Survey of euthanasia methods used in neotropical chiropterans in São Paulo State, Brazil: critical analyses and proposal for standardization of bat euthanasia methods / evantamento dos métodos de eutanásia utilizados em quirópteros neotropicais no estado de São Paulo, Brasil: análise crítica e proposta de padronização de métodos de eutanásia em morcegos

Zoonotic Surveillance Divisions (ZSDs) rescue and euthanize bats in contact with humans. The euthanasia procedure should be conducted safely for the animal and caretaker and minimal stress for the animal is important. The objectives of this study were: i. evaluate the methods of euthanasia used by ZSDs in the State of São Paulo; ii. compare the methods with national and international guidelines for animal euthanasia practices; iii. assess the methodologies considering taxonomy and eating habits of the main bat species, and iv. propose standardization of euthanasia procedures. Sixty-five ZSDs locations received an online questionnaire or were contacted by telephone and 33 ZSDs (50.8%) responded and are distributed in 11 mesoregions in the state to remain anonymous. The euthanasia methods were divided into chemical (injectable or inhalation), physical, or mixed methods. Bat specimens (n = 550) were identified and classified to evaluate the main genera found in the state. The location of the ZSD, species, eating habits, and the method of euthanasia used were analyzed. The specimens by bat families were Molossidae (n = 340), Phyllostomidae (n = 171), and Vespertilionidae (n = 39). Chemical methods were used in 25 ZSDs (75.75%), physical in 5 (15.15%), and mixed in 3 (9.09%). There is no uniformity or standardization in bat euthanasia methods used by ZSDs, although most are based on acceptable chemical methods. It was proposed an algorithm to assist the veterinarian in choosing the method of euthanasia for bats that will allow standardizing euthanasia procedures for this species, considering physiological differences, and respecting technical, bioethical, and animal welfare guidelines.(AU)

As Divisões de Vigilância de Zoonoses (DVZs) coletam e eutanasiam morcegos que tiveram contato com humanos. O procedimento de eutanásia precisa ocorrer de modo seguro para o animal e para o manipulador, sendo importante garantir o mínimo de estresse ao animal. Os objetivos deste estudo foram: i. avaliar os métodos de eutanásia praticados nas DVZ do estado de São Paulo; ii. comparar esses métodos com os guias nacionais e internacionais de práticas de eutanásia animal; iii. avaliar as metodologias aplicadas considerando a taxonomia e os hábitos alimentares das principais espécies de ocorrência de morcegos; e iv. propor a padronização dos procedimentos de eutanásia. Sessenta e cinco DVZs receberam o questionário online ou foram contatadas por telefone, dessas, trinta e três DVZs (50,8%) que responderam ao questionário foram incluídas no estudo e distribuídas em 11 mesorregiões para garantir anonimato. Os métodos de eutanásia reportados foram divididos em métodos químicos (injetáveis; inalatórios), físicos ou mistos. Os espécimes de morcegos (n = 550) foram identificados e classificados para avaliar os principais gêneros encontrados no estado. A localização da DVZ, as espécies, os hábitos alimentares e o método de eutanásia utilizado foram analisados. Os espécimes por família de espécies de morcegos foram Molossidae (n = 340), Phyllostomidae (n = 171) e Vespertilionidae (n = 39). Métodos químicos foram utilizados em 25 DVZs (75,75%), físicos em 5 (15,15%) e mistos em 3 (9,09%). Não há uniformidade ou padronização nos métodos de eutanásia de morcegos, embora a maioria seja baseada em métodos químicos aceitáveis. É proposto um algoritmo para auxiliar o veterinário na escolha do método de eutanásia, que permite a padronização desses procedimentos para os morcegos, considerando as diferenças fisiológicas e respeitando as diretrizes técnicas, bioéticas e de bem-estar animal.(AU)

Analysis of Volatile Compounds in Sea Bass (Lateolabrax japonicus) Resulting from Different Slaughter Methods Using Electronic-Nose (E-Nose) and Gas Chromatography-Ion Mobility Spectrometry.

