Cephalexin is an antibiotic used in dogs. It is most commonly prescribed after a surgery or to treat a bacterial infection, dermatological problems and urinary tract infections. Cephalexin for use in dogs is similar to the use of penicillin in humans.
Cephalexin is one of the most widely used antibiotics in dogs, according to VetInfo.com. It can be administered via capsule, tablet or in liquid form. To lessen side effects, have your dog take the medicine with food.
In dogs, common side effects of taking cephalexin are diarrhea and vomiting. A dog may experience rapid breathing, hyperactivity or drooling. Allergic reaction may include itching, scratching, swelling or a rash. Serious side effects include shock or seizures. Side effects are rare, however, according to PetEducation.com.
I also found this online from another owner,thought it might help?
My dog has not had any observed seizures before taking this medicine. My dog began this medicine and within 6 days we noticed him foaming at the mouth. The next day he was foaming at the mouth, coughing, and lost bowel control. The next evening he had two seizures so we took him to the vet. They thought from symptoms we described it was acid reflux. Next night he had two more severe seizures and we videotaped it. They confirmed they were seizures then. We discontinued this med.
Thank you, we stopped taking it. I lowered dose of anti seizure med and she had another seizure. So at this time I'm not sure what to do.