Felines play a leading role in the epidemiology of Toxoplasma gondii infection, but there is scarce information about the epidemiology of Neospora caninum, particularly in feline immunodeficiency virus (FIV)-infected cats. Cats seropositive to T. gondii do not usually show symptoms unless they are immunosuppressed, such as FIV-infected cats. The same relationship remains poorly known for N. caninum, although it has been associated with neurological disorders in HIV-infected people. Since FIV-infected cats are prone to develop encephalitis of unknown etiology, this study aimed to evaluate the presence of specific antibodies to T. gondii and N. caninum in a shelter for stray cats naturally infected with FIV. A total of 104 serum samples from cats living in a shelter, located in São Paulo city (Brazil), was assessed for T. gondii and N. caninum specific antibody by indirect fluorescent-antibody test (IFAT). Of the 104 cats, 25 (24%) were infected with FIV and, aside from these, 8 (32%) had antibodies against T. gondii (titers from 16 to 128). Only 1 (4%) of the FIV infected cats had antibodies against N. caninum, which was the first record of coinfection. Among the FIV-naïve cats, 11 (14%) were positive for T. gondii (titers from 16 to 256) and only 1 (1.2%) had antibodies against N. caninum. Serologically positive reactions to T. gondii and N. caninum were not correlated with age or sex (p>0.05), and there was no correlation between FIV and the occurrence of anti-T. gondii or anti-N. caninum antibodies (p>0.05). Further studies encompassing larger cat populations from different origins and locations are essential to clarify the prevalence of T. gondii and N. caninum antibodies in FIV-positive cats.

Serum samples from 116 horses and 47 dogs from the municipality of Paulicéia, in the state of São Paulo, Brazil, were examined for anti-Toxoplasma gondii, -Neospora spp. and -Sarcocystis neurona antibodies by means of the indirect fluorescent antibody test (IFAT). The results showed that only one horse was seropositive for T. gondii (0.9%) and anti-Neospora spp. antibodies were detected in three out of the 116 horses tested (2.6%). However, 27 horses showed antibodies against S. neurona (23.8%). Amongst the serum samples from the dogs, 10 out of the 47 dogs showed antibodies against T. gondii (21.3%) and three dogs showed antibodies against Neospora caninum (6.4%). This study reports that in the municipality of Paulicéia dogs in both the rural and the urban area were exposed to T. gondii and N. caninum, while horses in the rural area were exposed to all three protozoa studied, with high occurrence of anti-S. neurona antibodies.

The occurrence and distribution of antibodies against Sarcocystis neurona, Neospora caninum and Toxoplasma gondii was investigated in horses, dogs and cats from Curitiba, Paraná state, Brazil. Serum samples were selected from 100 horses, 100 dogs and 100 cats from the routine of the Veterinary Clinical Pathology Laboratory in the Veterinary Hospital of the University of Paraná (UFPR). The 100 dog samples were divided into two groups: 35 samples from dogs with neurological sign (convulsion) and 65 samples from dogs without neurological signs. The animals were adults of different breeds, males and females. Samples were analyzed by indirect fluorescent antibody test (IFAT) for protozoa S. neurona, N. caninum andT. gondii at the following cut-off dilutions: horses: 1:50, 1:50 and 1:16; dogs: 1:50, 1:50 and 1:16; cats: 1:50, 1:50 and 1:50, respectively. The obtained results were 42% of horses, 7% of dogs and 5% of cats seropositive for S. neurona; 58% of horses, 68% of dogs and 42% of cats seropositive to N. caninum, and 36% of horses, 20% of dogs and 21% of cats seropositive for T. gondii. Among the dogs with neurological signs, 8.6%, 68.6% and 25.7% were seropositive for S. neurona, N. caninum and T. gondii, respectively. Among the dogs without neurological signs, 6.2% 67.7% and 16.9% were seropositive for S. neurona, N. caninum and T. gondii, respectively. No statistical difference was found between groups of seropositive dogs for the three protozoa with neurological signs and without neurological signs. Co-infection and high antibody titers were detected. The antibodies against Sarcocystis neurona, Neospora caninum and Toxoplasma gondii were found widely distributed among horses, dogs and cats in the region of Curitiba, state of Paraná, Brazil.

Objective--To evaluate the immunologic response of a killed tachyzoite vaccine against Neospora caninum and its effectiveness in preventing fetal loss associated with experimentally induced neosporosis in sheep. Animals--30 Dorset ewes. Procedure--Ewes were randomly allocated to receive vaccination on days 1 and 60 of the study with a killed N caninum tachyzoite preparation in a commercially available adjuvant or a saline-adjuvant mixture. A ram was placed on pasture with the ewes from days 15 to 60. Blood was collected from ewes before primary and booster vaccinations and prior to experimental challenge with N caninum tachyzoite performed on day 90; sera were assessed via Neospora agglutination (NA) and immunofluorescence antibody (IFA) assays. Blood was collected from lambs before they suckled, and sera were tested for antibodies against N caninum. Results--Of the 14 vaccinated ewes that became pregnant, 12 gave birth to live-born lambs; in contrast, 5 of 11 pregnant control ewes gave birth to live-born lambs. Whereas vaccination improved fetal survival in pregnant ewes challenged with N caninum tachyzoites, it did not appear to have any appreciable effect on transmission of N caninum to offspring, as indicated by results of NA and IFA assays. Conclusions and Clinical Relevance--The N caninum tachyzoite vaccine used in this study appeared to provide protection against fetal loss associated with experimentally induced neosporosis in a high proportion of pregnant ewes.

In order to assess the frequency of dairy goats seropositive for Neospora caninum in the state of São Paulo, and its relationship with age, sex, presence of dogs and reproductive problems in goat pens, serum samples were obtained from 923 goats of both sexes older than 3 months of age. Samples were collected in 17 properties located in different municipalities. Neospora agglutination test (NATe"25) was used to determine the presence of Neospora caninum in all animals. Epidemiological and reproductive data were obtained through a questionnaire which was administered in all goat pens. Significance level was set at 5% for all statistical tests. N. caninum positivity rate was 19.77%. Only one of the properties had no seropositive animal revealing N. caninum diffusion in the state. Seropositivity frequency did not correlate with sex, age, or reproductive problems. However, the presence of dogs was associated with a higher frequency of N. caninum seropositivity. A choroplethic map with hatch patterns showing the geographical distribution of goats seropositive for Neospora caninum may considerably contribute to geographic epidemiological studies and the development of disease control strategies.