Goats reinfected with toxoplasma gondii: loss of viable prolificacy and gross revenue / Cabras reinfectadas com toxoplasma gondii: perdas de prolificidade viável e receita bruta

We determined the reproductive parameters and clinical disorders in pregnant goats infected and reinfected with Toxoplasma gondii, and posteriorly the loss of gross revenue due to congenital toxoplasmosis was estimated. Of the 25 non-pregnant females negative for T. gondii, 20 were orally inoculated (ME 49 strain) and of these, 15 pregnant females chronically infected were orally reinoculated (VEG strain) with T. gondii oocysts. Five groups were formed (n=5): GI, GII and GIII (reinoculations at 40, 80 and 120 days of gestation, respectively), GIV (inoculation) and GV (no inoculation). Clinical and serological exams were performed on days 0 (prior to inoculation), 3, 6 9, 15 and 21 and every 7 days post-inoculation. Exams were also performed on day 3 and every 7 days post-reinoculation. Reproductive management was performed on all females and initiated when the females infected displayed IgG titers IFAT<1,024. From the average prolificacy indexes of each experimental group were estimated: total production of kilograms of live weight (total kg LW) of goats for slaughter, gross revenue and loss of gross revenue in U.S. dollars (US$), designed for a herd of 1,000 matrices. The unviable prolificacy indexes were 0.8 (GI), 1.2 (GII) and 0.2 (GIII). Clinical disorders affected 57.1% (GI), 75.0% (GII) and 16.7% (GIII) of the offspring of goats reinfected with T. gondii. Congenital toxoplasmosis in goats reinfected resulted in the loss of 26.5% of gross revenues, being GI (US$ 10,577.60 or 57.1%) and GII (US$ 12,693.12 or 60%) holders of the highest values and percentages of economic losses. It was found that congenital toxoplasmosis reinfection cause clinical disorders in goats chronically infected with T. gondii and their offspring with birth of unviable animals and loss of gross revenue, at different stages of pregnancy (40, 80 and 120 days of gestation)...

Nós determinamos os parâmetros reprodutivos e distúrbios clínicos em cabras gestantes infectadas e reinfectados com Toxoplasma gondii, e posteriormente, foi estimada a perda de receita bruta devido à toxoplasmose congênita. Das 25 fêmeas não prenhes negativas para T. gondii, 20 foram inoculadas oralmente (cepa ME 49) e, destas, 15 fêmeas gestantes infectadas cronicamente foram reinoculadas (cepa VEG), via oral, com oocistos de T. gondii. Cinco grupos foram formados (n = 5): GI, GII e GIII (reinoculações aos 40, 80 e 120 dias de gestação, respectivamente), GIV (inoculação) e GV (não inoculação). Exames clínicos e sorológicos foram realizados nos dias 0 (antes da inoculação), 3, 6 9, 15 e 21 e a cada sete dias após a inoculação. Os exames também foram realizados nos dias 3 e a cada sete dias de pós-reinoculação. Manejo reprodutivo foi realizado em todas as fêmeas e iniciou-se quando as fêmeas infectadas exibiram títulos de anticorpos IgG<1.024. A partir dos índices médios de prolificidade de cada grupo experimental foram estimados: a produção total de kg de peso vivo (total kg PV) de cabritos para o abate, receita bruta e perda de receita bruta em dólares norte-americanos (US$), projetadas para um rebanho de 1000 matrizes. Os índices de prolificidade inviáveis foram de 0,8 (GI), 1.2 (GII) e 0,2 (GIII). Distúrbios clínicos afetaram 57,1% (GI), 75,0% (GII) e 16,7% (GIII) das crias de cabras reinfectados com T. gondii. A toxoplasmose congênita em crias das cabras reinfectadas com T. gondii resultou na perda de 26,5% da receita bruta, sendo GI (US $ 10,577.60 e 57,1%) e GII (US $ 12,693.12 e 60.0%) os detentores dos mais altos valores e porcentagens de perdas econômicas. Verificou-se que a reinfecção toxoplásmica congênita causa distúrbios clínicos em cabras cronicamente infectadas com T. gondii e sua prole com o nascimento de animais inviáveis e perda de receita bruta, em diferentes fases da gestação (40, 80 e 120 dias de gestação)...

Distribution of Taenia saginata metacestodes: a comparison of routine meat inspection and carcase dissection results in experimentally infected calves.

A comparison of techniques for detecting the presence of Cysticercus bovis in bovine carcasses was made by using carcass dissection and routine beef inspection guidelines. In the study, 28 calves were used after they were tested and found to be negative for the presence of anti-C. bovis serum antibodies and were inoculated orally with aliquots containing 6×10(4) Taenia saginata eggs. One hundred and twenty days after inoculation, the animals were slaughtered and a post mortem evaluation was done following Brazilian Federal Beef Inspection guidelines. This routine meat inspection was able to identify 71·42% of the assessed infected carcasses as being parasitized. This result implies that 28·58% of the infected carcasses would have been released as fit for human consumption since they would have been considered as free of C. bovis infection when using this method for carcass assessment. Only 3·07% of the total 2311 metacestodes present in the carcasses were identified by the conventional procedures of sanitary inspection. The assessment of different parts of the carcasses showed high infestation rates in shoulder clod (14·37%), head (11·21%), neck+chuck roll (8·05%), heart (7·75%) and top (inside) round (7·18%) which, together, were responsible for housing 48·51% of all the cysts found in the 24 beef cuts assessed. These numbers contrasted to the low incidence of cysts found in organs such as tongue (3·12%), diaphragm (1·69%) and esophagus (1·60%) which are usually described as predilection sites for the parasite.

