CPV- DRH SIDNA

8/10/2019 CPV- DRH SIDNA

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Parvoviruses

(canine parvovirus -2)September 7-8, 2010


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First reports of CPV enteritisAn enteric disease of dogs resembling feline

panleucopenia.

W.R. Kelly, Aust. Vet Jn. 54:593. 1978

Canine gastroenteritis associated with a

parvovirus-like agent.

G.W. Thompson and A.N. Gagnon. Can. Vet Jn.

19:346. 1978


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W.R. Kelly. 1978. An enteric disease of dogs

resembling feline panleucopenia. A.V.J. 54:593


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Kelly, 1978

intestinal crypts

normal

suspected

viral

enteritis

bone marrow


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First reports of CPV myocarditis

Diffuse subacute myocarditis of possible viral aetiology:

A cause of sudden death in pups.

W.R. Kelly.Aust. Vet Jn 55:36. 1979

Sudden death in puppies associated with a suspected

viral myocarditis

R.B. Atwell et al. Aust. Vet Jn 55:37. 1979


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Kelly,1979


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The evolution of CPVFeline parvovirus

Fox parvovirus

Raccoon parvovirus

Carnivore (?) parvovirus

1970,74-76

CPV-2 CPV-2a CPV-2b

1979 1987

cats

?

?

?

?(10-20% of

cats with parvo

enteritis)

~1900

?

CPV-2c

2004


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The virus

dimple

canyon

neutralizing epitopes,

host-range mutations


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Kennedy et al. 1995. Virucidal efficacy of the newer

quarternary ammonium compounds. JAAHA 31:254


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Kennedy et al 95


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American Jn of Inf. Control2006, 34:269-273

1000 ppm is equivalent to approx. 2% solution of household bleach


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Parvovirus in the scheme of things

Circoviridae

Parvoviridae

porcine circovirus

canine parvovirus-2

feline panleukopenia virus

porcine parvovirus (SMEDI)

Viruses with single stranded DNA


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Replicative cycle

Attachment

Requirement for dividing cells

Intranuclear inclusion bodies

Release by lysis - death of cell


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CPV attaches to cells using

transferrin receptor (host tropism)The natural host-range shift and

subsequent evolution of canine

parvovirus resulted from virus-

specific binding to the canine

transferrin receptor. Hueffer et al.

2003 J. Virol 77; 1718-1726

transferrin receptor


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Pathogenesis

infection

fecal-oral route

Virus extremely stable (> 6 months) Inactivated by 4% solution of bleach

Most virucidal disinfectants not effective

access to lymphatic nodules in tonsils or gut

(M-cells)


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Entry at mucosal surfaces (M cells)

M cell


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Entry at mucosal surfaces(M cells)

M cellTransport across M cell


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Entry at mucosal surfaces (M cells)

Infected

Lymphoid cell

spread


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Spread of virus in the body

mesenteric, systemiclymph nodes, bone marrow

(lymphoid and myeloid precursors)

crypt cells

no epithelial replacement,

collapse of lamina propria

virus in feces


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Actively dividing cells in gut

Peyers

patches

crypt cells


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Damage to the gut

collapsed crypts

depleted Peyers patches


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Incubation period and duration of

shedding

infection

virus shedding

clinical signs

day 0

4-14 days

incubation period


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After challenge

incubation period

vaccination does

not provide sterile

immunity

Ron D. Schultz


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Response to infection -

asymptomatic ->death

Depends on:

immune status of dog

Immune or able to make antibodies

individual variation

Intestinal and lymphoid cell turn-over

genetic susceptibility

variation among virus strains


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Risk factors for parvovirus

enteritis season - 3 times more likely - July to Sept

breeds - Rottweilers, Dobermans,

Shepherds

sex - intact dogs four times more likely

no vaccination - 13 times more likely

Risk factors associated with parvovirus enteritis in dogs:283

cases - D. M. Houston et al. JAVMA 208:542-546. 1996


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Most likely clinico-path findings

lethargy and vomiting - 84-87%

diarrhoea - 60%

leukopenia (at some time) - 45% neutropenia (at some time) - 51%

fever (>39.5) - 24%

Risk factors associated with parvovirus enteritis in dogs:283 cases - D. M.

