Experimental evaluation of tulathromycin as a treatment for Campylobacter jejuni abortion in pregnant ewes

Am J Vet Res. 2020 Mar;81(3):205-209. doi: 10.2460/ajvr.81.3.205.


Objective: To evaluate the efficacy of tulathromycin for prevention of abortion in pregnant ewes when administered within 24 hours after experimental inoculation with Campylobacter jejuni.

Animals: 20 pregnant ewes between 72 and 92 days of gestation.

Procedures: All ewes were inoculated with a field strain of C jejuni (8.5 × 108 to 10.6 × 108 CFUs, IV). Eighteen hours later, ewes received either tulathromycin (1.1 mL/45 kg [2.4 mg/kg], SC; n = 10) or sterile saline (0.9% NaCl) solution (1.1 mL/45 kg, SC; sham; 10). Ewes were euthanized immediately after observation of vaginal bleeding, abortion, or completion of a 21-day observation period. Necropsy was performed on all ewes, and tissue specimens were obtained for bacterial culture and histologic examination.

Results: 1 sham-treated ewe and 1 tulathromycin-treated ewe developed signs of severe endotoxemia and were euthanized within 24 hours after C jejuni inoculation. Seven sham-treated and 2 tulathromycin-treated ewes developed vaginal bleeding or aborted and were euthanized between 4 and 21 days after C jejuni inoculation. The proportion of tulathromycin-treated ewes that developed vaginal bleeding or aborted during the 21 days after C jejuni inoculation (2/9) was significantly less than that for the sham-treated ewes (7/9).

Conclusions and clinical relevance: Results suggested that administration of tulathromycin to pregnant ewes following exposure to C jejuni was effective in decreasing the number of C jejuni-induced abortions. Because of concerns regarding the development of macrolide resistance among Campylobacter strains, prophylactic use of tulathromycin in sheep is not recommended.

MeSH terms

  • Abortion, Induced / veterinary*
  • Abortion, Veterinary
  • Animals
  • Anti-Bacterial Agents
  • Campylobacter Infections / veterinary*
  • Campylobacter jejuni*
  • Disaccharides
  • Drug Resistance, Bacterial
  • Female
  • Heterocyclic Compounds
  • Macrolides
  • Pregnancy
  • Sheep
  • Sheep Diseases*


  • Anti-Bacterial Agents
  • Disaccharides
  • Heterocyclic Compounds
  • Macrolides
  • tulathromycin