Relation of clinical signs to pathological changes in 19 cases of canine distemper encephalomyelitis

Post-vaccinal distemper-like disease in two dog litters with confirmed infection of vaccine virus strain

Modified live canine distemper virus (CDV) vaccines are widely used and considered both safe and effective. Although there are occasional literature reports of suspected vaccine-induced disease, there are none where the vaccine strain has been identified in affected tissues. Here we describe two such cases in different litters. In litter A, five of ten puppies presented with fever, anorexia, vomiting, and diarrhea a few days post-vaccination. Four puppies died or were euthanized, and autopsy revealed atypical necrosis of the lymphoid tissue. In litter B, two of five puppies developed typical neurological signs some months post-vaccination and autopsy revealed encephalitis. In all cases, affected organs tested positive for CDV on immunohistochemistry, and CDV RNA extracted from the lesions confirmed the presence of vaccine strain. Since multiple puppies from each litter were affected, it cannot be excluded without further studies that some undiagnosed inherited immunodeficiency disorder may have been involved.

Detection and genetic characterization of canine distemper virus isolated in civets in Vietnam

Canine distemper (CD), caused by the canine distemper virus (CDV), is a lethal systemic disease to a wide range of wild and domestic carnivorous hosts, including civets. In this study, a possible CD outbreak in a backyard farm with 32 diseased civets (Viverricula indica) in Hanoi, Vietnam, was investigated. The sick civets showed CD-like clinical signs such as anorexia, sedentary behavior, diarrhea, dermatitis, nasal, and footpad hyperkeratosis. Various tissue samples collected from the dead civets were utilized for molecular screening of CDV and histopathological examination. The genetic detection and characterization confirmed that samples collected from dead civets tested positive for CDV. The phylogenetic analysis based on the full-length H gene sequences indicated that all CDV strains isolated from civets belonged to the Asia-1 lineage and were closely related to the CDV strains previously reported from dogs in Thailand, China, and Vietnam. Histopathological examination showed severe interstitial pneumonia, hemorrhagic alveolar septa, necrotic alveolar epithelial cells, necrotic, degenerated, or lost Purkinje cells, eosinophilic intracytoplasmic inclusion bodies, edema, and perivascular cuff. This study confirmed the detection of CDV in civets for the first time in Vietnam.

Understanding the incidence and timing of rabies cases in domestic animals and wildlife in south-east Tanzania in the presence of widespread domestic dog vaccination campaigns

The "Zero by 30" strategic plan aims to eliminate human deaths from dog-mediated rabies by 2030 and domestic dog vaccination is a vital component of this strategic plan. In areas where domestic dog vaccination has been implemented, it is important to assess the impact of this intervention. Additionally, understanding temporal and seasonal trends in the incidence of animal rabies cases may assist in optimizing such interventions. Data on the incidence of probable rabies cases in domestic and wild animals were collected between January 2011 and December 2018 in thirteen districts of south-east Tanzania where jackals comprise over 40% of reported rabies cases. Vaccination coverage was estimated over this period, as five domestic dog vaccination campaigns took place in all thirteen districts between 2011 and 2016. Negative binomial generalized linear models were used to explore the impact of domestic dog vaccination on the annual incidence of animal rabies cases, whilst generalized additive models were used to investigate the presence of temporal and/or seasonal trends. Increases in domestic dog vaccination coverage were significantly associated with a decreased incidence of rabies cases in both domestic dogs and jackals. A 35% increase in vaccination coverage was associated with a reduction in the incidence of probable dog rabies cases of between 78.0 and 85.5% (95% confidence intervals ranged from 61.2 to 92.2%) and a reduction in the incidence of probable jackal rabies cases of between 75.3 and 91.2% (95% confidence intervals ranged from 53.0 to 96.1%). A statistically significant common seasonality was identified in the monthly incidence of probable rabies cases in both domestic dogs and jackals with the highest incidence from February to August and lowest incidence from September to January. These results align with evidence supporting the use of domestic dog vaccination as part of control strategies aimed at reducing animal rabies cases in both domestic dogs and jackals in this region. The presence of a common seasonal trend requires further investigation but may have implications for the timing of future vaccination campaigns.

