If you think your guinea pig is sick, the sooner you identify what is wrong and get help, the better. Loss of appetite, runny discharge from the eyes or nose, or diarrhea may indicate your pet may be suffering from a life-threatening condition. Always contact an experienced small mammal veterinarian before you administer any medications to your guinea pig. Keep your veterinarian's phone number on hand, along with a small first aid kit specially equipped for guinea pig emergencies.
The dosage of many medications depends on the weight of your animal, so be sure your veterinarian knows how much your guinea pig weighs. Have your veterinarian fully explain the merits and dangers involved with every form of treatment. You should be wary of using any medication that is not specific to guinea pigs.
Medicines Toxic to Guinea Pigs
All medicines are not created equal, and some cat and dog treatments may be toxic to your guinea pig. Never give your guinea pig an antibiotic "as a precaution." This includes penicillin or any derivative of penicillin – amoxicillin, lincomycin, erythromycin, and cephalexin specifically. Antibiotics work by killing undesirable bacteria in the body but they can also kill the good bacteria that helps your pet process food normally. If this happens, your guinea pig may be vulnerable to an infestation of other pathogenic bacteria. This is not a full list, so be sure to request a complete record of all antibiotics toxic to guinea pigs from your veterinarian.
However, it is always safe to use small amounts of antibiotic ointments like Neosporin and cleaning fluids like hydrogen peroxide and Betadine scrub for minor cuts and scrapes. But always watch your guinea pig carefully when he is on any kind of medication. If he appears more listless or lethargic, has diarrhea, or loses his appetite after taking an antibiotic, stop giving your pet the medicine and contact your vet immediately.
How to Give a Pill
To administer a small pill to a guinea pig, place it in the very back of his mouth, on or at the level of his back teeth to make sure that he will swallow it. You may need someone else to hold your guinea pig's mouth open. An alternative means of giving your guinea pig a pill is to grind it up with a mortar and pestle and mix it with a small bit of water. This solution can then be administered with a 10cc syringe placed well into the mouth (about an inch in is good).
Insert the syringe at angle and push the plunger slowly to administer the liquid slowly so that the guinea pig doesn't gag and the fluid is not spilled. This method of administering medicine is favored over putting the medicine in your guinea pig's drinking water because you can control the dosage more carefully. Never try to put an injectable medication in your guinea pig's drinking water. Injectable medications only work by being absorbed through the tissue and not through the gastric wall.
As a general rule, you should give your guinea pig the drugs your veterinarian recommends and then evaluate his progress. If your veterinarian recommends an antibiotic, it may be a good idea to give your pet a pro-biotic to reseed his gut with good bacteria. You can feed him live culture yogurt or lactobacilli acidophilus capsules dissolved into water. Always give your guinea pig the acidophilus supplements at least an hour before you give him an antibiotic so that the supplemental bacteria will not be eliminated. Check your local pet store for availability of the capsules.
Stress and antibiotics are a bad and often fatal combination, so be extra careful to keep your guinea pig's life as stable and predictable as possible while he is on medication. Give him a consistent, high-fiber diet with lots of timothy hay to help keep his digestive system functioning. Move him into a clean, dry cage in a warm room isolated from all other guinea pigs. If he is not eating or drinking, you may need to force fluids on him every half hour or so. Ask your veterinarian. Remember that your guinea pig still needs a reliable source of vitamin C, especially when he is ill. Do not grind up multivitamins intended for humans for your guinea pig. Instead, try giving him orange juice or water vitamin C fortified water with a syringe.