Intraoperative and early postoperative pain in cats that underwent ovariohysterectomy using a spay hook: a randomised, masked, experimental study.

BACKGROUND: This study aimed to compare the feasibility and practicality of the ovariohysterectomy (OHE) technique in cats with or without a spay hook with respect to the incision size, surgical time, surgical variables, and intra- and postoperative pain. Twenty-nine female cats underwent OHE using a spay hook (spay hook group [SHG], n = 15) or without using a spay hook (control group [CG], n = 14) to achieve the ovaries and cervix. Physiological parameters were monitored during the intraoperative period, and postoperative pain was assessed using a multidimensional composite and visual analogue pain scales. RESULTS: The SHG had a significantly shorter operative time than the CG. The variables in the intraoperative period showed no statistically significant difference between both groups, as well as the early postoperative pain. CONCLUSIONS: Less invasive OHE using a spay hook could potentially be a viable and feasible technique when performed by an inexperienced surgeon with appropriate training, especially in sterilisation campaigns, reducing the time to perform the procedure and increasing the number of animals spayed per time.

Surgical sterilization of free-ranging capybaras (Hydrochoerus hydrochaeris): "Passos Nunes" uterine horn ligature

Capybaras are the primary hosts of Amblyomma sculptum tick, vectors of Rickettsia rickettsia bacteria, and the zoonotic agent of Brazilian Spotted Fever (BSF). In this context, contraceptive methods have been suggested for population control in order to reduce the number of free-ranging capybaras cohabiting with humans in urban and rural areas and acting as disease amplifiers. To maintain the group's expected behavior and social hierarchy, sterilization techniques that preserve the gonads are recommended. On 126 female capybaras in the Brazilian state of São Paulo, a new surgical technique named "Passos Nunes" uterine horn ligature was performed after adequate general anesthesia. It achieved effective surgical sterilization, with an incision length of about 3 cm in the periumbilical linea alba, cranial to the pubis. After entering the abdominal cavity, the urinary bladder is pulled laterally to access the uterine horns and the cervix. The uterine horn is folded up, forming a strap; the distal portion of the strap is ligated and its distal end sectioned. The exact process is performed on the opposite horn. After the surgical procedure, the musculature is sutured in a sultan pattern and the subcutaneous tissue with a horizontal mattress pattern. The skin is sutured in a separate simple format, using nylon 2.0 for all steps. The wide exposure of the uterine horns facilitates the confirmation of pregnancy, allowing the surgeon to choose between salpingo hysterectomy or ligature of the uterine horns. The present study presents a new technique of surgical sterilization that can be used in female free-ranging mammals in which maintenance of the gonads is recommended, and births of offspring should not occur.(AU)

Reproductive control of capybaras through sterilization in areas at risk of transmission of brazilian spotted fever / Controle reprodutivo de capivaras através de esterilização em áreas de risco de transmissão da febre maculosa brasileira

Groups of capybaras (Hydrochoerus hydrochaeris) are currently frequent inhabitants of urban areas. The species participates in the transmission cycle of Brazilian spotted fever (BSF), a zoonosis that is caused by the bacteria R. rickettsii and transmitted by vector ticks. This has led to discussions on strategies to decrease the presence of this rodent through contraceptive methods and euthanasia, thus reducing their capacity to carry and transport ticks, which would be an important contribution to public health. Two condominiums and one business establishment in the interior of the state of São Paulo were used as case studies in the present investigation. All areas were classified by the Endemic Control Superintendence as risk areas for the transmission of BSF and presented the specie of ticks A. sculptum and A. dubitatum The objective of this study was to carry out sterilization procedures with animals that presented seropositive results for BSF. A total of 85 surgical procedures were conducted on immune capybaras, with authorization from DeFau/SMA-SP. For all procedures the animals were anesthetized with ketamine hydrochloride combined with xylazine and morphine. Two alpha males isolated themselves from the group after the vasectomy procedure, returning to their hierarchical position after 5 to 14 days. Population monitoring in the areas should be maintained indefinitely and conducting annual serological management until the natural death of these individuals. Tubal ligation, vasectomy and salpingo-oophorectomy were demonstrated to be simple and low-risk procedures in capybaras. These techniques assist in the population control of this species in enclosed areas with risk of BSF transmission, thus decreasing the need for euthanasia.(AU)

