforward. Feed a fresh, commercially formulated chick starter as the primary diet. Avoid giving treats, scraps, or scratch grains during the first several weeks. These dilute the balanced nutrition in the starter feed and can trigger both deficiencies and digestive upset, including the pasty butt problems described above.
How Much Loss Is Normal
Losing a chick or two out of a batch is, unfortunately, not unusual. Mortality is highest in the first seven days, and some chicks simply fail to thrive due to genetic problems or complications during hatching that aren’t visible from the outside. A loss of one or two chicks out of a dozen, while sad, falls within the range many experienced keepers consider normal.
What isn’t normal is losing several chicks in rapid succession, especially if they were healthy at first and then declined. Multiple deaths within a short window point toward an environmental problem (temperature, water access) or an infectious cause (coccidiosis, aspergillosis). In unvaccinated flocks, disease outbreaks can cause losses as high as 70%. If you’re losing chicks daily and can’t identify an obvious environmental cause, a veterinarian who handles poultry can often diagnose the issue from a necropsy on a recently deceased chick, which is the fastest way to get a clear answer and protect the rest of your flock.