Even the birds with the best genetic potential and housing will not grow and produce efficiently if they are affected by disease or are infected by parasites.
Diseases are caused by nutrient deficiencies eg vitamins and minerals, consumption of toxic substances eg poisons, physical injury due to environmental extremes like birds getting burnt by heat sources, and internal and external parasites. The common external parasites are lice while liver flukes are common internal parasites.
Infectious diseases
Infectious diseases are caused by bacteria, viruses, plasmodia, fungi and protozoa. Antibiotics and other medicines do not cure viral diseases but can be used to cure secondary infection caused by virus. The best way to manage viral diseases is good hygiene, quarantine and vaccination.
There are several antibiotics effective against bacterial diseases however quarantine and good hygiene are important practices in defence against bacterial diseases.
Mycoplasmas mainly cause mycoplasmosis or Chronic Respiratory Disease. These respond to some antibiotics. Quarantine and good hygiene provide good control.
Fungi affects birds when they have been exposed to feed on which fungal spores grew due to exposure of the feed to moisture.
Disease prevention
Disease prevention is by quarantine, proper hygiene, timely vaccination, preventative medication programmes (prophylaxis) and regular monitoring.
Factors that affect susceptibility of a bird to disease include genetic resistance, initial health state of the bird, spacing, stress and immunity of the bird.
Disease infections can be clinical or sub clinical with clinical infections showing signs of disease and sub clinical infections not showing signs of the disease.
