Feline Panleukopenia I. Pathogenesis in Germfree and Specific Pathogen-Free Cats

Abstract

A bst ract. Ge rmfree a nd spe cific pathogen -fr ee cats we re inocul at ed wit h panleukopen ia viru s . Tot al leu cocyte co unts de creased signific antl y in both ger mfree a nd spec ific path ogen -fr ee cats. Clinical illness was not see n in a ny gc rmfree ca t. Spec ific pa thoge n-free ca ts had an or exi a and slight diarrhea 5-6 day s afte r ino cul ati on . No ne of the ca ts died . Both ge rmfree a nd spec ific pathogen -fr ee cat s had th ymi c involuti on . No o the r g ross lesions were see n. Ti ssu es fo r histolo gical virus isola tio n a nd immunofluor escence st udies we re ta ken dail y fro m days 2 th rou gh 6 after inoculation . Vir us-infected ce lls a nd lesion s o f panl eukop eni a we re see n in the sma ll inte stin e of both ge rmfree a nd specific path ogen-free ca ts . T he incid en ce o f virus-infecte d ce lls a nd lesion s was greate r in spec ific pa thoge n-f ree ca ts th an in germfree cats .Fe line panl euk openia is an imp ortant dise ase o f th e domestic cat. It is ex t re me ly conta gious and has a high fatalit y rate . Wh ilst there is co nsi de ra ble information o n the clin ical di sea se and its lesion s , littl e is kn own of th e pathogen e sis . T he re is con siderable co ntro ve rsy as to which cell s th e virus infects, how th e lesion s pro gr ess , and th e importanc e of seco nda ry bact er ial in fection s , especi ally in the int estin e.So me rese arch er s [7] have inferred that th e intestinal lesion s begin on the villi. O the rs hav e demonstrated that th e most specific lesion was cr yptal [4]. Sp ecifi c intranuclear inclusion bodies as a di agnostic crit eri on a lso has been controversial. Ear lie r researchers [10] inoculated both germfre e and conventional cat s wit h panleukopenia viru s . The typical fulminat ing dis ease occurred in the conventional cats and severa l of th em died . Only a transient mild di sea se occurred in the germfree cats and there wer e no lesion s in th e gut. O n the basi s of these results , it was inferred th at the enteritis , so co m mo n in clini cal panl eukopenia, was caused by bacterial, rather than viral infection .T his study is to determine th e effect s o f panl euk openia virus in the ca t by study ing th e progress of infection and to compar e possibl e differ en ces in the disea se in germfree and con ventional ca ts . Materials and Method sGe rmfree a nd specific pathoge n-fr ee ca ts X-'i wee ks o ld were inocul at ed subcuta neo usly wit h I ()' TCI D,." of panl euk op eni a viru s stra in C U-4 [1 21. seve nt h passage in fe line kid ney ce ll cult ure. Two 7'i

Feline Host Range of Canine parvovirus: Recent Emergence of New Antigenic Types in Cats

“…Experimental infection of specific pathogen-free (SPF) or germfree cats with FPLV generally leads to mild diseases ( 23 , 24 ). No or slight intestinal lesions can be observed in infected germfree cats ( 23 ), which suggests that the intestinal lesions are caused by secondary bacterial, rather than primary viral, infection.…”

“…Note, however, that the experimental infection of SPF cats with FPLV generally leads to mild disease ( 23 , 24 ). In this regard, the study reported by Goto et al ( 31 ) is intriguing.…”

Achados patológicos e imuno-histoquímicos em felinos domésticos com panleucopenia felina

“…Essas lesões são caracterizadas por necrose tecidual, atrofia e fusão de vilosidades intestinais e rarefação tecidual hematopoiética (Csiza et al 1971, Carlson et al 1977. Elas evidenciam o tropismo do parvovírus por células com elevada taxa de mitose e seu efeito citopático (Parrish 1995).…”

“…A panleucopenia felina é conhecida desde 1920 como uma importante doença contagiosa de felinos domésticos e selvagens (Carlson et al 1977 da panleucopenia felina (VPF) e parvovírus canino (CPV) (Garcia et al 2011, Battilani et al 2013, pertencentes à Família Parvoviridae. São vírus pequenos, não envelopados, com uma fita simples de DNA e extremamente resistentes no ambiente e a desinfetantes (Greene & Addie 2006).…”

Parvoviruses: agents of distinct pathogenic and molecular potential

“…The basis of these clinical manifestations is cytolytic replication of the infecting parvovirus in cells of the cryptal epithelium of the intestine [89][90][91]. Giving similar effects are nutritional stress conveyed by starving or change in diet and, last but not least, bacterial or parasitic superinfections [94][95][96]. For instance, cell proliferation in the intestine of suckling dogs is usually low and so is the incidence of severe enteritis [92,93].…”