The chicken farmer needs to have a good understanding of chicken diseases, their causes, symptoms, cures and prevention.
Diseases are any changes in the chicken’s natural body functions that affect their production, growth and survival.
Chicken diseases are one of the biggest challenges in poultry farming. Be it chicken, ducks, geese, turkey or any other poultry, diseases can wipe out entire flocks or cause major reduction in production, leading to loses.
Table of Content
- 1 Signs of healthy chicken and other poultry
- 2 Categories of Poultry Diseases
- 3 Coccidiosis.
- 4 Newcastle Disease
- 5 Avian Influenza
Signs of healthy chicken and other poultry
Whether you are keeping chicken, ducks, geese or parrots, all poultry share the same health traits. As a poultry farmer, you should be able to observe your birds and tell when something is wrong. Inspecting the health of your chicken involves observing their physical traits and behaviors.
The comb should be bright red, with no ulcerations or wounds
The vent of the chicken should be clear, without discharge or blockage.
Feet and toes
The feet should be smooth with no scales. The legs should be strong, fully supporting the bird’s weight. The toes should be pointing straight, with no skin in between the toes.
The chicken feathers should be smooth, with a slick-looking sheen on them. There should be no patches of missing feathers unless the bird is molting.
The eyes should be clear and bright, without any discharge. The eyelids should not be visible when the bird is fully alert.
The mouth should be closed as the bird should not be breathing from its mouth, unless in very hot climates, where chicken breath with their mouths in order to coll their bodies. Moving the bird in a cool area should lead it to close its mouth.
The nose should be clear without any discharge.
The wings should be close to the body and not droopy or twisted. In hot climates, birds tend to droop their wings in order to cool themselves.
Chicken and other birds are social creatures with high levels of energy, always moving around. If they look depressed and not moving around, then something must be wrong.
Chickens are always alert, unless at night when they cannot see. They should not be easy to catch. If the chicken looks dazed and does not react to your presence, you need further observation to ascertain if they are sick.
Egg production varies from breed to breed, but all chickens have a benchmark of which the farmer can peg production levels. Apart from the molting period, where production goes down to zero, any sudden drops in egg production indicate a disease or nutritional deficiency.
Categories of Poultry Diseases
Poultry diseases are categorized into four major categories. These include:-
- Parasitic poultry diseases
- Infectious poultry diseases
- Behavioral poultry diseases
- Nutritional and metabolic disease
Parasitic poultry diseases are caused when parasites infest poultry. Parasites are organisms that feed and live off other organisms. There are spread when poultry comes into contact with a parasite carrying organism or direct contact with the parasite. Common parasite carriers that spread parasites to poultry include other poultry, rodents, and wild birds. Parasites cannot live by themselves and depend on other organisms for survival. Common parasitic disease in poultry include:-
- Lice and Mites
- Parasitic Worms
Infectious poultry disease occurs when a disease-causing organism, pathogen, invades the body of poultry, multiplies in the body leading to sickness. Pathogens are spread through indirect or direct contact from one living organism to the other. Infectious poultry disease include:-
- Avian Encephalomyelitis
- Avian Influenza
- Infectious Coryza
- Infectious Laryngotracheitis
- Avian Tuberculosis
- Marek’s Disease
- Egg Drop Syndrome (EDS)
- Fowl CholeNecrotic Enteritis
- Newcastle Disease
- Salmonellosis (Pasteurellosis)
- Fowl Pox
- Infectious Bronchitis
- Infectious Bursal Disease (Gumboro)
- Infectious Coryza
- Infectious Laryngotracheitis
- Lymphoid Leukosis
- Marek’s Disease
- Chicken Anaemia Virus Infection (CAV)
- Avian Encephalomyelitis
- Avian Influenza
Behavioral poultry diseases are when birds start to behave abnormally dues to several factors that may include environmental, nutritional and housing environment. Behavioral poultry disease can lead to physical injury of the affected birds or other birds in the flock. An example of a behavioral disease is cannibalism and aggressive pecking.
