Dear Prabhani, 

This may interest you that broilers are highly susceptible to stress induced cardiac arrhythmia

Article A study on pathogenesis of sudden death syndrome in broiler chickens

Layers or broilers?

As you know, there are some selections during times in broiler, some selection was done especially for Growth performance (Meat production) then they will reach to suitable weight at 42 days-old but what happen will done for heart, do you think? is it mature at this time? with a little attention you can found that the biggest birds will be died in your salon when you have sudden stress such as ( Noise- feed deprivation or any thing else).

there are a lot of litterateurs in this area.

Regards,

M.Ommati

 It is Layer....Thanks very much for your valuble answers.

When did they stop laying? This might give some indication.

Sudden death syndrome is very common with heavy broilers exposed to heat stress. In such situations one should take cognizance of the ventilation within the pen. If one is able to reduce the pen temperature by any means, that would help the birds to manage the stress. Secondly, check out for the energy of the diet. A high density diet may be helpful so that the little they consume can meet their requirement. Finally, precocious fat deposition around the liver and heart regions may lead to fatty liver and sudden death. 

Dear Dr. Prahbani

the question is about sudden death syndrome but your request deals with layers that stop eating and show paralysis signs.

diseases such as Marek's may cause paralysis at about 6-9 weeks of age, the birds become partly or completely paralysed with one leg forward  and the other in the back, the birds are thin and many times you will se other pathological signs of Marek's .

if you can provide more information about the age of the birds, Marek's vaccination and vaccines etc may be we can try to help you 

To all my new friends and poultry medicine enthusiasts.

Beatrice , thanks for the paper.

As a clinical pathologist working in the field many years I believe that there is a strong link between genetics,  management, fast growing, heart failure and SDS in broilers.

Most of the SDS under field conditions occur in the heaviest birds among the flock, the birds are very well fleshed and with  apparently normal organs. but the most common pathological finding is a severe lung congestion, many times with oedema and accumulation of fluids in the lung, the fact that the combs and wattles are cyanotic also, indicate a lack of oxygen. most of the mortality occurs during the night when the birds rest or sleep for several hours. in many cases reducing the resting period (from 6-8 dark) time to 1-2 hours or 24 hours light. reduces drastically the daily  mortality of SDS suggesting a combination of cardiorespiratory failure involved in the SDS syndrome.

 after excluding causes of sudden death as poisoning by mycotoxins, other animal pests like rats and environmental management as noise, temperature and humidity, ideally is follow advices of Dr. Béatrice, regarding the pathogenesis.

Particularly, first rule out environmental factors, since I have had the experience of sudden deaths in broilers by rodents in the flock, this is supported by video cameras.

Regards.

Your question above related with broiler , while the comments and your answer talk about layer .

If we talk about broiler , the intensive selection for growth rate result heavy body weight while the vital organs like heart or respiratory system have not enough development to provide the bird with his requirements of oxygen needed for rapid growth . These condition cause sudden death or ascites .

Good Luck

It is reported that sudden death syndrome is linked to intensive broiler production where fast-growing birds die suddenly on their backs and sometimes on breast. Although the cause is unknown, but some studies suggested that it might be metabolic and related to carbohydrate metabolism. The symptoms shown are that birds suddenly extend their necks, gasp and die quickly. The suggested prevention for this disease is to control feed intake in order to slow the rapid growth especially during the first few weeks. We would always be confronted by such problems whenever dealing with intensive production systems as is the case with heavy yielding dairy cows.

Nutrient deficiency in diets can lead to loss of apatite due to lack of essential elements such as sodium chloride, phosphorus and iron. Secondly, the heat stress can cause sudden death when the pen is very confined where heat is maximum and/or birds got exposed to direct source of heat.

From personal experience, heat stress is a mostly likely cause especially when there is restricted air movement. this is especially true in the hot humid tropics.

The improvement in body weight for age of the modern broiler chickens, due to increased growth rate and associated higher nutrients supply, have lead to more frequent occurrence of metabolic and skeletal disorders (Robinson et al, 1992) or increased carcass fat deposition. The two main metabolic disorders affecting broiler chickens are ascitis disease and sudden death syndrome, which are closely related to the rapid growth rate and increased feed intake, particularly overconsumption of dietary energy. These pathological conditions commonly occur in fast growing broiler chickens fed ad-libitum. The energy intake of the fast growing broiler chickens, fed ad-libidum, is estimated to reach two or three times greater than their maintenance needs ; and so carcass fat deposition increases, causing broiler metabolic and skeletal disorders.

this a part of my research entitled (effect of dietary fat source and levels on broiler performance and serum- carcass lipids) 

the sudden death syndrome always associated with high weight birds (high fat deposition) with high temperature.

high fat deposition carcass is now made a wide argued  because of its effect on human health.

Heat stress and overcrowding are possible causes of sudden death in broiler pens

Fast growing broiler chickens are prone to sudden death, this may be as a result of their inabilities to meet up with the increased demand for oxygen.

Also, if the room temperature is low  ( below 25°C) within the first week of brooding , the Chicks are forced to generate energy to keep warm, consequently the demand for oxygen increases , which  is followed by an increase in the blood pressure , leading to sudden death.

is a  metabolic disease related to carbohydrate metabolism , acidosis and electrolyte imbalance