How to recognise leg weakness, ascites (water belly) and sudden death syndrome in broilers, what causes each, and the management that reduces them.
Halaal Farms Ghana team4 October 2026 · 13 min read
The birds this article is about are usually the best ones in the house. The cockerel that was first to the feeder every morning is found on his back at three weeks, dead, with a full crop. A big bird at five weeks sits apart with a swollen belly and a dark comb, breathing hard on a cool morning. Another of the heaviest shuffles two steps on its hocks and sits down again. None of the three has an infection that will spread through the flock. Each is paying for growing faster than part of its own body could manage.
These losses are small in number on most farms, but they come late, when the bird has eaten most of its feed, and they take the heaviest birds. They can be reduced with management that costs very little.
A modern broiler multiplies its hatch weight about fifty times in five to six weeks. Breeding has made the muscle grow at that rate. The skeleton, the heart and the lungs have improved too, but they have less to spare, and that is where the weak points lie.
Males grow faster than females and are affected more in all three cases. So are flocks that run ahead of the breeder's weight targets in the second and third weeks.
| Leg weakness | Ascites (water belly) | Sudden death syndrome | |
|---|---|---|---|
| Usual age | From about 2 weeks, worst in weeks 4 to 6 | From about 3 weeks, most deaths in weeks 5 and 6 | Mostly weeks 2 to 4, can continue to sale |
| What you see | Birds sitting, walking on hocks, legs bent or turned, wings used for balance | Swollen soft belly, bluish comb, panting in a cool house, dull and reluctant to move | A healthy bird flaps for a few seconds and dies, usually found on its back |
| Inside the bird | Bent bones, a soft plug in the top of the drumstick bone, or a crumbling hip | Clear yellow fluid in the belly, large flabby heart | Full crop and gut, nothing else obvious |
| Main drivers | Fast early growth, feed minerals, infection, wet litter | Fast growth plus cold, stale air or damaged lungs | Fast early growth, long light hours, dense feed |
"Leg weakness" is what the farmer sees. Underneath it are several different conditions, and the response depends on which one you have.
Walk slowly through the house and make the birds move ahead of you. A sound broiler rises and walks ten paces or more with an even stride. A lame one stays down until you almost touch it, walks a few steps with wings spread for balance, and sits. Pick up three or four of these and examine both legs, the hock joints, the hips and the footpads.
Twisted legs. The leg angles outward or inward at the hock, so the bird looks knock-kneed or bow-legged. It begins around two weeks and worsens as weight increases. It is the most common leg deformity in fast-growing flocks.
Tibial dyschondroplasia. A plug of cartilage at the top of the drumstick bone fails to turn into bone. The bird is reluctant to walk and squats, and in bad cases the bone bows or breaks. Fast growth is the background. An imbalance of calcium and phosphorus in the feed, and certain mould toxins in grain, make it more frequent.
Kinky back. A deformed bone in the spine presses on the spinal cord. The bird, usually three to six weeks old, sits back on its hocks and tail with its feet lifted, and falls over when it tries to move. There is no treatment.
Rickets. In chicks of one to four weeks, the bones and beak are soft and rubbery, the birds squat, and growth is poor. The cause is too little calcium, phosphorus or vitamin D3, or the wrong balance between them. If many young birds are affected at once, suspect the feed, particularly a home mix in which the premix, limestone or phosphate source was left out, wrongly weighed or badly mixed. A gut disease that stops absorption can give the same picture.
Slipped tendon. The hock is swollen and flattened and the tendon at the back slides off to one side, so the lower leg twists outward. It is linked to shortages of manganese, choline and some B vitamins. It is rare on complete feed from a reputable mill and is another warning about home mixes and old premix.
In birds of about four to six weeks, bacteria carried in the blood can settle in the growing ends of the thigh and drumstick bones. The bird goes lame quickly and props itself on a wing. At post-mortem the head of the thigh bone crumbles or breaks off when the hip is opened. The bacteria get in through an unhealed navel, a damaged gut, the airways or scratched skin, and flocks whose immunity has been weakened by Gumboro disease are more at risk.
