Supplementing narasin or monensin to control coccidiosis in naturally infected calves.

This experiment compared narasin and monensin as anticoccidials for calves naturally infected with Eimeria spp. Twenty-four weaned, non-castrated male calves (Bos indicus × B. taurus cross) were assigned to this experiment (days -8 to 42). All calves were infected by Eimeria spp. according to oocyst count per gram (OPG) from fecal samples collected on days -8 and -7 (average 1,059 ±â€…101 oocysts/g). Calves were housed in individual pens, received corn silage, mineral mix, and water for ad libitum consumption, in addition to a grain-based supplement at 200 g/head daily. Fecal samples were collected on days -2 and -1 for OPG, and results averaged as initial OPG value. Calves were blocked according to initial OPG into eight blocks of three calves each, ranked within each block according to body weight (BW) recorded on day -1, and assigned to receive narasin (NAR; 0.8 mg/kg of BW), monensin (MON; 1 mg/kg of BW), or no ionophore (CON; negative control). Ionophores were added to the grain-based supplement, and offered from days 0 to 42 of the experiment. Calf BW was recorded on days 7, 14, 21, 28, 35, and 42. Fecal samples were collected on days 6 and 7, 13 and 14, 20 and 21, 26 and 27, 34 and 35, and 41 and 42 for OPG analysis, and results from samples collected on consecutive days were averaged. Aliquoted fecal samples were also pooled across calves from the same treatment and collection days, and used to determine the prevalence of individual species of Eimeria. No treatment effects were detected (P ≥ 0.51) for calf BW or growth rate. A treatment × day interaction was detected (P < 0.01) for OPG, as NAR and MON calves had less (P < 0.01) OPG compared with CON calves beginning on day 7. The OPG was also less (P ≤ 0.03) in MON compared with NAR calves on days 7, 14, and 28, but did not differ (P ≥ 0.48) on days 21, 35, and 42. The anticoccidial efficacy of NAR and MON did not differ (P ≥ 0.16) when calculated across all Eimeria spp., or according to prevalence of E. bovis and E. alabamensins. A treatment × day interaction was detected (P = 0.04) for anticoccidial efficacy to E. alabamensis, which was greater (P < 0.01) in MON calves on days 7 and 14 and did not differ (P ≥ 0.40) afterward. Collectively, both ionophores were similarly effective in controlling coccidiosis upon completion of the 42-d study, although the anticoccidial effects of monensin were noted earlier in the experiment. Nonetheless, these results corroborate narasin as an efficient anticoccidial ionophore for naturally infected calves.

Biology of the non-parasitic phase of the cattle tick Rhipicephalus (Boophilus) microplus in an area of Amazon influence.

BACKGROUND: Rhipicephalus (Boophilus) microplus is the most important tick species affecting cattle in the world. Under field conditions, the non-parasitic phase of R. (B.) microplus is unknown in the Amazon biome, including Brazil. The present study aimed to evaluate the non-parasitic phase of R. (B.) microplus in field (grass plots) and laboratory conditions. METHODS: The study was conducted from September 2020 to April 2022 in an Amazonian region (Maranhão State, Brazil). We evaluated the biological parameters of R. (B.) microplus under laboratory and field conditions. Engorged females were exposed to experimental conditions every 14 days, totaling 20 months of study. The following biological parameters were observed: pre-oviposition period, egg mass incubation period, and maximum larval survival period. RESULTS: Abiotic data (e.g., temperature and humidity) varied little throughout the year. Precipitation was the factor that varied the most throughout the year (dry ~ 30 mm3 and rain 400 mm3), and the parameters of pre-oviposition and pre-hatching are longer during the rainy season. A possible negative effect of the dry season on the percentage of hatched eggs was observed. Larval longevity in the plots of both control and free females was short (mean ~ 50-60 days), below that recorded for larvae under controlled conditions (mean ~ 95 days). CONCLUSIONS: Rhipicephalus (Boophilus) microplus was able to complete its non-parasitic phase by producing host-seeking larvae in the pasture during all months of the study. The results indicate that R. (B.) microplus can complete up to six generations per year in biome Amazon. To our knowledge, this is the highest number of annual generations for R. (B.) microplus in Latin America.

Histopathology of the reproductive system of male sheep experimentally infected with Toxoplasma gondii.

