Amoxicillin In Dogs: Uses and Side Effects

Amoxicillin is an antibiotic closely related to penicillin.  Other antibiotics in this family are oxacillin, nafcillin and ampicillan.  If these antibiotics sound familiar, it’s because they are the exact same antibodies given to people, but in much smaller doses for dogs.  Brand names of amoxicillin for cats and dogs include Amoxi-Tabs, Amoxi-Drops, Trimox and Robamox.  There are also antibiotics using other medications blended with amoxicillin, such as Clavamox (amoxicillin and clavulanate potassium.)

Why Dogs Are Prescribed This

Amoxicillin kills bacterial infections.  It cannot help with infections brought on by other substances like parasites, viruses or fungi.  According to Dr. Mark Papich for PetPlace.com, the most common bacterial infections in dogs that can be treated with amoxicillin include skin infections, bladder infections, abscessed teeth and wounds that have become hot and pus-filled.

Amoxicillin may not be prescribed a second time to the same dog, even if the dog did well on amoxicillin before.  This is because bacteria can become resistant to amoxicillin.  Be sure the vet knows your dog’s past history of reactions to penicillin-like medications.  It is up to the vet to determine what antibiotic to prescribe to a dog. NEVER give dogs human-strength antibiotics as these could prove toxic.

Common Side Effects

The most common side effects are no side effects whatsoever.  But when they do occur, loss of appetite, nausea and vomiting are the most common.  Ask your vet if the dog should be given food along with medication as this may help to reduce the chances of nausea.  Another rare but minor side effect is mild diarrhea.  This tends to happen only after the dog has been amoxicillin for weeks or months.  Even this mild diarrhea should be reported to a vet because this means the dog’s helpful intestinal flora may have been killed off.

Please do not suddenly stop giving amoxicillin to a dog without a veterinarian’s approval.  This could make the bacterial infection return.

Severe Side Effects

Just like people, dogs can be allergic to penicillin and any antibiotic related to it.  These side effects are dramatic and a vet needs to be called at once.  These allergic reactions include hives, problems breathing, loss of coordination or sudden bleeding from the nose.  These could also be the signs of an overdose, according to The Pill Book Guide to Medication For Your Dog and Cat (Bantam Books; 1998.)

Other rare but severe side effects include blood in feces (black, tarry feces or fresh bright blood), blood in the vomit and seizures.  If the dog has been having diarrhea, bright red blood may be due to small blood vessels bursting as the dog strains, but it still should be checked out. 

References

• The Pill Book Guide to Medication For Your Dog and Cat. Kate A.W. Roby, VMD, et al.  Bantam Books; 1998.
• Pet Place. “Amoxicillin for Dogs and Cats.” Dr. Mark Papich.
• Vet Info. “Amoxicillin for Dogs.” 

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