Doxycycline (Vibramycin®)

Doxycycline (Vibramycin®)


Doxycycline is an antibiotic related to tetracycline.   It is effective against a variety of organisms, and is often used to treat bacterial infections. It is the antibiotic of choice for many diseases (such as Lyme disease) that are spread by ticks and some diseases caused by organisms known as Mycoplasma.  It is commonly employed in the treatment of respiratory infections and fever of unknown origin in cats.


Doxycycline is readily available as tablets, capsules, or a liquid suspension. Compounding pharmacies may be able to formulate palatable flavored suspensions of doxycyline.

Side Effects

Gastrointestinal upset (nausea, loss of appetite, diarrhea, or vomiting) is the most common side effect of most antibiotics, including doxycycline. The likelihood of this side effect occurring may be reduced if the medication is administered with food.

Doxycycline can lead to severe damage to the esophagus if pills become lodged in the throat. This side effect may occur less commonly when liquid formulations are used.  Pets should swallow a moderate amount of food or water after each dose of doxycycline (regardless of whether it is in liquid or pill form) to reduce the likelihood of esophageal damage.

Pets that take doxycycline may be at increased risk of skin damage and sunburn after exposure to sunlight.

Contact your veterinarian immediately if you suspect you pet is suffering side effects from doxycycline.


Many conditions require pets to take courses of doxycycline that last several months.  The vast majority of pets tolerate this well as long as precautions are taken to prevent damage to the esophagus (see above).  Unless otherwise instructed by a veterinarian, pets should complete their entire prescribed course of doxycycline.

Pets that take doxycycline regularly for long periods of time may require periodic blood and urine tests.

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The contents of this page are provided for general informational purposes only. Under no circumstances should this page be substituted for professional consultation with a veterinarian.