THE PET PHARMACY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

(for veterinary information only)

Brand name: Tylan®, Angel Eyes®

Available in oral powder, chewable tablet, or injectable

Background

Tylosin is an antibiotic of the macrolide class (same class as erythromycin). It is made naturally by the bacterium Streptomyces fradiae and acts to inhibit bacterial protein synthesis by inhibiting the 50S ribosome, a cellular structure that only certain bacteria have and use to make internal proteins. Mammals also have ribosomes to synthesize proteins but they are of a type not influenced by macrolide antibiotics.

How this Medication is Used

Tylosin is licensed for use in live stock as a broad spectrum antibiotic to treat infection but it has other uses that have little to do with its antibiotic activity. In small animals, tylosin is not used as an antibiotic at all but as an anti-inflammatory. Its chief use is for the treatment of colitis. Here, its anti-inflammatory properties soothe the large intestine. While few formal studies have been performed to examine the non-antibacterial property of tylosin, it certainly seems to work in this regard.

Another common use is to reduce tear staining, particularly in white dogs. Small breed dogs commonly have shallow tear wells that 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; in fact, the Angel Eyes® product listed above is marketed exactly for this use.

There are two controversies regarding this use of tylosin. The first is with the Angel Eyes® product itself. This product is a beef-flavored chewable but the exact amount of tylosin is not specified on the label, which means your dog would be using an unknown amount of drug every day. Obviously, if you’re going to use a drug, you should at the very least know how much is being used. As an alternative to Angel Eyes®, a precisely dosed capsule can be provided by a compounding pharmacy. The second controversy is whether or not it is even appropriate to use an antibiotic daily for a cosmetic problem. 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. Since tear-staining is simply a cosmetic issue, perhaps non-antibiotic treatment could be used instead. For more details on this see epiphora.

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

Side Effects

While there is definite side effect potential in large animal species, dogs can tolerate 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; that is usually done by a compounding pharmacy.

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

Interactions with other Drugs

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

It is our policy not to give dosing information over the Internet.

Date Published: 12/2/2002 3:20:00 PM
Date Reviewed/Revised: 06/17/2008