The aim of this study was to investigate the histopathological changes in reproductive system (testicles, epididymis, seminal vesicles, and prostate) of small male ruminants after Toxoplasma gondii infection. Eight sheep were inoculated with T. gondii: group I, four sheep (2.0 × 10(5) P-strain oocysts); group II, four sheep (1.0 × 10(6) RH-strain tachyzoites); and group III, two uninfected sheep maintained as control. Infection with T. gondii was confirmed by seroconversion (indirect fluorescent antibody test-IgG) in all the infected animals beginning on post-inoculation day (PID) 7. On PID 70, all the animals were euthanized and tissue samples (testicles, epididymis, seminal vesicles, and prostate) were collected and processed for histological analysis. The main changes detected were a focal mononuclear interstitial inflammatory infiltrate in the prostate and seminal vesicles; diffuse testicular degeneration associated with calcification foci and a multifocal mononuclear interstitial inflammatory infiltrate; and a mononuclear interstitial infiltrate and focal necrotic areas of the muscle fibers surrounding the seminal vesicles. The histopathological findings of this work, along with the detection of T. gondii in the examined parenchyma tissues (immunohistochemistry) and the results obtained by other authors examining different tissues, suggest that histological changes diagnosed in the reproductive system of rams infected with T. gondii are strongly suggestive of toxoplasmatic infection.

Comparison between the Mission Plus device and gold standard methods for measuring hemoglobin concentrations and packed cell volumes in cattle.

BACKGROUND: A point-of-care device that can provide immediate and reliable hemoglobin (Hb) concentrations and packed cell volumes (PCVs) would be useful in veterinary medicine. OBJECTIVES: We aimed to compare the use of a human device (Mission Plus; MP) with a gold standard (GS) method for measuring Hb concentrations and PCVs in cattle blood. METHODS: Blood samples from clinically healthy cattle (n = 122) were collected with or without an anticoagulant (K2 EDTA). The GS and MP methods were compared with correlation coefficients. Passing-Bablok regression analyses were also performed, and the acceptability judgment was completed using Bland-Altman plots. RESULTS: The CVmax for Hb values obtained using the GS method, the MP device without K2 EDTA, and the MP device with K2 EDTA were approximately 2.70%, 1.70%, and 2.0%, respectively, whereas the CVmax for PCVs was 0.90%, 1.83%, and 2.05%, respectively. A positive correlation (97.5% confidence interval) was observed between the Hb concentrations and PCV values detected using the MP and GS techniques in blood with and without K2 EDTA. Bland-Altman plots showed agreement between the MP and GS methods. For Hb using blood collected with or without the addition of K2 EDTA, the mean differences were -0.87 g/dL (95% CI: 1.35; -3.96) and 0.08 g/dL (95% CI: 2.16, -1.99), respectively. For PCVs using blood collected with or without the addition of K2 EDTA, the mean differences were -3.75% (95% CI: 0.61. -8.12) and -0.88% (95% CI: 2.86, -4.62), respectively. CONCLUSIONS: The MP device can be used to analyze Hb concentrations and PCVs in bovine blood to assist in field diagnoses.

Frequency of bovine cysticercosis in the state of Rondônia, Brazil.

Bovine cysticercosis remains as one of the most important cause of carcasses and viscera condemnation in Brazilian slaughterhouses. However, the efficiency of post-mortem inspection for the diagnosis of this zoonotic disease is relatively low, and few available studies were performed through serological exams. This study evaluated the frequency of bovine cysticercosis in cattle herds located in different farms of the state of Rondônia, Brazil. Among the 987 animals slaughtered from 33 farms, 21 animals (Frequency: 2.13%; 95C.I. 1.23-3.03) were considered as positive through indirect ELISA and confirmed by Immunoblot tests and the cysticercosis was detected in 12 farms (36.36% - C.I. 95% 19.95-52.78). The disease was detected in the municipalities Vale do Paraíso (12.50%), Theobroma (8.11%), Guaporé (7.27%), Rolim de Moura (5.71%), Presidente Médici (5.0%), Ouro Preto do Oeste (4.69%), Nova União (1.77%), Nova Brasilândia d'Oeste (1.14%) and Ministro Andreazza (1.01%). Therefore, prophylactic measures should be taken to improve beef production, control bovine cysticercosis and reduce costs to public health in this Brazilian state.

