It is recommended to allow the animals to become familiar with the facility equipment and staff for at least 2 weeks after arrival from the supplier. This can provide the animals the necessary time to get accustomed to the environment and reduce stress. An added benefit is that the researcher can become familiar with individual animals, can identify those that are not in a perfect health condition and prevent them from inclusion into the experimental group. Ultimately, the animals used in chronic studies must be housed for at least 72 h prior to any procedures being performed.

Each animal must be clearly identifiable during the all phases of the study – they have to be explicitly marked before the first manipulation. Rats are unable to vomit, thus it is not absolutely required to let them fast before the surgery. But, in order to reduce the volume of intestinal content and therefore to make easier the surgical manipulations within abdominal cavity, overnight fasting is recommended. This fasting does not mean starvation. Thus, in order to prevent ketosis and hypoglycaemia, food pellets should be replaced by glucose solution and water freely accessible for the animal.

Both approaches for total anaesthesia induction and maintenance can be utilised according to the routine of the researcher. Ventilation anaesthesia used in our group is performed with a mixture (3–5 %) of isoflurane in the air throughout the duration of the surgery. Intramuscular anaesthesia can be based on ketamine (10 mg/kg)/xylazin (1.5 mg/kg) or ketamine (10 mg/kg)/medetomidin (0.25 mg/kg), both of which can be extended by the reinjection of 30 % of the initial dose . During the anaesthesia, temperature maintenance is crucial – the animal should be placed on safe heating pad, the room temperature should not be under 22 °C and the saline used for visceral moisturising must be warmed to 37 °C.