Evaluation of the Efficacy and Safety of Silver Nanoparticles in the Treatment of Non-Neurological and Neurological Distemper in Dogs: A Randomized Clinical Trial

Canine distemper is caused by canine distemper virus (CDV), a multisystemic infectious disease with a high morbidity and mortality rate in dogs. Nanotechnology represents a development opportunity for new molecules with antiviral effects that may become effective treatments in veterinary medicine. This study evaluated the efficacy and safety of silver nanoparticles (AgNPs) in 207 CDV, naturally infected, mixed-breed dogs exhibiting clinical signs of the non-neurological and neurological phases of the disease. Group 1a included 52 dogs (experimental group) diagnosed with non-neurologic distemper treated with 3% oral and nasal AgNPs in addition to supportive therapy. Group 1b included 46 dogs (control group) diagnosed with non-neurological distemper treated with supportive therapy only. Group 2a included 58 dogs with clinical signs of neurological distemper treated with 3% oral and nasal AgNPs in addition to supportive therapy. Group 2b included 51 dogs (control group) diagnosed with clinical signs of neurological distemper treated with supportive therapy only. Efficacy was measured by the difference in survival rates: in Group 1a, the survival rate was 44/52 (84.6%), versus 7/46 in Group 1b (15.2%), while both showed clinical signs of non-neurological distemper. The survival rate of dogs with clinical signs of neurological distemper in Group 2a (38/58; 65.6%) was significantly higher than those in Control Group 2b (0/51; 0%). No adverse reactions were detected in experimental groups treated with AgNPs. AgNPs significantly improved survival in dogs with clinical signs of neurological and non-neurological distemper. The use of AgNPs in the treatment of neurological distemper led to a drastic increase in the proportion of dogs recovered without sequels compared to dogs treated without AgNPs. The evidence demonstrates that AgNP therapy can be considered as a targeted treatment in dogs severely affected by canine distemper virus.

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.

Histopathological Features of Spinal Cord Lesions in Dogs with Distemper-Associated Demyelinating Leucoencephalomyelitis

Demyelinating leucoencephalomyelitis (DLEM) is one of the pathological presentations of canine distemper, but its histological characteristics and topographical distribution of spinal cord injuries have been poorly explored. Seventeen dogs submitted for necropsy to a veterinary pathology service (2006-2008) and diagnosed with distemper-associated DLEM were investigated. Seventy-two of 231 spinal cord sections from these animals had histological lesions, which consistently affected the white matter. The lumbosacral region was mostly affected (13/17), followed by the thoracolumbar (11/17), cervical (9/17) and cervicothoracic (9/17) regions. Among the 72 affected cord sections, lesions in the lateral (42/72) and dorsal funiculi (31/72) were the most common. Demyelination (17/17), astrocytosis (17/17), microgliosis (17/17), gemistocytes (11/17) and non-suppurative inflammation (10/17) were frequently seen in the white matter. Grey matter changes were less common, and included gliosis (8/17), non-suppurative inflammation (7/17) and malacia (5/17). Acute lesions were most prevalent (13/17) but it was common (10/17) for the same dog to have lesions at different stages of evolution in distinct spinal cord regions. Pathological changes in several spinal cords did not correlate with the reported clinical signs and some dogs did not present with spinal cord-related clinical signs. Our results highlight important aspects of the distribution and morphology of spinal cord lesions in dogs with distemper-associated DLEM, and may assist clinicians and pathologists in the diagnosis of spontaneous cases of this important infectious disease and contribute to further studies concerning distemper pathogenesis.

Características epizootiológicas da infecção natural pelo vírus da cinomose canina em Belo Horizonte

RESUMO O perfil epizootiológico da cinomose canina em Belo Horizonte é desatualizado e não alberga algumas características relevantes. Uma análise recente da distribuição do vírus em relação às características do hospedeiro e do meio ambiente associada aos principais sinais clínicos e achados laboratoriais são importantes para se adotarem medidas estratégicas para o controle da enfermidade. Objetivou-se, assim, determinar as características epizootiológicas da infecção pelo vírus da cinomose canina associada à variedade de sinais clínico-neurológicos e laboratoriais em Belo Horizonte, auxiliando no diagnóstico precoce da infecção e na diminuição das taxas de morbidade e mortalidade da doença. A avaliação do perfil epizootiológico de 90 cães revelou que a doença é mais frequente em animais adultos (um a seis anos de idade) e que não receberam vacinas conforme recomendado pelos protocolos. Os sinais clínicos extraneurais e neurais foram variados, com predomínio para manifestações gastrentérica e respiratória, mioclonia e déficit motor, respectivamente. O exame do fluido cérebro-espinhal demonstrou predomínio de proteinorraquia associada à pleocitose linfocítica. O teste de imunocromatografia para pesquisa de antígeno com amostras do fluido cerebroespinhal foi eficaz para identificar a doença em pacientes com sinais neurológicos, diferentemente das amostras do swab conjuntival, que não devem ser utilizadas.

