Which Antibiotic for Dogs Has Risky Side Effects?

Just about any antibiotic given to dogs has a potential for risky side effects. Adverse effects of antibiotics fall into three main categories: toxicity, allergic reactions and increased drug resistence of bacteria. You should monitor a dog on antibiotics closely for potential side effects.

Culturing Bacteria Determines the Right Antibiotic

Your vet will prescribe antibiotics only if a suspected infection in your dog is confirmed by laboratory tests. Administering antibiotics unnecessarily or incorrectly can lead to overexposure of your dog to these drugs, decreasing their effectiveness. Your vet will likely perform a culture and susceptibility test, which involves culturing a sample of bacteria taken from your dog, then gauging different antibiotics' abilities to kill the bacteria. In this way, the vet can determine which strain of bacteria is causing the infection and then choose the appropriate antibiotic regimen for your dog.

Antibiotics and Their Side Effects

You should notify your vet if your dog experiences adverse affects from antibiotics. Here's a list of commonly prescribed antibiotics and possible side effects:

  • Penicillins - allergy, fever, rash, loss of white blood cells, anemia, gastrointestinal upset
  • Aminoglycosides - kidney damage, hearing loss, facial swelling, nerve damage
  • Amikacin, Gentamycin, Neomycin - kidney damage if injected
  • Cephalosporins - allergic reactions, cross-reactions with penicillin, gastrointestinal disease, diarrhea
  • Tetracyclines - gastrointestinal distress, discolored teeth, liver and kidney disease, hair loss, sensitivity to light
  • Clindamycin - gastrointestinal distress
  • Erythromycin - neurological problems, reduced white blood cell count, liver damage, blood in urine, vomiting and diarrhea
  • Enrofloxacin (baytril) - cartilage damage in growing dogs, urine crystals, gastrointestinal disease
  • Sulfa drugs - nausea, vomiting, fever, anemia, leukopenia, irritation of liver and kidneys
  • Metronidazole - neurological problems, reduced white blood cell count, liver damage, blood in urine, vomiting, diarrhea.
  • Rifampin - discolored tears and urine, gastrointestinal distress, liver damage

The goal in giving antibiotics to your dog is maximizing benefits while minimizing risks. Administering the right antibiotic at the right dosage is key. Always have your dog finish the entire prescription. And, never give your dog any antibiotic prescribed to another pet or to a human.