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Poultry Diseases

A disease is an abnormal condition that is caused by infection, basic weaknesses, or environmental stress. Diseases can be categorized by common causes, such as
genetic,
mechanical,
toxic,
and nutritional.
Infectious diseases are caused by germs such as  viruses, bacteria, and fungi. Parasitic diseases are caused by protozoa, worms, and external parasites such as mites and lice. These diseases can affect all poultry birds, including fowls, turkeys, ducks, and geese etc.

Poultry Diseases can cause significant economic losses and even lead to the death of birds.  According to the World Organization for Animal Health (OIE), around 20% of the world’s chicken population is infected with at least one poultry disease. Poultry are quite susceptible to a number of diseases. Some of the more common are fowl typhoid, pullorum, fowl cholera, chronic respiratory disease, infectious sinusitis, infectious coryza, avian infectious hepatitis, infectious synovitis, bluecomb, Newcastle disease, fowl pox, avian leukosis complex, coccidiosis, blackhead, infectious laryngotracheitis, infectious bronchitis, and erysipelas. Strict sanitary precautions, the intelligent use of antibiotics and vaccines, and the widespread use of cages for layers and confinement rearing for broilers have made it possible to effect satisfactory disease control( Garrigus 2023). Others include bird flu, or avian influenza with the primary host being  waterfowl such as wild ducks . Sick birds pass the viruses to healthy birds through saliva, nasal secretions, and droppings. Humans who are in close contact with sick birds—for example, poultry farmers and slaughterhouse workers—are at the greatest risk of becoming infected.
Parasitic diseases of poultry, including hexamitiasis of turkeys, are caused by roundworms, tapeworms, lice, and mites etc.

EFFECT OF POULTRY DISEASES
1. Reduce farmer’s income
2. Some diseases are contagious to human and other animals
3. Diseases can cause the death of birds
4. Certain diseases have the potential to decimate a region’s poultry industry.
5. When a disease strikes, a quarantine or embargo could suddenly be placed on a region or nation.
6. This could cause widespread economic hardship for both commercial and small flock owners.
Therefore, poultry farmers must be able to identify diseases quickly to prevent them from spreading to other animals. The sooner a disease is identified and action is taken, the better.

HOW POULTRY DISEASES ARE SPREAD
Diseases are spread by:

1. Direct contact –  bird-to-bird or contact with infected manure

2. Indirect contact – contaminated equipment, people, and environment

3. Vectors – spread by wild animals, rodents, insects)

4. Pathogens – bacteria, viruses and fungi

5. Malnutrition – not consuming a balanced diet feed

POULTRY DISEASES, CAUSATIVE AGENTS, SYMPTOMS, PREVENTION AND TREATMENT

Coccidiosis

Coccidiosis is a poultry disease caused by a protozoan parasite that resides in the walls of the chicken’s intestine and will kill the chicken at any age. It is caused by 8-9 species of protozoa of the genus Eimeria. Birds get infected through contaminated food, water or wet litter.

Signs and symptoms

Bloody droppings , pale comb, listlessness with droopy wings and ruffled feathers, loss of appetite, standing with the eyes closed and huddling together in corners.

Treatment

Coccidiosis can be treated with coccidiostats such as amprolium and sulpha drugs. Anti-coccidial drugs that can be used to treat coccidiosis include Prococ, Amprocox, Coxstop, Coccicare and Sulmet.

Fowl Pox
Fowl pox is a viral disease that could be transmitted through body wounds or scratches, a vector carrying the virus (e.g., mosquitos) and through the air.
Signs and symptoms
pox lesions on wattles, comb and/or legs, discharge from nostrils, white ulcers or cheesy membrane in the mouth, loss of appetite, a decline in egg production, foamy materials in corners of eyes or white spots on the skin.
Treatment
Since this is a viral disease, there is no exact drug. However, you should remove the necrotic membrane from the affected fowl’s mouth and larynx. You can stimulate appetite with wet feed (mash) and add antibiotics and multivitamins to their drinking water. Ensure that you use good disinfectant during the outbreak of the disease.
To prevent Fowl Pox, you need to vaccinate the fowl with the Fowl Pox vaccine and control mosquitoes in and around the fowl cages or housing units

Marek’s Disease
Marek’s Disease (MD), also known as “bird paralysis, Fowl paralysis, neurolymphomatosis gallinarum, or visceral leukosis” is a highly contagious viral disease that affects poultry, causing weakness or complete paralysis of the bird’s legs and sometimes other parts of the body. It is characterized by T-cell lymphomas and peripheral nerve enlargement.

Newcastle Disease
Newcastle disease (also known as Ranikhet disease) is a viral disease that is caused by paramyxoviruses. These viruses are of various types. This disease can be transmitted through the air, feed, water and carrier birds.
Signs and symptoms
With very harmful paramyxoviruses, the first sign is sudden death. Other signs like weakness, depression, greenish diarrhea, lying down, swelling of the face and nervous signs will also be observed. Torticollis (twisting of the neck), leg paralysis, and arching of the body are some other indications of Newcastle disease. In layers, laying of soft-shelled or shell-less eggs is an early sign, followed by a halting of egg laying. Moderately harmful paramyxoviruses are responsible for severe respiratory problems. In adult chickens, there is usually an obvious decline in egg production for many months. However, the mortality rate is low. The mildly harmful paramyxoviruses may not cause any disease or just mild respiratory problems.
Treatment
Newcastle disease has no treatment, but can be prevented through vaccination, maintaining a high level of farm hygiene, good management and biosecurity measures.

Infectious Bronchitis
This is a rapid, sudden and highly contagious viral poultry disease. It’s caused by a coronavirus and could be transmitted through the air, contaminated materials and carrier hosts.
Signs and symptoms
Abnormal respiratory sounds, snoring, gasping, sneezing and coughing, watery nasal discharge, ocular discharge and swelling of the face. Reduced egg production and poor egg shell quality. Watery albumen.
Treatment
Infectious bronchitis has no specific treatment, but you can administer antibiotics in mixed infections. You should also take affected fowls to a warm, dry place to recover. Some farmers have tried warm herb tea and fresh herbs, and they claimed they worked.
To prevent Infectious Bronchitis, vaccinate your chickens against the disease and maintain proper ventilation of chicks.

Fowl Cholera (Avian Pasteurellosis)
Fowl Cholera is a highly contagious bacterial disease that affects poultry birds. It is caused by Pasteurella multocida and could be transmitted through ingestion of contaminated food and water or from a carrier host chicken.
Signs and symptoms
Yellowish or greenish diarrhea, difficulty in breathing, swollen joint, purple comb and wattle, oral, nasal and ocular discharges, ruffled feathers and loss of appetite.
Treatment
Fowl cholera can be treated with penicillin, streptomycin, erythromycin, tetracyclines and sulphonamides. You will need to administer drugs for the long term because the disease usually returns after stopping the medication.
To prevent Fowl Cholera, administer the F. Cholera vaccine and maintain a high level of farm hygiene and sanitation. Prevent rodents, cats and wild birds from gaining access to the pen.

