Canine Distemper Virus Final

CANINE DISTEMPER VIRUS (Hard Pad Disease)  Highly contagious disease of dogs  Cause more death to young dogs than other infections. PANTROPIC MORBILLI VIRUS. HOST AFFECTED:  Canidae (dog, fox, wolf)-more susceptible  Felidae (cat, lion, tiger)  Hyaenidae (hyaena) MORPHOLOGY :- RNA virus o Single stranded, o -ve sense, o non segmented. •

Haemoagglutinine-neuraminidase protein.

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Responsible for binding with host cell membrane.

PHYSICOCHEMICAL PROPERTIES: SENSTIVITY •

Heat Labile in nature.

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Inactivated at 60˚c - 30 min.

RESISTENCE Survive at 55˚c -30 min Optimum pH -7.0 Partial HA property of chicken & g.pig RBC . 1

CULTIVATION:    

Unweaned mice Baby hamster Rabbits Chicken embryo- Virulence reduced by successive passages

About 10 passages of virus produces thickening of CAM in chicken embryo-level of adaptation About 100 passages in chicken embryo the virus become attenuated and used as vaccines for dogs-level of attenuation VACCINE EPIDEMIOLOGY:  Direct contact / aerosol.  Young Dogs -3 month to 6 month -more susceptible  Immunodepression-maternally Ab’s godown.  Less Population- More Spread- Rural Areas PATHOGENESIS: Incubation period: 3 to 8 days. Virus entry Initial Replication In UPPER RESPIRATORY TRACT spreads to Tonsils & Bronchial LN Primary Viraemia Leucopenia 2

Immunosuppression Secondary Viraemia

1.respiratory system 2.gi tract

3.nervous system 4.urinary bladder

5.skin

Clinical signs: Pharyngitis Occulonasal discharge Coughing

Vomiting Diarrhoea

Paresis Myoclonus Epilepsy

Pistules-Abdomen Hyperkeratosis(Hard Pad Disease)

BIPHASIC FEVER PM LESIONS: 1. 2. 3. 4.

Haemorrhagic enteritis-under 8 wks pups Lungs , bladder , renal pelvis -congested Spleen -enlarged Liver-necrotic spots

HP LESIONS: 1. Perivascular cuffing 2. Nerve cell degeneration 3. I/cytoplasmic or I/nuclear inclusion bodies–bladder , renal pelvis , respiratory epithelium , intestine ,brain DIAGNOSIS: 1.Clinical Signs 2.Isolation and identification 3.Detection -specific distemper antigen -immunofluorescence 4.CFT -hyper immune anti distemper sera 5.Serum neutralization test- chick embryo/ cell cultures -a suitable stain of virus antigen

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CONTROL: 1. After recovery - long time immunity-.the puppies cannot be vaccinated until they loose their maternal antibodies(8 to 12 wks) 2. Previously –inactivated virus followed by virulent virus administered to produce immunity. 3. Nowadays attenuated vaccine –ECE / ATC. 4. Combined cdv and ich vaccines

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PANTROPIC MORBILLI VIRUS

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