Ticks (Acari: Ixodidae) associated with domestic dogs in Franca region, São Paulo, Brazil

Ticks on 140 domestic dogs from both urban and rural areas of Franca region in São Paulo state were identified with 102 dogs from urban areas and 38 from rural areas. Of urban dogs, 27.5% were infested exclusively by Rhipicephalus sanguineus ticks. Of the rural dogs, 36.8% were infested with the following tick species: R. sanguineus, Boophilus microplus, Amblyomma ovale and A. cajennense. Mixed infestations included a dog hosting A. cajennense and A. ovale and another with B. microplus and R. sanguineus. The most intense infestations were detected on urban dogs. Hemolymph tests of these ticks performed to detect rickettsial or Borrelia bacteria yielded negative results.

LH Response (in vivo and in vitro) to an LHRH Agonist Administered to Domestic Male Cats

We investigated plasma luteinizing hormone (LH) concentration in domestic male cats challenged with Luteinizing Hormone Releasing Hormone Analog (LHRH-A) [des Gly10, (DTrp6)-LHRH ethylamide] that mediates the function of the hypothalamic-piruitary-gonadal axis (HPG). Plasma LH concentrations in cats treated daily with LHRH (10 μg/ 100 μl/kg/day, subcutaneously - sc) for 19 days (LHRH group) and in controls treated with saline (NaCl - 0.9%, same volume - SAL group) were chronically studied. LHRH administration (sc) for 15 days induced a significant fall (P < 0.05) in plasma LH concentrations during the chronic study. After the 15th day of treatment the groups were divided once more into animals treated with LHRH (10 μg/100 μl/kg) or saline (iv), and a time course study (300 min) was performed (acute study). Next, four groups of cats were compared in an acute study involving the sc/iv administration of SAL/SAL, SAL/LHRH, LHRH/SAL, and LHRH/LHRH. The responses of the SAL animals challenged by acute iv administration of LHRH (group SAL/LHRH) were significantly higher (P < 0.01) than those of animals treated with LHRH (sc) (group LHRH/LHRH). LH release was also significantly increased in the latter group (P < 0.05), although the effect was short lasting, being recorded only at the first observation (45 min). An in vitro study with the pituitaries was also performed on day 20. Mean (±SEM) LH concentrations in the culture medium containing pituitaries with LHRH (10-7 M) or saline were determined. In vitro analysis of these pituitaries demonstrated a significantly reduced response (P < 0.05) by animals treated sc with LHRH for 19 days. This study represents a source of data for the domestic cat going beyond its own physiology. Serving as a model, this animal provide important information for the study of reproductive physiology in other members of its family (Felidae), almost all of them threatened with extinction.

Genome-Wide Analysis Reveals Selection for Important Traits in Domestic Horse Breeds

Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an FST-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of selection in both the Paint and Quarter Horse. Gene sequencing and histological analysis of gluteal muscle biopsies showed a promoter variant and intronic SNP of MSTN were each significantly associated with higher Type 2B and lower Type 1 muscle fiber proportions in the Quarter Horse, demonstrating a functional consequence of selection at this locus. Signatures of selection on ECA23 in all gaited breeds in the sample led to the identification of a shared, 186-kb haplotype including two doublesex related mab transcription factor genes (DMRT2 and 3). The recent identification of a DMRT3 mutation within this haplotype, which appears necessary for the ability to perform alternative gaits, provides further evidence for selection at this locus. Finally, putative loci for the determination of size were identified in the draft breeds and the Miniature horse on ECA11, as well as when signatures of selection surrounding candidate genes at other loci were examined. This work provides further evidence of the importance of MSTN in racing breeds, provides strong evidence for selection upon gait and size, and illustrates the potential for population-based techniques to find genomic regions driving important phenotypes in the modern horse. © 2013 Petersen et al.

Comparison of infection by Brucella spp. in free-ranging and captive wild animals from São Paulo State, Brazil

The aim of the current study was to evaluate the infection rate by Brucella spp. in wild and in captive animals. Serum samples from 121 animals (94 free-ranging and 27 captive) of different mammal species were evaluated. Sera were submitted to rose Bengal test (RBT) for screening and serum agglutination tests (SAT) and 2-mercaptoethanol test (2-ME) for confirmatory results. Nine animals (five free-ranging and four captive) tested positive in RBT, but negative in the confirmatory tests. Several domestic animal diseases that have control programs are not focused on wild reservoirs, such as brucellosis in Brazil. The study of new reservoirs in wildlife is essential to prevent emerging diseases.

