Bacterial Poultry Diseases

rhod tecsonRaising native chicken is fun although when grown on a commercial scale a system and science is needed just like in any endeavors. Commercial-scale native chicken production needs ample time and enough capital.

The idea though is to start with a backyard set-up where an interested farmer can fully observe and understand the dynamics of the native chicken cycle and of course observe the behavior of the birds so that when the needed capital for a fully-commercialized production is made available, the farmer is already equipped of the basic knowledge as to the ways and means and the complexities of the chicken production.

In the past two issues, this page has already discussed the general overview of raising native chicken and the viral poultry diseases that may affect the birds and the ways to prevent  and cure the said infections. It is important to note that a single-contaminated chick can wipe out the whole group of birds around the area when not treated properly.

In this issue, we are publishing the Darag Bulletin No. 9*2010 of the University Research and Development Center of West Visayas State University created and compiled by George Fredrick A. Rojas.

This is about the bacterial poultry diseases which may affect the chickens in your place of farm.

Infectious Coryza

It is an acute respiratory disease of chickens characterized by nasal discharge, sneezing and swelling of the face under the eyes.

The causative bacterium, Haemophilus paragallinarum (gallinarum), does not live long outside the host body. The Hemophilus organism requires special nutrients for growth.

Transmission

Chronically ill or healthy carrier birds are the reservoir of infection. Chickens of all ages are susceptible, but susceptibility increases with age. Transmission is by direct contact, airborne droplets, and contamination of drinking water.

Signs

  1. Thin watery discharge from nostrils soon becomes thick and sticky, with an offensive odor, and has a tendency to dry up into a yellowish crusts around the nasal openings.
  2. As the inflammation extends, the adjacent sinuses become filled with mucus which gradually turns into dry cheesy form. As the dry cheesy form mucus accumulates in large quantities, bulging around the eye ocular roup becomes more prominent.
  3. Affected fowls sit quitely with feathers ruffled, have little or no appetite, shake their heads frequently in an effort to dislodge the mucus.

Prevention and Control

Prevention is the only sound method of control. “all-in/all-out” farm programs with sound management and isolation methods are the best way to avoid the disease.

Because early treatment is important, water medication is recommended immediately until medicated feed is available. Erythromycin and oxytetracycline are usually beneficial. Several antibiotics (fluoroquinolones, macrolides) are active against infectious choryza.

FOWL CHOLERA

Fowl cholera is a contagious, widely distributed disease that affects domestic and wild birds.  It usually occurs as a septicemia of sudden onset with high morbidity and mortality, but chronic and asymptomatics infections also occur.

Pasteurella multocida, the causal agent, is a small, gram-negative, non-motile rod that may exhibit pleomorphism after repeated subculture. The organism survives several months in soil, liiter as decayed matters, but is killed by disinfectants.

Transmission

Chronically infected birds are considered to be a major source of infection. Dissemination of P multocida within a flock is primarily by excretions from mouth, nose and conjunctiva of diseased birds which contaminate their environment.

Signs

  1. Fever, anorexia, mucous discharge from the mouth
  2. Diarrhea, dehydration
  3. Cynosis of combs and increased respiratory rates
  4. Edema of comb, wattles, sinusitis and arthritis in chronic form

Prevention and Control

This is a stress-related disease. Good management practices are essential to prevention. Rodents, which are often carriers of P multocida, must be excluded from poultry houses.

Sulfanomides and antibiotics are commonly used; early treatment and adequate dosages are important. Other antibiotics like streptomycin, oxytetracycline and chlortetracycline are effective parentally.

AVIAN MYCOPLASMOSIS

An infectious and contagious disease of poultry characterized by respiratory rales, coughing and nasal discharge.  The clinical manifestations are slow to develop and the disease has a long course.

M gallisepticum infection is commonly designated as chronic respiratory disease in chickens.  It is the most pathogenic avian mycoplasma.

Mycoplasma infection probably lies dormant until a stress factor – sudden change in environment, vaccination reaction, for example — triggers an outbreak of the disease.

Transmission:

  1. It is primarily transmitted through eggs.
  2. Spread by air-borne dust or droplets and contact.
  3. Outbreak of the disease is often started by carriers.

Signs:

  1. Persistent cough, tracheal rales, sneeze and gasp.
  2. Nasal discharge with no odor, foamy exudates in eyes and swollen periorbital sinuses.
  3. Feed counsumption is reduced, retarted growth and flock uneven in sizes.
  4. Egg production declines .
  5. Mortalilty is variable, depending on environmental climate condition and the type of secondary infection.

Prevention/control

Most strains of M gallisepticum are sensitive to a number of antibiotics, such as chlortetracycline, erythromycin, oxytetracycline, spectinomycin, tiamulin, tylosin, or a fluoroquinolone such as enrofloxacin.  Antibiotic is usually given in the feed or water for 5-7 days.

Medication is not a good long-term control method but is of value in treating individually infected flock.

PULLORUM DISEASE

Primarily an acute disease of chicks during the first month of life, characterized by high mortality.  It is often found in mature fowl as a chronic infection.  It is also known as Bacillary White Diarrhea.

Infections with Salmonella pullorum usually cause very high mortality (potentially approaching 100%) in young chickens.  In adult chickens mortality may be high, but frequently there are no clinical signs.

Transimission:

Transmission is primarily through the egg but also occurs via direct or indirect contact with infected birds.  Infection transmitted via egg or hatchery contamination usually results in death during the first few days of life up to 2-3 weeks of age.

 Signs:

  1. Chicks: weakness, poor growth, an inclination to huddle together, chalky white diarrhea and death.  Mortality peaks during the second or third week of life.
  2. Adults: drop in egg production feed condumption decreased fertility and hatchability, diarrhea, depression and dehydration.

Prevention/Control:

Treatment of infected flocks to alleviate the perpetuation of the carrier state is not recommended.  Control is based on routine serologic testing of breeding stock to assure freedom from infection.

Antibiotic treatment may reduce the mortality but does not prevent the birds from becoming carriers.  Strict sanitary measures are to be adopted in the face of outbreak.