Experimental infection of pregnant queens with two major Brazilian clonal lineages of Toxoplasma gondii.

Toxoplasma gondii isolates from Brazil are biologically and genetically different from European and North America isolates. Recently, four genotypes were considered the common clonal lineages in Brazil and were designated as types BrI, BrII, BrIII, and BrIV. The pathogenicity of two major Brazilian lineages was investigated after oral inoculation of queens in the middle third of their pregnancies with T. gondii cysts. Twelve pregnant queens without T. gondii antibodies were distributed in group A (infected with a type BrI isolate); group 2 (infected with type BrIII isolate), and group 3 (non-infected control). Infection with type BrI isolate caused toxoplasmosis manifestations and abortion from one litter. Toxoplasmosis manifestations besides premature stillbirth of one litter were observed in queens infected with type BrIII isolate. Indirect fluorescence antibody test showed T. gondii antibodies in all eight infected queens at 30 days after inoculation. In two 10-day-old kittens of the same litter (group 1), titers of 16 and 64 were detected. At the same time, titers of 16, 32, and 32 were detected in three kittens from the same litter (group 2). Experimental infection with tissue cysts from a type BrI and type BrIII isolates of T. gondii developed similar reproductive disturbance in primary infected pregnant queens.

Surtos consecutivos ocasionados por Eimeria zuernii em bezerros de corte de uma propriedade do estado de São Paulo / Consecutive outbreaks caused by Eimeria zuernii in calves on a rural property located in the municipality of São João da Boa Vista, State of São Paulo, Brazil

O presente trabalho tem como objetivo relatar surtos consecutivos (Agosto de 2015 e 2016) ocasionado por Eimeria zuernii em bezerros de corte, Canchim e Nelore, com aproximadamente 45 dias de vida, em uma propriedade rural localizada no município de São João da Boa Vista, estado de São Paulo. O primeiro surto foi diagnosticado em um lote composto por 78 bezerros, entre 35 e 55 dias de idade. Dos 78 bezerros, 32 eram Nelore e os outros 46 Canchim. Já o segundo, ocorreu em um novo lote de 66 bezerros (sendo 36 Nelore e 47 Canchim), com idade entre 30 e 45 dias. Alguns animais apresentaram diarreia sanguinolenta e desidratação. Colheitas de fezes de todos os animais (vacas e bezerros) foram realizadas para realização de exame coproparasitológico e quantificação de ovos e oocistos por grama (OPG e OoPG) de fezes de parasitos. Com base nos resultados encontrados neste estudo, é possível afirmar que os surtos consecutivos em bezerros de corte entre 30 e 55 dias de idade, na época seca do ano (agosto), foram desencadeados pelo elevado grau de infecção destes animais por E. zuernii. Analisando os dois anos em que os surtos ocorreram, a presença de sinais clínicos (diarreia sanguinolenta) e a mortalidade de bezerros desencadeada pela eimeriose/desidratação, aconteceram em 8,3% 1,4% do rebanho, respectivamente. Estes resultados destacam a importância em se realizar pesquisas de campo, com o objetivo de se melhor entender a dinâmica de parasitismo de E. zuernii e E. bovis em bezerros com idade inferior a três meses, em função dos motivos já discutidos neste estudo. Além disso, é necessário que se investigue as possíveis fontes de infecção, como a água ingerida pelos animais, para que condutas práticas possam ser adotadas/recomendadas aos proprietários, diminuindo desta maneira os prejuízos ocasionados por surtos de Eimeria spp em rebanhos bovinos.(AU)