Houston et al. JAVMA 208:542-546. 1996


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Vet Rec. 2010 Aug 7;167(6):196-201.

Epidemiology of canine parvovirus and coronavirus in dogs presented with

severe diarrhoea to PDSA PetAid hospitals.

Godsall SA, Clegg SR, Stavisky JH, Radford AD, Pinchbeck G.

Correlates with detectable CPV2 in feces of dogs

with diarrhoea:

Lack of vaccination in young dogs (


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Myocarditis


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Diagnosis of parvovirus enteritis

Clinical signs and clinico-pathological

parameters

why are these not sufficient to make a definitivediagnosis


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Some infectious causes of

enteritis in dogs Parvovirus

Distemper virus

Coronavirus

Rotavirus (


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Virus isolation

fecal suspension treated with chloroform

inoculate feline kidney cells

incubate 3-5 days

stain with parvo-

virus antibody+

fluoroscene


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Haemagglutination (HA)

virus No virus


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HaemagglutinationDilution

2 4 8 16 32 64 128 256 512

prozone titre

1024No

virus


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Comparison of sensitivity

dilution 0 1/10 1/100 1/1000 .... 10-7

IDEXX

Virus isolation

HA 1/8192 (HA titre during peak

clinical signs is 1,000 -

10,000)


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Incubation period and duration of

shedding

infection

virus shedding

day 0

4-14 days

incubation period clinical signs


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Haemagglutination inhibition

(HAI) heat to inactivate complement in serum

adsorb to RBC, then remove

dilute (1/20, 1/40 etc)

add virus

incubate

add RBC

incubate


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HAI Serumdilution

1/20

1/40

1/80

1/160

1/320

1/6401/1280

-ve control

1 wk8 wksVirusHA


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Protection of animals

(vaccination) by itself or as component of combined

vaccine (DA2PPv)

attenuated or inactivated


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Interference by maternal

antibodies

2 4 6 8 10 12

*

*

*

* *

*passive

antibody

weeks after birth

minimum

level needed

for

protection

interferes with

vaccination

window of

susceptibility

HAI - 80

HAI - 10 to 20Puppies can

Only be

Vaccinated

Below this level


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J Vet Med B Infect Dis Vet Public Health. 2000 May;47(4):273-6.Immunization of pups with maternally derived antibodies to canine parvovirus (CPV)using a modified-live variant (CPV-2b).Pratelli A, Cavalli A, Normanno G, De Palma MG, Pastorelli G, Martella V, Buonavoglia C.

Passive antibody decreases vaccine

efficacy


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Strategies for reducing/overcoming risk

of maternal interference

biweekly vaccinations

low passage, high titre vaccines


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Low-passage, high-titre vaccines

Pfizer - Vanguard puppy

Schering-Plough - Galaxy

Merial - Canine Parvo XL
http://www.pfizer.com/ah/level13/tref/trbull/parbull.html


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Vaccines should contain CPV2a and

CPV2bCPV vaccination:

comparison of

neutralizing antibodyresponses in pups after

inoculation with CPV2 or

CPV2b modified livevaccines. Pratelli et al.

2001. Clin. Diag. Lab.

Immunol. 8: 612-615


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Debate on frequency ofvaccination


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Parvovirus vaccines licensed in

Canada modified-live alone or in various combinations

CFIA
http://active.inspection.gc.ca/scripts/database/vetbio_submit.asp?lang=e&species=4&manufacturer=allhttp://active.inspection.gc.ca/scripts/database/vetbio_submit.asp?lang=e&species=4&manufacturer=allhttp://active.inspection.gc.ca/scripts/database/vetbio_submit.asp?lang=e&species=4&manufacturer=allhttp://active.inspection.gc.ca/scripts/database/vetbio_submit.asp?lang=e&species=4&manufacturer=all


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Potential antiviral therapy

Vet Rec. 2003 Jan 25;152(4):105-8.

