SIDE EFFECTS. The following adverse reactions have been identified during post-approval use of doxycycline. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Side effects that appear minor can have major effects on the long-term health of your dog if left uncorrected. As we have seen, side effects are generally rare. What are the possible Vetmedin side effects, and what should you watch for if the vet has prescribed this medication for your dog? This medicine is used to treat congestive heart failure, and there are a number of possible side effects that can occur with this treatment. Phenobarbital is a medication typically prescribed to treat dog seizures. Learn more about the side effects of Phenobarbital for dogs here. Most dogs take antibiotics at least once in their lives, whether for a current infection or as a preventative measure. One of the antibiotics commonly used Find patient medical information for Doxycycline Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Doxycycline is an antibiotic used for treating bacterial infections. The drug is also sold under the brand names Oracea, Doryx, Monodox, Periostat, and Vibramycin. Doxycycline for dogs is a broad spectrum antibiotic that kills different types of bacterial infections in pets. It’s a prescription medication that’s commonly administered to cure dogs suffering from Lyme disease and Chlamydia. Side effects of Prednisone in dogs! Prednisone for cough. Visit our online store. A Canadian Pharmacy offering discounts on cheap prescriptions medications. 24/7 Online support. Official Online Drugstore. Doxycycline is a broad-spectrum antibacterial synthetically derived from oxytetracycline. Doxycycline capsules, USP 100 mg, 75 mg, and 50 mg capsules contain Doxycycline Monohydrate equivalent to 100 mg, 75 mg, or 50 mg of doxycycline for oral administration.