Hair loss in guinea pigs can happen for a number of different reasons and it is important to consider the other factors affecting it before trying to decide what the cause might be. Pregnant females often lose a lot of hair because their hormones are unbalanced and this always grows back, so there is no need to worry if this happens to your expectant guinea pig. Other causes can be more worrying, but are not usually a sign of anything serious and can usually be easily sorted with a visit to the vet or even a change of lifestyle for the animal.
Hair loss due to parasites
You can usually tell whether the hair loss is due to parasites because the skin is also affected and looks red, painful and itchy. The animal will not simply present as going a bit bald, but will scratch frantically, drawing blood from the inflamed skin, and will also be very twitchy and ill at ease. In fact this behaviour is often the very first sign of a mite infestation and it is only when you hold your guinea pig to try and calm it down that you will be able to see the mites on the skin. Bad mite infestations must be dealt with promptly because if they are allowed to worsen they can cause serious anaemia as well as making the animal very unwell with the stress.
Also, if the guinea pig has cage mates – which most do, as they are sociable animals who often pine alone – they must be treated as they will certainly have mites as well, even if they are not yet showing any symptoms. The cage or habitat must be thoroughly cleaned with a disinfectant suitable for small caged animals and all bedding must be replaced. Mange can also make the hair fall out in clumps, but again the skin will look very flaky and sore.
Guinea pigs have very sensitive skin and are also rather nervous, so any stress situations will affect the skin and hair. Pregnant females and lactating mothers will also often lose their hair but it will always grow back. This hair loss will be equal on both sides of the body but the skin will look perfectly healthy underneath and it is just because the hormones are out of balance. This does not happen to every female, but if it happens once it is likely to happen with the next pregnancy as well. While young, unweaned guinea pigs are feeding their mother often will groom them. This is all part of the bonding process and should not be discouraged, but sometimes she can be a little overzealous and can make them lose their hair. If you notice this happening to a litter, try to get them weaned as soon as possible, to prevent the hair loss getting worse and possibly leading to skin problems.
Guinea pigs are friendly little animals and they like to stay bonded in a group. They do this by grooming each other, just as their mothers did when they were babies, but sometimes they over do it and can wear hair away. In extreme cases, they can start to pull at their own hair and that of other guineas, or even bite chunks off. If one of your guinea pigs starts to look a bit moth eaten and the others are all looking neat and tidy, check that there is no bullying going on. Sometimes, one animal is too meek and can become a bit of a scapegoat. If this happens, try isolating it for a while, or if you think the animals are getting bored, put more toys in the habitat for them or if possible give them more room. They like to wander about and explore, so it is quite a good idea to give them some tunnels to run through and some hidden places if they fancy a bit of time out. It may not be boredom, though, so be sure to check for mites in case this is the reason for their hair pulling. The mites are desperately itchy and the guinea pig will do anything to try and stop the irritation.
Guinea Pig Skin
Guinea pigs have got incredibly soft and thin skin. This is the main reason they were used in the cosmetics industry for so long, for testing. Because of this, it doesn’t take much to set up an irritation and the hair is often the first casualty. In a way, this is a good thing as the owner will probably notice hair loss quite quickly. Guinea pigs are very affectionate animals and most owners will handle them at least once a day, although getting them used to this gradually is essential as they are very nervous and can get very stressed by clumsy handling. This in turn – of course – will show itself in hair loss and skin problems. It is also important to make sure that their bedding is as inert as possible.
Some well meaning owners give cedar shavings as they smell so nice and look nice and soft – in fact, this is almost the worst thing, as the phenols in fresh cedar can play havoc with the guinea’s tender skin and can also cause respiratory problems. These little creatures are happy little souls if they are treated correctly, and with some of the more unusual types, such as the crinkly haired Texel, or the elegant Peruvian, their hair is certainly their best feature.