Infectious Coryza
Infectious Coryza or Fowl Coryza is a severe respiratory disease that affects chicken and it could be sudden. This disease is common in layers and broilers and it is caused by Haemophilus paragallinarum. It could be transmitted through water contaminated with nose discharges, through the air, or direct contact with an infected chicken.
Signs and symptoms
Swelling of the head (comb, wattle and eyes), sneezing, stringy discharge from the nose and eyes, conjunctivitis with closed eyes, difficulty in breathing and moisture under the wings. Other symptoms of infectious coryza include reduced feed and water consumption and a huge drop or halt in egg production.
Treatment
Infectious Coryza can be treated with antibiotics and sulpha drugs. Oxytetracycline, enrofloxacin, trimethoprim and sulpha drug can be combined to treat infectious coryza.

Chickens can be protected from infectious coryza through vaccination. Dispose of all infected chickens or those that had recovered. Sanitation and hygiene and avoid keeping chickens of different ages together.

AVIAN INFLUENZA

Avian influenza (AI) is a respiratory disease of birds. AI viruses can infect chickens, turkeys, pheasants, quail, ducks, geese, and guinea fowl, as well as a wide variety of other birds. Migratory waterfowl seem to be a natural host for AI viruses. This viruse is classified according to the severity of illness they cause. AI viruses can be classified into low pathogenic and highly pathogenic based on the severity of the illness they cause in birds.

How AI Is Spread: AI viruses spread primarily by direct contact between healthy and infected birds through respiratory secretions and feces. The disease can spread through: Exposure of poultry to wild waterfowl, Illegal international movement of birds, Movement of people and farm equipment, Smuggling of poultry and poultry products, Contaminated poultry equipment (such as cages and crates, manure, vehicles, and egg flats) and people whose clothing or shoes have come into contact with the virus and direct bird-to-bird contact

Signs and symptoms
Sudden death without clinical signs, lack of energy and appetite, decreased egg production and/or soft-shelled or misshapen eggs, swelling of the head, eyelids, comb, wattles, and legs, purple discoloration of the wattles, combs, and legs, nasal discharge, coughing, and sneezing, lack of coordination, and diarrhea
Prevention and treatment
House poultry indoors, avoid the use of farm ponds and bird feeders, avoid all contact with wild and domestic waterfowl, avoid live bird markets, control cats, rodents, beetles, insects, and other pests, seek diagnostic help on unusual deaths, avoid contact with your flock if working in poultry or swine processing, avoid sharing equipment. Borrowed equipment should be thoroughly clean and disinfected.

BUMBLEFOOT IN POULTRY

Bumblefoot in poultry is a condition that affects fowls and other birds, causing infection and swelling in the feet. It is typically caused by bacterial infection, often Staphylococcus aureus, that enters through small cuts or abrasions on the foot. The infection leads to the formation of abscesses, which can be very painful and may affect the bird’s ability to walk.
CAUSES:
Bumblefoot can be caused by several factors that open door for the bacterial infection. Such factors include:
a. Poor perches or flooring: Hard, rough surfaces, or areas with high moisture can cause abrasions on the feet.
b. Injury or trauma: Scratches or cuts on the feet are common entry points for the bacteria.
c. Obesity: Overweight bird may put extra pressure on their feet, making them more prone to developing bumblefoot.
d. Poor sanitation: Dirty, wet bedding or environments can increase the risk of bacterial infections.
COMMON SYMPTOMS OF BUMBLEFOOT:
-Swelling and redness on the foot pads
-A hard, raised abscess or scab on the foot
-Lameness or difficulty in walking
-Heat or pain in the affected area
-In severe cases, pus or discharge might be visible from the abscess

TREATMENT AND PREVENTION
TREATMENT

1. Soaking the foot: Soaking the affected foot in warm water or an antiseptic solution can help soften the scab and make it easier to treat.

2. Cleaning and removal of the abscess: Gently clean the affected area and, if necessary, surgically remove the abscess, being careful to disinfect the area thoroughly.

3. Antibiotics: Oral or topical antibiotics may be prescribed if an infection is present.

4. Bandaging: Keeping the foot clean and bandaged can help prevent further infection and aid healing.

5. Pain management: In some cases, pain relief may be necessary, depending on the severity of the infection.
PREVENTION
a. Ensure clean, dry bedding and regularly clean the chicken coop.
b. Provide soft, non-slip surfaces for perching to prevent injury.
c. Avoid overcrowding and ensure the birds have enough space to move around comfortably.
d. Maintain a healthy diet to prevent obesity, which can put extra strain on the feet.

If the condition is left untreated, it can lead to further complications, including systemic infection or permanent lameness. It is important to address bumblefoot as soon as possible to prevent these complications.

GUMBORO DISEASE

Gumboro disease, also known as Infectious Bursal Disease (IBD), is a viral infection that affects poultry, primarily young birds, and can cause significant damage to their immune system.

SYMPTOMS

Gomboro disease in fowl is characterized by symptoms like depression, ruffled feathers, watery diarrhea, and reduced feed and water consumption, often affecting birds between 3 and 6 weeks old. Infected chicks appear listless and may huddle or sit in a hunched position (sign of depression).  They release watery or mucoid (slimy) diarrhea , often with soiled vent feathers. Other signs include; Anorexia (Loss of appetite is a common sign),Vent Pecking, unsteady or wobbly gait, tremors or trembling may be observed and hemorrhages ( at the thigh and pectoral muscles). 

PREVENTION AND TREATMENT

PREVENTION. Preventing Gumboro disease in a poultry farm involves several key management practices:

1. Vaccination

a. Proper Vaccination Program: Vaccinate your birds at the right age using vaccines designed for Gumboro disease. The vaccination schedule typically includes:a. Initial vaccination for day-old chicks or at 7-14 days of age.

b. Booster doses at regular intervals, especially during high-risk periods.

c. Consult with a vet to determine the appropriate type of vaccine (live or inactivated) based on your flock’s needs.

2. Biosecurity Measuresa.

a. Strict Hygiene: Ensure cleanliness in the poultry house. Disinfect equipment, feed, and water troughs regularly.

b. Control Movement: Limit the entry of visitors, vehicles, and animals into the farm. Use footbaths and hand sanitizers at entry points.

c. Isolate New Birds: Quarantine any new or incoming birds for a few weeks to ensure they are not carrying infections.

3. Good Farm Management Practices

a. Adequate Ventilation: Maintain proper air circulation in poultry houses to reduce the buildup of harmful viruses.

b. Optimal Temperature and Humidity: Maintain the right environmental conditions to reduce stress on the birds, which can weaken their immune system.

c. Proper Feed and Water: Ensure that birds receive balanced nutrition and clean water. Proper diet strengthens their immune system to resist infections.