Sea bass (Lateolabrax japonicus) is known for its unique flavor and high nutritional value. In this study, the influence of slaughter methods on the volatile compounds (VOCs) in sea bass was investigated using electronic nose (E-nose) technology and gas chromatography-ion mobility spectrometry (GC-IMS). VOCs in raw and cooked sea bass resulting from different slaughter methods were effectively distinguished using both techniques. Aldehydes, ketones, and alcohols were associated with the basic flavor of sea bass, whereas esters, organic acids, and furans enriched the aroma. In raw sea bass, the fishy odor was the strongest in the HSD group (head shot control death), followed by that in the IFD (ice faint to death) and BDS (bloodletting to death) groups. The VOC content increased and stabilized after steaming, enhancing pleasant odors such as fatty and fruity aromas. In cooked sea bass, the content of diacetyl and ethanol was the highest in the EAD group (eugenol anesthesia to death), which may be a residue of eugenol, imparting a distinct irritating chemical odor. Furthermore, abundant (E)-2-octenal, 2-heptanone, benzaldehyde, and esters in the BDS group imparted a strong, pleasant aroma. The findings indicate that heart puncture and bloodletting is the preferred slaughter method to maintain sea bass quality, providing new insights into the volatile changes in sea bass induced by different slaughter methods.

Defining characteristics of immersion carbon dioxide gas for successful euthanasia of neonatal and young broilers.

This study investigated how the carbon dioxide (CO2) concentration within a chamber affects the efficacy of CO2 euthanasia and how the efficacy of CO2 induction methods changes as birds age. In experiment 1, pairs of broiler chicks (n = 192; 0, 3, and 6 D of age) were immersed into a chamber prefilled with 70, 80, 90, or 100% CO2. For experiment 2, 3- and 6-day-old broiler chicks (n = 88) were immersed in pairs into 100% CO2 or exposed to CO2 gradual fill in a chamber with a displacement rate of 28% chamber volume per minute. Latency to performance of headshaking (HS) and gasping (GS) as potential indicators of distress, loss of posture indicative of insensibility, and the cessation of rhythmic breathing (CRB) and cessation of movement (COM) as the indicators of death were monitored (live focal sampling/video recordings). The duration and frequency of HS and GS were assessed. For both experiments, behavior data were analyzed for CO2 method and age (4 × 3 factorial). Age and CO2 concentration interacted for latency to CRB and COM, with longer latencies for 0-day-old chicks immersed into 70% CO2 than other concentrations and ages. CO2 concentration did not affect latency to HS, GS, or loss of posture but affected CRB and COM, with latencies longest for 70% and shortest for 90 and 100% CO2. Newly hatched chicks had a longer latency to CRB and COM and longer duration and frequency of distress behaviors than older chicks. At all ages, initiation of all behaviors occurred later with gradual fill compared to immersion. There was an increased duration and frequency of distress behaviors with gradual induction compared with immersion. Overall, immersion into 90 to 100% CO2 resulted in the shortest time to insensibility and death, with a decreased duration and frequency of distress behaviors. Chicks immersed into 70% CO2 had the longest duration of GS and time to death. Age affects the efficacy of CO2 euthanasia, with increasing age decreasing time to death and the duration and frequency of distress behaviors.

Nitrogen gas produces less behavioural and neurophysiological excitation than carbon dioxide in mice undergoing euthanasia.

Carbon dioxide (CO2) is one of the most commonly used gas euthanasia agents in mice, despite reports of aversion and nociception. Inert gases such as nitrogen (N2) may be a viable alternative to carbon dioxide. Here we compared behavioural and electrophysiological reactions to CO2 or N2 at either slow fill or rapid fill in C57Bl/6 mice undergoing gas euthanasia. We found that mice euthanised with CO2 increased locomotor activity compared to baseline, whereas mice exposed to N2 decreased locomotion. Furthermore, mice exposed to CO2 showed significantly more vertical jumps and freezing episodes than mice exposed to N2. We further found that CO2 exposure resulted in increased theta:delta of the EEG, a measure of excitation, whereas the N2 decreased theta:delta. Differences in responses were not oxygen-concentration dependent. Taken together, these results demonstrate that CO2 increases both behavioural and electrophysiological excitation as well as producing a fear response, whereas N2 reduces behavioural activity and central neurological depression and may be less aversive although still produces a fear response. Further studies are required to evaluate N2 as a suitable euthanasia agent for mice.

Anesthesia protocols in laboratory animals used for scientific purposes.