Natural Canine Distemper Virus Infection in Linnaeus's 2-Toed Sloths (Choloepus didactylus)

An outbreak of canine distemper virus in a private zoo in eastern Tennessee in July 2016 led to fatal clinical disease in 5 adult, wild-caught Linnaeus's 2-toed sloths (Choloepus didactylus). Clinical signs included hyporexia, lethargy, mucopurulent nasal discharge, and oral and facial ulcers. At necropsy, affected animals had crusts and ulcers on the lips, nose, tongue, and oral cavity. Microscopically, all sloths had widespread, random, hepatic necrosis; lymphoid depletion; and bronchointerstitial pneumonia. The central nervous system did not contain gross or histopathologic lesions in any of the 5 sloths, although immunoreactivity for viral antigen was present within vessel walls. Epithelial cells and histiocytes within numerous organs contained intranuclear and intracytoplasmic inclusions and occasional syncytial cells. Canine distemper virus was confirmed with immunohistochemistry and virus isolation. Viral sequencing identified the novel American-4 strain prevalent in eastern Tennessee wildlife. This is the first pathologic characterization of canine distemper virus infection in sloths (family Choloepodidae, order Pilosa) and emphasizes the significant morbidity and mortality in this species.

Canine pancytopoenia in a Mediterranean region: a retrospective study of 119 cases (2005 to 2013)

OBJECTIVES

To further clarify the causes of pancytopoenia and to investigate whether underlying cause or severity were associated with survival in an area endemic for vector-borne pathogens.

METHODS

Retrospective review of medical records of 119 dogs with and 238 dogs without pancytopoenia.

RESULTS

Mixed-breed dogs and dogs younger than one year had higher odds of being pancytopoenic. The most common diagnoses included monocytic ehrlichiosis (n=42), leishmaniasis (n=28) and parvoviral enteritis (n=19). The mean white blood cell counts were lower in dogs with ehrlichiosis and parvoviral enteritis compared to dogs with leishmaniasis, while platelet counts were lower in ehrlichiosis compared to leishmaniasis or parvoviral enteritis. Total protein concentrations were lower in dogs with parvoviral enteritis compared to ehrlichiosis and leishmaniasis. Higher haematocrit, platelet and white cell counts were associated with better odds of survival.

CLINICAL SIGNIFICANCE

Infectious diseases appear to be the leading causes of canine pancytopoenia in endemic areas; severe leukopoenia (ehrlichiosis, parvoviral enteritis), thrombocytopoenia (ehrlichiosis) and hypoproteinaemia (parvoviral enteritis), represented potentially useful disease-specific diagnostic determinants. The severity of pancytopoenia significantly affects the clinical outcome.

Characterization of a novel Canine distemper virus causing disease in wildlife

Canine distemper virus (CDV) is a common cause of a multisystemic disease in both domestic dogs and wildlife species, including raccoons and foxes. Outbreaks of CDV in domestic dogs in eastern Tennessee have occurred since 2012, and it was determined that these outbreaks resulted from a novel genotype of CDV. We hypothesized that this virus is also infecting area wildlife and may be a source of the virus for these outbreaks in dogs. From 2013 to 2014, autopsies were performed and tissues collected from raccoons (Procyon lotor; n = 50) and gray foxes (Urocyon cinereoargenteus; n = 8) for CDV testing. A real-time reverse transcription PCR was used to document the presence of CDV in tissue samples, and a portion of the virus was subsequently sequenced for phylogenetic analysis. A high percentage of wildlife, both with (86%) and without (55%) clinical signs, tested positive for CDV, with the majority (77%) testing positive for the novel genotype. Microscopic findings, including syncytia in the lungs and viral inclusion bodies in urothelium, astrocytes, neurons, and bronchiolar epithelium, were also consistent with canine distemper. Minimal inflammation in the central nervous system of affected animals was indicative of the acute neurologic form of the disease. Pneumonia and parasitism were also commonly found in CDV-infected animals. Based on these results, CDV appears to be prevalent in eastern Tennessee wildlife. Subclinical or clinically recovered shedders are a potential source of this novel genotype for domestic dogs, and this genotype is genetically distinct from vaccine strains.