Nutritional and metabolic poultry diseases come along when poultry lacks certain nutrients or their bodies are not able to utilize nutrients well. These are caused by genetic defects, lack of balanced diets or improper nutrient utilization. Nutritional and metabolic diseases include:-
- Cage layer fatigue
- Slipped tendon (perosis)
- Fatty liver syndrome
Coccidiosis is caused by a tiny microscopic parasite called coccidia. It can manifest in the brooding stages of chicks and most commonly at 8 to 10 weeks of age.
Coccidiosis damages the intestines of chicken, therefore, affecting the intake of the much-needed nutrients.
Spread through chicken droppings, coccidiosis starts at its egg stage, known as an oocyst. The coccidiosis egg can stay in the environment for as long as a year, waiting for the perfect conditions so as to become active. Coccidiosis eggs can be carried on shoes, clothes, and any farm tools that come into contact with them.
The ideal conditions for coccidiosis are:-
- Temperatures of between 20 degrees Celsius and 30 degrees Celsius (60 to 90 degrees Fahrenheit ).
The coccidiosis oocyst will be found mostly around drinkers and feeders. The chicken will swallow the coccidiosis eggs when feeding. The eggs will reach the stomach, where the process of becoming active. The digestive acids in the stomach of the chicken will break down the tough outer covering of the eggs. The eggs then hatch and attach themselves to the linings of the small intestines. They will multiply very fast and start destroying cells on the walls of the intestines as they increase in number. The mature coccidiosis virus will then hatch eggs, which are passed out in the stool and the cycle continues
There are 6 strains of coccidiosis. Most chickens will carry some of them in their systems without ever being affected. Chickens are affected by coccidiosis are at early ages, as they have not yet developed the much-needed immunity. Do not rule out older chickens being affected by coccidiosis, especially if they have been infected by other diseases that may affect their immunity.
There is acute coccidiosis and chronic coccidiosis. Chronic coccidiosis persists for a long period and infected chickens do not die immediately, while with acute coccidiosis, the chicken will die 5 to 7 days after infection. In my case, the chicks appeared well one day and collapsed the following day.
Symptoms of Coccidiosis in Chicken
There are several symptoms of this disease. The major symptoms of coccidiosis ones are:-
- The chicken will have ruffled feathers
- The chicken will have pale beaks and shanks
- The chicken droppings will have blood stains or mucus.
Other symptoms of coccidiosis are lower egg production in laying chickens, loss of weight in mature chickens, loss of appetite, pale skin or comb, lack of energy, bloodstains at the vent, and decrease in expected weight gain in growing chickens.
Treatment of coccidiosis in Chickens
Coccidiosis, if caught in time, can be treated. The most popular treatment for coccidiosis is using Amprolium. It prevents the coccidiosis parasite from attaching to the intestines and it’s multiplication. You will find Amprolium being sold in either liquid form or powder form.
Amprolium cones in different formulations and brand names, with the most common being Corid.
If treating Coccidiosis using Amprolium, add the medicine into the chicken’s drinking water. If birds have lost appetite, you will have to give the coccidiosis treatment orally. Treat all chickens, not just the ones showing coccidiosis symptoms so as to control the disease.
The treatment for coccidiosis is given for seven days. If conditions are favorable for the coccidiosis parasite, give a second dose in order to get rid of the disease.
Coccidiosis treatment can be given periodically as a preventive measure. Please consult your veterinarian on this.
Prevention of coccidiosis in Chickens
- Medicated starter feed – Medicated feed with coccidiostat is one of the most common ways of preventing coccidiosis. Coccidiosis medication is added to the store-bought feed. A point of note is that medicated feed is not a treatment for birds that are already infected with coccidiosis.
- Good biosecurity measures – To prevent coccidiosis, it is advisable to adhere to strict biosecurity measures. Do not go into the coop with any clothing or shoes that you have used outside your chicken area. Some poultry keepers have separate wear when they are attending to their chickens. Do not use any tools that have been outside for long without cleaning and disinfection.
- Avoid Overcrowding – Overcrowding is one of the conditions that speed up the transmission of diseases like coccidiosis in chicken. To prevent this, make sure that there is adequate space for each bird, inside the coop and in the chicken run.
- Avoid wet and humid conditions in the coop – To prevent coccidiosis make sure that the Coop is dry and well ventilated. Wet and humid conditions provide the perfect environment for coccidiosis to thrive. Make sure the litter and the areas around the feeders and drinkers are dry as well. You can use drinkers that do not spill water so has to keep the area dry. Proper ventilation helps keep humidity levels in the coop at normal levels.
