Virus isolation and molecular characterization of canine distemper virus by RT-PCR from a mature dog with multifocal encephalomyelit

Abstract

A case of multifocal distemper encephalomyelitis in a mature dog is described. In the presented case the ante mortem clinical diagnosis of canine distemper virus (CDV) infection could not be ideally performed due to the absence of typical signs of distemper, such as myoclonus and systemic signs accompanying the nervous signs. The definitive diagnosis of distemper encephalomyelitis was only carried out at post mortem through virus isolation in cell culture from fresh central nervous system (CNS) fragments and CDV nucleoprotein gene detection in the CNS by RT-PCR.

Clinical syndromes of nervous distemper in dogs initially presented without conventional evidences of CDV infection

“…The literature claims that MDEMD is not preceded by, nor is it coincident with the systemic signs, as often seen in young dogs (VANDEVELDE et al, 1980;BRAUND, 1994;VITE, 2005;AMUDE et al, 2007b). However, in this study two dogs with MDEMD demonstrated gastrointestinal signs after the manifestation of neurological deficits; but the etiology remained unclear since no diagnostic procedure was performed to rule out nor confirm other causes of such manifestations.…”

“…According to the literature MDEMD is a rare distemper clinical syndrome (BRAUND, 1994;VITE, 2005;AMUDE et al, 2007b), but it may be recognized more often than previously stated, especially in areas where CDV infection is endemic such as Brazil. However, ODE is an extremely rare non-conventional syndrome and may be not confused with conventional distemper in an old dog (VANDEVELDE et al, 1980;APPEL, 1994).…”

“…In order to contribute with both veterinarian clinicians and veterinary scientific literature, we established inclusion criteria that selected mainly animals presented without the classical clinical picture of distemper. The most of the current papers about nervous distemper (clinical, pathological, molecular, and diagnostic aspects) have been working with dogs presented with typical signs of CDV infection such as myoclonus and respiratory/gastrointestinal signs (SHIN et al, 1995;BAUMGÄRTNER, 2000;JÓŽWIK;FRYMUS, 2002;KOUTINAS et al, 2002;GEBARA et al, 2004b;SAITO et al, 2006;LAN et al, 2006;SILVA et al, 2007); however, the clinical diagnosis of distemper encephalomyelitis is often difficult in cases presented without these conventional evidences of CDV infection (TIPOLD; VANDEVELDE; JAGGY, 1992), and in such situations the clinical diagnosis of nervous distemper may be a challenge for the clinicians (TIPOLD; VANDEVELDE; JAGGY, 1992; VANDEVELDE; CACHIN, 1993;BAUMGÄRTNER, 2000;AMUDE et al, 2006c;AMUDE et al, 2007b). Additionally, although distemper in immature dogs has been the most common presentation of CDV infection (BRAUND, 1994;FRISK et al, 1999;KOUTINAS et al, 2002;VITE, 2005), in this investigation distemper encephalomyelitis in mature dogs were presented.…”

“…MDEMD is a type of multifocal encephalomyelitis in mature dogs with relatively low incidence that is characterized by a chronic course and does not appear to be related to breed or sex (VANDEVELDE et al, 1980;VITE 2005;AMUDE et al, 2007b). Vaccinated animals may also be affected, as observed in 3 out of 6 MDEMD dogs.…”

“…Although MDEMD is typically a multifocal CDV encephalomyelitis (VANDEVELDE et al, 1980;VITE, 2005;AMUDE et al, 2007b), two dogs suffering from this syndrome demonstrated signs suggestive of focal CNS lesion at the first neurological examination. One dog (n o 07) was presented with focal spinal cord signs (spastic paraplegia), and the other (n o 06) with typical focal cerebellar involvement (truncal and head ataxia, intentional tremor of the head, and dysmetria with severe hypermetria).…”