BACKGROUND: A suitable, effective and free of complications anesthetic protocol is very important in experimental studies on animal models since it could bias the outcome of a trial. To date there is no universally accepted protocol for induction, maintenance and recovery from anesthesia. The endotracheal intubation with the use of inhalation anesthesia is used very especially in the from of large size laboratory animals, because it is a secure and easy control mode. However, it is not common for small laboratory animals because of the high technical skills required. AIM: The aim of this paper is a review of the main methods of induction of anesthesia in laboratory animals. MATERIALS AND METHODS: We performed an electronic search of MEDLINE (PubMed interface), ISI Web of Science and Scopus using the keywords "anesthesia" and "animal (s)" or "protocol (s)" or "surgery", without the data or the language restriction. We consider only the most common laboratory animals (rats, mice, rabbits, pigs). We identify all the scientific articles that refer to the use of anesthetics for studies on laboratory animals in all areas: experimental surgery, CT, MRI, PET. All documents identified the search criteria are subject to review only by identifying relevant studies. CONCLUSIONS: There is a strong need for application of existing guidelines for research on experimental animals; specific guidelines for anesthesia and euthanasia should be considered and reported in future studies to ensure comparability and quality of animal experiments.

Local anaesthetic refinement of pentobarbital euthanasia reduces abdominal writhing without affecting immunohistochemical endpoints in rats.

Sodium pentobarbital is a commonly used agent for euthanizing laboratory rats, however its high pH can cause abdominal discomfort after intraperitoneal injection. Previous studies suggest that the addition of a local anaesthetic may alleviate this discomfort, but the practice has not been widely adopted. We examined the effect of combining lidocaine with pentobarbital on abdominal writhing, defecation, ultrasonic vocalizations, the rat grimace scale and immunohistochemical staining for c-Fos in the nucleus accumbens and basolateral amygdala of the brain. We also compared the amount of abdominal writhing following intraperitoneal administration of pentobarbital-lidocaine with that of pentobarbital-bupivacaine. Our results show that lidocaine reduces abdominal writhing and defecation without affecting immunohistochemistry for c-Fos or latency to loss of posture. However, scores on the rat grimace scale were low in both situations and almost no ultrasonic vocalizations were recorded. Additionally, we found that the amount of abdominal writhing was not significantly different when bupivacaine was used rather than lidocaine. Our results suggest that pentobarbital-induced euthanasia can be refined with the addition of lidocaine or other local anaesthetics.

Comparison of water-based foam and carbon dioxide gas emergency depopulation methods of turkeys.

Recommended response strategies for outbreaks of avian influenza and other highly contagious poultry diseases include surveillance, quarantine, depopulation, disposal, and decontamination. The best methods of emergency mass depopulation should maximize human health and safety while minimizing disease spread and animal welfare concerns. The goal of this project was to evaluate the effectiveness of 2 mass depopulation methods on adult tom turkeys. The methods tested were carbon dioxide gassing and water-based foam. The time to unconsciousness, motion cessation, brain death, and altered terminal cardiac activity were recorded for each bird through the use of an electroencephalogram, accelerometer, and electrocardiogram. Critical times for physiological events were extracted from sensor data and compiled in a spreadsheet for statistical analysis. A statistically significant difference was observed in time to brain death, with water-based foam resulting in faster brain death (µ = 190 s) than CO2 gas (µ = 242 s). Though not statistically significant, differences were found comparing the time to unconsciousness (foam: µ = 64 s; CO2 gas: µ = 90 s), motion cessation (foam: µ = 182 s; CO2 gas: µ = 153 s), and altered terminal cardiac activity (foam: µ = 208 s; CO2 gas µ = 242 s) between foam and CO2 depopulation treatments. The results of this study demonstrate that water-based foam can be used to effectively depopulate market size male turkeys.

Gas alternatives to carbon dioxide for euthanasia: a piglet perspective.