Grupos de capivaras (H. hydrochaeris) são atualmente habitantes frequentes de áreas urbanas. A espécie participa do ciclo de transmissão da febre maculosa brasileira (FMB), uma zoonose causada pela bactéria R. rickettsii e transmitida por carrapatos vetoriais. Isso levou a discussões sobre estratégias para diminuir a presença desse roedor por meio de métodos contraceptivos e eutanásia, reduzindo sua capacidade de carrear e transportar carrapatos, o que seria uma importante contribuição para a saúde pública. Dois condomínios e um estabelecimento comercial no interior de São Paulo foram utilizados como estudos de caso na presente investigação. Todas as áreas foram classificadas pela Superintendência de Controle Endêmico como áreas de risco para a transmissão da FMB e apresentaram a espécie do carrapato A. sculptum e A. dubitatum. O objetivo deste estudo foi realizar procedimentos de esterilização com animais que apresentaram resultados soropositivos para a FMB. Foram realizados 85 procedimentos cirúrgicos em capivaras imunes, com autorização do DeFau / SMA-SP. Para todos os procedimentos, os animais foram anestesiados com cloridrato de cetamina combinado com xilazina e morfina. Dois machos alfa se isolaram do grupo após o procedimento de vasectomia, retornando à sua posição hierárquica após 5 a 14 dias. O monitoramento populacional nas áreas deve ser mantido indefinidamente e conduzindo-se o manejo sorológico anual até a morte natural desses indivíduos. Foi possível demonstrar que a ligação tubária, vasectomia e salpingo-ooforectomia são procedimentos de baixo risco em capivaras. Essas técnicas auxiliam no controle populacional desta espécie em áreas fechadas e com risco de transmissão de FMB, diminuindo a necessidade de eutanásia.(AU)

Uterine secretory activity and histology of prepubertal female dogs in an animal model of partial ablation of endometrial glands development / Atividade secretória uterina e histologia de cadelas pré-púberes em um modelo animal de ablação parcial do desenvolvimento das glândulas uterinas

Inadequate exposure of the female reproductive system to steroids in uterine developmental periods can partially inhibit the development of endometrial glands in dogs. However, the effects of steroids on the formed glands functionality remain unknown, as well as the possible occurrence of endometrial fibrosis. This study aimed to evaluate the secretory activity of endometrial glands in prebubertal female dogs submitted to a protocol of partial ablation of the uterine adenogenesis. Sixteen females of non-specific breed were distributed into two groups; MPA (n=8), females that received applications of medroxyprogesterone acetate every 3 weeks; and C (n=8) untreated control females. Ovariohysterectomy was performed in all animals at the age of 6 months and evaluated the uterine horns by histological and histochemistry exams. The secretion intensity (degrees 1-4) was evaluated using periodic acid-Schiff (PAS) and alcian blue (AB) pH 2.5. Histological evaluation was performed using Masson's trichrome and toluidine blue. Only degree 1 and 2 marks for PAS were observed in both groups, with no difference of uterine secretion intensity between the groups regarding the degrees found. However, the MPA group revealed higher intensity of uterine secretion compared to group C (p<0.05). Staining with AB pH 2.5 also revealed only degree 1 and 2 marks in both groups, with no statistically significance between them. Masson's trichrome staining revealed no marks in the periglandular region in both groups. A higher among of mast cells was observed in the myometrial region of the uterus in both groups. Prepubertal female dogs with partial ablation of the uterine adenogenesis present minimal uterine secretory activity, absence of periglandular fibrosis and increased presence of mast cells in the myometrium compared to endometrium.(AU)