4. Monitor and Control Stress

a. Reduce Stress Factors: Keep the birds free from stress caused by overcrowding, poor ventilation, or poor handling, as stress can lower immunity and increase susceptibility to diseases.

b. Monitor for Symptoms: Be on the lookout for any signs of disease, such as lethargy, loss of appetite, diarrhea, or sudden deaths, and consult a veterinarian immediately if you suspect an outbreak.

5. Use of Antibodies (Passive Immunity) Colostrum or Maternal Antibodies: Ensure chicks receive adequate passive immunity from their mothers, especially if the hens have been vaccinated against Gumboro. This can help protect the chicks during the early stages of life.

6. Infection Control and Early Detection

a. Routine Health Checks: Regularly inspect birds for any signs of illness and report to a vet if you suspect an outbreak.

b. Prompt Isolation: If Gumboro is suspected in a flock, isolate infected birds immediately to prevent the virus from spreading to healthy ones. By following these strategies, farmers can significantly reduce the risk of Gumboro disease on your poultry farm.

TREATMENT

Gumboro disease, or Infectious Bursal Disease (IBD), has no specific cure, meaning there is no antiviral medication or treatment that can directly eliminate the IBD virus. So treatment focuses on supportive care and preventing secondary infections. 

Prevention through vaccination and strict biosecurity measures is crucial as stated above. 

Supportive care may include; focusing on alleviating symptoms and preventing complications. Give vitamin and electrolyte supplements to help maintain hydration and support the bird’s weakened immune system. And lastly, administer antibiotics if secondary bacterial infections develops. 

DIARRHEA
Diarrhea in poultry is characterized by loose, watery, or abnormally frequent droppings. It is caused by bacterial, viral, and parasitic infections (like E. coli or coccidiosis), dietary issues (such as imbalances or mycotoxins), environmental stressors (like heat stress), and even organ damage (from kidney or other disease). Identifying the underlying cause is crucial, as it can lead to dehydration, poor growth, decreased egg production, and can also be a symptom of more serious and contagious diseases.

COMMON CAUSES OF DIARRHEA
a. BACTERIAL INFECTIONS:
Bacteria such as E. coli and Salmonella can infect the digestive tract, causing inflammation and diarrhea.
b. VIRAL INFECTIONS:
Viruses like those causing Newcastle disease and infectious bronchitis can lead to diarrhea.
c. PARASITIC INFECTIONS:
Coccidiosis, a protozoan parasite, directly damages the gut and is a common cause of diarrhea in young chicks.
d. DIETARY ISSUES:
Poor quality feed, mycotoxins (fungal toxins), a sudden change in diet, or an imbalance of nutrients can disrupt the digestive system.
e. ENVIRONMENTAL STRESS:
Heat stress can increase water intake, while other environmental factors can damage the intestinal lining, both leading to watery feces.
f. ORGAN DAMAGE:
Kidney damage, often from infections or high mineral/salt levels, can impair water absorption and lead to watery droppings.
Other causes from poor management practices include;
g. Direct or indirect contact with infected birds . This happens through air of poop.
h . Contaminated feed, water, or litter
i . Infection from mother hen to chicks through egg laid, usually results in death during the first few days of life up to 2–3 weeks of age.
j. Hatchery contamination.
k . Poor biosecurity.

SIGNS AND SYMPTOMS
i. Loose or watery droppings
ii. Increased frequency and volume of defecation
iii. Lethargy and weakness. Birds become weak, depressed, and have white poop material pasted to the vent area.
iv. Reduced appetite and poor growth. That is, birds become anorectic. The birds loose appetite which lowers feed consumption, hence a loss of weight.
v. Decreased egg production
vi. Bloody droppings (especially in coccidiosis)
vii. Affected birds group themselves near a heat source.
viii. In addition, the birds may have respiratory disease, blindness, or swollen joints.
ix. The birds that survive become small in size and frequently become asymptomatic carriers.
x. Some of the survivors have infection of the ovary. This means that Some of the eggs laid by such hens may hatch and produce infected chicks.

TYPES OF DIARRHEA
The colour of diarrhea and texture is an indication of what type of diarrhea is affecting the fowl and how to treat them. The following are the types of diarrhea;

a. YELLOW DIARRHEA
This often indicates coccidiosis or a bacterial infection such as clostridial enteritis. It may also appear when digestion is disturbed by stress or feed changes.

b. GREEN DIARRHEA
This usually comes from excess bile pigments due to rapid gut transit or an infection. Stress and certain diseases can also play a role.

c. WHITE DIARRHEA
White, chalky droppings point to a yeast or fungal overgrowth (candidiasis) or a general imbalance in gut flora, often after antibiotics or poor hygiene.
treatment:

d. RED OR BLOODY DIARRHEA
This is a sign of severe coccidiosis, intestinal bleeding, or heavy parasite load. Mortality can be high if not treated quickly.

e. WHITE DIARRHOEA; This is a type of diarrhea found in young chick. This can be caused by several factors. Such factors include;
i . Gumboro disease.
ii. Pullorum infections.
iii . Worms.
Etc
i. Gumboro mostly attacks the chicks from about 5-6 weeks of age or it can be earlier.
ii. Serious worms attack symptoms starts showing at about 7 weeks and above.
iii. Pullorum can attack from day one of age. This factor causes high rate of deaths in young Chick. Actually it can wipe all the flock in a matter of days.

GENERAL PREVENTION AND MANAGEMENT
a. SANITATION:
Keep the coop and water sources clean.
b. BALANCED DIET:
Provide a well-balanced diet and avoid sudden changes to prevent digestive upset.
c. WATER QUALITY:
Ensure access to clean, fresh water, but monitor for high mineral content that could lead to diarrhea.
d. PARASITE CONTROL:
Implement preventative measures against coccidiosis, especially for young chicks.
e. STRESS REDUCTION:
Manage heat and other environmental stressors to keep birds comfortable and reduce water intake.

GREENISH DROPPINGS: Greenish poultry droppings could mean a number of things. It can be a sign of disease in birds, it also has other causes like a sign that the birds are being underfed.Birds that feed on local food such as vegetables, leaves, or seeds also have green coloured droppings. If the birds are well fed and have not been consuming any green vegetables or the likes, and still gestures green droppings, then the most likely cause is a disease.

DISEASES THAT CAUSES GREEN DROPPINGS IN POULTRY

There are two diseases that brings about symptoms of greenish droppings in poultry.The diseases include;

i. New Castle disease and

ii. Fowl Cholera.

DETERMINATION OF THE DISEASE THAT BRINGS ABOUT GREEN DROPPINGS IN POULTRY

To determine which of the above diseases is responsible for the green droppings in poultry, the farmer should;

i. Examine the symptoms of each disease and identify which disease symptoms are the most consistent with the birds.

ii. Recognize the causative disease

SYMPTOMS OF EACH DISEASES

Above are listed symptoms of various diseases. Lets go over each again for clarity of identification of disease causing green droppings .

