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Gumboro disease is a Viral infection that mainly affects chicks between the first 3 and 6 weeks of life. It can also affect other birds such as ducks and turkeys, which is why it is one of the most common diseases in poultry. The disease is characterized by affecting the lymphoid organs, especially the bursa of Fabricio in birds, causing immunosuppression by affecting the production of immune cells. In addition, type III hypersensitivity processes occur with damage to kidneys or small arteries..
Keep reading this AnimalWised article to know exactly what is Gumboro disease in birds, your symptoms and treatment.You may also be interested in: Marek's disease in birds - Symptoms, diagnosis and treatment Index
- What is Gumboro disease?
- What virus causes Gumboro disease in birds?
- Symptoms of Gumboro disease in birds
- Diagnosis of Gumboro disease in birds
- Treatment for Gumboro disease in birds
What is Gumboro disease?
Gumboro disease is a infectious and contagious disease of birds, It clinically affects 3-6 week old chicks, although it can also affect turkeys and ducks. It is mainly characterized by the atrophy and necrosis of the Fabricio bursa (a primary lymphoid organ in birds that is responsible for producing B lymphocytes), which causes immunosuppression in these birds..
It is a disease of great health and economic importance that affects poultry. It presents a high morbidity, infecting between 50 and 90% of the birds. Due to its great immunosuppressive action, it favors secondary infections and compromises vaccination.
The contagion is carried out by contact with the feces of infected chickens or by water, fomites and food contaminated by them.
What virus causes Gumboro disease in birds?
Gumboro disease is caused by avian infectious bursal disease virus, belonging to the Birnaviridae family and the Avibirnavirus genus. It is a virus that is very resistant in the environment, to temperature, to a pH between 2 and 12 and to disinfectants..
It is an RNA virus that has a pathogenic serotype, serotype I, and a non-pathogenic serotype, serotype II. Serotype I includes four pathotypes:
- Classic strain.
- Mild and Vaccine Field Strains.
- Antigenic variants.
- Hypervirulent strains.
Pathogenesis of Gumboro disease in birds
The virus enters orally, reaches the intestine where it replicates in macrophages and T lymphocytes in the intestinal mucosa. Then the first viremia (virus in blood) 12 hours after infection. It passes to the liver where it replicates in hepatic macrophages and immature B lymphocytes in the bursa of Fabricio.
After the above process, the second viremia to then replicate in the lymphoid organs of Fabricio's bursa, thymus, spleen, harder glands of the eye and cecal tonsils. This causes destruction of lymphoid cells, which causes a disability of the immune system. In addition, a type 3 hypersensitivity occurs with deposition of immune complexes in the kidneys and small arteries, causing nephromegaly and microthrombi, hemorrhages and edema, respectively..
Symptoms of Gumboro disease in birds
Two clinical forms of the disease can occur in birds: subclinical and clinical. Depending on the presentation, the symptoms of Gumboro disease can vary:
Subclinical form of Gumboro disease in birds
The subclinical form occurs in chicks less than 3 weeks old who have low maternal immunity. In these birds there is a low conversion rate and average daily gain, that is, as they are weaker, they need to eat more but, nevertheless, they do not gain more weight. Likewise, there is an increase in water consumption, immunosuppression and mild diarrhea..
Clinical form of Gumboro disease in birds
This form appears in chickens 3-6 weeks, characterized by showing the following symptoms:
- Ruffled feathers.
- Cloacal prolapse.
- Small hemorrhages in muscles.
- Dilation of ureters.
In addition, there is an increase in the size of Fabricio's pouch in the first 4 days, later congestion and hemorrhages occur from 4 to 7 days and finally it decreases in size due to lymphoid atrophy and depletion, causing the immunosuppression that characterizes the disease. disease.
Diagnosis of Gumboro disease in birds
The clinical diagnosis will make us suspect a Gumboro disease, or infectious bursal disease, with symptoms similar to those indicated in chicks 3 to 6 weeks of age, having to do a differential diagnosis with the following diseases of birds:
- Avian infectious anemia.
- Marek's disease.
- Lymphoid leukosis.
- Avian influenza.
- Newcastle disease.
- Avian infectious bronchitis.
- Avian coccidiosis.
The diagnosis will be made after the extraction of samples and their sending to the laboratory for direct laboratory tests in search of the virus and indirect in search of antibodies. The direct tests include:
- Virus isolation.
- Antigen capture ELISA.
The indirect evidence its about:
- Viral seroneutralization.
- Indirect ELISA.
Treatment for Gumboro disease in birds
Treatment for infectious bursal disease is limited. Due to damage to the kidneys, many drugs are contraindicated for its side effects on the kidney. Therefore, the use of preventive antibiotics for secondary infections can no longer be done today..
For all this, no treatment for Gumboro disease in birds and control of the disease should be done by preventive measures and biosafety, such as:
- Vaccination with live vaccines in growing animals 3 days before loss of maternal immunity, before those antibodies drop below 200; or inactivated in breeders and laying hens to increase maternal immunity for future chicks. Thus, there is a vaccine against Gumboro disease, but not to combat it once the chick has been infected, but to prevent it from developing..
- Cleaning and disinfection farm or home.
- Control of access to the farm.
- Insect control in feed and beds that can carry the virus.
- Prevention of other debilitating diseases (infectious anemia, marek, nutritional deficiencies, stress ...)
- Measure all in-all out, which consists of separating chicks from different places into different spaces. For example, if an animal sanctuary rescues chicks from different farms, it is preferable to keep them separate until they are all healthy..
- Serological monitoring to assess vaccine responses and field virus exposure.
This article is merely informative, at AnimalWised.com we do not have the power to prescribe veterinary treatments or make any type of diagnosis. We invite you to take your pet to the vet in the event that it presents any type of condition or discomfort.