A exposição inadequada do sistema reprodutor feminino a esteróides em períodos do desenvolvimento uterino pode inibir parcialmente o desenvolvimento das glândulas endometriais em cães. Entretanto, não se conhece os efeitos dos esteróides sobre a funcionalidade das glândulas formadas, bem como a possível ocorrência de fibrose endometrial. Objetivou-se avaliar a atividade secretória das glândulas endometriais de cadelas pré-púberes submetidas a protocolo de ablação parcial da adenogênese uterina. Foram utilizadas 16 fêmeas, sem-raça-definida, distribuídas nos grupos MPA (n=8), fêmeas que receberam aplicações de acetato de medroxiprogesterona a cada 3 semanas, e C (n=8), fêmeas controle não tratadas. Aos seis meses de idade, foi realizada ovariohisterectomia em todos os animais, e avaliados os cornos uterinos pelo exame histológico e de histoquímica. Para avaliar a intensidade de secreção (graus 1-4), foram utilizadas periodic acid-Schiff e alcian blue (AB) pH 2,5. Para a avaliação histológica foram utilizados tricrômico de Masson e azul de toluidina. Apenas marcações graus 1 e 2 foram observadas para PAS em ambos os grupos, sem diferença na intensidade de secreção uterina entre grupos com relação aos graus encontrados. Entretanto, o grupo MPA apresentou maior intensidade de secreção uterina em relação ao grupo C (p<0,05). Com relação ao AB pH 2,5, em ambos os grupos também foram encontradas apenas marcações de graus 1 e 2, sem diferença estatística entre grupos. Não foram observadas marcações para a coloração de tricrômico de Masson na região periglandular, em ambos os grupos. Foi observada maior quantidade de mastócitos presentes no útero na região do miométrio, em ambos os grupos. Conclui-se que cadelas pré-púberes com ablação parcial da adenogênese uterina apresentam mínima atividade secretória uterina, ausência de fibrose periglandular e maior presença de mastócitos no miométrio em relação ao endométrio.(AU)

Uterine secretory activity and histology of prepubertal female dogs in an animal model of partial ablation of endometrial glands development / Atividade secretória uterina e histologia de cadelas pré-púberes em um modelo animal de ablação parcial do desenvolvimento das glândulas uterinas

Inadequate exposure of the female reproductive system to steroids in uterine developmental periods can partially inhibit the development of endometrial glands in dogs. However, the effects of steroids on the formed glands functionality remain unknown, as well as the possible occurrence of endometrial fibrosis. This study aimed to evaluate the secretory activity of endometrial glands in prebubertal female dogs submitted to a protocol of partial ablation of the uterine adenogenesis. Sixteen females of non-specific breed were distributed into two groups; MPA (n=8), females that received applications of medroxyprogesterone acetate every 3 weeks; and C (n=8) untreated control females. Ovariohysterectomy was performed in all animals at the age of 6 months and evaluated the uterine horns by histological and histochemistry exams. The secretion intensity (degrees 1-4) was evaluated using periodic acid-Schiff (PAS) and alcian blue (AB) pH 2.5. Histological evaluation was performed using Masson's trichrome and toluidine blue. Only degree 1 and 2 marks for PAS were observed in both groups, with no difference of uterine secretion intensity between the groups regarding the degrees found. However, the MPA group revealed higher intensity of uterine secretion compared to group C (p<0.05). Staining with AB pH 2.5 also revealed only degree 1 and 2 marks in both groups, with no statistically significance between them. Masson's trichrome staining revealed no marks in the periglandular region in both groups. A higher among of mast cells was observed in the myometrial region of the uterus in both groups. Prepubertal female dogs with partial ablation of the uterine adenogenesis present minimal uterine secretory activity, absence of periglandular fibrosis and increased presence of mast cells in the myometrium compared to endometrium.(AU)

A exposição inadequada do sistema reprodutor feminino a esteróides em períodos do desenvolvimento uterino pode inibir parcialmente o desenvolvimento das glândulas endometriais em cães. Entretanto, não se conhece os efeitos dos esteróides sobre a funcionalidade das glândulas formadas, bem como a possível ocorrência de fibrose endometrial. Objetivou-se avaliar a atividade secretória das glândulas endometriais de cadelas pré-púberes submetidas a protocolo de ablação parcial da adenogênese uterina. Foram utilizadas 16 fêmeas, sem-raça-definida, distribuídas nos grupos MPA (n=8), fêmeas que receberam aplicações de acetato de medroxiprogesterona a cada 3 semanas, e C (n=8), fêmeas controle não tratadas. Aos seis meses de idade, foi realizada ovariohisterectomia em todos os animais, e avaliados os cornos uterinos pelo exame histológico e de histoquímica. Para avaliar a intensidade de secreção (graus 1-4), foram utilizadas periodic acid-Schiff e alcian blue (AB) pH 2,5. Para a avaliação histológica foram utilizados tricrômico de Masson e azul de toluidina. Apenas marcações graus 1 e 2 foram observadas para PAS em ambos os grupos, sem diferença na intensidade de secreção uterina entre grupos com relação aos graus encontrados. Entretanto, o grupo MPA apresentou maior intensidade de secreção uterina em relação ao grupo C (p<0,05). Com relação ao AB pH 2,5, em ambos os grupos também foram encontradas apenas marcações de graus 1 e 2, sem diferença estatística entre grupos. Não foram observadas marcações para a coloração de tricrômico de Masson na região periglandular, em ambos os grupos. Foi observada maior quantidade de mastócitos presentes no útero na região do miométrio, em ambos os grupos. Conclui-se que cadelas pré-púberes com ablação parcial da adenogênese uterina apresentam mínima atividade secretória uterina, ausência de fibrose periglandular e maior presença de mastócitos no miométrio em relação ao endométrio.(AU)