The search for alternative methods to euthanize piglets is critical to address public concern that current methods are not optimal. Scientific evidence supports that blunt force trauma is humane when performed correctly, but most people find it visually difficult to accept. The use of CO2 is often recommended; at the same time, it is criticized as being aversive to pigs. This research sought to 1) identify a method of scientifically determining if piglets find a gas aversive, using an approach-avoidance test, which relies on the perspective of the piglet, and 2) test different gas mixtures to determine if they are effective and humane for neonatal piglet euthanasia. Pigs were allowed to walk freely between 1 chamber filled with air and another chamber either gradually filled with gas mixtures (Exp. 1) or prefilled with gas mixtures (Exp. 2). Experiment 1 tested CO2 (90%) and air (10%), N2O (60%) and CO2 (30%), Ar (60%) and CO2 (30%), and N2 (60%) and CO2 (30%). Because piglets had to be removed when they started to flail, the test was shortest (P < 0.01) for the pigs in the CO2 treatment compared with pigs in the N2O/CO2, Ar/CO2, and N2/CO2 treatments, 3.1 ± 0.2, 8.5 ± 0.6, 9.6 ± 0.4, and 9.9 ± 0.1 min, respectively. Nonetheless, all gas mixtures adversely affected the pigs, causing the pigs to leave the test chamber. In Exp. 2, piglets were allowed to enter a chamber prefilled with N2/CO2 or N2O/CO2 (both 60/30%). Pigs exposed to the prefill chambers started to flail in fewer than 20 s, much faster in comparison with the gradual fill method, which supports that this method was more aversive. In Exp. 3, piglets were euthanized using a 2-step procedure. Pigs were first placed in a gradual fill chamber with 1 of 4 gas mixtures: 90% CO2, N2/CO2, N2O/CO2, or N2O/O2 (the last 3 mixtures at 60/30%) followed by placement into a 90% CO2 prefill chamber when the pigs started to flail or were anesthetized. All 3 gas treatments that contained CO2 killed pigs more quickly than N2O/O2 (P < 0.05). However, N2O/O2 was the only treatment that anesthetized the pigs instead of causing squeals or flailing although requiring about 12 min longer. Although longer, a 2-step procedure in which pigs are anesthetized with a mixture of N2O and O2 before being euthanized by immersion in CO2 may prove to be more humane than CO2 alone.

Comparison of water-based foam and carbon dioxide gas mass emergency depopulation of White Pekin ducks.

The mass depopulation of production birds remains an effective means of controlling fast-moving, highly infectious diseases such as avian influenza and virulent Newcastle disease. Two experiments were performed to compare the physiological responses of White Pekin commercial ducks during foam depopulation and CO(2) gas depopulation. Both experiment 1 (5 to 9 wk of age) and 2 (8 to 14 wk of age) used electroencephalogram, electrocardiogram, and accelerometer to monitor and evaluate the difference in time to unconsciousness, motion cessation, brain death, altered terminal cardiac activity, duration of bradycardia, and elapsed time from onset of bradycardia to onset of unconsciousness between foam and CO(2) gas. Experiment 2 also added a third treatment, foam + atropine injection, to evaluate the effect of suppressing bradycardia. Experiment 1 resulted in significantly shorter times for all 6 physiological points for CO(2) gas compared with foam, whereas experiment 2 found that there were no significant differences between foam and CO(2) gas for these physiological points except brain death, in which CO(2) was significantly faster than foam and duration of bradycardia, which was shorter for CO(2). Experiment 2 also determined there was a significant positive correlation between duration of bradycardia and time to unconsciousness, motion cessation, brain death, and altered terminal cardiac activity. The time to unconsciousness, motion cessation, brain death, and altered terminal cardiac activity was significantly faster for the treatment foam + atropine injection compared with foam. Both experiments showed that bradycardia can occur as a result of either submersion in foam or exposure to CO(2) gas. The duration of bradycardia has a significant impact on the time it takes White Pekin ducks to reach unconsciousness and death during depopulation.

Mass depopulation of laying hens in whole barns with liquid carbon dioxide: evaluation of welfare impact.

