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NEWCASTLE DISEASE

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8^th SEMESTER

Dr. ANIL Kumar

Asst. Professor

Dept. of VCC

NEWCASTLE DISEASE

ETIOLOGY: Paramyxo virus., RNA Virus.

• First time recorded in New castle in 1926 in England and in Ranikhet in 1928 in Uttaranchal(India).
• It occurs throughout the year, but is most common in the summer.
• On the basis of virulence:

1.LENTOGENIC VIRUS(MILD).

2. MESOGENIC VIRUS(MODERATE).

3.VELOGENIC VIRUS(SEVERE).

• ND disease confused with Avian influenza :
• Avian influenza virus-HA-Rabbit but ND doesn’t.
• Avian influenza virus doesn’t produce disease in pigeons but ND can.
• ND Virus losses its HA activity at at5,90,180 minutes but pathogenicity lost at 180 minutes but AI Virus become non-infectious before HA property of the virus is lost.

HOST : In poultry(virulent form), but in ducks, turkey, wild birds and pheasants have less severe form of disease.

SPREAD :

• Inhalation and Ingestion.
• Feed, Water and Equipments.
• Movement of people.
• Air transmission is very important.
• In Humans, the virus causes conjunctivitis, headache and influenza like symptoms.

SYMPTOMS :

• In velogenic form :
• Depression
• Closed eyes and facial swelling.
• Drooping wings and anorexia with greenish/yellowish diarrhea.
• Some times in neural form--- Torticollis, incordination or even paralysis of legs and arched back position of the body.

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Paralysis of legs

Torticollis

Abnormal perching reflex

Edema(Head),Conjunctivitis, Cornea edema(Eye)

Greenish diarrhea

Greenish diarrhea with white urates

Coughing and gasping

• In mesogenic form :
• Severe respiratory distress.
• Marked drop in egg production.
• Some times soft shelled egg or shell less egg.
• In lentogenic form:
• Only mild respiratory distress.

DIAGNOSIS :

• Isolation of virus.
• P.M finding :

1. Pin point haemorrhage in proventriculus.

2.Enlarged and haemorrhagic caecal tonsil.

3.Intestinal haemorrhage in intestinal wall.

4. Necrotic spleen.

• Serological test :

1.H I Test 2. ELISA Test 3.CFT Test 4. V N Test.

• Biological test :

1. Inoculation --- Pigeon-----Produce disease in 6 day.

2. Immunized Poultry-----not produce disease where as unimmunized poultry------ produce disease.

Fig 2: Caecal tonsils with necrosis and marked hemorrhagic lesions

Fig 1:Proventriculus shows edematous glands with some areas of hemorrhages.

Fig 3 :Severe hemorrhages on caecal tonsils and mucosa of the rectum.

Fig 4 : Entire length of intestinal mucosa shows hemorrhagic changes.

PM FINDINGS

TREATMENT: No treatment

PREVENTION AND CONTROL :

• Good hygiene, good management, and good biosecurity practices.
• Along with vaccination.
• There are 3 types of commercially available vaccines for RD disease:

1. Live lentogenic vaccines:

• They have F, Hitchner B1, LaSota and V4 vaccines.
• Least harmful vaccines(LaSota and B1 most widely used).
• Of these F has lowest disease producing power.
• LaSota is not used for first vaccination but often as a booster after one or more B1 strain/ F strain vaccines.
• Given by eye drop, drinking water or by machine producing spray.

2. Live mesogenic vaccines:

• They are Mukteswar (R2b), Roakin, Komarow, and H (Hartford shire).
• They are capable of causing severe disease and must be given after earlier vaccination with least harmful vaccines (Live lentogenic vaccines).
• Capable of producing a high secondary immune response.

3. Killed vaccines:

• Prepared from both virulent and avirulent form.
• Given either by i.m or s.c route.

MATERNAL IMMUNITY :

• This may prevent the effectiveness of primary vaccination, so, the birds are either vaccinated at 3-4wks of age or vaccinated with live virus at one day old chicks by eye drops or coarse spray and revaccinate at 3-4 wks of age.
• Killed vaccines successfully in one day old maternally immune chicks.

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