Table of Contents





Product Use Usage note
Erythromycin delayed release capsules USP (250 mg)
(aka ERYC)
Oral Not a veterinary labeled product. Absorption of these dose forms has not been confirmed in animals.
Erythromycin tablets USP (250, 500 mg) Oral
Erythromycin delayed-release tablets (250, 333, 500 mg)
(aka E-Mycin)
Erythromycin injection USP (100, 200 mg/ml)
(aka Gallimycin)
Intramuscular Veterinary approval
Erythromycin estolate oral suspension USP (25, 50 mg/ml) (oral) Human labeled product. A recommended dose form for foals.
Erythromycin lactobionate for injection USP Intravenous Human labeled product.
Erythromycin phosphate powder for oral solution.
 (260 mg/g, 231 mg/g of base)
Oral Approved for chickens, has been used in foals.
Erythromycin stearate oral suspension (25, 50 mg/ml base)
Oral Human labeled product.
Erythromycin stearate tablets USP (250, 500 mg base
(aka Erythrocin)
Oral Human label product.
Erythromycin thiocyanate for medicated feed 
(220 grams/kg 203 grams base/kg)
(aka Gallimycin)
Oral Veterinary product
Erythromycin intramammary
(50 mg/ml)
(aka Gallimycin)
Intramammary Veterinary product
USP/AAVPT Monograph for Macrolides
USP/AAVPT Monograph for Erythromycin dose forms analysis (horses)

Activity profile (Erythromycin)
Good Gram (+) aerobes: Bacillus, Corynebacterium sp., E. rhusiopathiae, Listeria sp., staphylococci, Streptococci. Gram (-) aerobes:Actinobacillus, Brucella, Campylobacter, Leptospira, Anaerobic bacteria: Actinomyces, Bacteroides(except B. fragilis), Clostridium, some Fusobacterium, anaerobic cocci.
Moderate Enterococci, some Bordetella, Haemophilus, Legionella, Ehrlichia, Pasteurella
Resistant Enterobacteriaceae, Pseudomonas, Nocardia, Mycoplasma, Chlamydia psittaci, Mycobacterium sp. other than M. kansasii

Tilmicosin, Tulathromycin, Tildipirosin, Azithromycin, Clarithromycin

Product Use Usage note
Tilmicosin medicated feed (200 g/kg 90.7 g/lb base) Oral  
Tilmicosin injection USP (300 mg/ml base)
(aka Micotil)
Tulathromycin injection (100 mg/ml)
(aka Draxxin)
Tildipirosin injection (180 mg/ml)
(aka Zuprevo)
Azithromycin tablets (250, 600 mg)
(aka Zithromax)
Oral Human label product. 250 mg tabs are scored.
Azithromycin for injection Intravenous Human label product. Should not be administered as an IV bolus. Should not be given intramuscularly.
Clarithromycin for oral suspension USP (25, 50 mg/ml)
(aka Biaxin)
Oral Human label product.
Clarithromycin tablets USP (250, 500 mg)
(aka Biaxin)
Oral Human label product
Clarithromycin extended-release tablets USP (500 mg)
(aka Biaxin XL)
Oral Human label product
USP/AAVPT Monograph for Macrolides
Clarithromycin kinetics in horses
Clarithromycin vs Azithromycin R. equi

Activity profile (Tilmicosin, Tulathromycin, Azithromycin, Clarithromycin)
New to veterinary medicine. Restricted list of species/disorders evaluated. Similar spectrum to Erythromycin but higher portion of all bacteria probably susceptible.


Product Use Usage note
Tylosin injection (50, 200 mg/ml) Intramuscular Base
Tylosin granulated (22, 88, 220 g/kg)
(aka Tylan)
Oral Phosphate, feed premix
Tylosin tartrate powder for oral solution (100 g) Oral Labeled for food animal drinking water, this would be the appropriate choice for dogs if indicated.
USP/AAVPT Monograph for Macrolides
Tylosin for dogs?

Activity profile (Tylosin)
Similar spectrum to Erythromycin. Less active against most bacteria except T. hyodysenteriae, but more active against most Mycoplasma.

Tiamulin (Pleuromutilins)

Product Use Usage note
Tiamulin soluble powder (45% soluble powder)
(aka Denagard)
Oral Choice depends on farm management practices.
Tiamulin for medicated feed (5, 10 or 113.4 g/lb) Oral
Tiamulin concentrated liquid (12.3% tiamulin) Oral

Activity profile (Tiamulin)
Similar spectrum to that of tylosin but much greater activity. Active against only a few Gram (-) bacteria and inactive against Enterobacteriaceae. Subinhibitory concentrations are thought to reduce adhesiveness of E. coli.