Appropriate emergency disaster preparedness is a key priority for agricultural agencies to allow effective response to serious avian disease outbreaks. There is a need to develop rapid, humane, and safe depopulation techniques for poultry that are widely applicable across a range of farm settings. Whole barn depopulation with carbon dioxide (CO(2)) has been investigated as a humane and efficient means of killing large numbers of birds in the event of a reportable disease outbreak. It has also been considered as a method for depopulating barns containing end-of-lay hens, particularly when there is limited local slaughter and rendering capacity. Determining the best method of humanely killing large flocks of birds remains problematic and is being investigated by a coordinated international effort. While whole barn depopulation using CO(2) inhalation has been explored, physiologic responses of chickens have not been characterized in field settings and assessment of animal welfare is hampered without this information. In this study, 12 cull laying hens were surgically instrumented with telemetry transmitters to record electroencephalographs, electrocardiographs, body temperature, and activity during 2 large-scale field CO(2) euthanasia trials of end-of-lay hens. The day following surgery, instrumented hens were placed in barns with other birds, barns were sealed, and animals were killed by CO(2) inhalation delivered via a specially designed liquid CO(2) manifold. Instrumented birds were monitored by infrared thermography, and ambient temperature, CO(2), and O(2) concentrations were recorded. Results from these studies indicate that instrumented hens lost consciousness within 2 min of CO(2) levels reaching 18 to 20%. Mild to moderate head shaking, gasping, and 1 to 2 clonic muscle contractions were noted in hens before unconsciousness; however, brain death followed rapidly (<5 min). Evaluation of welfare costs and benefits suggest clear advantages over catching and transporting cull hens for slaughter. The financial costs with this method are greater, however, than those estimated for traditional slaughter techniques. Results of these studies are being used to develop national protocols for whole barn depopulation of hens by CO(2) inhalation.

Review of palliative sedation and its distinction from euthanasia and lethal injection.

Palliative sedation evolved from within the practice of palliative medicine and has become adopted by other areas of medicine, such as within intensive care practice. Clinician's usually come across this practice for dying patients who are foregoing or having life support terminated. A number of intolerable and intractable symptom burdens can occur during the end of life period that may require the use of palliative sedation. Furthermore, when patients receive palliative sedation, the continued use of hydration and nutrition becomes an issue of consideration and there are contentious bioethical issues involved in using or withholding these life-sustaining provisions. A general understanding of biomedical ethics helps prevent abuse in the practice of palliative sedation. Various sedative drugs can be employed in the provision of palliative sedation that can produce any desired effect, from light sedation to complete unconsciousness. Although there are some similarities in the pharmacotherapy of palliative sedation, euthanasia, physician-assisted suicide, and lethal injection, there is a difference in how the drugs are administered with each practice. There are some published guidelines about how palliative sedation should be practiced, but currently there is not any universally accepted standard of practice.

Sedation or inhalant anesthesia before euthanasia with CO2 does not reduce behavioral or physiologic signs of pain and stress in mice.

CO(2) administration is a common euthanasia method for research mice, yet questions remain regarding whether CO(2) euthanasia is associated with pain and stress. Here we assessed whether premedication with acepromazine, midazolam, or anesthetic induction with isoflurane altered behavioral and physiologic parameters that may reflect pain or stress during CO(2) euthanasia. Mice were assigned to 1 of 6 euthanasia groups: CO(2) only at a flow rate of 1.2 L/min which displaces 20% of the cage volume per minute (V/min; control group); premedication with acepromazine (5 mg/kg), midazolam (5 mg/kg), or saline followed by 20% V/min CO(2); induction with 5% isoflurane followed by greater than 100% V/min CO(2) (>6L/min); and 100% V/min CO(2) only (6 L/min). Measures included ultrasonic sound recordings, behavioral analysis of video record- ings, plasma ACTH and corticosterone levels immediately after euthanasia, and quantification of c-fos from brain tissue. Compared with 20% V/min CO(2) alone, premedication with acepromazine or midazolam did not significantly alter behavior but did induce significantly higher c-fos expression in the brain. Furthermore, the use of isoflurane induction prior to CO(2) euthanasia significantly increased both behavioral and neuromolecular signs of stress. The data indicate that compared with other modalities, 20% V/min CO(2) alone resulted in the least evidence of stress in mice and therefore was the most humane euthanasia method identified in the current study.

Method of euthanasia affects amygdala plasticity in horizontal brain slices from mice.

