Guinea pigs can become flea infested, although they are more likely to get mites or lice. When they do get fleas, they need to be treated as proactively as you would have to treat any larger pet. You also need to treat both the inside and outside areas of your home to completely eradicate the problem and prevent fleas from returning.
The type of flea that sometimes attacks guinea pigs is the cat flea. Its scientific name is ctrenocephalides felis. This small black flea leaves dry black droppings in the fur. If you comb your guinea pig with the very small kind of comb that comes with delousing shampoo and find small black flakes, even if you don't see any live fleas, the guinea pig may be infested.
If your guinea pig has fleas, it probably is also suffering from these symptoms. Fleas crawling around and biting cause a guinea pig to itch. The scratching combined with the lesions from the bites may cause it to lose some of its fur. In a very serious case, your guinea pig may even develop anaemia from a flea infestation.
The most successful way to treat your flea infested guinea pig is with a pet shampoo product that contains pyrethrin. Make sure that the label of the product you choose says that it is safe for use on cats. If you want to make certain that the dosage will be safe for your guinea pig, consult a veterinarian that has experience treating guinea pigs or other small animals, such as rabbits.
Because fleas reproduce very rapidly, once you notice them on your guinea pig, you probably have a larger problem. There are probably fleas in your carpet, upholstery, and in the grass in your yard. Not only will you need to thoroughly vacuum and steam clean your furniture and floors, you may need to employ the services of an exterminator to get rid of the problem. If you have other pets in the home, they will also need to be treated with a similar pet shampoo that contains pyrethrin to kill the fleas.
Some plants repel fleas too. While they won't help you end the flea infestation attacking your guinea pig, once you fix that problem, you can use strategic outdoor plantings to prevent another infestation from happening. Lavender, mint and eucalyptus plants all repel fleas. Lavender and mint are hardy perennials while eucalyptus is a bit more difficult to grow.