Download - Canin parvovirus disease
Canine Parvovirus
Prepared By:
Pradhuman YadavB.V.Sc & A.HB.V.Sc & A.H
History
• Emerged in 1977-1978• Feline Panleukopenia• Extremely hardy• Survives outside its host for up to
6 months• Species specific
What is it?
• Canine parvovirus• Smallest virus• Naked, icosahedral capsid• ssDNA
Replicates only when host is replicating! • 2 Syndromes:
• Acute myocarditis• Hemorrhagic enteritis
Incidence
• Any age can become infected• Mild and Asymptomatic• Severe clinical disease
• Puppies 2 to 6 months of age• Rottweilers and Doberman Pinchers
Life cycle of Parvovirus
Clinical syndrome • Host vitality
• Immune experience, vaccination status
• Environment • Humidity, temperature, etc
• Virulence of the virus• Including viral load
Protection
• Colostrum• Maternal antibodies protective until 2 month
of age
• Regular Vaccination• Keep indoors
• Until the vaccination series are complete
PathogenesisTonsilsTonsils
Replicates in Lymphocytes in the next 3-4 days
Cell lysis Cell lysis Viremia Viremia
Bone MarrowBone MarrowStem cells GITGIT
Mechanisms of Death
1. Diarrhea and vomiting extreme dehydration SHOCK
2. Loss of intestinal barrier bacterial invasion SEPTIC SHOCK
Symptoms
• Fever, lethargy, anorexia.• Severely dehydrated.• Vomiting.• Diarrhea: watery, bloody, with a tell-tale
odor.
Symptoms Shown By Dog
Hemorrhagic enteritis
• Villi become blunted and unable to absorb nutrients.
• Barrier to GIT flora is broken down.
Biopsy of the Small IntestineCollapsed cryptsCollapsed crypts
Depleted Peyer’s patchesDepleted Peyer’s patches
Inclusion bodies in Crypt cells
Kelly, 1978Kelly, 1978
Diagnosis• History and physical examination.• Symptoms• ELISA
• False positives with recent vaccination Hx• Antibody titer• CBC (Complete Blood Count).• Biopsy• Necropsy
• Lower and middle small intestines• Bone marrow
Additional tests
• Serum chemistry.• UA (Urine Analysis).• Fecal flotation• Rapid immunochromatographic tests.• Hemmaglutination inhibition test.• Fluorescence antibody test.
Symptomatic Treatment
• Fluids - Colloids, Plasma, RBC
• Antimetics - Metoclopramide• Antibiotics - Cefoxitin, Enrofloxacin.• Antihelmintics - Pyrental
• Analgesic - Buprenorphine
Prognosis• Most recover with intensive therapy
• Dobermans and Rottweilers • Sensitive to the virus
• Poor prognosis• Intussusception
• Hypoproteinemia
• No improvement after 4th day of intesive care
Home care• Antibiotics (PO)• Diet management
• Bland, highly digestible food• Frequent, small feedings
• Restricted activity• Avoid introducing new puppies
• Disinfect with bleach
Maternal Antibodies
• Critical period and vaccine response varies with the individual • Dams antibody level
• First born, aggressive pups
• More colostrum Higher MA
Vaccine Failure: Interference by Maternal
Antibodies
2 4 6 8 10 12
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Pass
ive
antib
ody
Weeks after birth
Minimum level needed for protection
Window ofsusceptibility
HAI - 80
HAI - 10 to 20Successful Vaccination
Vaccine Failure
• Ineffective Vaccine • Inappropriate storage
• Inappropriate administration
• Low titer vaccine
• Immunogenicity and Serological response• Virulence of parent viral strain
• Method and level of virus attenuation
• No vaccine produces 100% immunity
Vaccine Failure
• Health Status• Fever• Immunocompromised animals
• Client Compliance• Recommended vaccination schedule
• Breed• A disproportionate number of Rottweilers
that have been properly vaccinated will develop parvo