An important consideration in any terminal experiment is the method used for euthanizing animals. Although the prime consideration is that the method is humane, some methods can have a dramatic impact on experimental outcomes. The standard inhalant anesthetic for experiments in brain slices is isoflurane, which replaced the flammable ethers used in the pioneer days of surgery. To our knowledge, there are no data available evaluating the effects of the method of euthanasia on plasticity changes in brain slices. Here, we compare the magnitude of long-term potentiation (LTP) and long-term depression (LTD) in the lateral nucleus of the amygdala (LA) after euthanasia following either ether or isoflurane anesthesia, as well as in mice decapitated without anesthesia. We found no differences in input-output curves using different methods of euthanasia. The LTP magnitude did not differ between ether and normal isoflurane anesthesia. After deep isoflurane anesthesia LTP induced by high frequency stimulation of cortical or intranuclear afferents was significantly reduced compared to ether anesthesia. In contrast to ether anesthesia and decapitation without anesthesia, the low frequency stimulation of cortical afferents induced a reliable LA-LTD after deep isoflurane anesthesia. Low frequency stimulation of intranuclear afferents only caused LTD after pretreatment with ether anesthesia. The results demonstrate that the method of euthanasia can influence brain plasticity for hours at least in the interface chamber. Therefore, the method of euthanasia is an important consideration when brain plasticity will be evaluated.

Efeitos de jejum de curta duração na evolução de peritonite fecal em camundongos / Effects of short term fasting on the evolution of fecal peritonitis in mice

PURPOSE: To investigate the effect of 72 hours food suppression on the evolution of fecal peritonitis in mice evaluating the mortality and measuring the number and size of abscesses formed into the peritoneal cavity. METHODS: Mice receiving commercial diet and water ad libitum (control group, N=35) and mice fasted during 72 h (N=35), receiving only water ad libitum, were inoculated by i.p. route, with 4uL/g body weight of a fecal suspension diluted 1:6 or 1:9 in 0.15M NaCl solution (1:6 dilution, 22 controls and 18 fasted; 1:9 dilution, 13 controls and 17 fasted). Animals were followed up until two weeks after fecal inoculation, when the survivors were euthanized for evaluation of the number and size of intra-peritoneal abscesses. Mortality was evaluated by Kaplan Meyer curves. RESULTS: Mortality was significantly higher in fasted groups than in controls. However the number and size of abscesses were significantly less in fasted groups than in controls. CONCLUSION: Seventy two hours food suppression increased the susceptibility to endotoxic shock (high mortality after peritonitis induction) and the resistance to infection with fecal microorganisms (less number and size of intra-peritoneal abscesses).

OBJETIVO: Investigar o efeito de jejum de 72 horas na evolução de peritonite fecal em camundongos, avaliando a mortalidade e o número e tamanho dos abscessos formados na cavidade peritoneal. MÉTODOS: Camundongos recebendo dieta ad libitum (grupo controle, N=35) e camundongos submetidos a jejum durante 72h (N=35) foram inoculados, por via intraperitoenal, com 4uL/g de peso corporal de uma suspensão de fezes diluída a 1:6 ou 1:9 em NaCl 15M (diluição 1:6, 22 controles e 18 jejum; diluição 1:9, 13 controles e 17 jejum). Os animais foram acompanhados até duas semanas após a inoculação das fezes quando eram eutanaziados para avaliação do número e tamanho dos abscessos intraperitoneais. A mortalidade foi avaliada através das curvas de Kaplan Meyer. RESULTADOS: A mortalidade foi significativamente maior nos animais submetidos ao jejum. No entanto o número e tamanho dos abscessos foram significativamente menores neste grupo. CONCLUSÃO: O jejum de 72 horas aumentou a susceptibilidade ao choque endotóxico (maior mortalidade nas primeiras 48 horas) e aumento da resistência aos microorganismos fecais (menor número e tamanho dos abscessos intraperitoneais).

Estudo da eficácia de espuma para a depopulação de avespara situações de emergência sanitária / Experimental evaluation of foam-based poultry depopulation for emergencies