Semen variables of sheep (Ovis aries) experimentally infected with Toxoplasma gondii.

The influence of Toxoplasma gondii on semen variables and sperm morphology of sheep was evaluated in eight reproductive males distributed into three experimental groups: GI, three sheep inoculated with 2.0x10(5) of P strain oocytes; GII, three sheep infected with 1.0x10(6) of RH strain tachyzoites and; GIII two control sheep. Clinical (rectal temperature, cardiac and respiratory frequencies), parasite and serology exams (IIF) were realized. Sperm variables (volume, motility, vigor and concentration) and semen morphology for each sheep were also evaluated. Thus, semen and blood collections were assessed on post-inoculation days (PIDs)-1,3,5,7,11,14 and weekly thereafter up to PID 70. Clinical alterations were observed (hypothermia and anorexia) in infected sheep from groups GI and GII. Parasitic outbreaks were detected in five sheep. All the infected sheep produced antibodies against T. gondii from PID 5 onwards, reaching a peak of 4096 and 8192 for group GI and GII sheep, respectively. Differences (P<0.05) were observed regarding the ejaculate volume between the inoculated groups (oocytes and tachyzoites) and control. Even though experimental toxoplasmic infection resulted in clinical symptomology in the inoculated sheep, the minimal alterations in sperm pathologies could not be directly attributed to T. gondii.

Relative potency of ketamine and S(+)-ketamine in dogs.

The aim of this study was to determine the relative potency of racemic ketamine and S(+)-ketamine for the hypnotic effect and to evaluate the clinical anesthesia produced by equianesthetic doses of these two substances in dogs. One hundred and eight dogs were allocated in groups R2, R2.5, R3, R6, R9, R12, S2, S2.5, S3, S6, S9, and S12, to receive by intravenous route 2, 2.5, 3, 6, 9, and 12 mg/kg of ketamine or S(+)-ketamine, respectively. A dose-effect curve was drawn with the dose logarithm and the percentage of dogs that presented hypnosis in each group. The curve was used to obtain a linear regression, to determine the effective doses 100 and the potency relationship. In another experimental phase, eight groups of five dogs received 3, 6, 9 and 12 mg/kg of ketamine or S(+)-ketamine to evaluate the periods of latency, hypnosis, and total recovery. The times in which the dogs reached the sternal position, attempted to stand up for the first time, recovered the standing position, and started to walk were also recorded. The hypnotic dose for ketamine was 9.82 +/- 3.02 (6.86-16.5) mg/kg and for S(+)-ketamine was 7.76 +/- 2.17 (5.86-11.5) mg/kg. The time of hypnosis was longer in R3 and the first attempt to stand up occurred early in R6 when compared with S3 and S6 respectively. When R9 (100% of hypnosis with ketamine) and S6 [100% of hypnosis with S(+)-ketamine] were compared (1:1.5 ratio), the time to sternal position (12 +/- 2.5 and 20.2 +/- 5.6 min respectively) and the total recovery time (45 +/- 5.5 and 60.2 +/- 5.2 min respectively) were significantly shorter with S(+)-ketamine. It was concluded that the potency ratio between ketamine and S(+)-ketamine in dogs is smaller than the one reported in other species, and that the dose obtained after a reduction of 50%, as usually performed in humans, would not be enough to obtain equianesthetic effects in dogs.

Endectocide activity of a new long-action formulation containing 2.25% ivermectin+1.25% abamectin in cattle.

The present work aimed to evaluate the endectocide activity of a new injectable long-action formulation, containing ivermectin (IVM) and abamectin (ABA). In each one of the four experiments performed, the following groups were formed: group I: 2.25% IVM (450 microg/kg)+1.25% ABA (250 microg/kg), group II: 3.15% IVM (630 microg/kg) and group III: control. Eighteen bovine naturally infected by gastrointestinal nematoda were selected for anthelmintic evaluation and necropsied on posttreatment day (PTD) 14 to estimate the total parasitic burden. For the Rhipicephalus (Boophilus) microplus field trial, 30 bovine were selected by means of counts of semi-engorged R. (B.) microplus and the therapeutic and residual efficacy evaluated by tick counts on PTDs 1, 3, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84 and 91. In the stall test, 15 calves were artificially infested with 5000 R. (B.) microplus (Mozzo strain) larvae three times a week and daily collections of all the engorged female ticks detached from each calf were performed until the PTD 80. Forty bovine naturally infected with Dermatobia hominis larvae were selected and the number of larvae was counted by visual and tactile inspection on PTDs 3, 7, 14, 28, 35, 49, 63, 77, 91 and 105. In this trial, a formulation containing 1% doramectin (200 microg/kg) was also used. IVM+ABA formulation and 3.15% IVM eliminated four of the eight species of nematode identified. The anthelmintic efficacy of the avermectins association against Haemonchus placei, Cooperia spatulata and C. punctata was 89.64%, 98.84% and 97.69%, while 3.15% IVM achieved 30.98%, 84.79% and 75.56%, respectively. The two formulations evaluated showed reduced acaricide action on the PTD 1 and 3, reaching high efficacy percentages from PTD 14 onward. The IVM+ABA showed efficacy above 95% in the period between PTDs 21 and 49. In the stall test, it observed no difference (P>0.05) between the two formulations regarding the R. (B.) microplus counts during the entire evaluation period. IVM+ABA reduced the number of ticks from the PTD 1 to 77 (P<0.05) and 3.15% IVM reduced (P<0.05) the tick number from PTD 4 up to PTD 80. The three endectocides showed no difference (P>0.05) regarding the number of D. hominis larvae and prevented this parasite reestablishment until PTD 105. These results indicate that the IVM+ABA association showed higher anthelmintic activity and similar efficacy against arthropods to the formulation containing 3.15% IVM.