Hot, swollen hock joints or swollen footpads in a number of birds point to an infectious arthritis. Both of these need a vet, because treatment, if any is worthwhile, depends on identifying the organism.
Black scabs on the footpads, brown burns on the hocks and blisters on the breast are contact injuries from sitting on wet, caked litter. They are painful, they make birds less willing to walk to feed, and they let bacteria in. The cure is in the floor, as described in litter management for poultry.
Chicks whose legs slide out sideways in the first days of life have splay leg, an early-chick problem that comes from slippery flooring or the incubator and is not related to the conditions above.
Ascites is the end stage of a heart that has been overworked for weeks. When the body's demand for oxygen is higher than the lungs can meet, the right side of the heart pumps harder to force more blood through them. Its wall thickens, then stretches, and the valve begins to leak. Blood backs up into the liver, and under that pressure fluid seeps out of the liver into the abdominal cavity.
The bird is dull and stands or sits apart. Its belly is enlarged and feels soft and full of liquid, like a water bag, and the skin over it may look red or bluish. The comb and wattles darken. It pants even when the house is cool, because the fluid presses on the air sacs. Such birds often die when caught or chased. If you open one, straw-coloured fluid runs out, sometimes with soft yellow jelly-like clots, and the heart is large and flabby.
Anything that raises the need for oxygen, or lowers the supply, adds to the risk.
High altitude is the classic cause in other countries. Ghana's poultry areas are low-lying, so here the causes are the ones listed above, and all of them are under the farmer's control.
Sudden death syndrome takes birds that looked perfectly well a minute earlier. The bird may squawk, loses its balance, flaps violently for a few seconds and dies, most often ending on its back with its legs in the air, which is why farmers call it flip-over. It is usually one of the biggest birds in the house and more often a male. Cases appear from the first week, are most frequent between about two and four weeks, and can carry on at a lower rate until sale.
Opened up, the bird is well fleshed with a crop and gut full of feed. There is nothing dramatic to see: no fluid, no swollen organs, no bleeding. The cause is a sudden failure of the heart's rhythm in a bird growing at full speed. Flocks on continuous or near-continuous light and very dense feed have more of it.
An occasional death of this kind is part of raising fast broilers. A steady trickle, week after week, is a sign that early growth is too fast and should be steadied.
Do not assume. Several diseases and one weather event can look similar from the door.
Open every dead bird, or have it opened. Ask your vet to show you once how to look for fluid in the belly, the size of the heart, the contents of the crop and the state of the hip joint. Write the finding beside each death in your record. If you are unsure, or deaths are rising week on week, take fresh carcasses to a vet or the district veterinary office. Do not give medicines on a guess. None of the three growth-related problems responds to antibiotics.
Because these conditions share a root, the same handful of habits reduces all of them.
The most effective single measure is darkness. Chicks need long light hours for the first few days so that they find feed and water. From about day 7, give at least four to six hours of unbroken darkness in every 24. Birds rest, the skeleton and heart get time to keep up with the muscle, and growth in weeks two and three is a little slower. Most of that ground is made up in the later weeks, and fewer birds are lost.
A farm with no night lighting already has this from Ghana's twelve-hour nights. The farms at risk are those that burn bulbs all night to push growth. If you light the house in the evening so that birds can eat in the cool, switch off by nine or ten. More detail is in our article on lighting programmes.
Brood at the correct temperature, so that chicks are neither chilled nor gasping, and never buy warmth by sealing the house. Leave an opening along the top of the curtain on the side away from the wind so that fumes and stale air escape and fresh air enters above the chicks' heads. If you heat with charcoal, read brooding heat sources compared for the safety points, and see our chick brooding guide for temperatures by age. In the harmattan and the rains, close the windward curtain on cold nights for older birds as well, still leaving the gap at the top. Keep dust and ammonia down, and follow the vaccination programme your vet sets against respiratory disease.
Use complete feed from a reputable mill, or a concentrate mixed exactly at the maker's ratio. If you mix your own, weigh the premix, limestone and phosphate source every time, mix thoroughly, and keep premix cool, dry and within its date. Never add salt beyond the formula. If your borehole water tastes salty, have it tested. Reject musty maize.
