Interstitial pneumonia in neonatal canine pups with evidence of canine distemper virus infection

Pneumomediastino, pneumotórax e enfisema subcutâneo em cão com pneumopatia e infecção pelo vírus da cinomose: relato de caso

RESUMO Relata-se um caso de pneumomediastino, pneumotórax e enfisema subcutâneo em um cão com pneumopatia associada à cinomose. As queixas principais eram tosse, secreção nasal purulenta, apatia e enfisema subcutâneo em face, região cervical e torácica. O exame radiográfico evidenciou pneumomediastino, pneumotórax e broncopneumopatia grave com áreas de consolidação pulmonar. Teste rápido imunocromatográfico para detecção de antígeno da cinomose foi positivo e houve melhora dos sinais respiratórios com antibioticoterapia, porém o quadro evoluiu para alterações neurológicas. De acordo com a revisão de literatura realizada, não há casos semelhantes relatados.

Interstitial pneumonia and pulmonary hypertension associated with suspected ehrlichiosis in a dog

Background

In dogs with canine monocytic ehrlichiosis (CME), respiratory signs are uncommon and clinical and radiographic signs of interstitial pneumonia are poorly described. However, in human monocytic ehrlichiosis, respiratory signs are common and signs of interstitial pneumonia are well known. Pulmonary hypertension (PH) is classified based on the underlying disease and its treatment is aimed at reducing the clinical signs and, if possible, addressing the primary disease process. PH is often irreversible, but can be reversible if it is secondary to a treatable underlying etiology. CME is currently not generally recognized as one of the possible diseases leading to interstitial pneumonia and secondary PH in dogs. Only one case of PH associated with CME has been reported worldwide.

Case presentation

A seven-year-old, male intact, mixed breed dog was presented with 2 weeks history of lethargy and dyspnea. The dog previously lived in the Cape Verdean islands. Physical examination showed signs of right-sided congestive heart failure and poor peripheral perfusion. Thoracic radiography showed moderate right-sided cardiomegaly with dilation of the main pulmonary artery and a mild diffuse interstitial lung pattern with peribronchial cuffing. Echocardiography showed severe pulmonary hypertension with an estimated pressure gradient of 136 mm Hg. On arterial blood gas analysis, severe hypoxemia was found and complete blood count revealed moderate regenerative anemia and severe thrombocytopenia. A severe gamma hyperglobulinemia was also documented. Serology for Ehrlichia canis was highly positive. Treatment with oxygen supplementation, a typed packed red blood cell transfusion and medical therapy with doxycycline, pimobendan and sildenafil was initiated and the dog improved clinically. Approximately 2 weeks later, there was complete resolution of all clinical signs and marked improvement of the PH.

Conclusion

This report illustrates that CME might be associated with significant pulmonary disease and should be considered as a possible differential diagnosis in dogs presenting with dyspnea and secondary pulmonary hypertension, especially in dogs that have been in endemic areas. This is important because CME is a treatable disease and its secondary lung and cardiac manifestations may be completely reversible.

Cetacean Morbillivirus-Associated Pathology: Knowns and Unknowns

The present minireview deals with the pathology of Cetacean Morbillivirus (CeMV) infection in free-ranging cetaceans. In this respect, while "classical" CeMV-associated lesions were observed in the lung, brain, and lymphoid tissues from striped dolphins (Stenella coeruleoalba) and pilot whales (Globicephala melas) which were victims of the 1990-1992 and 2006-2008 epidemics in the Western Mediterranean, an apparent reduction in CeMV neurovirulence, along with a different viral antigen's tissue and cell distribution, were found during the 2010-2011 and the 2013 outbreaks in the same area. Of remarkable concern are also the documented CeMV ability to induce maternally acquired infections in wild cetaceans, coupled with the progressively expanding geographic and host range of the virus in both Hemispheres, as well as in conjunction with the intriguing forms of "brain-only" morbilliviral infection increasingly reported in Mediterranean-striped dolphins. Future research in this area should address the virus-host interaction dynamics, with particular emphasis on the cell receptors specifying viral tissue tropism in relation to the different cetacean species and to their susceptibility to infection, as well as to the CeMV strains circulating worldwide.

The adaptive value of morphological, behavioural and life-history traits in reproductive female wolves

Reproduction in social organisms is shaped by numerous morphological, behavioural and life-history traits such as body size, cooperative breeding and age of reproduction, respectively. Little is known, however, about the relative influence of these different types of traits on reproduction, particularly in the context of environmental conditions that determine their adaptive value. Here, we use 14 years of data from a long-term study of wolves (Canis lupus) in Yellowstone National Park, USA, to evaluate the relative effects of different traits and ecological factors on the reproductive performance (litter size and survival) of breeding females. At the individual level, litter size and survival improved with body mass and declined with age (c. 4-5 years). Grey-coloured females had more surviving pups than black females, which likely contributed to the maintenance of coat colour polymorphism in this system. The effect of pack size on reproductive performance was nonlinear as litter size peaked at eight wolves and then declined, and litter survival increased rapidly up to three wolves, beyond which it increased more gradually. At the population level, litter size and survival decreased with increasing wolf population size and canine distemper outbreaks. The relative influence of these different-level factors on wolf reproductive success followed individual > group > population. Body mass was the primary determinant of litter size, followed by pack size and population size. Body mass was also the main driver of litter survival, followed by pack size and disease. Reproductive gains because of larger body size and cooperative breeding may mitigate reproductive losses because of negative density dependence and disease. These findings highlight the adaptive value of large body size and sociality in promoting individual fitness in stochastic and competitive environments.

Detecção molecular e análise filogenética do gene H de amostras do vírus da cinomose canina em circulação no município de Campinas, São Paulo

O vírus da cinomose canina (CDV), um Morbillivirus da família Paramyxoviridae, é o agente etiológico de doença neurológica e sistêmica em cães. O diagnóstico laboratorial da infecção requer o isolamento viral ou detecção do material genético do vírus em secreções ou tecidos de cães com suspeita clínica da doença. A diversidade genética entre os isolados de CDV pode ser aferida pelo sequenciamento efilogenia molecular do gene que codifica a hemaglutinina viral (gene H), havendo atualmente um especial interesse em comparar as amostras circulantes a campo com o genogrupo América-1, que abrange as cepas presentes nas vacinas disponíveis no mercado. No presente estudo, foi realizada a detecção molecular do gene H de CDV a partir de amostras biológicas colhidas ante- e post- -mortem de 15 cães com sinais clínicos sugestivos de cinomose na região metropolitana de Campinas, São Paulo. Dez dos 15 cães analisados tiveram ao menos um órgão positivo na detecção molecular e os amplicons obtidos foram submetidos ao sequenciamento nucleotídico seguido de análise filogenética molecular. De forma semelhante ao que já foi reportado para estudo analisando a diversidade do gene H em outros países, a reconstrução filogenética obtida para as amostras de casos de cinomose da região de Campinas demonstrou as mesmas foram agrupadas junto a amostras norte-americanas, europeias e japonesas recentes, em um grupo genético distinto do grupo de amostras clássicas de CDV, nomeado America-1, o qual engloba as estirpes vacinais Snyder Hill, Onderstepoort e Lederle.