Anal impaction

In older male guinea pigs, the muscles of the anus stretch and weaken, leading to the guinea pig being no longer able to pass faeces properly. These collect in the perineal sac, and become impacted. There are things you can do to help your guinea pig.

All breeds of guinea pigs are affected, and generally it is usually older, un-neutered male guinea pigs. Younger males and females have a smaller perineal sac, so are rarely affected.

As part of a normal and healthy diet, guinea pigs eat some of their own droppings – this is known as coprophagia. They are normally eaten directly from the anus as they are passed. These droppings are referred to as the caecal pellets and contain lots of nutrients that is important for your guinea pigs overall health.

Around the anus is a perineal sac, and as the guinea pig ages the muscles around the sac weaken. As the caecal pellets are passed they become trapped in the sac on their way out.

You may notice that your guinea pig loses body condition, weight or generally looks unwell. This is because the guinea pig will be unable to eat the caecal pellets as they are trapped within the perineal sac. If you turn your guinea pig upside down you may notice that the perineal area looks swollen and may be uncomfortable for the guinea pig.

If your guinea pig does develop this condition you will need to manually clear the impaction. This may need to be done on a daily basis depending upon the severity.

To do this, turn the guinea pig upside down and carefully lay them on their back. Smear a small amount of mineral oil around the anus and carefully push down on the bottom side of the anus and ease the impacted mass out. You may need to use a cotton bud to remove the impacted material. Take care not to probe around in the sac and if the guinea pig resents the procedure, stop and give them a break before trying again.
If you are unsure how to do this or are worried, then speak to your vet and they will be able to guide you or demonstrate how to do it.

There are certain steps that you can take to lessen the likelihood of the problem occurring.

Always ensure that your guinea pig is fed a good diet; a diet high in fibre and hay is essential to ensure that they produce good faecal pellets on a regular basis.

Encourage your guinea pig to exercise and don’t allow them to become overweight.

Castrating your guinea pig at a young age may also help reduce the risk of this occurring.