Selwyn Arlington Headley

Cinomose: achados epidemiológicos de 250 casos

A review of the number of dogs submitted for necropsy at the Department of Veterinary Pathology of the Federal University of Santa Maria, RS, between 1985-1997 has shown that 11.7% (250/2136) had lesions and inclusion bodies characteristic of infection by canine distemper virus (CDV). Most of these cases occurred during the winter months in dogs that were less than 1.5 year old, which were submitted by residents from the city of Santa Maria. Canine distemper is considered endemic in this city. Significant differences in susceptibility were not observed between males and females. Mongrel dogs were super-represented, but dolichocephalic breeds were more affected than brachycephalic ones. Distemper encephalopathy with typical CDV inclusion bodies, especially in astrocytes, was the main lesion and occurred in 82% of these cases. Eosinophilic inclusion bodies characteristic of canine distemper were also observed in epithelial cells of the urinary bladder (15%), lung (6%), stomach (3%), kidney (1%), and tonsil (0.5%).

Molecular Detection of Canine Distemper Virus and the Immunohistochemical Characterization of the Neurologic Lesions in Naturally Occurring Old Dog Encephalitis

The current article describes a spontaneous case of old dog encephalitis (ODE) in a 7–year-old, intact, female Miniature Schnauzer dog from Londrina, Paraná, southern Brazil. Unlike conventional distemper encephalomyelitis, ODE is a poorly understood and extremely rare manifestation of Canine distemper virus (CDV) infection. The dog was presented with progressive clinical manifestations consistent with cerebral dysfunction. Briefly, histopathologic lesions were restricted to the forebrain and included chronic multifocal lymphoplasmacytic encephalitis with extensive perivascular cuffing, astrocytosis, and intranuclear inclusions within astrocytes and giant cells, with both intracytoplasmic and intranuclear inclusions. Immunohistochemistry (IHC) was used to identify the antigens of the nucleoprotein (NP) of CDV and to detect cluster of differentiation (CD)3, CD79a, macrophage (MAC) 387, glial fibrillary acidic protein, and vimentin to characterize the neuroparenchymal lesions. By IHC, CDV NP was demonstrated predominantly within neurons and astrocytes. Cells that formed perivascular cuffs and some astrocyte-like cells reacted intensely to vimentin. Reverse transcription polymerase chain reaction assay from brain sections further confirmed a role for CDV in this disease by the amplification and partial sequence analysis of the NP gene. These findings confirmed simultaneous detection of CDV in ODE by IHC and molecular assays. In addition, results of the current study could contribute to the neuropathologic characterization of this rare manifestation of CDV.

Neorickettsia helminthoeca and salmon poisoning disease: A review

Neorickettsia helminthoeca is an obligate intra-cytoplasmic bacterium that causes salmon poisoning disease (SPD), an acute, febrile, fatal disease of dogs. The complex life-cycle of this pathogen involves stages in an intestinal fluke (Nanophyetus salmincola), a river snail (Oxytrema silicula), in fish, and in fish-eating mammals. This complexity has created confusion with respect to the various bacterial and parasitic infections associated with the disease and its significance in dogs in specific geographical locations has likely to have previously been under-estimated. This paper addresses the history, taxonomy, microbiology of N. helminthoeca and summarises the pathogenesis, clinical signs and pathological features associated with infection. Furthermore, the biological cycles, treatment, control, and both public and veterinary health impacts associated with this pathogen and the intestinal fluke N. salmincola are discussed.

First analysis of the secretome of the canine heartworm, Dirofilaria immitis

BackgroundThe characterization of proteins released from filariae is an important step in addressing many of the needs in the diagnosis and treatment of these clinically important parasites, as well as contributing to a clearer understanding of their biology. This report describes findings on the proteins released during in vitro cultivation of adult Dirofilaria immitis , the causative agent of canine and feline heartworm disease. Differences in protein secretion among nematodes in vivo may relate to the ecological niche of each parasite and the pathological changes that they induce.MethodsThe proteins in the secretions of cultured adult worms were run on Tris-Glycine gels, bands separated and peptides from each band analysed by ultra mass spectrometry and compared with a FastA dataset of predicted tryptic peptides derived from a genome sequence of D. immitis.ResultsThis study identified 110 proteins. Of these proteins, 52 were unique to D. immitis . A total of 23 (44%) were recognized as proteins likely to be secreted. Although these proteins were unique, the motifs were conserved compared with proteins secreted by other nematodes.ConclusionThe present data indicate that D. immitis secretes proteins that are unique to this species, when compared with Brugia malayi. The two major functional groups of molecules represented were those representing cellular and of metabolic processes. Unique proteins might be important for maintaining an infection in the host environment, intimately involved in the pathogenesis of disease and may also provide new tools for the diagnosis of heartworm infection.

Clinical observations of cattle and buffalos with experimentally induced chronic copper poisoning.