1. SIGNS/SYMPTOMS OF NEW CASTLE DISEASE

The signs and symptoms are:

i. Drooping feathers

ii. Dragging legs

iii. Circling

iv. Inappetence

v. Diarrhea (that is the greenish dropping)

vi. and even complete paralysis

2. SIGNS/SYMPTOMS OF FOWL CHOLERA

i. . Ruffled feathers

ii. Weight loss (anorexia)

iii. Fever (yes chickens have fever)

iv. diarrhea (yellow/greenish droppings)

v. increased respiratory rate which is usually visibly noticeable

Each of these diseases are highly contagious, meaning, they can easily spread and infect the rest of the flock, and the result of their infection can be very devastating. Therefore, after identification of the disease, action must be taken immediately. (Read about treatment of each diseases above).

ENCEPHALOMALACIA (DEADLY VITAMIN E DEFICIENCY)

Encephalomalacia in poultry is also called Crazy Chick Disease.It is a neurological disorder caused by a deficiency in vitamin E.

CAUSES OF ENCEPHALOMALACIA

Several factors can result in the disease called Encephalomalacia. But the major cause is vitamine E deficiency. Other causes include: Feeding on rancid feeds, and high quantity of linoleic acid in the diet of the birds.

a. VITAMIN E DEFICIENCY:The primary cause of Encephalomalacia is a lack of vitamin E. Vitamin E is a powerful antioxidant that protects the brain’s fatty tissues. Lack of this vitamin result in peroxidation of polyunsaturated fatty acids build up in the brain’s tissues, which result in the disease. Therefore, leading to oxidative damage to the cerebellum and results in symptoms like ataxia

b. RANCID FEED: High-fat diets can become rancid, which destroys vitamin E, increasing the risk of the disease. Feeds can become rancid when the fat ( unsaturated fatty acids) content in it undergo oxidation. The fats break down in the presence of oxygen, light, and heat, forming volatile, malodorous compounds like aldehydes and ketones in a process called free-radical chain reaction, leading to unpleasant flavors and smells characteristic of rancidifity . But Saturated fats resist this process, which is why unsaturated fats, found in many liquid oils, are far more susceptible to turning rancid. So as chicks consume the rancid feeds, indirectly, they consume the unsaturated fatty acids, like linoleic acid. This unsaturated fats are prone to oxidation, forming peroxides that damage tissue and deplete vitamin E, leading to cell damage and lesions in the brain, particularly the cerebellum, which is the hallmark of the disease.

c. HIGH LINOLEIC ACID DIETS: Linoleic acid is a polyunsaturated fatty acid (PUFA) that is particularly vulnerable to oxidation. Diets rich in linoleic acid can increase the demand for vitamin E in the brain’s developing tissues. It affect chicks by promoting lipid peroxidation, which damages brain tissue. The Linoleic acid (LA) is highly susceptible to oxidative damage, and its accumulation in the absence of sufficient vitamin E, a potent antioxidant, leads to the formation of reactive byproducts that attack cell membranes in the brain, particularly the cerebellum, resulting in the degenerative lesions characteristic of ENCEPHALOMALACIA.

SYMPTOMS

Symptoms of Encephalomalacia include ataxia, tremors, falling over, clonic spasms of the legs, and an inability to get up. It is characterized by brain lesions, such as hemorrhages, cellular deterioration, and capillary thrombosis (clotting in small blood vessels) most often in the cerebellum. The ataxia (loss of coordination), staggering, trembling, and falling over are all neurological disorders. The clonic spasms of the legs and involuntary wing movements are muscle spasms disorders. It can also cause head retraction or twisting (torticollis), inability to stand, weakness, and stupor.

PREVENTION

i. Prevention involves ensuring adequate vitamin E and selenium is available in the diet and using only fresh feed, as a deficiency can occur when diets are low in vitamin E and high in fats that can become rancid. Vitamin E and selenium supplements in the diet can prevent encephalomalacia. They act as an antioxidant to protect against the peroxidation of polyunsaturated fatty acids in the brain’s tissues.

ii. USE FRESH FEED: Store feed properly in airtight containers and use it within a short period to prevent rancidity.

iii. CHECK FEED AGE AND EXPIRATION: Avoid using feed or vitamin supplements that have passed their expiration date.

iv. FOR BREEDERS: Ensure breeder hens and their diet also have sufficient vitamin E to pass it to the chicks.

TREATMENT

Treatment is difficult if the disease has already progressed to advanced stages.

i. Affected birds can be treated with vitamin E preparations (alpha-tocopherol) if caught early enough. If Vitamin E is to be used, it can be water-soluble Vitamin E or feed additives.

ii. In the case of selenium, both Selenium and Vitamin E should be mixed together as both work together.

iii. Improve feed quality and store feed properly to avoid oxidation of its nutrients.

iv. Breeder hens should be administered adequate Vitamin E so that their chicks hatch with better reserves. v Feed fresh, high-quality feed, rich in Vitamin E (e.g., wheat germ, sunflower meal).

vi. Supplement bird feed regularly with vitamin E and Selenium in high-stress or high-fat diets conditions. Remember Early detection saves lives. Supplement sick chicks quickly and adjust the flock’s nutrition.

CANDIDIASIS

Candidiasis also called crop mycosis is a fungal infection caused by Candida albicans. It mainly affects the digestive tract especially the crop, mouth, and oesophagus of fowls.It typically occurs secondary to predisposing factors such as prolonged antibiotic use, unsanitary conditions, vitamin A deficiency, and stress, which disrupt the normal gut microflora. Birds become infected through consumption of contaminated feed, water, or dirty equipment. The major birds at risk of being infected are the ones with weak immunity and that are under stress or treated with antibiotics (which kill good gut bacteria). The fungus overgrows in the crop or mouth, forming white, crusty patches or yellow plaques. It spread and damage the lining of the crop and interfere with digestion and nutrient absorption.

CAUSES

a. DISRUPTION OF NORMAL FLORA: Candida is a normal commensal in the gut, but the disease arises when the healthy bacterial population is suppressed.

b. ANTIBIOTIC USE: Long-term or excessive use of antibiotics kills beneficial bacteria, allowing Candida to overgrow.

c. POOR HYGIENE: Unsanitary water sources and general lack of good hygiene create an environment conducive to fungal growth.

d. IMMUNOSUPPRESSION AND STRESS: Conditions that weaken the immune system, including stress, make birds more susceptible to opportunistic infections.

e. VITAMIN A DEFICIENCY: Malnutrition, particularly a lack of vitamin A, can impair the integrity of the digestive tract lining.

f. HEAVY PARASITISM: Severe parasitic infections can also weaken the host and contribute to the disease development.

