Aspectos epidemiológicos, clínicos e hematológicos de 251 cães portadores de mórula de Ehrlichia spp. naturalmente infectados

Glomerulotubular pathology in dogs with subclinical ehrlichiosis

Subclinical stage of ehrlichiosis is characterized by absence of clinical or laboratory alterations; however, it could lead to silent glomerular/tubular changes and contribute significantly to renal failure in humans and animals. The aim of this study was to evaluate glomerular and tubular alterations in dogs with subclinical ehrlichiosis. We evaluated renal biopsies of 14 bitches with subclinical ehrlichiosis and 11 control dogs. Samples were obtained from the left kidney, and the tissue obtained was divided for light microscopy, immunofluorescence, and transmission electron microscopy. Abnormalities were identified by light microscopy in 92.9% of dogs with ehrlichiosis, but not in any of the dogs of the control group. Mesangial cell proliferation and synechiae (46.1%) were the most common findings, but focal segmental glomerulosclerosis and ischemic glomeruli (38.4%), focal glomerular mesangial matrix expansion (30.7%), mild to moderate interstitial fibrosis and tubular atrophy (23%), and glomerular basement membrane spikes (23%) were also frequent in dogs with ehrlichiosis. All animals with ehrlichiosis exhibited positive immunofluorescence staining for immunoglobulins. Transmission electron microscopy from dogs with ehrlichiosis revealed slight changes such as sparse surface projections and basement membrane double contour. The subclinical phase of ehrlichiosis poses a higher risk of development of kidney damage due to the deposition of immune complexes.

Epidemiology of canine visceral leishmaniasis in a vulnerable region in Brazil

Visceral leishmaniasis (VL) is a neglected and endemic zoonosis that occurs throughout Brazil; nevertheless, few studies have focused on the early detection of the disease. The municipality of Ourinhos is a non-receptive, silent and vulnerable area for VL, where the seroprevalence of this disease has so far not been investigated. The present study aimed to determine the seroprevalence of canine VL in Ourinhos-SP, and to identify the presence of risk factors. Blood samples were obtained from 604 dogs during a rabies vaccination campaign together with application of a socioeconomic questionnaire, environmental and animal characteristics and tutor's knowledge about the disease. The samples were subjected to indirect ELISA and new samples were collected from reactive and suspect animals, including whole blood and lymph node aspiration evaluated by parasitological method, complete blood count and PCR. No animal was diagnosed as positive based on the combination of direct and indirect tests and the tutors' answers indicated little knowledge about leishmaniasis, being often confused with other diseases transmitted by arthropods; hence, according to the proposed methods, the presence of canine leishmaniasis in the city of Ourinhos was not confirmed and health education campaigns about the disease should be carried out.

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.

Canine rangeliosis: the need for differential diagnosis

Rangeliosis is a hemoparasitosis that affects dogs in Brazil. The disease has similar clinical and pathological characteristics to other hemo-protozoan infections. So, this paper has aimed to report a clinical case of infection by Rangelia vitalii in one dog, focusing on the need for the differential diagnosis to other infectious diseases. The animal showed apathy, anemia, thrombocytopenia, alteration of leucogram, and bleeding. The first difference was the observation of parasites in blood smears, where R. vitalii was visualized within leukocytes and erythrocytes. The confirmation of the clinical diagnosis was made by molecular test to R. vitalii. The dog was debilitated, and died a few hours after treatment at the veterinary hospital. At necropsy, splenomegaly, lymphadenopathy, and mild jaundice in the abdominal viscera were found. This article draws attention to the need for the parasitological, serological, and molecular to differential diagnosis in order to differentiate from other clinically similar disorders.

Ehrlichiosis in Brazil

Ehrlichiosis is a disease caused by rickettsial organisms belonging to the genus Ehrlichia. In Brazil, molecular and serological studies have evaluated the occurrence of Ehrlichia species in dogs, cats, wild animals and humans. Ehrlichia canis is the main species found in dogs in Brazil, although E. ewingii infection has been recently suspected in five dogs. Ehrlichia chaffeensis DNA has been detected and characterized in mash deer, whereas E. muris and E. ruminantium have not yet been identified in Brazil. Canine monocytic ehrlichiosis caused by E. canis appears to be highly endemic in several regions of Brazil, however prevalence data are not available for several regions. Ehrlichia canis DNA also has been detected and molecularly characterized in three domestic cats, and antibodies against E. canis were detected in free-ranging Neotropical felids. There is serological evidence suggesting the occurrence of human ehrlichiosis in Brazil but its etiologic agent has not yet been established. Improved molecular diagnostic resources for laboratory testing will allow better identification and characterization of ehrlichial organisms associated with human ehrlichiosis in Brazil.

Risk factors and clinical disorders of canine ehrlichiosis in the South of Bahia, Brazil

The aim of this work was to study the clinical disorders and risk factors of canine ehrlichiosis in Ilhéus and Itabuna, Bahia, and compare different diagnostic methods. Blood samples were collected from 200 dogs. Each dog was clinically examined. A questionnaire was used to evaluate the risk factors. The blood samples were analyzed using the Dot-ELISA test; hematometry, platelet counts and searches for morulae on blood smears were performed. Nested PCR was carried out on 50 serologically positive samples and 50 negative samples. Three positive PCRs were sequenced. Thirty-six percent were serologically positivity and 5.5% from blood smears. The animals were anemic and thrombocytopenic. Presence of ticks and living in areas on the urban periphery were considered to be risk factors (p < 0.05). Nested PCR identified 11 positive dogs of which nine were serologically positive and two were negative. The DNA sequencing was consistent with the presence of Ehrlichia canis.