ABDOMINAL ULTRASONOGRAPHIC FINDINGS IN DOGS NATURALLY INFECTED WITH BABESIOSIS

Canine babesiosis is a tick‐borne disease with a worldwide distribution that can involve multiple organs and result in a wide variety of clinical manifestations. Our goal was to describe the sonographic changes occurring in 72 dogs naturally infected with babesiosis. Seven healthy Beagle dogs were used as a control group. The most common finding in all dogs was splenomegaly with a diffuse heterogenic parenchyma and generally reduced echogenicity. Diffuse hypoechoic hepatomegaly and bilaterally increased cortical echogenicity of the renal parenchyma were found more frequently in severe uncomplicated and complicated babesiosis groups. Mean renal resistive index and pulsatility index (PI) values were 0.66/1.35, 0.73/1.91, and 0.71/1.73 for mild uncomplicated, severe uncomplicated, and complicated babesiosis groups, respectively. A markedly increased PI for complicated and severe uncomplicated groups correlated with anemia and severity of renal damage. Ultrasonography can be an adjunct for diagnosis and monitoring canine babesiosis and its systemic complications. The detection of diffuse heterogeneous splenomegaly can support the diagnosis of Babesia infection, because of the high prevalence of this lesion in these patients.     

Immunohistochemical detection of virus antigen in the nasal planum of rabid dogs

The rabies virus is one of the most neurotropic of all viruses infecting mammals. During the terminal phases of infection, the virus spreads to peripheral tissues, including the skin. The external skin of the nose, called the nasal planum, is a sensory organ where numerous nerve bundles and terminal nerves are distributed. Therefore, the nasal planum is expected to serve as a postmortem diagnostic material. However, the distribution of rabies virus antigens in the nasal planum in rabid animals has not yet been studied. In this study, the nasal planum was obtained from 45 rabid dogs. In all rabid dogs, the viral antigen was detected in the peripheral nerve tissues, Merkel cells, and squamous cells. The viral antigen in the epidermis exhibited three patterns: first, a diffuse positive pattern from the basal layer to the squamous layer; second, a reticular positive pattern along the cell membrane in the squamous layer; and third, a basal layer pattern of the epidermis. In the dermis, viral antigens were detected more often in lamellated corpuscles just beneath the rete pegs. These results suggest that the nasal planum could serve as a useful alternative source for postmortem diagnosis in rabies endemic countries.     

Relating spatial and temporal scales of climate and ocean variability to survival of Pacific Northwest Chinook salmon (Oncorhynchus tshawytscha)

Pacific Northwest Chinook, Oncorhynchus tshawytscha, have exhibited a high degree of variability in smolt‐to‐adult survival over the past three decades. This variability is summarized for 22 Pacific Northwest stocks and analyzed using generalized linear modeling techniques. Results indicate that survival can be grouped into eight distinct regional clusters: (1) Alaska, Northern BC and North Georgia Strait; (2) Georgia Strait; (3) Lower Fraser River and West Coast Vancouver Island; (4) Puget Sound and Hood Canal; (5) Lower Columbia Tules; (6) Columbia Upriver Brights, Willamette and Cowlitz; (7) Oregon and Washington Coastal; and (8) Klamath River and Columbia River Summers. Further analysis for stocks within each of the eight regions indicates that local ocean conditions following the outmigration of smolts from freshwater to marine areas had a significant effect on survival for the majority of the stock groups analyzed. Our analyses of the data indicate that Pacific Northwest Chinook survival covaries on a spatial scale of 350–450 km. Lagged time series models are presented that link large‐scale tropical Pacific conditions, intermediate‐basin scale northeastern Pacific conditions, and local sea surface temperatures to survival of Pacific Northwest stocks.