Efficacy of use of tramadol in analgesia of prepubertal queens submitted to ovaryhysterectomy / Eficácia do uso de tramadol na analgesia de gatas pré púberes submetidas à ovariohisterectomia

É crescente o número de animais errantes nos grandes centros urbanos, sendo a população de felinos bastante significativa. A esterilização pré púbere promove de forma precoce a incapacidade reprodutiva do animal; reduz o desenvolvimento de patologias relacionadas ao trato reprodutivo, além de outras vantagens. Entretanto a anestesia em animais pré púberes ainda é um desafio e o uso de opióides nestes pacientes tem sido questionado devido a ocorrência de hipotensão em alguns casos. Sendo assim tornam-se necessários estudos para verificar as consequências do uso de opióides nestes animais. Portanto, o presente estudo teve como objetivo avaliar a eficiência do uso de Tramadol em gatas pré-púberes submetidas à ovariosalpingohisterectomia. Foram utilizadas oito fêmeas da espécie felina, com idade entre dois e quatro meses. As gatas foram divididas aleatoriamente em dois grupos (grupo Controle e grupo Tramadol), constituídos de 4 animais cada. Durante o trans operatório foram avaliadas a temperatura corporal, frequência respiratória, frequência cardíaca e saturação de oxigênio e pressão arterial não invasiva. Foram aferidos imediatamente antes da administração das drogas anestésicas (T0 – Controle) e a cada 4 minutos durante o transoperatório de 20 minutos (T4, T8, T12,T16, T20); os parâmetros de frequência cardíaca; frequência respiratória, temperatura corporal, nível de saturação de oxigênio e pressão arterial sistólica (PAS). O grupo Tramadol apresentou valores de frequência cardíaca e respiratória inferiores quando comparados com os obtidos no grupo Controle nos períodos de T0 até o T8. Em todos os momentos analisados a temperatura corporal e saturação de oxigênio não revelaram diferença significativa entre os dois grupos; sendo que os valores se mantiveram entre 35,6°C a 37,7°C e 78,5% a 90,25% respectivamente. Neste estudo foi possível concluir que o Tramadol foi eficiente na analgesia após esterilização...

The number of wandering animals in large urban centers is increasing, and the cat population is quite significant. Pre-pubertal sterilization promotes early reproductive failure of the animal; reduces the development of pathologies related to the reproductive tract, in addition of other advantages. However, anesthesia in prepubertal animals is still a challenge and the usage of opioids in those patient has been questioned due to the occurrence of hypotension in some cases. Accordingly, it is necessary further studies to verify the consequences of the use of opioids in these animals. Therefore, the present study had as objective to evaluate the effectiveness of the use of Tramadol in prepubescent queens submitted to ovariohisterectomy. Eight females of the feline species, aged between two and four months, were used. The queens were randomly divided into two groups (Control group and Tramadol group), consisting of four animals each. During the transoperative period, body temperature, respiratory rate, heart rate and oxygen saturation, and noninvasive blood pressure had been monitored. They have been measured immediately prior to administration of anesthetic drugs (T0 – Control) and every 4 minutes during 20 minute of transoperative period (T4, T8, T12, T16, T20); heart rate parameters; respiratory rate, body temperature, oxygen saturation level and systolic blood pressure (SBP). The Tramadol group presented lower values – of heart rate and respiratory rate when compared to those obtained in the Control group in the periods from T0 to T8. In all analyzed moments body temperature and oxygen saturation did not reveal significant difference between the two groups; with values – between 35.6° C and 37.7° C and 78.5% and 90.25%, respectively. In this study it was possible to conclude that Tramadol was efficient in analgesia after surgical sterilization of prepubertal cats, without causing significant hypotension.