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.

Pathologic and Molecular Virologic Characterization of a Canine Distemper Outbreak in Farmed Civets

In October 2011, a fatal disease outbreak occurred in 3 civet species farmed for their use in the coffee industry in Thailand. The disease quickly killed 20 animals in a mixed population of Asian palm civets (Paradoxurus hermaphroditus; n = 18), a masked palm civet (Paguma larvata; n = 1), and small Indian civet (Viverricula indica; n = 1). Clinical signs consisted of severe lethargy, weakness, vomiting, and diarrhea with associated dehydration, dyspnea, nasal and footpad hyperkeratosis, and seizures. All civets were positive for canine morbillivirus using the commercial canine distemper virus (CDV) antigen test kit. Consistently observed necropsy findings consisted of severe pneumonia and hemorrhagic enteritis. Microscopic examination revealed severe gastroenteritis, bronchointerstitial pneumonia, lymphadenitis, necrotizing dermatitis, nonsuppurative polioencephalitis, and characteristic intranuclear/intracytoplasmic eosinophilic viral inclusions in multiple tissues. Immunohistochemical analysis revealed immunoreactivity of varying intensity, while virus isolation demonstrated typical cytopathic effects. To confirm CDV infection, reverse transcription-polymerase chain reaction against fusion (F), phosphoprotein (P), and hemagglutinin (H) genes showed bands of expected size using conjunctival swabs (9 civets, 1 dog [Canis lupus familiaris] living on the farm). Phylogenetic analyses and restriction fragment length polymorphism results indicated that the civets were infected by the Asia-1 strain of CDV commonly found in dogs in Thailand. The deduced amino acid sequences of the signaling lymphocyte activation molecule binding region of the CDV-H proteins revealed a Y549H mutation in both CDV-infected Asian palm civets (n = 4) and a co-located dog. We report a canine distemper outbreak in a civet colony with lineage classification and a Y549H mutation in noncanid species in Thailand.

The Use of Botulinum Toxin for the Treatment of Generalized Myoclonus in a DogS

A 13 mo old spayed female mixed-breed dog presented in a nonambulatory state that was attributed to severe myoclonus secondary to distemper. The authors hypothesized that mitigating the myoclonus would help the dog become ambulatory and expedite convalescence. They injected the severely affected muscles with botulinum toxin on two separate occasions over a period of 18 days. Those injections reduced the myoclonus, helping the dog become ambulatory and attaining a comfortable, functional state.

Neuropatologia da cinomose canina: 70 casos (2005-2008)

Este estudo teve como objetivo realizar uma investigação anátomo-patológica detalhada das lesões e sua distribuição no sistema nervoso central (SNC) de cães com cinomose. Foram avaliadas secções padronizadas do encéfalo e da medula espinhal de 70 cães. Os casos foram agrupados de acordo com a idade dos cães e classificados conforme a evolução das lesões. Os resultados permitem concluir que: (1) encefalomielite induzida pelo vírus da cinomose canina é mais prevalente em filhotes e adultos; (2) lesões macroscópicas no SNC ocorrem com baixa freqüência; (3) o encéfalo é mais acometido do que a medula espinhal; (4) as cinco regiões anatômicas mais afetadas do encéfalo são, em ordem decrescente de freqüência, o cerebelo, o diencéfalo, o lobo frontal, a ponte e o mesencéfalo; (5) a região anatômica mais afetada da medula espinhal é o segmento cervical cranial (C1-C5); (6) lesões subagudas e crônicas são mais comuns do que lesões agudas; (7) desmielinização é a lesão mais prevalente e ocorre principalmente no cerebelo, na ponte e no diencéfalo, quase sempre acompanhada de astrogliose e inflamação não-supurativa; (8) na maior parte dos casos em que há astrogliose, observam-se astrócitos gemistocíticos, freqüentemente com formação de sincícios; (9) leptomeningite não-supurativa, malacia e necrose cortical laminar são lesões relativamente freqüentes no encéfalo, mas não na medula espinhal; (10) corpúsculos de inclusão no encéfalo são muito comuns, ocorrem principalmente em astrócitos e com freqüência menor em neurônios; no entanto, independentemente da célula afetada, são vistos predominantemente no núcleo; (11) uma classificação da encefalite na cinomose com base em síndromes clínicas relacionadas com a idade do cão é imprecisa.