The susceptibility of cattle and buffalos to chronic copper poisoning (CCP) was compared by using cattle (n=10) and buffalo (n=10) steers distributed into two copper supplemented (n=6) and two control (n=4) groups. Supplemented animals received 2 mg copper (Cu)/kg body weight daily for one week, with an additional 2 mg weekly until the end of the experiment (day 105). Three liver biopsies (day 0, 45, and 105) were obtained for mineral analyses; clinical examinations and blood samples were obtained every 15days. Three supplemented cattle and two buffalos with typical manifestations of CCP died. There were no differences in the frequency of mortality between cattle and buffalos; hepatic copper concentration was higher in cattle than buffalos. These findings suggest that buffalos and cattle might be equally susceptible to CCP. However, buffalos accumulate less liver copper than cattle and have a lower threshold of hepatic Cu accumulation, which leads to clinical manifestation of CCP.

Occurrence of Ehrlichia canis and Anaplasma platys in household dogs from northern Parana

Canine monocytic ehrlichiosis caused primarily by Ehrlichia canis and canine thrombocytic anaplasmosis induced by Anaplasma platys are important emerging zoonotic tick-borne diseases of dogs. There is evidence that these pathogens can also affect humans. This study evaluated the presence of E. canis and A. platys in blood samples collected from 256 domiciled dogs in the municipality of Jataizinho, located in north region of the State of Parana, Brazil, by PCR assay. The occurrence of E. canis and A. platys was 16.4% (42/256) and 19.4% (49/256), respectively; while 5.47% (14/256) of the dogs evaluated were co-infected by these two organisms. The presence of E. canis and A. platys was not significantly associated with the variables evaluated (sex, age, outdoor access, and presence of ticks during blood collection). Infection of dogs by E. canis was associated with anemia and thrombocytopenia, while infection induced by A. platys was related only to thrombocytopenia. Canine monocytic ehrlichiosis and canine thrombocytic anaplasmosis should be included in the differential diagnoses when these hematological alterations are observed during routine laboratory evaluation of dogs.

Leishmaniose visceral (Calazar): cinco casos em cães de Santa Maria, Rio Grande do Sul, Brasil

Five canine cases of visceral leishmaniasis were diagnosed. All five dogs presented with icterus, intermitent fever, vomition, anorexia and emaciation. The most prominent gross lesions were hemorrhagic gastroenteritis, interstitial pneumonia and splenomegaly. In tissue sections, free and intracellular forms of Leishmania spp were depicted in macrophages and endothelial cells of all organs scanned. Epidemiological survey to detect either the agent or the sandfly was negative.

Clinical Manifestations of Senecavirus A Infection in Neonatal Pigs, Brazil, 2015

We identified new clinical manifestations associated with Senecavirus A infection in neonatal piglets in Brazil in 2015. Immunohistochemical and molecular findings confirmed the association of Senecavirus A with these unusual clinical signs and more deaths. Other possible disease agents investigated were not associated with these illnesses.

Equine cutaneous pythiosis: a report of four cases

Cutaneous pythiosis is described in four horses in Northern Parana, Brazil. All animals presented ulcerative, granulomatous, cutaneous lesions that did not invade adjacent muscular tissues. Histopathological evaluations revealed eosinophilic granulomatous reactions associated with intralesional hyphae suggestive of Pythium insidiosum observed at the margins of coagula. P. insidiosum hyphae were visualized by Gomori’s methenamine silver stain.

Concomitant canine distemper, infectious canine hepatitis, canine parvoviral enteritis, canine infectious tracheobronchitis, and toxoplasmosis in a puppy

The concomitant infections of Canine distemper virus (CDV), Canine adenovirus A types 1 (CAdV-1) and 2 (CAdV-2), Canine parvovirus type 2 (CPV-2), and Toxoplasma gondii are described in a 43-day-old mixed-breed puppy. Clinically, there were convulsions and blindness with spontaneous death; 14 siblings of this puppy, born to a 10-month-old dam, which was seropositive (titer: 1,024) for T. gondii, also died. Necropsy revealed unilateral corneal edema (blue eye), depletion of intestinal lymphoid tissue, non-collapsible lungs, congestion of meningeal vessels, and a pale area in the myocardium. Histopathology demonstrated necrotizing myocarditis associated with intralesional apicomplexan protozoa; necrotizing and chronic hepatitis associated with rare intranuclear inclusion bodies within hepatocytes; necrotizing bronchitis and bronchiolitis; interstitial pneumonia associated with eosinophilic intracytoplasmic inclusion bodies within epithelial cells; atrophy and fusion of intestinal villi with cryptal necrosis; and white matter demyelination of the cerebrum and cerebellum associated with intranuclear inclusion bodies within astrocytes. Polymerase chain reaction (PCR) amplified the partial fragments (bp) of the CDV N gene (290 bp), CPV-2c VP2 capsid protein gene (583 bp), and CAdV-1 (508 bp) and CAdV-2 (1,030 bp) E gene from urine and tissue samples. The PCR assays demonstrated that the apicomplexan protozoa observed within several organs contained DNA specific for T. gondii; genotyping revealed T. gondii type III. The findings support the characterization of concomitant infections of CDV, CAdV-1, CAdV-2, CPV-2, and T. gondii in this puppy. Further, seroreactivity to T. gondii of the dam in association with the systemic disease observed in the puppy described herein is suggestive of congenital toxoplasmosis.