Newcastle disease virus is a viral disease caused by Newcastle disease virus under the family of paramyxoviridae. It is considered as the most economical disease in poultry. Newcastle Disease causes huge mortality and production losses throughout the world. the article will discuss etiology, clinical signs, postmortem findings and treatment of Newcastle disease.
Newcastle disease may not be caused by a single virus but it caused by closely related group viruses that form Avian paramyxovirus type 1 (AMV-1). It’s also serologically related to another Avian Paramyxivirus type 3(AMV-3). AMV-3 characterized by nonsegmented, single-stranded RNA virus. Newcastle disease also is known as Ranikhet disease in the southern part of Asia.
It mainly affects the three-body systems of poultry. for instance, respiratory system, digestive and reproductive system of poultry. It divided into three categories
Per acute Types
There is no clinical sign. Birds became died without clinical signs. died birds showing feverish body with congested abdominal muscles
Cyanosis of comb & wattle is common clinical signs which result from severe viremia in chicken blood where carbon dioxide pretty higher than oxygen. deoxygenated area show cyanosis by Newcastle Disease in poultry.
The incubation of NDV required 6-7 days to develop clinical signs into the host. Urate layer with greenish feces started earlier but fully greenish color in later when viremia fully covered the body. Some literature suggests that gall bladder hyperplasia by Newcastle disease induce excessive secretion of to intestinal tract of poultry.
Respiratory difficulty & coughing with jerking head due to tracheal hemorrhage & mucus filled with trachea in Newcastle disease
Bilateral Swallen head when affecting cerebral palsy of head in the Newcastle Disease
Swallen infraorbital sinus due to conjunctivitis in Newcastle disease
increase egg breakage reduces the size & pale colors of eggs in Newcastle disease.
Pinpoint hemorrhage on Trachea are common in Acute type NDV
Severe hemorrhage in tips of Proventriculur gland in Newcastle Disease
Brush point hemorrhage in the intestine at Newcastle Disease
Hemorrhage in caecal tonsil in Newcastle Disease
Blood vessels highly congested & hemorrhage in eggs follicles in Newcastle Disease
White necrotic foci on Spleen Newcastle Disease
To treat NDV, several things should be considered as
Mortality: Varies from strain to strain. Like lentogenic types mortality reach to 40 %& vvNDv goes to 100%.
Egg production: Recovered flock never reaches previous production level due to virus shedding in the reproductive tract & destruction of ovarian follicles.
body weight: Birds can lose body weight within a week by NDV infection either it involved Gastro-Intestinal Tract & Reproductive tract.
Time: Infected flock can be recovered with two weeks if properly treat the flocks. It requires 11days to stop complete mortality.
Cost: Sometimes it’s can be expensive due to the mortality of birds & medicinal cost
This procedure protocols main two way
There is no specific treatment of NDV. Primary basic principles to treat infected flock of NDV to induced immunity of Al birds. The development of immunity depends on species to species. Laying chicken produces better immunity then broiler chickens due to muscle integrity in the field. Vaccination is required first of the induction of immunity during the outbreak.
Several strains are used in the field by poultry experts with their experience.
In early, consultant suggested lassota live vaccine by eye drop/water to neutrilize the disease strain at primary stage of NDv. live lassota produce severe respiratory distress during outbreak. This is proven now this time .Please avoid lassota after primary stage of NDV.
It’s better to used lassota killed vaccines to produce cell-mediated immunity. Cell-mediated immunity also depends on
Intracerebral pathogenicity index (ICPI) unit of the vaccine strain. Several two vaccine strain ulster & lassota killed have lower Intracerebral pathogenicity index (ICPI) value & produced greater immunity in a short period of time. That’s are fast to reach an immune site.
It’s possible to inject the vaccine at first-day infection which is to minimize mortality during the outbreak.
Newcastle Disease (NDv) not single organisms involved in this case but other organisms associated with a disease like
which caused several lesion like
swollen head syndrome etc.
So the application o antibiotics should be needed to prevent these infections & save the birds.
It should be avoided to give antibiotics in the oral route to reduce intake water & thus causes dehydration of birds & increased mortality.
1) Mycoplasma- Antimycoplamal drug should be used like Tiamulin, Tilmycosin, erythromycin, Azithromycin, etc. if refused water & feed intake please avoid oral antibiotics. Enter the injectable solution like ciprofloxacin 20mg/kg, Enrofloxacin 25mg/kg, Tiamulin@ 30mg/kg body weight, tylosin @10mg/kg body weight intramuscular for several days should suggest.
2) Avoid gram-negative bacterial infections using bettered antibiotics which great susceptibilities to gram-negative like Florfenicol, gentamycin, colistin sulfate, neomycin, etc.
If coverage out of control, cephalosporin drug of choice in this situation like ceftriaxone @10mg/kg body weight, cefoperazone 12mg/kg, azotonium @10 mg/kg & ceftiofur 7mg/kg body weight should apply for several days.
3) In young broiler & layer, coccidiosis where involved can apply toltrazuril salt in water
Ref: diseases of poultry,13th edition, Poultry diseases, sixth edition