Recently there have been a number of articles involving the unfortunate burying of pet hamsters when hibernation has been mistaken for death. This is a real problem for hamster owners and a potentialy fatal situation for the hamster itself, when being buried alive.

Hamsters in the wild are found in a variety of habitats ranging from Eastern Europe, the Middle East, Africa, China and Siberia. This means they have to cope with a range of environmental situations and hardship. The Syrian, Russian and Chinese hamster are the most common species kept as pets in the UK, the Syrian (or golden) being the leader with a population of around 1 million.

The average lifespan for the hamster is 18-24 months and they are crepuscular / nocturnal animals so activity is normally observed from dusk to dawn.

The preferable temperature for hamsters to be kept at is 65� - 70� F (18.3 – 21.1� C). They can tolerate lower temperatures although it is recommended to be slightly higher than this when newborn pups are in the nest. As they are nocturnal they do not require high levels of illumination (300-400 lux) but rely on a 12-hour light cycle to maintain normal activity.

As a general rule hamsters are not seasonal hibernators but they enter a state of torbidity, leading to hibernation, when exposed to ambient temperatures of less than 40� F (4.4� C). Torbidity is where activity is reduced but there is response to external stimuli. Hibernation can then follow, where the animal’s metabolic rate drops greatly below the normal values. To the average eye this may appear as death.

The normal values of an active hamster are: -

• Body Temperature37-38� C (98-99� F)

• Respiratory rate35-135 beats per minute

• Heart Rate250-500 bets per minute

These values are extremely high and the owner would have a great deal of difficulty actually taking them. So observe your hamster in order to familiarise yourself with what appears as normal metabolic activity.

Hibernation of hamsters depends on a variety of variables including temperature, photoperiod and food supply, it is not spontaneous. Hibernation can last from a few minutes to a week with the average being 2-3 days. It is not continuous; the animals have periods of arousal e.g. to feed, during a 12-hour period, then returning back to sleep.

During this phase the hamsters body temperature will drop 1-2 degrees lower than ambient temperature. The heart rate lowers to 4-15 beats per minute and respiratory rate of less than 1 beat per minute which may go unnoticed.

These values are dramatically different to that of normal activity and may be noticeable to the owner. The hamster will also roll up in a ball making observation of vital signs almost impossible.

In the majority of cases the animal’s metabolic rate will slowly increase and they wake up, others may remain in this state and others die.

So how do you tell and what can you do?

The general ruling is observe your hamster very carefully to see if there are any vital signs before assuming it has passed away, and try warming it up slowly. Hamsters can be encouraged out of hibernation by slowly warming them up by provision of a heat source or increasing the external temperature. If this is done too quickly it can cause the animal metabolic stress and should be avoided.