Efficacy of use of tramadol in analgesia of prepubertal queens submitted to ovaryhysterectomy / Eficácia do uso de tramadol na analgesia de gatas pré púberes submetidas à ovariohisterectomia

É crescente o número de animais errantes nos grandes centros urbanos, sendo a população de felinos bastante significativa. A esterilização pré púbere promove de forma precoce a incapacidade reprodutiva do animal; reduz o desenvolvimento de patologias relacionadas ao trato reprodutivo, além de outras vantagens. Entretanto a anestesia em animais pré púberes ainda é um desafio e o uso de opióides nestes pacientes tem sido questionado devido a ocorrência de hipotensão em alguns casos. Sendo assim tornam-se necessários estudos para verificar as consequências do uso de opióides nestes animais. Portanto, o presente estudo teve como objetivo avaliar a eficiência do uso de Tramadol em gatas pré-púberes submetidas à ovariosalpingohisterectomia. Foram utilizadas oito fêmeas da espécie felina, com idade entre dois e quatro meses. As gatas foram divididas aleatoriamente em dois grupos (grupo Controle e grupo Tramadol), constituídos de 4 animais cada. Durante o trans operatório foram avaliadas a temperatura corporal, frequência respiratória, frequência cardíaca e saturação de oxigênio e pressão arterial não invasiva. Foram aferidos imediatamente antes da administração das drogas anestésicas (T0 Controle) e a cada 4 minutos durante o transoperatório de 20 minutos (T4, T8, T12,T16, T20); os parâmetros de frequência cardíaca; frequência respiratória, temperatura corporal, nível de saturação de oxigênio e pressão arterial sistólica (PAS). O grupo Tramadol apresentou valores de frequência cardíaca e respiratória inferiores quando comparados com os obtidos no grupo Controle nos períodos de T0 até o T8. Em todos os momentos analisados a temperatura corporal e saturação de oxigênio não revelaram diferença significativa entre os dois grupos; sendo que os valores se mantiveram entre 35,6°C a 37,7°C e 78,5% a 90,25% respectivamente. Neste estudo foi possível concluir que o Tramadol foi eficiente na analgesia após esterilização...(AU)

The number of wandering animals in large urban centers is increasing, and the cat population is quite significant. Pre-pubertal sterilization promotes early reproductive failure of the animal; reduces the development of pathologies related to the reproductive tract, in addition of other advantages. However, anesthesia in prepubertal animals is still a challenge and the usage of opioids in those patient has been questioned due to the occurrence of hypotension in some cases. Accordingly, it is necessary further studies to verify the consequences of the use of opioids in these animals. Therefore, the present study had as objective to evaluate the effectiveness of the use of Tramadol in prepubescent queens submitted to ovariohisterectomy. Eight females of the feline species, aged between two and four months, were used. The queens were randomly divided into two groups (Control group and Tramadol group), consisting of four animals each. During the transoperative period, body temperature, respiratory rate, heart rate and oxygen saturation, and noninvasive blood pressure had been monitored. They have been measured immediately prior to administration of anesthetic drugs (T0 Control) and every 4 minutes during 20 minute of transoperative period (T4, T8, T12, T16, T20); heart rate parameters; respiratory rate, body temperature, oxygen saturation level and systolic blood pressure (SBP). The Tramadol group presented lower values of heart rate and respiratory rate when compared to those obtained in the Control group in the periods from T0 to T8. In all analyzed moments body temperature and oxygen saturation did not reveal significant difference between the two groups; with values between 35.6° C and 37.7° C and 78.5% and 90.25%, respectively. In this study it was possible to conclude that Tramadol was efficient in analgesia after surgical sterilization of prepubertal cats, without causing significant hypotension.(AU)

Calcium chloride combined with dimethyl sulphoxide for the chemical sterilization of dogs.

