Side Effects of Canine Cephalexin & Abdominal Pain

Cephalexin is a broad spectrum antibiotic, meaning it is effective against a variety of canine infections. Cephalexin is not approved by the Food and Drug Administration (FDA) for use on companion animals, but is commonly prescribed by veterinarians for off-label use under the brand name Keflex. It's effective against bacterial skin infections, bone and joint infections and infections of the urinary and respiratory tract. Cephalexin does have some side effects, including abdominal pain and upset.

  1. Stomach Upset

    • While cephalexin can be given to a dog on an empty stomach, it's less likely to cause abdominal upset and vomiting if administered with a meal, according to directions on the 1-800-PetMeds website and Dr Wendy C. Brooks, DVM. Since generally you give cephalexin to your dog twice a day, mixing it with morning and evening meals (try hiding it in a little peanut butter, canned dog food or cheese if your dog leaves it in the bowl) is an effective way of preventing stomach upset.

    Diarrhea

    • Diarrhea is a frequent canine side effect of many antibiotics, although it's not a common complaint with cephalexin, according to Dr Mark Papich writing for Pet Place. Contact your veterinarian if your dog has severe diarrhea or vomiting, or refuses to eat because of nausea. She may want to re-evaluate the drug, prescribe a different antibiotic or suggest another medication to ease the side effects. Never give your dog any over-the-counter medications without first consulting with your veterinarian.

    Mild Side Effects

    • If your dog has soft stool or mild diarrhea, nausea or develops a yeast infection, don't stop giving the cephalexin, but do call your veterinarian. These are not usually serious side effects and may simply mean your dog has an intolerance or sensitivity to the ingredients, but always let your vet know if you're concerned.

    Serious Side Effects

    • Some dogs are allergic to antibiotics like cephalexin. Symptoms include drooling, panting, swelling or hives and excitability. If your dog develops these symptoms, discontinue use and call your veterinarian immediately. Dr. Brooks states that dogs who are allergic to cephalexin may need a different antibiotic.