SYMPTOMS

Candidiasis symptoms are often nonspecific, including depression, anorexia, and poor growth, while lesions appear as white plaques in the crop and esophagus.

a. NONSPECIFIC SIGNS: Birds may show depression, lethargy, and a poor appetite.

b. GROWTH RETARDATION: Stunted growth is a common sign in affected birds.

c. DIARRHEA: In some cases, birds may experience diarrhea, though it can be masked by signs of the primary disease.

LESIONS (SYMPTOMS DURING POST-MORTEM)

a. WHITE PLAQUES: White, raised, and wrinkled lesions are found on the lining (mucosa) of the digestive tract, especially in the crop and oesophagus.

b. PSEUDOMEMBRANES: These lesions can appear as tough, whitish, or yellowish pseudomembranes and can easily be removed.

Other symptoms include;

a. White or yellow patches in the mouth or crop

b. Crop feels swollen or sour-smelling

c. Poor weight gain

d. Drooling or difficulty in swallowing

DIAGNOSIS

Diagnosis of the disease is usually carried out and confirmed by laboratory analysis.

a. HISTOPATHOLOGY: Microscopic examination of tissue samples can reveal fungal hyphae, confirming the presence of the yeast.

b. LABORATORY CULTURE: Culturing Candida from affected tissues provides a definitive diagnosis. treatment and prevention

PREDISPOSING FACTORS: The most crucial step is to resolve the underlying cause, such as improving hygiene or adjusting antibiotic use.

a. ANTIFUNGALS:

i. COPPER SULFATE: A 1:2000 solution in drinking water can be used for prevention and control.

ii. NYSTATIN: This antifungal medication can be added to water or feed to treat infections, especially in turkeys. iii. GOOD HYGIENE: Maintaining clean water sources and overall sanitation is essential for prevention. iv. PROBIOTICS:Incorporating probiotics into the diet can help restore healthy gut flora.

PREVENTION AND TREATMENT

a. Feeders and drinkers should be regularly kept clean

b. Avoid overuse of antibiotics

c. Proper ventilation should be maintained.

d. Treatment involves resolving the underlying cause and using antifungals like copper sulfate or Nystatin.

e. GOOD HYGIENE This involves proper cleaning of the drinkers and feeders. Fresh water and high-quality feed should also be administered. Any moldy or spoiled feed should be discarded and probiotics can be administered to restore gut health

LARYNGOTRACHEITIS (ILT)

Infectious Laryngotracheitis (ILT) is a highly contagious viral disease in poultry caused by a herpesvirus (Gallid herpesvirus 1). It mainly affects the respiratory tract especially the larynx and trachea. It is a severe respiratory disease in poultry, which spreads through airborne droplets, contaminated equipment, or infected birds. Among all poultry birds, the most susceptible one is the fowl. It can also impact pheasants, partridges, and peafowl.

CAUSES

Infectious laryngotracheitis (ILT) is caused by a virus called Gallid alphaherpesvirus 1 (GaHV-1). The virus spreads through infected birds, contaminated equipment, and aerosols, and latently infected birds can become long-term carriers.

MODE OF TRANSMISSION

The virus is highly contagious and spreads through various means.

a. DIRECT CONTACT: Contact with sick birds or birds that have recovered and are carriers.

b. CONTAMINATED SURFACES: Through contact with infected dead birds, tissues, or contaminated equipment and housing.

c. AEROSOLS: Airborne spread of the virus can occur. d. Humans: People can inadvertently spread the virus on their shoes, clothes, or hands.

SYMPTOMS

Diagnosis relies on laboratory testing . Some of the signs include; gasping, neck extension, conjunctivitis, nasal discharge, potentially fatal respiratory obstruction from bloody mucus, swollen, watery eyes, decreased egg production and gurgling or rasping sounds The symptoms can vary from mild to severe and can be explained thus:

i. RESPIRATORY DISTRESS: Gasping, extension of the neck, rattling, wheezing, and coughing.

ii. OCULAR/NASAL SIGNS: Watery eyes, tearing, nasal discharge, and swollen orbital sinuses.

iii. MUCUS AND BLOOD: The formation of bloody or fibrinous mucus casts in the trachea can cause obstruction and asphyxiation.

iv. PERACUTE FORM: Sudden onset with high mortality rates, where birds may die quickly before showing other signs.

PREVENTION AND TREATMENT

Prevention and control strategies include strict biosecurity, quarantine, and vaccination programs, with no effective treatment for infected birds.

a. BIOSECURITY: Implement and maintain strict biosecurity measures to prevent the introduction of the virus to a farm.

b. QUARANTINE: Practice site quarantine and ensure no introduction of potentially contaminated materials or personnel.

c. VACCINATION: Vaccination is available and is a key tool for preventing infection, especially in high-risk areas.

d. DISPOSAL OF DEAD BIRDS: Incinerate dead birds to prevent the spread of the virus.

e. VETERINARY CONSULTATION: Collaborate with government and poultry industrial bodies for coordinated control efforts and to ensure compliance with national regulations regarding vaccine use.

TREATMENTS

ILT is a viral disease, therefore, no direct cure is available for it. Some measures taken as treatments to suppress the virus effects include;

i. Give supportive care to keep the infected birds warm, reduce stress, and give vitamins/electrolytes.

ii. Antibiotics can be given. But it will not cure ILT rather can help prevent secondary bacterial infections.

iii. Vaccination can be administered to areas with history of ILT. Use of eye-drop or spray vaccines for prevention

iv. Infected birds should be isolated immediately.

v. Disinfect all equipment and housing thoroughly.

NECROTIC ENTERITIS

Necrotic Enteritis is a bacterial disease caused by Clostridium perfringens. It affects the intestines of poultry, especially broilers, and can kill quickly without obvious early signs.It leads to intestinal damage, poor digestion and absorption, production losses, and can be financially devastating to the poultry industry. This disease usually attack poultry following coccidiosis infection or a poor diet (high in protein or non-digestible ingredients). The bacteria produce toxins that damage the intestinal lining, causing internal bleeding and death. Birds may show signs of weakness, not eating, and may die suddenly.

CAUSES

The primary cause is the bacterium Clostridium perfringens, which is a natural inhabitant of the intestinal tract. Other secondary causes include;

a. TOXINS PRODUCTION:C. perfringens produces toxins that damage the intestinal lining, leading to necrosis (tissue death).

b. PREDISPOSING FACTORS: Stressful conditions (like increased stocking density), certain diets (high in non-starch polysaccharides), and other diseases such as coccidiosis can increase the risk and severity of NE outbreaks.

SYMPTOMS

Damage to the intestinal may impair nutrient digestion and absorption, directly affecting growth and feed conversion. Under acute cases, a sudden increase in mortality, lethargy, ruffled feathers, and depression are common. In subclinical cases, more damages to the industry may occur. The birds may show reduced growth rates and poor feed efficiency, leading to increased condemnation at processing due to liver lesions. It also have economic impact. The bacteria is the most costly bacterial diseases in the poultry industry. Its infection result in losses from reduced bird performance and treatment costs.