Effect of dietary supplementation with vitamin E and stocking density on macrophage recruitment and giant cell formation in the teleost fish, Piaractus mesopotamicus.

The effect of dietary supplementation with 0, 100 and 450 mg of vitamin E (DL-alpha tocopheryl acetate)/kg of a dry diet on the kinetics of macrophage recruitment and giant cell formation in the pacu, maintained at different stocking densities (5 kg/m(3) and 20 kg/m(3)), was investigated by insertion of round glass coverslips into the subcutaneous connective tissue. After a feeding period of 18 weeks, the coverslips were implanted and later removed for examination at 2, 7 and 15 days post-implantation. Fish fed diets supplemented with 450 mg of vitamin E showed an increase (P<0.05) in the accumulation of macrophages, foreign body giant cells and Langhans type cells. The kinetics of macrophage recruitment and giant cell formation on the glass coverslips appeared to be strongly influenced by vitamin E supplementation, since fish fed a basal diet and held at high stocking densities showed low numbers of adhering cells on the coverslips, and high concentrations of plasma corticosteroids. On the other hand, fish given a diet supplemented with 450 mg of vitamin E did not show a similar difference in plasma cortisol concentrations related to stocking density. The effect of cortisol concentrations on carbohydrate metabolism, analysed by assessment of plasma glycaemia, was not clear. Blood glucose concentrations did not vary substantially with the different treatments examined. These results suggest that vitamin E may contribute to the efficiency of the fish's inflammatory response by increasing macrophage recruitment and giant cell formation in the foreign body granulomatous reaction. Vitamin E appeared to act on the stress response of pacus by preventing a stress-related immunosuppression.

Comparative efficacy evaluation of moxidectin gel and ivermectin paste against internal parasites of equines in Brazil.

A total of 24 male and female equines of mixed breed, 10-20 months of age and naturally infected with internal parasites was utilized in a controlled test to evaluate the efficacy of a moxidectin 2% gel formulation at the dosage of 0.4 mg moxidectin per kg of live weight and an ivermectin 1.87% commercial paste formulation at the dosage 0.2 mg ivermectin per kg applied orally. Animals were allocated into three groups of eight horses each based on pre-treatment eggs per gram (EPG) counts and treatments were randomized among the groups. One group was kept as untreated controls. One animal in the moxidectin-treated group died before the end of the trial from a cause unrelated to treatment leaving a total of seven animals in this group. Fecal egg counts were performed three times post-treatment and the number of parasites remaining in each animal was determined. Statistical analyses using geometric means were performed at the 1% level of significance. Both moxidectin and ivermectin preparations reduced initial EPG from a mean of 1600 to 0 on Days 5, 7 and at the end of the trial on Day 14. Efficacy percentages of moxidectin and ivermectin against immature and adult nematodes were as follows: Trichostrongylus axei, Parascaris equorum, Strongylus edentatus, S. vulgaris, Triodontophorus spp. and Gyalocephalus capitatus, 100% for both products; Habronema muscae 99.5 and 99.6%, respectively, Strongyloides westeri, 100 and 99.2%, respectively; Oxyuris equi, 99.6 and 100%, respectively; small strongyles, 99.7% for both products. Of the latter, the most numerous were: Cylicocyclus insigne, Cylicostephanus longibursatus and Cyathostomum catinatum. No Gasterophilus nasalis were found in horses from either treated group, while two of eight control horses had infections with thisparasite. Moxidectin showed greater efficacy (84.9%) than ivermectin (67.8%) against Strongylus vulgaris larvae found in the mesenteric artery aneurisms, but the difference was not statistically significant. Total parasite counts for both treated groups were significantly lower (p<0.01) than in the non-treated group. No significant differences were noted between moxidectin and ivermectin. Efficacy against the 30 nematode species found in this study was very evident for both products. As expected, neither moxidectin nor ivermectin was effective in controlling the tapeworm Anoplocephala perfoliata. No adverse reactions were observed during the experimental period.