- Practice proper hygiene – To prevent coccidiosis, clean your drinker and feeders on a daily basis.
- Provide clean water – Water is one of the entry points for coccidiosis. Make sure you give your chicken clean water, in clean drinkers every day.
- Quarantine new chickens – It is always advisable to practice the all-in all-out stocking method for chicken. This is not always the case, especially for backyard poultry keepers. If you have to introduce new chicken to your existing flock, make sure you put then in quarantine for a while. This will help you observe them in order to make sure that they are healthy and will not introduce coccidiosis to your current flock.
Named after a town in England where it first caused havoc in 1927, Newcastle disease is a highly infectious disease that affects all birds, both domestic and wild. The disease was discovered in Indonesia in 1926. Newcastle disease is also called Ranikhet, Pseudofowl pest, and avian pneumoencephalitis.
Newcastle disease is a viral disease that occurs in three forms. mild, moderate, and very virulent. Very virulent Newcastle disease has the ability to wipe out all of your chickens. In most countries, it required to report all incidents of Newcastle disease, as it may spread to other poultry keepers around the country, leading to a pandemic.
Newcastle disease is spread across the flock through the air when birds inhale air that has been contaminated with the Newcastle virus. Infected birds shed the virus in their droppings, bodily fluids, and breath. These in turn contaminate the surrounding air and is the reason why Newcastle disease spreads so fast.
Newcastle disease can be Introduced to your flock through contaminated tools and equipment, clothing, shoes, fed sacks, vehicles, or other sick birds, wild or domestic. The disease has high mortality levels and can penetrate eggshells. Infected eggs will not hatch.
Symptoms of Newcastle Disease in Chicken.
If your birds are infected by Newcastle disease, you will notice the following symptoms:-
- Infected chickens will die suddenly.
- The birds will twist their heads and necks, droop wings. They will move in circular patterns.
- The chickens will sneeze, grasp for air, discharge from the nose, and will be coughing.
- The chickens will have watery greenish diarrhea.
- There will be reduced production of eggs. It may stop completely.
- Eggs will have thin shells.
- The tissue around the eyes will swell.
Treatment of Newcastle Disease in Chicken.
There is no treatment for Newcastle disease in Chicken. Antibiotics can be administered to the birds that survive to ward off secondary bacterial infections. If your birds are live through a Newcastle outbreak, their production might never be optimal.
Prevention of Newcastle Disease in Chicken.
To prevent Newcastle disease from infecting your chickens,
- Implement proper biosecurity measures where you control access by people and wild birds, prevent contaminating the chicken area, and disinfect any equipment used at the coop.
- Vaccinate your chickens against Newcastle disease. Vaccination schedules against the Newcastle disease vary from region to region.
Avian influenza, also known as bird flu is a respiratory disease that affects several birds. This includes domestic and wild birds. It is spread through contact with any contaminated material or birds. The virus can last for weeks in the environment.
Bird Flu is categorized into two categories, low pathogenic bird flu, and high pathogenic bird flu. The differences in these two categories are the extremities of the disease.
With low pathogenic avian influenza, the chicken will develop very few symptoms that might not be noticeable. Noticeable symptoms of low pathogenic avian flu in the chicken are swollen faces and breathing issues. Some strains of low pathogenic avian flu might develop into high pathogenic bird flu
High pathogenic bird flu spreads very fast with the flock and is fatal. It is estimated that a gram of chicken manure with the bird flu virus can infect up to one million chickens.
Symptoms of Bird Flu in Chicken.
The symptoms of avian influenza in chicken include sudden death, diarrhea, sneezing, coughing, discharge from the nose, swollen legs, swollen wattles, swollen heads, swollen eyelids, low energy, lack of appetite.
Chickens infected by bird flu may die suddenly without showing any symptoms.
Prevention of Bird Flu in Chicken.
To prevent bird flu in chicken, disinfect any equipment that comes into contact with your chicken, especially if it is shared with other poultry keepers.
Prevent your birds from direct contact with wild birds or their droppings. This can be done by keeping your birds indoors or completely fenced out coops and chicken runs.
The disease can also be carried by pets and rodents that come into contact with your chickens.