Where ascites or flip-over keeps returning, ask your feed supplier or a nutritionist about using mash or a less dense feed for the first two to three weeks. Do not ration or starve birds on your own initiative. Hungry birds gorge when fed, which is the opposite of what you want.
Keep litter dry and loose. Give enough floor area that birds can walk, and spread feeders and drinkers through the house so that they must walk between them. Legs strengthen with use. Catch and carry birds with both legs held, or with the body supported, never swinging from one leg.
Bone and joint infections often begin at the navel or in a house that was not cleaned between batches. Clean, disinfect and rest the house, and reject chicks with wet or open navels. Weigh a sample every week. A flock far ahead of target at 14 and 21 days is the one to watch, and broiler weight targets gives the figures.
A bird that cannot walk to feed and water will not recover on the floor of a broiler house. It loses weight, is trampled, and suffers. A bird with a fluid-filled belly will die. In both cases the right action is prompt, humane culling, followed by deep burial or burning. Do not sell these birds or dead birds, and do not leave them for the rest of the flock to peck at.
A mildly lame bird that still eats and drinks can be moved to a small pen with feed and water close by and sold with the rest if it is otherwise healthy. Count and record every case with the age. Three batches of records will show you whether your problem peaks after cold nights, in a particular house, or on a particular feed.
If the same losses return batch after batch despite good air, a dark night and sound feed, look at what you are asking of the bird. The risk is highest in birds pushed to heavy weights, so selling at a lighter weight removes the most dangerous final week. Cool-season batches under tightly closed curtains suffer more ascites than those reared with better air.
The chick also matters. Day-old chicks with healed navels, from one hatch, give you an even flock with fewer early infections. Halaal Farms Ghana supplies Ross 308 and Cobb 500 broiler day-old chicks, vaccinated at the hatchery before they leave, and you should ask what a batch has had so your vet can plan the rest.
For farmers who sell live birds to customers willing to wait, slower-growing coloured birds are a real alternative. They take longer to reach weight, and because they grow at a gentler rate they rarely show these three problems. You can see them on our Sasso, Kuroiler and Noiler page.
If you are losing birds and are not sure which of these conditions you have, call Halaal Farms on 024 915 1503 with the age of the flock, the number affected and what you found when you opened a bird. Advice is free before and after an order, and the order form is there when you are ready to book the next batch.
Heavy broilers rest a lot, but a bird that will not rise, or sits again after two or three steps, is in pain or weak. Common reasons are bones bending under fast weight gain, soft bones from a feed fault, infection in a joint or the hip, or sore feet from wet litter. Look at the legs, joints and footpads, and ask a vet if several birds are affected.
Water belly, or ascites, is heart failure brought on when a fast-growing bird needs more oxygen than its heart and lungs can deliver. The heart overworks, pressure builds in the liver and fluid leaks into the abdomen. Cold spells, stale air during brooding, charcoal fumes, dust, ammonia, lung disease and too much salt all make it more likely.
No. Birds found dead should never be sold or eaten, whatever the cause, because they were not bled and you cannot be certain why they died. A live bird with a swollen, fluid-filled belly is a sick bird and is also unfit for sale. Remove such birds humanely and dispose of them by deep burial or burning.
No. It is a metabolic failure of the heart in an individual fast-growing bird, not an infection, so it does not spread through the flock. Losses are scattered, a bird or two at a time. If many birds die together, or the dead include small or visibly sick birds, suspect disease or heat and have fresh carcasses examined by a vet.
Written by the Halaal Farms Ghana team. We hatch and import day-old chicks at Opeikuma, Kasoa, and deliver to all 16 regions. This article is general guidance for farmers. For diagnosis and treatment of sick birds, speak to a vet or your district veterinary office.
A practical method for choosing your broiler sale day: the daily feed-against-gain sum, how per-kilo and per-bird pricing change the answer, and what waiting for a better price really costs you.
How to turn live broilers into clean, well-chilled dressed chicken on a small farm, from the last feed to the freezer, with the temperatures, timings and hygiene habits that keep the meat safe and saleable.
How to run broilers as single-age batches: what the empty days between flocks achieve, the arithmetic of cycles per year, timing batches for festive demand and rotating several houses without mixing ages.
