Swissmedic: Risks and consequences of a large-scale use of isoflurane in piglet castration
Every year, around 1.3 million male piglets are castrated in Switzerland. The previously common method of piglet castration without pain elimination is prohibited from 2010.
One way to eliminate pain during surgical castration of piglets is to use the anesthetic gas isoflurane. Due to the current discussion and the broad interest, the Swiss Agency for Therapeutic Products Swissmedic is providing information about the consequences and risks that can result from the large-scale use of isoflurane.
In the proposed method, mobile anesthetic devices are to be used. The piglets inhale the isoflurane through a face mask for around two minutes. Once anesthetized, they can be spayed. Isoflurane is a reliable and safe anesthetic when used properly. However, when used, it places special demands on the monitoring of the animals, the equipment and the expertise of the person using it. Isoflurane is a prescription drug and may only be dispensed with a prescription from a doctor or veterinarian. Isoflurane has a slight analgesic effect, and this is for a short period of time during the period of anaesthesia. For this reason, experts only recommend the use of isoflurane together with an injectable painkiller.
Even slight deviations in the isoflurane content in the breath during anesthesia lead to strong fluctuations in the depth of anaesthesia. In addition, under certain circumstances, carbon monoxide may be produced. Swissmedic points out that operating an anesthetic machine requires appropriate medical expertise.
In addition, the body temperature of the piglets must be monitored during use, since hypothermia can occur very quickly in smaller animals when isoflurane is used. Other known risks are reduced breathing, a slow heartbeat and a sharp drop in blood pressure.
Isoflurane is very volatile. The rooms in which isoflurane is used must therefore be well ventilated and should be equipped with an active exhaust. When filling the anesthetic machine and decanting isoflurane, care must be taken to ensure that no anesthetic gas that has escaped can be inhaled. Other risks can also arise when transporting isoflurane in mobile anesthetic machines in passenger cars.
Isoflurane can also have a damaging effect on the climate. It is responsible for the destruction of the ozone layer and, as a greenhouse gas, it is around 500 times more potent than CO2. If all male piglets in Switzerland were castrated under isoflurane anesthesia, around 1.95 tons of isoflurane would be released each year. This corresponds to the same impact on the climate as an annual release of almost 1000 tons of CO2. For this reason, the approved preparations stipulate that isoflurane must not be released directly into the ambient air, but that the isoflurane-containing exhaust air should be filtered using activated carbon.
Source: Berne [ swissmedic ]