The aim of this study was to evaluate the effect of intratesticular injection of calcium chloride (CaCl2 ) combined with dimethyl sulphoxide (DMSO) as a chemical sterilization in dogs. Twelve dogs were divided into two groups: the treated group (n = 6), in which 15 mg/kg of a 7.5% CaCl2 solution combined with 0.5% DMSO was injected into each testicle (volume range 1.0-4.76 ml); and a control group (n = 6) that received the same volume/kg of 0.9% sodium chloride solution (NaCl). Semen characteristics pre- and post-treatment were evaluated. Serum testosterone concentration was determined before the injection (D-1) and at 15 (D15), 30 (D30) and 60 (D60) days after intratesticular injection. Testicle sizes and local pain were evaluated for 7 consecutive days (D1 to D7) and at D15, D30 and D60 after injection. At D60, testicle histological evaluation was performed after orchiectomy. No pain was observed by testicular palpation, with the exception of one dog in the treated group; this dog then received analgesic therapy. An increase in testicular volume was evident within 24 hr after treatment, followed by gradual reduction for 3 weeks. Five of 6 dogs from the treated group presented azoospermia at D15; the remaining dog presented at D30. There was no significant difference in testosterone concentrations in the treated group during the experimental period. Histological evaluation showed testicular degenerative lesions, especially at the proximal and middle portions. The results indicated that one injection of 7.5% CaCl2 combined with 0.5% DMSO into each testis is a viable alternative for canine sterilization.

Vigilancia, prevención y control de la rabia: Ciudad de Buenos Aires: Junio 2018 / Surveillance, prevention and control of rabies: City of Buenos Aires: June 2018

La rabia es una enfermedad viral, de distribución mundial que afecta al hombre y a todos los mamíferos tanto domésticos como silvestres, con una letalidad del 100% afectando el sistema nervioso central. Se transmite por medio de la inoculación del virus contenido en la saliva del animal infectado, principalmente por mordeduras o el lamido de heridas, o por predación cuando un animal caza un murciélago infectado y toma contacto con el virus desde el encéfalo del quiróptero. Otras formas de transmisión, menos frecuentes son por trasplante de tejidos infectados o por aerosoles. En este apartado, se describe la situación epidemiológica de esta zoonosis en la Ciudad de Buenos Aires: observación de animales mordedores, detección de virus rábico en muestras mediante diagnóstico de laboratorio, vacunación de animales y control poblacional mediante esterilizaciones quirúrgicas, acciones de control de focos de rabia, y seguimiento de animales con exposición a murciélagos positivos a rabia o no analizables

Modeling the effect of surgical sterilization on owned dog population size in Villa de Tezontepec, Hidalgo, Mexico, using an individual-based computer simulation model.

Surgical sterilization programs for dogs have been proposed as interventions to control dog population size. Models can be used to help identify the long-term impact of reproduction control interventions for dogs. The objective of this study was to determine the projected impact of surgical sterilization interventions on the owned dog population size in Villa de Tezontepec, Hidalgo, Mexico. A stochastic, individual-based simulation model was constructed and parameterized using a combination of empirical data collected on the demographics of owned dogs in Villa de Tezontepec and data available from the peer-reviewed literature. Model outcomes were assessed using a 20-year time horizon. The model was used to examine: the effect of surgical sterilization strategies focused on: 1) dogs of any age and sex, 2) female dogs of any age, 3) young dogs (i.e., not yet reached sexual maturity) of any sex, and 4) young, female dogs. Model outcomes suggested that as surgical capacity increases from 21 to 84 surgeries/month, (8.6% to 34.5% annual sterilization) for dogs of any age, the mean dog population size after 20 years was reduced between 14% and 79% compared to the base case scenario (i.e. in the absence of intervention). Surgical sterilization interventions focused only on young dogs of any sex yielded greater reductions (81% - 90%) in the mean population size, depending on the level of surgical capacity. More focused sterilization targeted at female dogs of any age, resulted in reductions that were similar to focusing on mixed sex sterilization of only young dogs (82% - 92%). The greatest mean reduction in population size (90% - 91%) was associated with sterilization of only young, female dogs. Our model suggests that targeting sterilization to young females could enhance the efficacy of existing surgical dog population control interventions in this location, without investing extra resources.