Evaluation of water beef buffalo from birth to two years using different growth curves

The buffalo is a domestic animal species of growing world-wide importance. Research to improve genetic improvement programs is important to maintain the productivity of buffalo. The objective this research was to evaluate the growth of Brazilian buffalo to two years of age with different growth curves. Growth curves consolidate the information contained in the weight-age data into three or four biologically meaningful parameters. The data included 31,452 weights at birth and 120, 205, 365, 550 and 730 days of buffalo (n = 5,178) raised on pasture without supplementation. Logistic, Gompertz, quadratic logarithmic, and linear hyperbolic curves (designated L, G, QL, and LH, respectively) were fitted to the data by using proc NUN of SAS (SAS Institute, Inc., Cary, NC, USA). The parameters estimates for L [WT= A * (((1 + exp (-k * AGE)))**-m)] were A = 865.1 +/- 5.42; k= 0.0028 +/- 0.00002; M= 3.808 +/- 0.007; R(2) = 0.95. For G [WT= A * exp (-b * exp (-k * age)] the parameters estimates were A= 967.6 +/- 7.23; k = 0.00217 +/- 0.000015; b = -2.8152 +/- 0.00532. For QL [WT= A + b*age + k*(age*age) + m*log (age)] parameters estimates were A= 37.41 +/- 0.48; k= 0.00019 +/- 6.4E(-6); b= 0.539 +/- 0.006; m= 2.32 +/- 0.23; R(2)=0.96. For LH [WT= A + b*AGE + k*(1/AGE)] the parameters estimates were A= 23.15 +/- 0.44; k=15.16 +/- 0.66; b= 0.707 +/- 0.001; R(2)= 0.96. Each of these curves fit these data equally well and could be used for characterizing growth to two years in beef buffalo.

The efficacy of a single chain recombinant equine luteinizing hormone (reLH) in mares: Induction of ovulation, hormone profiles, and inter-ovulatory intervals

The objectives of this study were to determine the efficacy of recombinant equine luteinizing hormone (reLH) in shortening the time to ovulation in cycling mares and to determine the effects of treatment on endogenous hormones and inter-ovulatory intervals. In study 1, mares of light horse breeds (3-20 years) were treated with either a vehicle, various doses of reLH, or human chorionic gonadotropin (hCG). Cycling mares were examined by palpation and ultrasound per rectum daily or every 12 h from the time of treatment to ovulation. In studies 2 and 3, jugular blood samples were collected daily or every 12 h from the time of treatment to ovulation for analysis of LH, follicle stimulating hormone (FSH), estradiol-17 beta (E-2), and progesterone (P-4) by radioimmunoassays (RIA). Increasing doses of reLH (0.3, 0.6, 0.75, and 0.9 mg) showed increasing effectiveness at inducing ovulation within 48 h of treatment. Treatments with the 0.75 and 0.9 mg doses of reLH resulted in 90% and 80% ovulation rates, which were similar to hCG treatment (85.7%). Except for the early rise in LH after treatment with 0.5, 0.65, and 1.0 mg of reLH, hormone profiles appeared to be similar between control and treated cycles. Inter-ovulatory intervals were similar between control and treatment cycles. In conclusion, reLH is a reliable and effective ovulatory agent that does not significantly alter endogenous hormone profiles or affect inter-ovulatory intervals.(c) 2007 Elsevier B.V. All rights reserved.

Fibroblast growth factor-10 maintains the survival and promotes the growth of cultured goat preantral follicles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bat rabies in the north-northwestern regions of the state of São Paulo, Brazil: 1997-2002