Treatment of canine parvoviral enteritis with interferon-

omega in a placebo-controlled field trial.de Mari K, Maynard L, Eun HM, Lebreux B.

J Vet Pharmacol Ther. 2010 Aug;33(4):352-6.

Hematologic improvement in dogs with parvovirus infection

treated with recombinant canine granulocyte-colony

stimulating factor.

Duffy, A, Dow S, Ogilvie G, Rao S, Hackett T.


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Other parvoviruses of veterinary

importance feline panleukopenia virus (related

carnivore parvoviruses)

porcine parvovirus

aleutian mink diseases

human parvovirus B19


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Feline parvovirus

normal

cerebellar

hypoplasia

from:

Veterinary Virology

Murphy et al.


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CzarMr. S brought Czar, a 7 month old Rottweiler, to the WCVM clinic on August 30. Czar had had severe

vomiting and diarrhea for the previous two days. He had vomited two or three times on the previous

evening and once that morning. The diarrhea was watery with no blood. Czar had not eaten in the two

days prior to presentation.

Czar did not have a history of raiding garbage cans and Mr. S thought it unlikely that Czar had eaten

anything unusual. The dog was fed a commercial puppy chow and there had been no change in his diet.

Czars vaccinations were up to date with extra parvovirus boosters up to 20 weeks of age. According to

the WCVM records Czar had been vaccinated at 8, 12, 16 and 20 weeks with a vaccine containingdistemper virus, parvovirus and adenovirus-2.

The attending veterinarian found Czar to be listless and quiet. The dog was anorexic and slightly

dehydrated. There appeared to be no discomfort on palpation.

His temperature was 39oC (N 37.239.2), pulse was 116 (N 70160) and respiration was 32 (N 10 -

30).

1 You suspect that Czar has parvovirus enteritis What tests would you request


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1. You suspect that Czar has parvovirus enteritis. What tests would you request

to confirm (or refute) your suspicions?

2. What are your reasons for requesting these tests? What would you expect the

tests to show?

3. Would you treat Czar with antibiotics? Why?4. If you requested a complete blood count (CBC) for Czar, what might the

CBC pattern be? How might you expect the pattern to change over the next

few days?

5. Which tissues is the parvovirus most likely to affect? What changes would

you expect in these tissues?6. Assume that Czar has parvovirus enteritis. Why do you think he became sick

despite your having vaccinated him against parvovirus?

7. Are any of Mr. Ss family members likely to be infected by Czars virus? Is

there a human parvovirus? How is it related to canine parvovirus 2?

8. Can Czar pass parvovirus on to the family cat?

9. What advise would you give Czars owner about disinfecting areas

contaminated with Czars feces?

10. Czar was hospitalized but a week later he had recovered and was sent home.

Would you expect Czar to be contagious at that time?


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Questions 1 and 2: Liz AndreeColleen Chan

Questions 3 and 4: Sydney ChowShannon Gruen

Questions 5 and 6: Amber HamiltonAngela Le

Questions 7 and 8: Ellen LittleyJanine RegehrQuestions 9 and 10: Dane RichardsonAnita Yee


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Blood was taken for CBC, a faecal sample was submitted for bacteriological

analysis and a ParvoCITE test was performed. On the basis of the ParvoCITE

test, which was strongly positive, a diagnosis of parvovirus enteritis was made.

Czar was put in an isolation ward and started immediately on IV fluids.

Ampicillin as well as gentamicin were administered. Over the next 3 days Czar's

condition deteriorated. Diarrhea became bloody. The IV fluids and antibioticswere continued. On the fourth day after admitting, the diarrhea appeared to stop.

Although weak, Czar seemed willing to walk around. The dog's condition

improved steadily over the next few days. By day 6 Czar was able to drink

without vomiting and a day later he ate small amount of Hill's I/D diet.

Once it was established that he could maintain his body's fluid levels he was

weaned off the I.V. fluids. Eight days after being admitted to hospital he was sent

home.

What happened


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CPV- DRH SIDNA