Content
- What is Gumboro Disease?
- Which virus causes Gumboro disease in birds?
- Pathogenesis of Gumboro Disease
- Symptoms of Gumboro Disease in Birds
- Diagnosis of Gumboro disease in birds
- Treatment for Gumboro Disease in Birds
Gumboro disease is a viral infection which 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 fabricius bursa of birds, causing immunosuppression by affecting the production of cells of the immune system. In addition, type III hypersensitivity processes occur with damage to the kidneys or small arteries.
Keep reading this PeritoAnimal article to find out exactly what the Gumboro disease in birds - symptoms and treatment.
What is Gumboro Disease?
Gumboro disease is a infectious and contagious bird disease, which clinically affects chicks 3 to 6 weeks of age, although it can also affect turkeys and ducks. It is mainly characterized by atrophy and necrosis of the bursa of Fabricius (a primary lymphoid organ in birds, which is responsible for the production of B lymphocytes), causing immunosuppression in these birds.
It is a disease of great health and economic importance, which affects poultry farming. It presents high mortality rate and is capable of infecting between 50% and 90% of birds. Due to its great immunosuppressive action, it favors secondary infections and compromises the vaccination already carried out.
O Contagion it occurs through contact with feces from infected chickens or by water, fomites (worms) and food contaminated by them.
Which virus causes Gumboro disease in birds?
Gumboro disease is caused by Avian infectious bursitis virus (IBD), belonging to the Birnaviridae family and the Avibirnavirus genus. It is a very resistant virus in the environment, temperature, pH between 2 and 12 and 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 strains.
- Light field strains and vaccines.
- Antigenic variants.
- Hypervirulent strains.
Pathogenesis of Gumboro Disease
The virus enters orally, reaches the intestine, where it replicates in macrophages and T lymphocytes in the intestinal mucosa. THE first viremia (virus in blood) starts 12 hours after infection. It passes to the liver, where it replicates in hepatic macrophages and immature B lymphocytes in the bursa of Fabricius.
After the previous process, the second viremia occurs and then the virus replicates in Organs lymphoid organs of the bursa of Fabricius, thymus, spleen, harder glands of the eyes and cecal tonsils. This leads to the destruction of lymphoid cells, which causes a deficiency in the immune system. In addition, there is a type 3 hypersensitivity with deposition of immune complexes in the kidneys and small arteries, causing nephromegaly and microthrombi, hemorrhages and edema, respectively.
Perhaps you might be interested to test another article on ringworm in birds.
Symptoms of Gumboro Disease in Birds
Two forms of the disease can occur in birds: subclinical and clinical. Depending on the presentation, symptoms of Gumboro disease may vary:
Subclinical form of Gumboro disease
The subclinical form occurs in chicks under 3 weeks old with low maternal immunity. In these birds, there is a low conversion rate and average daily weight gain, that is, as they are weaker, they need to eat more, and even so they do not gain weight. Likewise, there is an increase in water consumption, immunosuppression and mild diarrhea.
Clinical form of Gumboro disease in birds
This form appears in birds between 3 and 6 weeks, being characterized by presenting the following symptoms:
- Fever.
- Depression.
- Feathers ruffled.
- Itch.
- Prolapsed cloaca.
- Dehydration.
- Minor hemorrhages in the musculature.
- Dilation of ureters.
In addition, there is an increase in the size of the bursa of Fabricius in the first 4 days, subsequent congestion and hemorrhage within 4 to 7 days, and finally, it decreases in size due to lymphoid atrophy and depletion, causing the immunosuppression that characterizes the disease.
Diagnosis of Gumboro disease in birds
The clinical diagnosis will make us suspect Gumboro disease or infectious bursitis, with symptoms similar to those indicated in chicks from 3 to 6 weeks of age. It is necessary to make a differential diagnosis with the following bird diseases:
- Avian infectious anemia.
- Marek's Disease.
- Lymphoid leukosis.
- Bird flu.
- Newcastle disease.
- Avian infectious bronchitis.
- Avian coccidiosis.
The diagnosis will be made after collecting the samples and sending them to the laboratory for direct laboratory tests for the virus and indirect for antibodies. You direct exams include:
- Viral isolation.
- Immunohistochemistry.
- Antigen capture ELISA.
- RT-PCR.
You indirect exams consist of:
- AGP.
- Viral serum neutralization.
- Indirect ELISA.
Treatment for Gumboro Disease in Birds
Treatment of infectious bursitis is limited. Due to kidney damage, many drugs are contraindicated for its renal side effects. Therefore, it is currently no longer possible to use antibiotics for secondary infections in a preventive manner.
For all this, there is no treatment for Gumboro disease in birds and disease control should be done through Preventive measures and biosafety:
- Vaccination with live vaccines in growing animals 3 days before maternal immunity is lost, before these antibodies drop below 200; or inactivated vaccines in breeders and laying hens to increase maternal immunity for future chicks. So there is a vaccine against Gumboro disease, not to fight it once the chick has been infected, but to prevent it from developing.
- Cleaning and disinfection from the farm or house.
- Farm access control.
- insect control that can transmit the virus in feed and bedding.
- Prevention of other debilitating diseases (infectious anemia, marek, nutritional deficiencies, stress...)
- Measure all in, all out (all-in-all-out), which consists of separating the chicks from different places in 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 exposure to field virus.
Now that you know all about Gumboro disease, be sure to read this other article with 29 types of chickens and their sizes.
This article is for information purposes only, at PeritoAnimal.com.br we are not able to prescribe veterinary treatments or perform any type of diagnosis. We suggest that you take your pet to the veterinarian in case it has any type of condition or discomfort.
If you want to read more articles similar to Gumboro Disease in Birds - Symptoms and Treatment, we recommend that you enter our section on Viral diseases.