OBJETIVO: Os relatos sobre a ocorrência de raiva em morcegos no Brasil são esporádicos e isolados. Assim, o objetivo do estudo foi descrever a detecção do vírus da raiva em morcegos do Estado de São Paulo. MÉTODOS: Foram analisados 7.393 morcegos provenientes de 235 municípios do norte e noroeste do Estado de São Paulo, no período de 1997 a 2002 e identificados por meio de características morfológicas e morfométricas. Para a detecção do antígeno viral foi utilizada a técnica de imunofluorescência direta e o isolamento do vírus foi realizado por inoculação em camundongos. RESULTADOS: Das amostras examinadas, 1,3% foram positivas para raiva, com variação de 0,2% em 1997 a 1,6% em 2001. Foram encontrados 98 morcegos com o vírus, 87 deles em área urbana. O vírus da raiva foi detectado pela imunofluorescência direta em 77 do total de amostras positivas, enquanto 92 produziram doença em camundongos inoculados e o período de incubação variou entre 4-23 dias. em 43 municípios foi encontrado pelo menos um morcego positivo. Entre as espécies analisadas o vírus da raiva foi detectado com maior freqüência (33,7%) em Artibeus lituratus. Os vespertilionideos do gênero Eptesicus e Myotis totalizaram 24,5% dos morcegos positivos e as espécies do gênero Molossus (Molossus molossus e Molossus rufus), 14,3%. A distribuição do vírus da raiva foi semelhante entre fêmeas (33; 48,5%) e machos (35; 51,5%). CONCLUSÕES: Morcegos positivos para raiva foram encontrados em situações que colocam em risco tanto a população humana como animais de estimação, exigindo medidas voltadas para o manejo destas espécies e de educação da população.

Non-ventilation during early incubation in combination with dexamethasone administration during late incubation: 1. Effects on physiological hormone levels, incubation duration and hatching events

This study investigated the effect of non-ventilation of the incubator during the first 10 days of incubation and its combination with dexamethasone administration at day 16 or 18 of incubation on hatching parameters and embryo and post-hatch chick juvenile physiology. A total of 2400 hatching eggs produced by Cobb broiler breeders were used for the study. Blood samples were collected at day 18 of incubation, at internal pipping stage (IP), at the end of hatch (day-old chick) and at 7-daypost-hatch for T-3, T-4 and corticosterone levels determination. From 448 to 506 h of incubation, the eggs were checked individually in the hatcher every 2 h for pipping and hatching. The results indicate that non-ventilation during the first 10-day shortened incubation duration up to IP, external pipping (EP) and hatch, had no effect on hatchability and led to higher T-3 levels at IP but lower corticosterone levels at 7-day-post-hatch. The injection of dexamethasone at days 16 and 18 of incubation affected hatching and blood parameters in both the ventilated and non-ventilated embryos differentially and the effect was dependent on the age of the embryo. Dexamethasone increased T-3 levels and T-3/T-4 ratios but the effect was greater with early non-ventilation of eggs. Dexamethasone decreased hatchability but the effect was greater when injected at day 16 and especially in ventilated embryos. The effects of incubation protocols and dexamethasone treatments during incubation were still apparent in the hatched chicks until 7 days of age. The changes in T-3, T-4 and corticosterone levels observed in response to the early incubation conditions and late dexamethasone treatments in this study suggest that incubator ventilation or non-ventilation may influence the hypothalamic-pituitary-adrenal axis (HPA) regulation of stress levels (in terms of plasma corticosterone levels) and thyroid function in the embryo with impact on incubation duration, hatching events and early post-hatch life of the chick. Our results also suggest that some stages of development are more sensitive to dexamethasone administration as effects can be influenced by early incubation protocols. (c) 2006 Elsevier B.V. All rights reserved.

Ticks associated with armadillo (Euphractus sexcinctus) and anteater (Myrmecophaga tridactyla) of Emas National Park, State of Goias, Brazil

This study was conducted in October 1998 and November 1999 in the Emas National Park (131,868 ha), a savanna-type cerrado region situated in the far south of Goias State, Brazil, near the geographic center of South America (15degrees-23degrees S; 45degrees-55degrees W). Animals were captured with the aid of nets and anesthetized (15 mg/kg ketamine + 1 mg/kg xylasine) in order to collect ticks for identification and to establish laboratory colonies. They included giant anteaters (Myrmecophaga tridactyla) (n = 4) and yellow armadillos (Euphractus sexcinctus) (n = 6). Free-living ticks (larvae, nymphs, and adults) were collected from the field by using a 1 X 2-m flannel cloth. Free-living ticks were identified as Amblyomma sp., A. cajennense, and A. triste. Adult ticks collected from anteaters were identified as Amblyomma cajennense and A. nodosum and from armadillos as A. pseudoconcolor and A. nodosum. The relevance of these host-tick relationships to possible mechanisms underlying emergence of tick-borne pathogens of importance to public health is discussed.

