Mar Vista Animal Medical Center

3850 Grand View Blvd.
Los Angeles, CA 90066




(for veterinary information only)



Available in



In simple terms, tylosin is a natural antibiotic made by bacteria. It acts by interfering with the protein manufacturing abilities of other bacteria. It only affects bacterial protein manufacture and thus does not affect protein manufacture by mammals, birds or reptiles. Tylosin is an antibiotic of the macrolide class (same class as erythromycin).




Tylosin is licensed for use in livestock as a broad spectrum antibiotic for treatment of infections but it has other uses that have little to do with its antibiotic activity. In small animals, tylosin is not used for its antibiotic properties nearly as much as it is for its an anti-inflammatory properties in the intestine. Its chief use in pets is for the treatment of colitis. In this situation, it is not used as an antibiotic to treat infection but instead as an anti-inflammatory to soothe the large intestine. While few formal studies have been performed to examine this non-antibacterial property of tylosin, it certainly seems to work in this regard and there are many patients whose diarrhea will not resolve unless tylosin is given continually. Tylosin is safe for long term use and provides a good alternative to metronidazole, another bowel anti-inflammatory/antibiotic that is not as amenable to long term use. Tylosin has been used against intestinal infection caused by Cryptosporidium, a single-celled parasite, as well as those caused by the toxin-producing bacterium Clostridium perfringens.


Another common use is to reduce tear staining, particularly in white colored dogs. Small breed dogs commonly have shallow tear wells which lead to tear overflow down their face, a condition called "epiphora." The subsequent red-brown staining of the fur from tear pigments is felt to be unsightly and through an unknown mechanism tylosin seems to alleviate this condition. Tear pigments create staining of the fur which is especially visible in white-coated animals.Tear pigments create staining of the fur which
is especially visible in white-coated animals.

Tylosin can also be used in ferrets, rabbits, birds, reptiles, and pocket pets.

 Tylosin can be given with our without food. If a dose is accidentally skipped, do not double up on the next dose; simply pick up as usual.


While there is definite side effect potential in large animal species, dogs in particular can tolerate very high doses of tylosin with no adverse effects. The biggest problem with small animal use seems to be the especially foul taste of tylosin which necessitates formulation into capsules, which is usually done by a compounding pharmacy.

Tylosin may falsely elevate certain liver blood tests (ALT and AST).



Tylosin can increase digoxin blood levels and should be used cautiously in patients taking digoxin for heart failure.



In the past there have been several tylosin products marketed without prescription for control of tear staining. Some listed the amount of tylosin they contain and some did not. There is controversy in the use of an antibiotic in an unprescribed manner for what is basically a cosmetic problem. The first controversy is whether or not it is appropriate to use an unknown amount of medication in animal for any reason (in the case of products that do not even list the amount of tylosin they contain). The second issue regards the implications of antibiotic overuse


Casual use of antibiotics is responsible for antibiotic resistance of bacteria in the environment and, in general, bacteria that become resistant to tylosin also become resistant to erythromycin and possibly even other antibiotics. Since tear-staining is simply a cosmetic issue, perhaps non-antibiotic treatment could be used instead. For more details on this please visit the page on epiphora. Losing the reliable efficacy of antibiotics has life-threatening implications for both human beings as well as animals and we must be judicious in their use.

Printer Friendly Version


Short version (to help us comply with "Lizzie's Law")

Page last updated: 5/23/2022