Pathogenesis and immunopathology of systemic and nervous canine distemper

Canine distemper is a worldwide occurring infectious disease of dogs, caused by a morbillivirus, closely related to measles and rinderpest virus. The natural host range comprises predominantly carnivores. Canine distemper virus (CDV), an enveloped, negative-sense RNA virus, infects different cell types, including epithelial, mesenchymal, neuroendocrine and hematopoietic cells of various organs and tissues. CDV infection of dogs is characterized by a systemic and/or nervous clinical course and viral persistence in selected organs including the central nervous system (CNS) and lymphoid tissue. Main manifestations include respiratory and gastrointestinal signs, immunosuppression and demyelinating leukoencephalomyelitis (DL). Impaired immune function, associated with depletion of lymphoid organs, consists of a viremia-associated loss of lymphocytes, especially of CD4+ T cells, due to lymphoid cell apoptosis in the early phase. After clearance of the virus from the peripheral blood an assumed diminished antigen presentation and altered lymphocyte maturation cause an ongoing immunosuppression despite repopulation of lymphoid organs. The early phase of DL is a sequel of a direct virus-mediated damage and infiltrating CD8+ cytotoxic T cells associated with an up-regulation of pro-inflammatory cytokines such as interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha and IL-12 and a lacking response of immunomodulatory cytokines such as IL-10 and transforming growth factor (TGF)-beta. A CD4+-mediated delayed type hypersensitivity and cytotoxic CD8+ T cells contribute to myelin loss in the chronic phase. Additionally, up-regulation of interferon-gamma and IL-1 may occur in advanced lesions. Moreover, an altered balance between matrix metalloproteinases and their inhibitors seems to play a pivotal role for the pathogenesis of DL. Summarized, DL represents a biphasic disease process consisting of an initial direct virus-mediated process and immune-mediated plaque progression. Immunosuppression is due to early virus-mediated lymphocytolysis followed by still poorly understood mechanisms affecting antigen presentation and lymphocyte maturation.

B, Graça DL, Kommers GD, Irigoyen LF, Barros CS. Aspectos clinicopatológicos de 620 casos neurológicos de cinomose em cães: Clinicopathological features in 620 neurological cases of canine distemper

Os protocolos de 5.361 necropsias de cães realizadas no Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria de 1965 a 2006 foram revisados à procura de casos de cinomose. Seiscentos e oitenta e três casos (12,7%) da doença foram encontrados, dos quais 620 apresentavam sinais neurológicos. Desses 620, os seguintes dados foram recuperados para cada caso: idade, sinais clínicos, achados histopatológicos e presença ou não de doença concomitante. Faixas etárias foram classificadas como filhotes (até 1 ano), adultos (de 1 a 9 anos) e idosos (10 anos de idade ou mais). Lesões histológicas foram observadas em 565 (91,1%) dos 620 casos com sinais neurológicos de cinomose e em 554 desses casos a idade foi registrada no protocolo com a seguinte distribuição por faixa etária: 45,9% de filhotes, 51,4% de adultos e 2,7% de idosos. Os sinais neurológicos compreendiam um largo espectro de distúrbios motores, posturais e do comportamento, que podiam ocorrer juntos ou individualmente. Os sinais clínicos mais freqüentes foram mioclonia (38,4%), incooordenação motora (25,0%), convulsões (18,5%) e paraplegia (13,4%). Em 98,4% dos 565 cães com alterações histopatológicas no encéfalo, foram observadas desmielinização, encefalite não-supurativa ou uma combinação dessas duas lesões. Corpúsculos de inclusão foram observados em diferentes células de 343 dos 565 cães com alterações histopatológicas no encéfalo. Em 170 (49,6%) o tipo celular com inclusão não foi mencionado no protocolo; nos restantes, as inclusões foram vistas em astrócitos (94,8% dos casos), neurônios (3,5%), oligodendrócitos (1,1%) e células do epêndima (0,6%). Levando em consideração o tipo de lesões e as faixas etárias, casos com desmielinização e encefalite não-supurativa ocorreram em 40,0% dos filhotes, 51,2% dos adultos e 72,7% dos cães idosos. Somente desmielinização foi descrita em 48,4% dos filhotes, 41,3% dos adultos e 35,7% dos cães idosos. Somente encefalite não-supurativa foi descrita em 11,6% dos filhotes, 7,5% dos adultos e 7,1% dos cães idosos.