Plasma anti-mullerian hormone: an endocrine marker for in vitro embryo production from Bos taurus and Bos indicus donors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Pharmacokinetics and pharmacodynamics of the glucagon-like peptide-1 analog liraglutide in healthy cats

Glucagon-like peptide-1 (GLP-1) is an intestinal hormone that induces glucose-dependent stimulation of insulin secretion while suppressing glucagon secretion. Glucagon-like peptide-1 also increases beta cell mass and satiation while decelerating gastric emptying. Liraglutide is a fatty-acid derivative of GLP-1 with a protracted pharmacokinetic profile that is used in people for treatment of type II diabetes mellitus and obesity. The aim of this study was to determine the pharmacokinetics and pharmacodynamics of liraglutide in healthy cats. Hyperglycemic clamps were performed on days 0 (HGC) and 14 (LgHGC) in 7 healthy cats. Liraglutide was administered subcutaneously (0.6 mg/cat) once daily on days 8 through 14. Compared with the HGC (mean +/- standard deviation; 455.5 +/- 115.8 ng/L), insulin concentrations during LgHGC were increased (760.8 +/- 350.7 ng/L; P = 0.0022), glucagon concentrations decreased (0.66 +/- 0.4 pmol/L during HGC vs 0.5 +/- 0.4 pmol/L during LgHGC; P = 0.0089), and there was a trend toward an increased total glucose infused (median [range] = 1.61 (1.11-2.54) g/kg and 2.25 (1.64-3.10) g/kg, respectively; P = 0.087). Appetite reduction and decreased body weight (9% +/- 3%; P = 0.006) were observed in all cats. Liraglutide has similar effects and pharmacokinetics profile in cats to those reported in people. With a half-life of approximately 12 h, once daily dosing might be feasible; however, significant effects on appetite and weight loss may necessitate dosage or dosing frequency reductions. Further investigation of liraglutide in diabetic cats and overweight cats is warranted. (C) 2015 Elsevier Inc. All rights reserved.

Pharmacology of the glucagon-like peptide-1 analog exenatide extended-release in healthy cats

Exenatide extended-release (ER) is a microencapsulated formulation of the glucagon-like peptide 1-receptor agonist exenatide: It has a protracted pharmacokinetic profile that allows a once-weekly injection with comparable efficacy to insulin with an improved safety profile in type II diabetic people. Here, we studied the pharmacology of exenatide ER in 6 healthy cats. A single subcutaneous injection of exenatide ER (0.13 mg/kg) was administered on day 0. Exenatide concentrations were measured for 12 wk. A hyperglycemic clamp (target = 225 mg/dL) was performed on days 7 (clamp I) and 21 (clamp II) with measurements of insulin and glucagon concentrations. Glucose tolerance was defined as the amount of glucose required to maintain hyperglycemia during the clamp. Continuous glucose monitoring was performed on weeks 0, 2, and 6 after injection. Plasma concentrations of exenatide peaked at 1 h and 4 wk after injection. Comparing clamp I with clamp II, fasting blood glucose decreased (mean standard deviation = 11 8 mg/dL, P = 0.02), glucose tolerance improved (median [range] +33% 14%-138%], P = 0.04), insulin concentrations increased (+36.5% [-9.9% to 274.1%], P = 0.02), and glucagon concentrations decreased (-4.7% [0%-12.1%], P = 0.005). Compared with preinjection values on continuous glucose monitoring, glucose concentrations decreased and the frequency of readings <50 mg/dL increased at 2 and 6 wk after injection of exenatide ER. This did not correspond to clinical hypoglycemia. No other side effects were observed throughout the study. Exenatide ER was safe and effective in improving glucose tolerance 3 wk after a single injection. Further evaluation is needed to determine its safety, efficacy, and duration of action in diabetic cats. (C) 2015 Elsevier Inc. All rights reserved.

Development of resistance to nymphs of Amblyomma cajennense ticks (Acari : Ixodidae) in dogs

Ticks have long been regarded as constraints to humans and domestic animals, but hosts often develop resistance to ticks after repeated infestations. The purpose of this investigation was to study the possible acquisition of immunity in domestic dogs to nymphs of A. cajennense by determining the tick alimentary performance after successive controlled infestations. Mean engorged weight of nymphs was not significantly different among the three infestations; molting rate from nymph to adult ticks, and the percentage of nymph recovery were also very close in all infestations. These results are similar to those obtained in studies of the dog-adult Rhipicephalus sanguineus interface. It is concluded that domestic dogs do not develop resistance against nymphs of A. cajennense ticks.