São inúmeras as dificuldades observadas na depopulação de elevado número de aves e é importante proceder-se àdepopulação no interior do próprio aviário por questões de biossegurança do homem em casos de emergência sanitáriacausada por doenças de aves de elevada transmissibilidade, como a influenza aviária e a doença de Newcastle. Construiuseo equipamento gerador de espuma para provocar a anóxia física em aves. Verificou-se a eficácia da espuma geradaatravés do uso de líquido detergente de alta expansão sobre o sacrifício de galinhas, avaliando-se os sinais sensoriais,tempo de morte, letalidade e lesões macro e microscópicas. Duzentas galinhas de postura com 78 semanas de idadeforam divididas em dez grupos experimentais e submetidas a diferentes períodos de exposição à espuma, variando de5min30s a 8min15s . A partir de seis minutos de exposição à espuma 100% das aves foram mortas. A presença de bolhasde espuma na cavidade oral e traqueia foram constatadas em todos os períodos de exposição à espuma, indicando aocorrência de asfixia física. Congestão nas mucosas da cavidade oral e traqueia foram também observadas em todos osperíodos de exposição. No exame histopatológico dos pulmões de todas as aves, observou-se a presença de congestãoe hemorragia difusa de moderada intensidade. Nenhuma alteração foi observada na traqueia das aves. A eficácia daespuma como método de depopulação de aves foi constatada neste trabalho, podendo ser recomendada diante danecessidade de atendimento a emergências sanitárias.

There are several difficulties in the control of quick spreading and highly contagious poultry diseases such as avianinfluenza and Newcastle disease, which require large numbers of poultry to be rapidly killed inside the poultry housesin order to minimize human exposure and disease spreading. We have built and tested an equipment that uses a waterbasedfoam from high expansion fire detergent that induces poultry anoxia measured by sensorial signs, time to death,lethality and macro and microscopically lesions. Two hundred 78-weeks old hens were divided into ten groups andexposed to different times of death according to exposure to water-foam varying from 5min30s to 8min15s. All poultrydied after six minutes of water-foam cover. Foam bubbles were observed in oral cavity and trachea of all poultry ateach time of exposure to foam, revealing physical asphyxia. Macroscopically, congestion in oral cavity and in tracheamucosa was observed. Histopathology revealed diffuse and moderate hemorrhage in lungs and no lesion in trachea.The efficacy of water-foam procedure for poultry depopulation was demonstrated validating its recommendation incase of emergency.

Considerations for the use of anesthetics in neurotoxicity studies.

Anesthetics are widely used in experiments investigating neurotoxicity and neuroprotection; however, these agents are known to interfere with the outcome of these experiments. The purpose of this overview is to review these effects and suggest methods for minimizing unintended consequences on experimental outcomes. Information on the neuroprotective and neurotoxic effects of isoflurane, dexmedetomidine, propofol, ketamine, barbiturates, halothane, xenon, carbon dioxide, and nitrous oxide is summarized. The pertinent cell signaling pathways of these agents are discussed. Methods of humane animal euthanasia without anesthetics are considered. Most anesthetics alter the processes of neuronal survival and death. When designing survival surgeries, sham controls subjected to anesthesia but not the surgical intervention should be compared with controls subjected to neither anesthesia nor surgery. Additional controls could include using an anesthetic with a different mechanism of action from the primary anesthetic used. Because the effects of anesthetics lessen with time after surgery, survival surgeries should include later time points until at least 7 d after the procedure. Humane methods of animal euthanasia that do not require anesthetics exist and should be used whenever appropriate.

Comparison of water-based foam and inert-gas mass emergency depopulation methods.

Current control strategies for avian influenza (AI) and other highly contagious poultry diseases include surveillance, quarantine, depopulation, disposal, and decontamination. Selection of the best method of emergency mass depopulation involves maximizing human health and safety while minimizing disease spread and animal welfare concerns. Proper selection must ensure that the method is compatible with the species, age, housing type, and disposal options. No one single method is appropriate for all situations. Gassing is one of the accepted methods for euthanatizing poultry. Whole-house, partial-house, or containerized gassing procedures are currently used. The use of water-based foam was developed for emergency mass depopulation and was conditionally approved by the United States Department of Agriculture in 2006. Research has been done comparing these different methods; parameters such as time to brain death, consistency of time to brain death, and pretreatment and posttreatment corticosterone stress levels were considered. In Europe, the use of foam with carbon dioxide is preferred over conventional water-based foam. A recent experiment comparing CO2 gas, foam with CO2 gas, and foam without CO2 gas depopulation methods was conducted with the use of electroencephalometry results. Foam was as consistent as CO2 gassing and more consistent than argon-CO2 gassing. There were no statistically significant differences between foam methods.