Other Symptoms include; Watery, bloody, or foul-smelling droppings, dirty vent, dehydration and sudden death in flock

PREVENTION AND TREATMENT

Some prevention strategies include; good management practices, using feed additives like probiotics and prebiotics, controlling coccidiosis, avoiding high-risk feed ingredients (like certain grains and fishmeal), and managing factors that cause stress or compromise the immune system.

a. FARM MANAGEMENT: Good farm management practices are crucial to prevent and control NE. Such management practices include; proper hygiene and reduce wet litter.

b. FEED STRATEGIES: This can be inform of feed additives. Probiotics, prebiotics, and short-chain fatty acids can be added, which help maintain gut health and control the disease. Also, dietary management can be practice through the avoidance of high levels of fishmeal in the compoundment. Grains rich in non-starch polysaccharides (like wheat, rye, and barley) can be used as source of energy in the feed. Using enzymes for non-starch polysaccharides can also help.

c. DISEASE CONTROL: Effective control of coccidiosis (through vaccines or anticoccidials) is essential as it often accompanies and exacerbates NE.

d. VACCINATION: While not a primary control, developing new vaccines is an active area of research due to the increase in NE cases after the ban of in-feed antibiotics.

e. Use of antibiotics like Amoxicillin, Bacitracin, or Tylosin (under veterinary guidance).

f. Addition of probiotics and electrolytes to feeds or drinking water to restore gut health.

Also, organic acids can be added into the birds drinking water or feed.

MYCOPLASMA

Mycoplasma is a bacterial infection causing respiratory disease in poultry, with the most common types being Mycoplasma gallisepticum (MG) (causing respiratory symptoms) and Mycoplasma synoviae (MS) (causing joint, respiratory, and reproductive issues).

CAUSES

The bacteria spread through direct contact, contaminated surfaces, and the air. Therefore, proper biosecurity is crucial.

COMMON TYPES OF MYCOPLASMA IN POULTRY AND THEIR UNIQUE SYMPTOMS.

i. MYCOPLASMA GALLISEPTICUM (MG) : This is the most common cause of respiratory illness in backyard poultry like fowl and turkey.

SYMPTOMS

Symptoms include; nasal discharge, coughing, sneezing, watery eyes, and swollen eyelids, foamy eye discharge, noisy breathing (rales), gasping and open-mouth breathing, poor/stunted growth in chicksand ruffled feathers and weakness

ii. MYCOPLASMA SYNOVIAE (MS) : This strain affects multiple systems, including joints, the respiratory tract, and the reproductive organs.

SYMPTOMS

It can cause lameness, swollen joints, decreased egg production, and can even lead to infertility in breeding birds. Other types of Mycoplasma include; Mycoplasma meleagridis (MM) and Mycoplasma iowae (MI). All affect poultry.

HOW MYCOPLASMA SPREAD

These disease spread through several mechanisms.

a. DIRECT CONTACT: The bacteria spread through direct contact between birds.

b. ENVIRONMENTAL CONTAMINATION: It can be transmitted through dust, contaminated bedding, and on shoes and clothing.

c. AIRBORNE TRANSMISSION: The disease can spread through the air over short distances.

d. WILD BIRDS: Wild birds can carry and spread the infection to domestic flocks.

GENERAL SYMPTOMS OF MYCOPLASMA

The general symptoms include coughing, sneezing, watery or swollen eyes (MG), lameness, and swollen joints (MS), along with reduced egg production and weight loss.

Based on each mycoplasma types, the symptoms can vary but often include:

i. RESPIRATORY SIGNS: Coughing, sneezing, raspy breathing, and watery nasal discharge.

ii. EYE AND SINUS ISSUES: Swollen or puffy eyelids, watery and foamy eyes, and sinus swelling.

iii. DECREASED PRODUCTION: Reduced egg production in layers and decreased hatchability.

iv. MOBILITY PROBLEMS (MS): Lameness, difficulty walking, and swollen joints.

v. GENERAL SIGNS: Reduced feed consumption, weight loss, and in severe cases, death.

PREVENTION AND TREATMENT

Treatment may involve use of antibiotics. But prevention through good management, biosecurity, and sometimes vaccination is key to controlling this disease in a flock.

a. BIOSECURITY: Practice good biosecurity measures to prevent introducing the bacteria into the flock, such as controlling access to the birds and cleaning shoes, clothing and washing of hands before entering and handling the birds respectively.

b. STRESS REDUCTION: Avoid stressors like changes in housing, new bird introduction, dietary changes, or extreme weather, as these can trigger the disease.

c. FLOCK MANAGEMENT: Implement strategies like using clean bedding, regular change of soiled beddings, cleaning of water troughs and regular change of water, avoiding overcrowding, and maintaining good air quality in the housing units.

d. WILD BIRD CONTROL: Free-range birds should be prevented or limited from having contact with wild birds as such wild birds carry unknown diseases.

e. VACCINATION: Vaccination programs are used to control Mycoplasma and improve flock health.

f. CHICK PURCHASE: Purchase chicks from certified farms andquarantine the new birds for at least 2 weeks on entry into the farming.

g. Administration of antibiotics like Tylosin, Tiamulin, or Tylvalosin. h. Immediate isolation of sick birds

TREATMENT.

a. Once a bird died of the above mentioned symptoms, farmers are advised to perform a postmorterm.
This is done to check for lassic lesions that include gray nodules in the liver, spleen, lungs, heart, gizzard, and intestine and cecal cores. If these lesions are found, it means the bird is suffering from pullorum disease. Therefore, the farmer is advised to clear the rest of the infected flock as soon as possible.

b. Farmers are also encouraged to carry out protection measures against the disease through maximum biosecurity measures because once infected, Treatment will not eliminate the pathogens.

c. Also, if the farmer is not sure whether the disease is gumboro or pullorum, such farmers are advised to consult a veterinarian.

REOVIRUS

Reoviruses cause several diseases in poultry, such as viral arthritis and tenosynovitis. These diseases result in lameness and economic losses through reduced weight gain and impaired feed efficiency.
It is a widespread and resilient virus belonging to the Reoviridae family. It affect poultry like fowls, turkeys, and other birds, though meat-type birds are more susceptible to viral arthritis than other species due to their rapid growth rates compared to other poultry species like layers.

CAUSES OF AVIAN REOVIRUS (ARV) IN POULTRY

A non-enveloped virus with an icosahedral structure, belonging to the Orthoreovirus genus causes the disease.

MODE OF TRANSMISSION
The virus is transmitted through the fecal-oral route, spreading horizontally and contact with infected surfaces, and to a lesser extent, vertically from infected breeders to their offspring.
It can persist in the environment, requiring strict biosecurity, cleaning, and vaccination for control.