Triploid or hybrid tetra: Which is the ideal sterile host for surrogate technology?

This work was aimed at developing an effective procedure to obtain sterile ideal host fish in mass scale with no endogenous germ cells in the germinal epithelium, owning permanent stem-cell niches able to be colonized by transplanted germ cells in surrogate technology experiments. Thus, triploids, diploid hybrids, and triploid hybrids were produced. To obtain hybrid offspring, oocytes from a single Astyanax altiparanae female were inseminated by sperm from five males (A. altiparanae, A. fasciatus, A. schubarti, Hyphessobrycon anisitsi, and Oligosarcus pintoi). Triploidization was conducted by inhibition of the second polar body release using heat shock treatment at 40 °C for 2 min. At 9-months of age, the offspring from each crossing was histologically evaluated to access the gonadal status of the fish. Variable morphological characteristics of the gonads were found in the different hybrids offspring: normal gametogenesis, gametogenesis without production of gametes, sterile specimens holding germ cells, and sterile specimens without germ cells, which were considered "ideal hosts". However, only in the hybrid derived from crossing between A. altiparanae and A. fasciatus, 100% of the individuals were completely sterile. Among them 83.3% of the male did not present germ cells inside germinal epithelium, having only somatic cells in the gonad. The other 16.7% also presented spermatogonia inside the niches. Such a methodology allows the production of sterile host in mass scale, opening new insights for application of surrogate technologies.

Abundance, survival, recruitment and effectiveness of sterilization of free-roaming dogs: A capture and recapture study in Brazil.

The existence of free-roaming dogs raises important issues in animal welfare and in public health. A proper understanding of these animals' ecology is useful as a necessary input to plan strategies to control these populations. The present study addresses the population dynamics and the effectiveness of the sterilization of unrestricted dogs using capture and recapture procedures suitable for open animal populations. Every two months, over a period of 14 months, we captured, tagged, released and recaptured dogs in two regions in a city in the southeast region of Brazil. In one of these regions the animals were also sterilized. Both regions had similar social, environmental and demographic features. We estimated the presence of 148 females and 227 males during the period of study. The average dog:man ratio was 1 dog for each 42 and 51 human beings, in the areas without and with sterilization, respectively. The animal population size increased in both regions, due mainly to the abandonment of domestic dogs. Mortality rate decreased throughout the study period. Survival probabilities did not differ between genders, but males entered the population in higher numbers. There were no differences in abundance, survival and recruitment between the regions, indicating that sterilization did not affect the population dynamics. Our findings indicate that the observed animal dynamics were influenced by density-independent factors, and that sterilization might not be a viable and effective strategy in regions where availability of resources is low and animal abandonment rates are high. Furthermore, the high demographic turnover rates observed render the canine free-roaming population younger, thus more susceptible to diseases, especially to rabies and leishmaniasis. We conclude by stressing the importance of implementing educational programs to promote responsible animal ownership and effective strategies against abandonment practices.

Controle populacional de espécies silvestres invasoras por meio de laqueadura e vasectomia em primatas Callithrix penicillata: relato de caso / Population control of invasive wild species through tubal ligation and vasectomy in primates Callithrix penicillata: case report / Control de la población de especies silvestres invasoras mediante ligadura de trompas y vasectomía en primates Callithrix penicillata: informe del caso

Saguis-de-tufo-preto (Callithrix penicillata) são consideradas espécies invasoras em regiões do sul e sudeste do Brasil. Espécies invasoras interferem com a dinâmica do ecossistema em áreas nas quais foram introduzidas. A hibridização, a competição e a predação de outros animais são alguns dos problemas causados por estes calitriquídeos. A esterilização de primatas que se encontram em Centros de Recuperação para Animais Silvestres é um procedimento necessário que visa o controle populacional da espécie quando são destinadas para soltura. Técnicas como a de laqueadura e vasectomia, que preservam as glândulas sexuais que são imprescindíveis nestes primatas, pois necessitam de sua produção hormonal para se estabelecer e viver em grupos na natureza. Sendo assim, objetivou-se descrever a técnica cirúrgica de esterilização de um macho e uma fêmea da espécie C. penicillata.

