How to know if your Guinea Pig is sick.
Guinea pigs rarely recover from illness without a veterinarian's care. The   following article is the curtsy of ehow.com

Instructions

1. Know What a Healthy Guinea Pig Looks Like

   • 1
     Hold your guinea pig. It should feel firm and solid.
   • 2
     Check the eyes. They should look bright and clear, without any crustiness or discharge.

1. • 3
     Check the nose for discharge. A healthy guinea pig won't have any.
   • 4
     Examine the teeth for evenness. They will look chisel-shaped.
   • 5
     Know that a bald spot behind each ear is normal. Baldness on the body is not.
   • 6
     Look at the genital area, which should be clean and dry.

   Identify and Treat Diarrhea

   • 7
     Check your guinea pig's stool from time to time. A sick guinea pig will have black or watery droppings.
   • 8
     Eliminate fresh fruits and vegetables from your guinea pig's diet, and replace them with timothy hay.
   • 9
     Bring your guinea pig to the vet for treatment. When removing fresh vegetables from the diet doesn't work, your vet will prescribe special medications including a special bacterial biotic.

   Identify and Treat an Ear Infection

   • 10
     Note the symptoms of ear infection. Guinea pigs with an ear infection will walk with difficulty. They may hold their head to one side.
   • 11
     See a vet immediately when you guinea pig presents the symptoms of an ear infection.
   • 12
     Know that timely treatment is necessary for a guinea pig with an ear infection.

   Identify and Treat Fleas

   • 13
     Examine your guinea pig's behavior. If you guinea pig is scratching and has bald, scaly, or sore patches, it may have fleas.
   • 14
     Look for "flea dirt" in your guinea pig's fur, which is dark brown and granular. Use a flea comb to go through your guinea pig's hair with ease.
   • 15
     Consider consulting your vet before continuing with treatment. You can also dust your guinea pig with a pyrethin product to treat fleas.

   Identify and Treat Scurvy

   • 16
     Know that guinea pigs require vitamin C in their diets. Without it, they can develop scurvy from vitamin deficiency.
   • 17
     Examine your guinea pig for weight loss, difficulty breathing, eye discharge and dehydration.
   • 18
     Provide your guinea pig with fresh fruits and vegetables daily, and check their regular food to make sure that it contains vitamin C.

   Identify and Treat an Upper Respiratory Infection

   • 19
     Listen to your guinea pig breathe. Labored breathing, rattling in the lungs and discharge from the lungs may indicate an upper respiratory infection or URI.
   • 20
     See a vet immediately. Your vet will prescribe an antibiotic for the URI.
   • 21
     Know that allergies can produce the same symptoms, but due to the severity of a URI, it is imperative that you see a veterinarian. Untreated respiratory infections almost always result in death.

   Identify and Treat Anorexia

   • 22
     Pay attention to your guinea pig's feeding schedule. They may seem like they are always eating, but that's normal.
   • 23
     Know that when a guinea pig stops eating, the liver cells begin to deteriorate after 16 hours.
   • 24
     Bring your guinea pig to the vet to seek the cause of anorexia and the appropriate treatment.

   Identify and Treat Mites

   • 25
     Watch your guinea pig's behavior. Excessive scratching with open sores may indicate that it has mites.
   • 26
     Know that mites can be fatal.
   • 27
     Treat your guinea pig by bringing it to the veterinarian, where it will be treated with ivermectin treatments 10 days apart.