- Sick birds show changes in their physical condition that can be detected by careful observation.
- Regularly observing the flock, ideally twice a day (once in the morning and once in the evening) is essential.
Image: AGATHA NGOTHO
Dr Nicholas Muyale, a poultry expert, says maintaining flock health is crucial for success.
He warns that if even one or a few birds are sick and the illness is not identified early, there is a risk of the disease spreading throughout the flock.
This is especially if the cause is microorganisms or disease-causing germs.
“Therefore, poultry farmers need to be able to differentiate sick birds from healthy ones. Mastering this skill allows for early diagnosis, enabling timely prevention and control measures, which can help reduce economic losses,” he says.
Disease, meaning "not at ease," refers to a deviation from normal bodily function.
Sick birds show changes in their physical condition that can be detected by careful observation.
Regularly observing the flock, ideally twice a day (once in the morning and once in the evening) is essential.
During these observations, Muyale advises that the inspecting officer should wear clean, disinfected clothing designed for the purpose.
It’s a good practice to use disinfectant sprays and to disinfect footwear by dipping it in disinfectant solution (like water mixed with Dettol, phenyl, or Savlon) before entering the poultry house.
Additionally, carrying gloves, a mask, a cap, sterile vials, disposable syringes, a catching hook and specimen bottles.
Others are polythene bags and slides for collecting materials for further examination.
The interior of the poultry house should not be uncomfortable, with no excessive heat or eye irritation.
Observing the flock without causing disturbance is crucial. Look for signs such as birds seeking corners, appearing dull, sleeping while standing, or exhibiting abnormal postures.
A gentle clap or whistle can help assess their alertness; in a healthy flock, birds will respond promptly, especially at feeding time.
Droppings should be monitored for abnormal colours, such as black, chalky white, green, red, or yellowish white, which can indicate various disease conditions.
The consistency of the droppings also provides clues; loose or dry droppings suggest an unhealthy state.
Posture is another important indicator. Look for abnormal postures, such as backward movements, lameness, or a twisted neck, which may signal a disease issue.
Pay attention to any abnormal sounds like gurgling or high-pitched chirping, as these can indicate poor health.
Abnormal behaviours, such as cannibalism or pecking, should also be noted. If any dead birds are found, they should be collected in a polythene cover for post-mortem examination.
The positioning and condition of feeders and drinkers are also important. Check for spillage and wet litter and assess the space allocation for feeders and drinkers.
Record any other unusual observations, such as dry drinkers, eggs on the litter, or eggshells on the litter.
For individual examination, sick birds should be handled gently, usually by hand, as they do not move as quickly as healthy ones.
If necessary, use a catching hook. For heavier birds, catching by the wings is recommended.
Once restrained by holding both wings at the base, inspect the bird for abnormalities.
Sick birds may show a range of symptoms, including a weak, long, narrow, or swollen head, and reduced or shrunken eyes with watery, sticky, or bloody discharge.
The comb and wattles may appear dry, bluish, swollen, or show growths like nodules. Abnormalities in the beak, such as bending or twisting, and discharge around the nose or mouth are also signs.
Feathers may be rough, raised and dry, and there might be feather loss or non-healing wounds.
Skin abnormalities, such as rough patches or growths and indications of bleeding below the skin should also be noted.
Other signs include paralysis, twisted feathers, drooping, and uneven feather arrangements.
Legs may appear twisted or swollen and the bird might have difficulty walking or show curled toes.
Diseases in poultry can be transmitted directly or indirectly.
Indirect causes include conditions that stress the birds and lower their resistance to disease, such as improper temperature, overcrowding, inadequate feed, or over-medication.
Direct causes include bacteria, viruses, parasites, fungi, nutritional deficiencies, chemical poisons and over-medication.
Muyale says sometimes, the exact cause of a disease may be unknown. Infectious diseases are caused by living organisms like bacteria, viruses, or fungi.
Contagious diseases spread readily from one host to another. Not all infectious diseases are contagious, but all contagious diseases are infectious.
Diseases can spread through several routes, including the introduction of diseased or carrier birds into a flock, contact with contaminated inanimate objects or improperly disposed carcasses, and exposure to contaminated water, pests, or equipment.
Other sources of transmission include contaminated feed, litter, airborne agents, or eggs.
Common poultry diseases include bacterial infections such as fowl cholera, salmonellosis, and colibacillosis; viral infections like avian pox, Newcastle disease, and avian influenza.
Others are fungal infections like aspergillosis; and parasitic diseases such as coccidiosis and worms (roundworms, gapeworms).
External parasites include lice, mites, and ticks, while nutritional and metabolic diseases include rickets, osteomalacia and vitamin deficiencies.
To manage poultry disease outbreaks effectively, Muyale advises farmers to implement a robust vaccination programme and strict biosecurity measures to prevent disease entry and spread.
Regular monitoring for signs of illness is essential for early detection and prompt action.
Sick birds should be isolated from healthy ones. New birds should be quarantined before introduction to the flock.
Diagnostic testing should be conducted to identify specific diseases, and treatment should be administered under veterinary guidance.
Thorough cleaning and disinfection of the farm, equipment and facilities are crucial.
Staying informed about local disease outbreaks and collaborating with other farmers and veterinary professionals is equally important.
Early intervention and proactive measures are key during disease outbreaks.
Consulting with a veterinarian for personalised advice is highly recommended.