Black-tufted marmosets (Callitrhix penicillata) are considered invasive species in the regions of Southern and Southeast of Brazil. Invasive species interfere with the dynamics of ecosystem in areas which they were introduced. The hybridization, the competition and the predation of other animals are some of the problems caused by callitrichids. The sterilization of primates that are in wildlife rehabilitation centers is a necessary procedure because it is intended to control the population growth from species destined to reintroduction into the wild. Technics like tubal ligation and vasectomy that maintain the sexual glands are essential to these primates since they need their hormones production to be able to live in groups in the wild. Therefore the aim of this work is to describe in details the sterilization technique of a male and a female of C. penicillata.

Los titíes de Pincel Negro (Callithrix penicillata) son considerados especies invasoras en las regiones del sur y el surdeste de Brasil. Las especies invasoras interfieren con la dinámica de los ecosistemas en las áreas en las que fueron introducidas. La hibridación, la competencia y la depredación de otros animales son algunos de los problemas causados por estos callitrícidos. La esterilización de los primatas que se encuentran en Centros de Recuperación de Animales Silvestres es un procedimiento necessário dedicado a controlar la población de la especie destinada a su liberación. Técnicas como la ligadura de trompas y la vasectomía, las cuales preservan las glándulas sexuales, son imprescindibles para estos primatas ya que necesitan su producción hormonal para establecerse y vivir en grupos en la naturaleza. Por tanto, este estudio tiene como objetivo describir la técnica quirúrgica de esterilización de un macho y una hembra de la especie C. penicillata.

Controle populacional de espécies silvestres invasoras por meio de laqueadura e vasectomia em primatas Callithrix penicillata: relato de caso / Population control of invasive wild species through tubal ligation and vasectomy in primates Callithrix penicillata: case report / Control de la población de especies silvestres invasoras mediante ligadura de trompas y vasectomía en primates Callithrix penicillata: informe del caso

Saguis-de-tufo-preto (Callithrix penicillata) são consideradas espécies invasoras em regiões do sul e sudeste do Brasil. Espécies invasoras interferem com a dinâmica do ecossistema em áreas nas quais foram introduzidas. A hibridização, a competição e a predação de outros animais são alguns dos problemas causados por estes calitriquídeos. A esterilização de primatas que se encontram em Centros de Recuperação para Animais Silvestres é um procedimento necessário que visa o controle populacional da espécie quando são destinadas para soltura. Técnicas como a de laqueadura e vasectomia, que preservam as glândulas sexuais que são imprescindíveis nestes primatas, pois necessitam de sua produção hormonal para se estabelecer e viver em grupos na natureza. Sendo assim, objetivou-se descrever a técnica cirúrgica de esterilização de um macho e uma fêmea da espécie C. penicillata.(AU)

Black-tufted marmosets (Callitrhix penicillata) are considered invasive species in the regions of Southern and Southeast of Brazil. Invasive species interfere with the dynamics of ecosystem in areas which they were introduced. The hybridization, the competition and the predation of other animals are some of the problems caused by callitrichids. The sterilization of primates that are in wildlife rehabilitation centers is a necessary procedure because it is intended to control the population growth from species destined to reintroduction into the wild. Technics like tubal ligation and vasectomy that maintain the sexual glands are essential to these primates since they need their hormones production to be able to live in groups in the wild. Therefore the aim of this work is to describe in details the sterilization technique of a male and a female of C. penicillata.(AU)

Los titíes de Pincel Negro (Callithrix penicillata) son considerados especies invasoras en las regiones del sur y el surdeste de Brasil. Las especies invasoras interfieren con la dinámica de los ecosistemas en las áreas en las que fueron introducidas. La hibridación, la competencia y la depredación de otros animales son algunos de los problemas causados por estos callitrícidos. La esterilización de los primatas que se encuentran en Centros de Recuperación de Animales Silvestres es un procedimiento necessário dedicado a controlar la población de la especie destinada a su liberación. Técnicas como la ligadura de trompas y la vasectomía, las cuales preservan las glándulas sexuales, son imprescindibles para estos primatas ya que necesitan su producción hormonal para establecerse y vivir en grupos en la naturaleza. Por tanto, este estudio tiene como objetivo describir la técnica quirúrgica de esterilización de un macho y una hembra de la especie C. penicillata.(AU)