We report consecutive outbreaks (August 2015 and 2016) of disease caused by Eimeria zuernii in Canchim and Nelore calves about 45 days of age on a rural property in the municipality of São João da Boa Vista, state of São Paulo, Brazil. The first outbreak infected 78 calves (32 Nelore and 46 Canchim) between 35 and 55 days of age. The second outbreak infected 66 calves (36 Nelore and 47 Canchim) between 30 and 45 days of age. Some calves had bloody diarrhea and were dehydrated. Feces were collected from all animals (cows and calves) for coproparasitological examination and quantification of parasite eggs and oocysts per gram. The consecutive outbreaks in the 30 to 55 day-old calves occurred during the dry season (August). These outbreaks were caused by a high degree of infection by E. zuernii. Clinical signs (bloody diarrhea) and mortality of the calves triggered by eimeriosis/dehydration occurred in 8.3 and 1.4% of the herd in 2015 and 2016, respectively. These results highlight the importance of conducting field studies to better understand the parasitic dynamics of E. zuernii in calves younger than three months. Identifying the sources of infection, such as the water ingested by the animals, is also necessary, so that practical husbanddry can be recommended and adopted by the producers, to reduce the damage caused by outbreaks of Eimeria spp. in cattle herds.(AU)

Geospatial distribution and risk factors for bovine cysticercosis in the state of Rondônia, Brazil / Distribuição espacial e fatores de risco para a cisticercose bovina no Estado de Rondônia, Brasil

This study focused on assessing the prevalence, geospatial distribution and risk factors for bovine cysticercosis in cattle from the state of Rondônia, Brazil, through the years 2012 to 2015. The prevalence established was 0.014% (95% C.I. 0.013-0.014), with a higher detection of unviable cysticerci (84.80%). The municipalities of Itapuã do Oeste, Candeias do Jamari, Nova Brasilândia D'Oeste, Pimenteiras do Oeste, Porto Velho, Nova Mamoré, Urupá and Guajará-Mirim had higher risk (OR>1; p<0.05) for cysticercosis occurrence compared with the municipality of Castanheiras (OR=1). The Administrative Regions of Porto Velho, Guajará-Mirim, Colorado D'Oeste, Cacoal, Ji-Paraná had higher risk (OR>1; p<0.05) for cysticercosis occurrence in the slaughtered animals than those reared in Ariquemes Administrative Region (OR=1). Some variables such as human population density (OR=2.15; 2.15-2.16), percentage of urban houses with inappropriate sewage system (OR=1.91, 1.91-.1.92) and percentage of inappropriate rural sewage system (OR=1.14, 1.14-1.14) were significantly associated (p<0.05) with the occurrence of bovine cysticercosis. In conclusion, the prevalence of bovine cysticercosis in the state of Rondônia was 0.014% (95% C.I. 0.013-0.014) and higher-risk areas were identified, providing useful information to Official Sanitary Inspection System in order to improve cysticercosis detection. Also, human population density and the lack of appropriate sewage system in urban and rural areas are closely related to bovine cysticercosis occurrence in this state.(AU)

Este estudo objetivou avaliar a prevalência, distribuição espacial e fatores de risco para a ocorrência de cisticercose bovina em animais abatidos oriundos do Estado de Rondônia, Brasil, entre os anos de 2012 a 2015. A prevalência observada foi de 0,014% (I.C. 95% 0,013-0,014), com maior detecção de cisticercos inviáveis (84,80%). Os municípios de Itapuã do Oeste, Candeias do Jamari, Nova Brasilândia D'Oeste, Pimenteiras do Oeste, Porto Velho, Nova Mamoré, Urupá e Guajará-Mirim apresentaram maior risco (OR>1; p<0.05) para a ocorrência da enfermidade quando comparadas ao município de Castanheiras (OR=1). As Regiões Administrativas de Porto Velho, Guajará-Mirim, Colorado D'Oeste, Cacoal, Ji-Paraná, respectivamente, apresentaram maior risco (OR>1; p<0.05) para a ocorrência de cisticercose nos bovinos abatidos comparadas à Região Administrativa de Ariquemes (OR=1). Algumas variáveis como a densidade populacional humana (OR=2,15; 2,15-2,16), percentual de domicílios urbanos com saneamento inadequado (OR=1,91, 1,91-1,92) e percentual de saneamento rural inadequado (OR=1,14, 1,14-1,14) apresentaram-se como fatores de risco significativos (p<0.05) para a ocorrência de cisticercose bovina. Conclui-se que a prevalência de cisticercose bovina no Estado de Rondônia foi 0,014% (I.C. 95% 0,013-0,014) e que áreas de maior ocorrência puderam ser identificadas, fornecendo informações a serem utilizadas pelo Serviço de Inspeção Federal para melhorar a detecção dos casos. Ainda, a densidade da população humana e a deficiência de sistemas de tratamento de esgotos urbanos e rurais estão intimamente relacionadas com a ocorrência da cisticercose bovina neste estado.(AU)

Preferential infection sites of Cysticercus bovis in cattle experimentally infected with Taenia saginata eggs.