DIAGNOSIS:
Presumptive diagnosis can be made from clinical signs. Laboratory diagnosis involves microscopic examination, serological testing to detect antibodies, or virus isolation using techniques like RT-PCR.

ECONOMIC IMPACT:
Can cause significant economic losses due to diminished flock performance, increased condemnation rates during processing, and reduced animal welfare.

SYMPTOMS:
The primary symptoms of reovirus are viral arthritis and tenosynovitis. They are characterized by lameness and swelling of the legs and joints. Other associated issues include immunosuppression, malabsorption, and in some cases, myocarditis (Heart lesions) and hepatitis. It also shows the following;

i. Footpad necrosis due to inflammation or poor circulation
ii. Depressed posture weakness and pain
iii. Muscle degeneration due to poor nutrient use and systemic viral impact
iv. Growth retardation
v. Viral inclusion bodies
vi. Proventricular hemorrhages and bursal changes may also appear but are not typical for all Reovirus strains

PREVENTION AND CONTROL

a. BIOSECURITY: Implement strict biosecurity measures, including proper cleaning and disinfection protocols, to minimize virus spread in poultry houses.
b. VACCINATION: Vaccination is an important strategy for controlling reovirus infections. By vaccinating breeder hens, the chicks receive maternal antibodies indirectly.
c. FOMITE CONTROL: Reoviruses are highly resistant to environmental factors and disinfectants, making thorough cleaning and management of fomites crucial.
d. Good sanitation
e. Avoid introducing infected birds

TREATMENT
For every viral infecion, there is no specific antiviral treatment. The only management practices are as follows;
i. Supportive care (clean water, quality feed, vitamins)
ii. Reduce stress and overcrowding
iii. Use antibiotics only to prevent secondary bacterial infections

STAPHYLOCOCCOSIS

Staphylococcosis in poultry is a bacterial infection caused by Staphylococcus aureus. It is common in poultry, especially when there is injury, poor hygiene, or overcrowding.
It enters through damaged skin or mucous membranes. It can cause localized lesions like bumblefoot (swollen feet), arthritis, tenosynovitis (tendon sheath inflammation), and osteomyelitis (bone infection), or systemic disease leading to septicemia.

PREDISPOSING FACTORS THAT CAUSES REOVIRUS
i. Poor litter management (wet litter).
ii. Environmental stress and trauma.
iii. Nutritional deficiencies (e.g., biotin).
iv. Immunosuppressive diseases.

DIAGNOSIS:
This is confirmed by isolating coagulase-positive Staphylococcus species, which appear as white to orange colonies on blood agar.

CAUSES AND TRANSMISSION
Staphylococcus spp. (especially S. aureus) is a bacteria commonly found in the environment and is normal skin flora. It gains entry into the body of the birds through tissues invasion. Such tissues invasions include; wounds, cuts, pecking injuries and scratches. Also, through footpad lesions or dirty litter and poor handling or equipment injuries. These injuries can be caused from wet litter, ammonia burns, or interventions like beak trimming. Also included are compromised skin and mucous membranes, through contaminated eggs or hatcheries. And also, when the immune system of the birds are weak.
Once inside the wound, it spreads quickly, especially in stressed or weak birds.

SYMPTOMS
Symptoms of reovirus vary depending on the affected areas. General symptoms such as lameness, swollen joints, ruffled feathers, and sudden death in severe cases can be noticed.
Other symptoms include:
a. LOCALIZED LESIONS:
Bumblefoot: Swollen, infected footpads.
b. ARTHRITIS/TENOSYNOVITIS: Lameness, swollen joints (especially hocks and stifles), and difficulty moving.
c. OSTEOMYELITIS: Bone lesions in the limbs.
d. BREAST BLISTERS: Fluid-filled swellings on the breast.
e. SYSTEMIC INFECTION (SEPTICEMIA):
Listlessness and poor appetite.
Congestion of organs like the liver, spleen, and kidneys. And also can lead to sudden death in severe cases.
Other Signs include :
Ruffled feathers, drooping wings, drop in egg production in layers, skin abscesses, swollen wattles or comb and sudden death in severe cases (septicemia)

TREATMENT AND CONTROL
i. Primarily involves good farm biosecurity and management to prevent entry points.
ii. Maintaining clean and dry litter.
iii. Preventing wounds and managing ammonia levels.
iv. Promptly treating or culling affected birds due to the low cure rate and potential for spread.
v. Avoid sharp objects and overcrowding in pen.
vii. Regularly check birds for wounds or injuries .
viii. Supplement with vitamins and immune boosters
Treatments given to infected birds include:
ix. Use antibiotics (like amoxicillin, tylosin) but only after veterinary recommendation or sensitivity testing
x. Clean and disinfect wounds
xi. Apply topical antiseptics for skin infections
xii. Isolate affected birds to prevent spread

HEMORRHAGIC OVARIAN FOLLICLES

Hemorrhagic ovarian follicles in poultry refer to atretic follicles ( that is, follicles undergoing degeneration). This disease show signs of bleeding spots on the ovary surface due to the follicular membrane rupturing and causing hemorrhages. This condition can be caused by viral infections, stress, age, and endocrine imbalances, and it results in a decline in egg production.

CAUSES OF HEMORRHAGIC OVARIAN FOLLICLES
Hemorrhagic ovarian follicles occur when the blood vessels in developing ovarian follicles rupture, leading to internal bleeding. This is often linked to factors like; high egg production, nutritional imbalances (especially Vitamin E or selenium deficiency) and trauma.
Other factors that result to this disease in poultry include;
a. VIRAL INFECTIONS:
Infections like the Turkey Meco virus (TMUV) can cause severe lesions, including hemorrhage of follicular membranes and deformation.
b. STRESS:
Environmental stresses can lead to follicular atresia, which can manifest as hemorrhage.
c. AGE:
As hens age, particularly in low-yield laying hens, there is an increase in the number of atretic follicles.
d. ENDOCRINE IMBALANCE:
Dysregulation of hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH) can disrupt follicular development and maturation, contributing to atresia.
e. OOPHORITIS:
Inflammation of the ovary (oophoritis) can lead to ovarian regression and the leakage of free yolk, a condition associated with follicular dysfunction.

DIAGNOSIS
This condition is often fatal and is usually only diagnosed after death. It typically involves examining the ovary for bleeding and deformation of follicles. Such diagnosis could be carried out through:
i. VETERINARY EXAMINATION:
A veterinarian will conduct a gross examination of the ovary to look for signs of hemorrhage and follicular damage.
ii. HISTOPATHOLOGY:
Microscopic examination of the follicle tissue can reveal the cellular changes characteristic of atresia, such as loose cell layers and disorganized follicle walls.

