Suspecting lice or Mites

Question
Hi I have a female guinea pig and i noticed a spot on her hip with fur missing and looks like skin missing fleshy looking. It is about the size of a dime and I'm thinking maybe mites or lice. My Friend gave me some mite and lice bird spray the ingredients are Pyrethrins .03% and piperonyl butoxide, technical .30% it also says on bottle below that Equivalent to .240% (butylcarbityl)(6-propylpiperonyl) ether and .06% related compounds. Do you think this would be safe and if not do you have any suggestions. Thank you for your time.

Answer
I've used Pyrethrins many times over the years and found them to be very effective. But I have questions about whether or not you're seeing evidence of mites. Most often the first sign of mites is a 'V' shaped break in the coat because they tend to gravitate toward the top of the back and the pig can only turn its head just so far to bite at them. That leaves that appearance of a V having been chewed out on the back, either side of the spine.

Lice are very difficult to see, especially if your pig is white or light colored. The lice are like tiny grains of rice, smaller in diameter than a thin hair. When you push the hair back you can sometimes see them move, but they move very slowly.

However, it certainly will not hurt her to be treated prophylactically. My personal choice is Adams Spray or Adams Dip. They also contain Pyrethrins. Adams Spray contains 0.20%, and Pioeronyl Butoxide Tech. .037% so it's a bit different in strength. But for all intents and purposes it should still work.

If you're able to see mites then you need to spray her until she's nearly dripping wet. Don't towel dry her. Just put her either on a towel or back in her cage and let her drip dry. Then clean out the bedding, wash everything with warm soapy water and spray the insides and the bottom of the cage.

You will know within a week or so if you've removed the mite problem because you'll see evidence of the hair growing back. Should that spot get any larger you may be dealing with some other skin condition, possibly mange. Still very treatable, but with different medication. For that you may need advice from your vet. But I have a feeling that the spray may just do the trick.