The preferential sites of infection of Cysticercus bovis were evaluated in the skeletal muscle and entrails of 25 cattle that were experimentally infected with Taenia saginata (2×10(4) eggs). Two other animals were not inoculated (control). Ninety days after inoculation, all the cattle were euthanized. The carcasses were deboned and dissected into 26 anatomical sections (masseter muscles, brain, tongue, esophagus, heart, diaphragm, lungs, liver, kidneys, spleen, top sirloin butt, bottom sirloin butt, outside round, top (inside) round, transversus abdominus, top sirloin cap, strip loin, full tenderloin, eye of round, knuckle, shoulder clod, foreshank, shank, chuck, back ribs, and tail muscles). The dissected tissues were sliced into 5mm sections. From the 25 cattle, 9258 C. bovis (cysticerci) were recovered; 75.02% (6946) of these were recovered from skeletal muscles and 24.98% (2312) from the entrails. A high parasitism level was found in the shoulder clod (12.55%), heart (11.02%), liver (9.48%), masseter muscles (8.51%), chuck (8.25%), strip loin and full tenderloin (7.26%), knuckle (6.63%), and back ribs (5.53%), totaling 69.23% (5738) of all of the detected cysticerci. On the other hand, there was a low C. bovis parasitism level in the brain, spleen, tail muscles, kidneys, esophagus, and diaphragm, representing just 3.9% of the total number of cysticerci. Given these results, we conclude that specific skeletal musculature regions, such as the shoulder blade, chuck, strip loin and full tenderloin, knuckle, back ribs and top round, which are not officially examined in many countries, are effective sites to efficiently screen C. bovis infection. To date, these regions have not been considered as preferential sites of C. bovis infection. Based on our work, however, these regions deserve greater attention from health inspectors because they contained a greater number of Cysticercus than the other regions of carcasses that are parasitized by T. saginata larvae.

[Associated arthropodes in the laying hen excrement]. / Artrópodes associados ao excremento de aves poedeiras.

A research about arthropode fauna in laying hen excrement was carried out in a poultry house in the State of São Paulo, from January 2001 to December 2002. The objective was to verify the frequency of Diptera and Coleoptera collected by Berlese funil and flutuation methods, and to show correlation between the collect methods and sazonality possible in the currents seasons. A total of 29,499 insects were collected from seventy five collects, being 16,702 Diptera (six families) and 12,797 Coleoptera (four families). Some arthropodes presented direct relation with the collect method, the seasons of the years and the rainfall precipitation, with significant increase in the number of insects collected in certain periods of the year.

Artrópodes associados ao excremento de aves poedeiras / Associated arthropodes in the laying hen excrement

Realizou-se um estudo sobre a fauna de artrópodes associados a fezes de aves poedeiras em granja do estado de São Paulo, de janeiro de 2001 a dezembro de 2002. O objetivo foi verificar a freqüência de dípteros e coleópteros coletados por meio do funil de Berlese e pelo método de flutuação, além de correlacionar os métodos de coletas e a possível sazonalidade dos mesmos ao longo das estações. Das setenta e cinco coletas realizadas, capturaram-se 29.499 artrópodes, sendo 16.702 Diptera (seis famílias) e 12.797 Coleoptera (quatro famílias). Algumas espécies de artrópodes apresentaram relação direta entre o método de coleta, as estações do ano e a precipitação pluvial, com aumento significativo do número de insetos coletados em determinadas épocas do ano.

A research about arthropode fauna in laying hen excrement was carried out in a poultry house in the State of São Paulo, from January 2001 to December 2002. The objective was to verify the frequency of Diptera and Coleoptera collected by Berlese funil and flutuation methods, and to show correlation between the collect methods and sazonality possible in the currents seasons. A total of 29,499 insects were collected from seventy five collects, being 16,702 Diptera (six families) and 12,797 Coleoptera (four families). Some arthropodes presented direct relation with the collect method, the seasons of the years and the rainfall precipitation, with significant increase in the number of insects collected in certain periods of the year.