Euthanasia in Lab Animals PDF

 Euthanasia as part of ethical Approved protocol At the end of an experiment or when there might be continuing adverse effect. To provide blood and other tissues for a scientific purpose. When levels of pain, distress and suffering are likely to exceed the designated level....

 Euthanasia as part of ethical Approved protocol At the end of an experiment or when there might be continuing adverse effect. To provide blood and other tissues for a scientific purpose. When levels of pain, distress and suffering are likely to exceed the designated level. When the health or welfare of the animals are grounds for concern. When they are no longer for breeding. Unwanted stock or those with unsuitable characteristics , for example, type or sex, are not needed. Application Euthanasia of animals may be required for q Emergency euthanasia of animals with untreatable injuries incurred during capture, handling or transit. q Cases of untreated disease where an animal is suffering. q Collection of voucher specimens. q Requirement of a research procedure, eg when fresh tissues are required for analysis. q Destruction of live-captured declared pest animals EUTHANASIA AS AN OPTION FOR ALLEVIATION OF PAIN   Not cause anxiety, alarm, fear, vocalization, muscular spasms or clinical sign of autonomic activation.  Painless  Fast acting  Reliable - work properly every time  Safe to use for properly trained person  Easy to use for properly trained person  Esthetically acceptable  Practical to use  Economically  Not pollute environment  Not cause tissue changes  Physical methods  These methods must cause immediate loss of consciousness through physical trauma to the brain.  They are most useful when pharmacological methods would interfere with the purpose of the experiment.  While physical methods may be aesthetically less pleasant for observers and those killing animals, in skilled hands they are quick and certain and possibly the least distressing for the animal.  Specialist training is essential for all of these methods. These methods require restraint which may cause extra stress for some animals.  If possible the animal should not be killed in the sight or smell of other  Shooting Gunshot is an effective and practical means of humanely killing some animals in particular circumstances, such as field studies, rural settings (farm animals), and emergencies.  Concussion (stunning) This may be carried out by several means depending on the size of the animal. In smaller animals such as small rabbits, new- born kittens and newborn puppies, rats, mice, young guinea pigs, hamsters, birds, small reptiles, amphibians and fish, a blow on the head may be sufficient to render the animal insensible Experience and training are essential for the correct choice of method to be used.  Cervical dislocation Ø Cervical dislocation is commonly used to euthanatize small laboratory animals (e.g., poultry, mice, and immature rats and rabbits). Ø It causes almost immediate loss of consciousness because of cerebral shock, and all voluntary motor and sensory functions cease because of damage to the spinal cord. Ø This method can cause considerable involuntary muscle activity. However, there is no evidence that animals feel pain, if it is performed correctly. Ø The technique consists of a separation of the skull and brain from the spinal cord by anteriorly directed pressure applied to the base of the skull. Decapitation Ø Decapitation with a guillotine (or heavy shears) is used primarily when pharmacologic agents and CO2 are contraindicated, e.g., in pharmacologic and biochemical studies. Ø The procedure causes rapid death if properly performed. Ø An animal should be properly restrained, and its head must be completely severed from its body at the atlanto-occipital joint. Ø The guillotine must be kept in good operating condition, and the blade must be sharp. Ø The equipment should be thoroughly cleaned after each use. a guillotine Overdose of Anesthetic drug Overdose pentobarbitone (e.g. 120mg/kg body weight) intraperitoneally (i.p.) kill most species after Hirst passing into gentle sleep As end point in non‐recovery surgery or after sedation  Potassium chloride (KCl) Cardiac arrest using saturated KCl iv Cheap Fast Only be used on animals in deep anesthesia cardiotoxic. Potassium chloride causes gasping, vocalizations, muscle spasms and convulsive seizures Carbon Dioxide - CO2 Rats and mice placed in a transparent Perspex chamber able to observe during exposure to the carbon dioxide Expose the animals to a slowly rising concentration of gas. This will ensure that the animal loses consciousness because of the effects of carbon dioxide to the CNS, rather than suffocating because of immediate exposure to 100% CO2 T-61 This agent combines a local anaesthetic (tetracaine HCL), a hypnotic agent and curariform drug It must only be injected intravenously and slowly as it is otherwise painful.  Rodent Euthanasia - Special Considerations Rodents, especially neonates, are particularly resistant to euthanasia by overdose of inhaled agents such as CO2 or even injectable agents; for this reason, the IACUC requires a secondary physical method of euthanasia FOR INHALANTS (recommends for all rodent euthanasia), after the animal is profoundly anesthetized, prior to carcass disposal. Acceptable physical methods for adult and neonatal rodents include: Ø Decapitation Ø Cardiac perfusion Ø Removal of vital organs (e.g. heart, lungs, brain) Ø Opening of the chest cavity to induce pneumothorax Ø Cutting the major blood vessels to induce exsanguination (e.g. aorta, vena cava) Ø Cervical dislocation – formal training is recommended Euthanasia Criteria