Clinicopathological findings in dogs with distemper encephalomyelitis presented without characteristic signs of the disease

The clinical diagnosis of distemper is difficult in dogs presented with nervous deficits in the absence of extraneural signs and myoclonus. The aim of this study is to verify how the clinicopathological findings may suggest distemper encephalomyelitis in such cases. We prospectively investigated 20 necropsied dogs presented with neurological signs without those characteristic signs of distemper at the time of hospital admission. Eight out of 20 dogs were diagnosed with distemper encephalomyelitis at post mortem by reverse transcription-polymerase chain reaction (RT-PCR) and histological examination. Cerebellar and/or vestibular signs progressing to tetraparesis/plegia were frequent neurological signs. Abnormalities in hematologic findings were non-specific, nevertheless the cerebrospinal fluid evaluation could suggest canine distemper virus (CDV) infection by a lymphocytic pleocytosis. At post mortem chronic CDV encephalomyelitis was predominant. Our clinical results, as well as the predominance of chronic encephalomyelitis, differ from other studies about CDV encephalomyelitis with naturally infected dogs presenting extraneural signs and myoclonus.

A molecular study of hippocampus in dogs with convulsion during canine distemper virus encephalitis

In this study, we have investigated the expression of the nuclear transcription factor (c-Fos, NFkB), growth factors (nerve growth factor--NGF, brain-derived neurotrophic factor--BDNF), peptides (enkephalin, galanin) and glutamate transporter (AA 504-523 rat EAAC1) in 6 dogs sacrificed immediately after seizure attack during encephalomyelitis due to canine distemper virus (CDV) (as assessed by clinical examination, RT-PCR and viral RNA detection either in blood or brain tissue and CDV immunohistochemistry in brain slices). In all these CDV affected dogs, the observed neurological signs included untreatable seizures, leading to cluster seizure activity and status epilepticus. In the inter-ictal phase abnormal mentation, postural and gait deficits and sometimes involuntary movements such as myoclonus were recorded. The same investigation was carried out in 5 control dogs affected by different disorders, all characterized by the absence of seizures. Brains were dissected out immediately after euthanasia and fixed; sections collected from the dorsal hippocampus were processed for immunohistochemistry. By comparing hippocampus sections obtained from dog with and without seizure, the following regulations were observed. A strong up-regulation of glutamate transporter throughout the cell layers was found together with the onset of nuclear Fos and NFkB-IR in the pyramidal cell layer X. Among the investigated peptides, we observed a slight increase in enkephalinergic fibers and a strong up-regulation of mu-opioid receptors, whereas galanin-IR seemed to be weaker. Finally, both NGF and BDNF expression was strongly up-regulated. BDNF-IR was mainly localized in the apical dendrite in pyramidal neurons. To our knowledge, these data offer the first indication that molecular events described in experimental kindling also occur during spontaneous pathology in animal species sharing close similarities to human neuropathology.

Antemortem Diagnosis of CDV Infection by RT-PCR in Distemper Dogs with Neurological Deficits without the Typical Clinical Presentation

In dogs with neurological disturbances without myoclonus and extraneural signs, the clinical diagnosis of distemper is difficult perform. Considering the great infectious potential of the disease, the possibility of carrying out an antemortem diagnosis of distemper is important, particularly in hospitalized patients with neurological disease. The present study was carried out to evaluate RT-PCR for antemortem CDV detection in hospitalized dogs with neurological disturbances without the typical findings of distemper. We investigated five dogs with canine distemper virus (CDV) encephalomyelitis, in which the clinical diagnosis was not performed owing to the absence of characteristic signs of the disease, such as myoclonus and systemic signs. We observed an apparent high sensitivity of RT-PCR in urine samples for detection of CDV: four out of five urine samples were RT-PCR positive. The results of the present study suggest that urine is a good biological sample for antemortem CDV detection by RT-PCR in dogs with distemper encephalomyelitis in which the clinical diagnosis is likely to be difficult owing to the absence of suggestive distemper signs. The use of two different body fluids (urine and CSF) may increase the RT-PCR sensitivity for antemortem diagnosis of distemper in such cases.

Pediatric Neurology of the Dog and Cat

The neurologic examination in the puppy or kitten can be a challenging experience. Understanding the development of behavior reflexes and movement in puppies and kittens enables us to overcome some of these challenges and to recognize the neurologically abnormal patient. Subsequently,we can identify the neuroanatomic localization and generate a differential diagnosis list. This article first reviews the pediatric neurologic examination and then discusses diseases unique to these individuals.