Atypical necrotizing encephalitis associated with systemic canine distemper virus infection in pups

Evaluation of Intrathecal Injection of Modified Live Newcastle Disease Virus Vaccine in Dogs with Canine Distemper Encephalitis

The neurological form of canine distemper virus (CDV) infection can occur concurrently with systemic signs or develop following apparent recovery. There are no specific antiviral or immunomodulatory therapies recognized for treatment of CDV infections, and the neurological form typically carries with it a high mortality rate. The intrathecal injection of a modified live Newcastle disease virus vaccine (NDV-MLV) has been proposed for the treatment of the neurological forms of CDV infections. Thirteen dogs confirmed to have canine distemper infections by polymerase chain reaction testing and with neurological signs consistent with CDV infection were treated with an intrathecal injection of NDV-MLV and were scheduled for re-evaluation 3-4 mo later. Six dogs survived to follow-up and four dogs survived long term (>3 yr). Cerebrospinal fluid cytokines were measured and reported. Changes in cerebrospinal fluid cytokines and long-term survival could not be attributed to the intrathecal injection of NDV-MLV, and this therapy cannot be recommended for treatment of dogs with neurological forms of CDV infection.

How Behavioral Changes Can Indicate Serious Cerebral Pathology: A Case Report of Concomitant Olfactory Neuroblastoma and Distemper Virus Encephalitis in a Swiss Shepherd Dog

Behavioral alterations in dogs are not easy to understand and cure. The situation is more difficult when an encephalitis due to Canine Distemper Virus (CDV) and a concomitant olfactory neuroblastoma are present. This case report deals with the story of a 5-year-old Swiss shepherd dog with behavioral changes, seizures, epistaxis and ataxia. Following clinical and laboratory exams, a suspected diagnosis of CDV infection was hypothesized, and a therapy based on Ω-interferon was administered. Every supporting therapy failed and the worsening of the clinical conditions led to the euthanasia of the patient. A neoformation in the right frontal lobe was found post mortem. Histopathology and immunohistochemistry investigation showed a non-suppurative demyelinating encephalitis, suggestive of CDV infection, and a desmoplastic epithelioid olfactory neuroblastoma. To the best of authors’ knowledge, this is the first clinical pathological report of a non-suppurative encephalitis due to CDV infection and olfactory neuroblastoma in a dog.

Molecular detection and phylogenetic relationship of wild-type strains of canine distemper virus in symptomatic dogs from Uberlândia, Minas Gerais

This study investigated the occurrence of canine distemper virus (CDV) by evaluating the presence of viral RNA within urine samples of dogs from Uberlândia, MG, with clinical manifestations suggestive of infection by CDV by targeting the CDV N gene. Of the clinical samples collected ( n =33), CDV viruria was detected in 45.5%. Five dogs died spontaneously; all had characteristic CDV-associated histopathological alterations and demonstrated CDV viruria. Statistical analyses revealed that the age, gender, breed, or the organ system of the dog affected had no influence on the occurrence of canine distemper. Myoclonus and motor incoordination were the most significant neurological manifestations observed. A direct association was observed between keratoconjunctivitis and dogs with CDV viruria. These findings suggest that CDV viruria in symptomatic dogs might not be age related, and that symptomatic dogs can demonstrate clinical manifestations attributed to CDV without viruria identified by RT-PCR. Additionally, the results of the sequence identities analysed have suggested that all Brazilian wild-type strains of CDV currently identified are closely related and probably originated from the same lineage of CDV. Nevertheless, phylogenetic analyses suggest that there are different clusters of wild-type strains of CDV circulating within urban canine populations in Brazil.

Genotyping of canine distemper virus strains circulating in Brazil from 2008 to 2012

Canine distemper virus (CDV) is a major pathogen of dogs and represents a serious threat to both unvaccinated and vaccinated animals. This study surveyed dogs with or without clinical signs related to canine distemper from different regions of Brazil from 2008 to 2012. A total of 155 out of 386 animals were found to be CDV positive by RT-PCR; 37 (23.8%) dogs were asymptomatic at the time of sampling, and 90 (58%) displayed clinical signs suggestive of distemper. Nineteen (12.2%) dogs had a record of complete vaccination, 15 (9.6%) had an incomplete vaccination protocol, and 76 (49%) had no vaccination record. Based on the sequence analysis of the complete hemagglutinin gene of 13 samples, 12 of the strains were characterized as Genotype South America-I/Europe. Considering criteria of at least 95% nucleotide identity to define a genotype and 98% to define a subgenotype, South America-I/Europe sequences segregated into eight different phylogenetically well-defined clusters that circulated or co-circulated in distinct geographical areas. Together, these findings highlight the relevance of CDV infection in Brazilian dogs, demonstrate the predominance of one genotype in Brazil and support the need to intensify the current control measures.