This article first appeared in the June 2001 issue of the NGS Journal
Gerbils are well adapted to extremes of temperature, for example in Mongolia, the temperature can rise to plus and minus 40C. However like us and other animals they can suffer from heat stroke, especially if they are left in areas of direct sunlight and areas where there is insufficient ventilation.
Although coming from an area with an extreme climate, gerbils shelter from the worst excesses of temperature by burrowing underground. The burrow temperature varies far less than the surface temperature. Even so, gerbils cope very well with temperatures as high as the low 30s Celsius. Above about 25C they will become less active and lie spread out when resting. As the air temperature rarely gets high enough to injure gerbils it is especially important to avoid allowing the gerbils to become trapped in strong sunlight, or be kept in a room with still heated air where pockets of much higher temperature can arise. Strong sunlight can make some rooms much hotter than the outside temperature For example, with the outside temperature being about 30C, the temperature in a building exposed to the sun can easily get to higher than 40 unless it is well insulated.
As we are still in the height of summer, you may want to reconsider where your gerbils are sited and move them to a cooler part of the house. If you keep them in a shed or other outbuilding, it is worth investing in a good quality extractor fan which will draw cooler air in from the outside. A stable door and opening windows fitted are also useful. Make sure you have a grill fitted which keeps cats and other unwelcome visitors out. As an added precaution, move the tanks down on to the floor on hot days, where there is cooler air. Not very tidy but it does the trick! Even if you are unable to ensure that fresh air is sucked in from outside, you can stop pockets of warm air forming in the hottest parts of the room using a standard desk fan. The most dangerous thing is if the air is allowed to heat up and stand still. Even a little movement will help distribute the temperature more evenly and make your animals more comfortable.
The first signs of heat stress are easily recognised, the gerbils lie prone in their tanks or cages and they will be panting, sometimes moving bedding out of the way in their search for somewhere cool to lie. If you notice this, move the gerbils immediately and situate them in a cooler part of the house or shed. You can keep a large smooth stone in the fridge and place it in the cage for the gerbil to lie on if it so wishes. In more advanced cases, the gerbils will be wet around the mouth area and may well be unconscious. This is a sign of serious heat stress. It is vitally important that you get the gerbil’s temperature down as quickly as you can, otherwise it will die. To get the temperature of the gerbil down, use cool rather than freezing water. If the water is too cold, the shock of the change in temperature may well kill the gerbil. It is also important to try and get some fluids into the gerbil, again do not use freezing water.
It is important that you get your gerbil to a vet immediately. Heat stroke can cause irreparable damage to internal organs and if the gerbil is not strong enough to drink, may well need an injection of fluids, which the vet will inject subcutaneously.
A related problem is hypothermia. This is obviously more of a problem in winter, although a gerbil that gets soaking wet can quickly lose heat so it is worth bearing in mind at any time. Gerbils are well protected from cold by their thick fur and hairs on the tail, ears and feet. However, if left for too long in temperatures below freezing they can become seriously affected.
In severe cases the gerbil or gerbils will be very cold to the touch and will be huddled together in a group. They will not respond if you touch them. It is possible to revive the gerbil, using gradual heat. I use a heated pad sold more commonly for reptiles. You can place the gerbil in a show pen, or other small plastic container, on the pad. Place some bedding in the pen, so that the gerbil is not in direct contact with the pad. Having bedding in the pen will allow the floor to heat up gradually, so that the gerbil is warmed gradually. Always have a part of the pen off the heated pad, so that when the gerbil has recovered, it can go to the cooler end of the box if it so wishes.
If you have no heated pad, then you can use a hot water bottle. Wrap a towel around the bottle so that the gerbil is not directly exposed to the heat. You will need to keep a close eye on the gerbil so that it can be moved once it is conscious and able to move around on its own.
Another method you can try which I have used successfully in the past and on a more recent trip to Belgium, is to place the gerbil next to your skin under your clothes. It restricts your movements somewhat, but is a very successful way to revive a torpid gerbil. If nothing appears to be happening, do not give up, it can take at least an hour before the gerbil starts to move.
Once the gerbil is moving around offer it some fluids and seek veterinary treatment and ensure it is kept warm and comfortable.