Avian Influenza Treatment
Avian Influenza Treatment is very difficult task ever in the field industry. But, all types of Avian Influenza are controllable except H5 type strain. Avian Influenza is an infectious disease, which is caused by influenza type A virus. The virus causes clinical symptoms that range from mild or even asymptomatic to an acute, fatal form. Avian Influenza treatment based on the following observation.
Avian Influenza Definition
According to Diseases of poultry books Avian influenza” is a broad term used to explain any infection or disease in birds caused by Type A influenza viruses. Some specific drugs are using to treat avian influenza type a virus
In other words, it also called “Bird Flu” or “Fowl Plaque”. Treatment of this disease totally depends on the type of infection and geographic location, which takes a strict control mechanism, which we can not elucidate in this topic.
Avian Influenza Types
There is a two-type infection, which is caused by the Avian Influenza virus in the poultry population.
The World Organization for Animal Health (Office International des Epizooties [OIE]) uses the designation of the virus as a notifiable Avian Influenza (HNAI). In which HP notifiable AI means HPNAI and LP notifiable AIdenotes LPNAI for international animal health regulatory purposes.
HPNAI encompasses all HPAI (High Pathogenic Avian Influenza [ H5N1] ). whereas LPNAI encompasses only H5 and H7 LPAI (Low Pathogenic Avian Influenza). This subtypes that have been shown to convert from LP to HP viruses naturally in poultry
Therefore, we are appending the treatment separately-
High Pathogenic Avian Influenza ( H5N1)
With the HPAI viruses, morbidity and mortality rates are very high (50%–89%) and can reach 100% in some flocks. Typically, the virus spreads rapidly among poultry housed on the floor with peak mortality (70%–100%) occurring in three to five days of first clinical signs. but in poultry housed in cages, the virus spreads slower through the house with peak mortality taking 10–15 days
Maximum Cases. peracute death is found. But un some cases, It may appear in live affected birds. That can be diagnosed by the naked eye without lab diagnosis.
Per acute death means, you can see the birds having normal feeding and watering, but sudden death of sound birds.In severe outbreak, you can observed that at least 30 birds became die per hour.Ramzan, DVM, poultry veterinarian
HPAI, External clinical symptoms are basically differentiated by the two ways
- Comb color
It is causing multifocal necrosis and hemorrhage of comb and wattles. but the starting point from the lower to the upper side of the comb and wattle fully bluish in color. HPAI virus is present in the plasma and red and white blood cell fractions and causing severe oxygen insufficiency thereby increase carbon dioxide causing cyanosis in comb and wattle.
In case of, Severe edema of comb and wattles with accompanying periorbital edema and necrosis of epidermis at the base of the comb.
2. Feces color
In a sudden death condition, milky white diarrhea is seen due to extensive viral replication into the intestinal tract especially Peyer’s patches.
there are several types of drugs, which are available for treating HPAI infection, but there are lots of limitations in the case of birds. these are-
a) Amantadine Hydrochloride:
the exact mode of action is still clearly unknown. but it is generally hampering the producing of viral nucleic acid into the host by obstructing the operation of the transmembrane domain of the viral M2 protein.
It has been registered for use in humans treating Influenza type A virus since 1966. But, it is just reducing the severity of the infection of Influenza type A virus, while never cure the disease completely.
in the labrotory examination, the drug was found to reduce losses in poultry. but initial benefit was negated by emergences of drug resistancevirus, hence it is not advised for the treating in poultry.
the writer has tried this drug during the outbreak of HPAI in the broiler. where was mortality reached 50 birds/hours, @ 5mg/kg body weight in 48 hours drinking water?
but, unfortunately, the case was never cured ultimately culled the flocks. But, the finding is initially carried out due to severe virulency of Avian influenza virus assuage develope resistance in this drug.
It is the broad spectrum anti-influenzal drug, that effective in all types of Neuraminidase (NA) protein a viral surface enzyme.
which is responsible for the replication and deactivate of influenza viruses A and B, by preventing the release of viruses from infected host cells. but the application of this drug is documented yet the poultry.
Prophylaxis treatment of Avian Influenza infection in poultry is being treated by Oseltamivir successfully result-oriented in the field @1mg/kg body weight.
In the year 2018. HPAI was breaking out throughout Bangladesh. but this drug practically applies in some egg-laying farms, fortunately, the symptoms were totally denied, where to apply this drug prophylactically.
But, In the case of the egg layer hen, when birds are affected, & showing hemorrhagic egg peritonitis caused by HPAI. There is no treatment is successful, So it is a wise decision to culled the birds immediately.
Low Pathogenic Avian Influenza (LPAI)
It is less devastating compared to mortality between HPAI. It is being effectively controlled without the application of Anti-Influenzeal drugs in the field.
The success of the treatment depends on the complication of the clinical sign, postmortem findings,& diagnosis of disease. If you unaware, please visit the links:
It is required at least two weeks to fully recover to its previous state, and birds became off feed at least one week at the final stage.
But in this period, severe viral replication occurred especially in the egg-follicle, which is why drop off egg production for a long time due to the destruction of egg follicle or inability to produce ovum in the reproductive tract in the poultry.
For Broiler Birds
The common clinical symptoms are coughing, gurgle, coughing with jerking head with normal watering and feeding but no mortality. It is also easily diagnosed without s\lab support by the application of antimycoplasma drugs. If the coughing not subsides, it is 100% sure that it is LPAI and it takes another one week to recover it. So, don’t worry about your coughing problem.
Some poultry consultant suggests disinfectant with paracetamol in drinking water but avoids antibiotics due to resistance by the virus at least seven days in case of the broiler.
For Laying Hen
In the case of the egg layer, the birds are placed in the cage. Sometimes it is affected by the mycoplasma gallisepticum with other gram-negative bacteria. In this case.
drugs for mycoplasma and other broad-spectrum antibiotic continue for several weeks. (How to apply these drugs click here) Treatment continues as per broiler but floor rearing system iodine-based disinfectants with antimycoplasmal drugs successful.
Md. Ramzan Ali, DVM, Poultry veterinarian
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