SYMPTOMS.
Some of the symptoms of this disease include;
i. GROSS APPEARANCE:
Follicles appear deformed, with bleeding spots on their surface, and in advanced stages, may appear collapsed.
ii. REDUCED EGG PRODUCTION:
A significant number of atretic follicles can lead to a decrease in overall egg production.
iii. YOLK PERITONITIS:
If the follicular membrane ruptures, free yolk can leak into the abdominal cavity, leading to a serious condition called yolk peritonitis.
iv. Pale comb and wattles
v. Weakness or sudden death
vi. Distended abdomen (due to internal bleeding)
vii. Yellowish or bloody fluid in the abdominal cavity on post-mortem

TREATMENT AND PREVENTION.

The treatment focuses on addressing the underlying cause listed above by identification and managment. Such treatment include;
i. Maintain balanced nutrition (especially antioxidants)
ii. Avoid overstimulation of egg production
iii. Reduce stress and manage lighting properly
iv. Treating a viral infection or reducing environmental stress.
v. SUPPORTIVE CARE:
In cases of oophoritis, supportive care may be needed to manage the severe stress associated with the condition.
vi. GENETIC SELECTION:
In commercial poultry, focusing on genetic lines known for higher egg-laying rates can help reduce the incidence of atretic follicles.

Mycoplasma iowae

Mycoplasma iowae is a bacterial infection that affects mainly breeder poultry birds and their offspring. It damages internal organs and causes deformities, especially in embryos and chicks. It mostly spreads through eggs (vertical transmission) but can also pass between birds (That is, it usually spread from parent to chick through eggs or through contact in hatcheries or between infected flocks).

SYMPTOMS IN POULTRY
Mycoplasma iowae is not as common as Mycoplasma gallisepticum, but it can cause serious economic loss, especially in hatcheries.
It shows symptoms such as twisted necks (Torticollis), rough feathers, walking difficulty, swollen sinuses, poor feather development and reduced hatchability and embryo deaths.

PREVENTION AND CONTROL
i. Use Mycoplasma-free breeder stock
ii. Practice strict biosecurity
iii. Disinfect hatcheries and equipment regularly
iv.Monitor breeder flocks with blood tests
v. No effective treatment prevention is the best strategy

EGG DROP SYNDROME (EDS) IN POULTRY BIRDS

Egg Drop Syndrome (EDS) is a viral disease that affects all poultry birds, layers, breeders, and sometimes broilers kept to older ages. It is caused by an avian adenovirus, specifically Duck Adenovirus-1 (DAdv-1). The virus naturally circulates in domestic and wild ducks and geese, which act as asymptomatic carriers. It is characterized by a reduction in egg production and the laying of poor-quality, thin-shelled, soft-shelled, or shell-less eggs.It is one of the major causes of sudden fall in egg production and poor egg quality in layer fowl, leading to serious economic losses. EDS is a significant economic concern for the poultry industry due to reduced egg output.

NATURAL CARRIERS: The natural hosts are ducks and geese, which can be latently infected without showing symptoms but can transmit the virus to fowl.

TRANSMISSION

The viral transmission can be vertical or horizontally transmitted.

i. VERTICAL TRANSMISSION: The virus can spread from infected parents to offspring through the embryonated egg.

ii. HORIZONTAL TRANSMISSION: It spreads horizontally through contaminated water, feces, and by mechanical means, such as through contaminated equipment (e.g., egg trays) and contact with wild birds.

CLINICAL SIGNS

i. EGG PRODUCTION DECLINE: A sudden drop in the number of eggs laid or failure to reach the expected peak production is a primary indicator.

ii. EGG QUALITY ISSUES: The most prominent sign is the production of defective eggs, which are pale, thin-shelled, soft-shelled, or lack a shell entirely.

iii. OTHER SIGNS: Diarrhea, dullness, and a temporary loss of eggshell color can also occur.

DIAGNOSIS

This disease can be diagnosed by:

i. LABORATORY TESTS: Serological tests, such as the HA (Hemagglutination) and ELISA (Enzyme-Linked Immunosorbent Assay), are used to detect antibodies against the EDS virus in the blood of affected birds.

ii. VIRUS ISOLATION: The presence of the Haemagglutination virus can be confirmed by isolating and identifying it from affected chickens or infected embryonated duck eggs.

EFFECT OF NON ADMINISTRATION OF THE 3-in-1 VACCINE (EDS, ND, IB) TO BIRDS

This is a major preventive measure before infection can take place. I helps boost the bird immune system against the disease. The 3-in-1 vaccine protects birds against:

a. EDS (EGG DROP SYNDROME) : Sudden drop in egg production, soft-shelled or shell-less eggs.

b. NEWCASTLE DISEASE (ND) : a deadly viral disease that causes coughing, greenish diarrhea, twisted necks, paralysis, and high mortality.

c. INFECTIOUS BRONCHITIS (IB): a viral infection that damages the respiratory system and egg production, causing watery whites and misshapen eggs.

Without this vaccine, poultry birds are exposed to:

i. Sudden drop in egg production (up to 40–50%)

ii. Poor shell quality and weak eggs

iii. High mortality during ND outbreaks

iv. Respiratory stress, reduced feed intake, and stunted growth (especially in broilers)

v. Long-term production losses that cannot be recovered

PREVENTION

Prevention is Better than Cure. There is no treatment for EDS, prevention through biosecurity measures, such as excluding waterfowl and proper hygiene, and vaccination programs can be effective.

i. VACCINATION: Vaccinate layers and breeders at 14–18 weeks with the 3-in-1 vaccine before they start laying.

ii. MAINTAIN STRICT BIOSECURITY: clean water, disinfect equipment, and keep wild birds away.

iii. Provide good nutrition with calcium, vitamins, and balanced feed.

iv. FLOCK MANAGEMENT:Proper management practices, such as avoiding mixed rearing of fowl with ducks and geese, can help control the disease.

ECONOMIC IMPACT

i. PRODUCTION LOSS: The significant reduction in egg production directly impacts the profitability of egg production.

ii. EGG LOSS: The production of shell-less or soft-shelled eggs leads to a loss of usable eggs.

STEPS TO TAKE WHEN A DISEASE IS NOTICED ON THE FARM OR TO REDUCE IT

To prevent a disease from spreading from one bird to more birds—both within your flock and to other flocks in other farms, take the following precautions:

1. Separate the sick bird(s) from the rest of the flock and isolate them

2. Reduce the number of visitors that visit the farm and if visitors visit, they should adhere to the farm biosecurity precautions
3. Wash and disinfect all equipment that come into contact with your flock or property

4. Disinfect your clothing and footwear after contact with the sick bird(s) or its environment;

5. Contact your veterinarian.
When a bird shows signs of being ill, symptoms alone may not be enough to diagnose a particular disease, since some diseases share similar symptoms. You should ask your local veterinarian to diagnose all unidentified illnesses. If you do not have a veterinarian, contact your county extension office

Note: Prevention is better than cure. Diseases can wipe off a whole flock within a day. Let’s make sure our birds are taken care of.