Based on recent research shared at the 2023 Leman Conference, Feedstuffs talked with Zoetis veterinarian Dr. Micah Jansen about the study and why the results are relevant to veterinarians and producers making treatment decisions for swine respiratory disease (SRD).

Q: What did the presentation at the Leman Conference focus on and who conducted the study?

A: Sarah Lutz, a third-year veterinary student at Auburn University, interned with Zoetis in 2023 as part of the Swine Veterinary Internship Program. During her internship, she collaborated with Doug Powers, DVM with Four Star Veterinary Service, on a study to understand how quickly EXCEDE for Swine reaches therapeutic concentrations based on minimum inhibitory concentrations (MIC) values for Streptococcus suis (S. suis).¹

Q: What questions were they trying to answer and why?

A: We wanted to know more about the short-term (immediate) pharmacokinetics of EXCEDE for Swine. Previously published data showed that EXCEDE for Swine has a long duration of therapy — up to seven days² — but the first time point measured was at one-hour post-injection. The objective of the study was to look at the pharmacokinetics in the first hour after administration of EXCEDE for Swine.

Q: You mentioned pharmacokinetics and MIC values — can you tell us what those terms mean and why they are important when producers are making decisions about what antibiotic to use to treat swine respiratory disease?

A: The minimum inhibitory concentration 90 (MIC90) is the antibiotic concentration at which 90% of bacterial isolates are inhibited. For Streptococcus suis, the MIC90 for ceftiofur crystalline free acid is 2.0 ug/mL.

Pharmacokinetics is the study of the characteristics of the time course and extent of drug exposure in individuals and populations and deals with the absorption, distribution, metabolism, and excretion (ADME) of drugs.³ Basically, it looks at how long and at what levels a pharmaceutical product is present in the animal.

Pharmacokinetics is important, especially when it comes to antibiotics, because it helps us understand where the antibiotic will go in the animal’s body, what the concentration will be, and how long it will stay at a level that can be considered effective against a given pathogen.

Q: How was the study conducted and what were the results? And were there any surprises?

A: We collected blood from a group of pigs immediately prior to an intramuscular dose of EXCEDE for Swine. Then we collected blood at time points of 5-, 10-, 15-, 30-, 45- and 60-minutes post-injection and submitted plasma to a pharmacokinetics laboratory. The lab then used a specific test that can measure the concentration of EXCEDE for Swine and its active metabolite, desfuroylceftiofur.

The results at 15 minutes showed almost all of the pigs reached therapeutic plasma concentration levels greater than the MIC90 of S. suis.² At 30 minutes, all six pigs reached plasma concentrations above the MIC90 for S. suis. We weren’t sure what to expect and it was exciting to find how quickly it reached those plasma concentrations.

Q: Why are these results important to veterinarians and producers?

A: Swine practitioners consider many factors when implementing antibiotic regimens, including labeled pathogens, MIC, cost, ease of implementation, and withdrawal times. Duration of therapy is another factor to consider, especially with today’s challenges in labor.

Strep suis was very purposely used in the study because it’s a growing threat and has been negatively impacting producer profitability.

Producers and practitioners can be confident that EXCEDE for Swine has not only a long duration of therapy, but also reaches therapeutic plasma levels quickly.

Photo submitted by Zoetis

Q: Now that we know how quickly EXCEDE for Swine reaches therapeutic levels, what about the outcomes of using EXCEDE for Swine to treat swine respiratory disease? What can a producer expect?

A: EXCEDE for Swine has been helping producers overcome respiratory disease challenges for 20 years. It’s a proven solution. We recently conducted a five-trial summary including almost 2,000 nursery-aged pigs.^2,5-8 The results demonstrated significantly improved mortality, reduced lung lesion scores and treatment success outcomes, as shown in both APP-challenged models and naturally occurring SRD infections.

One thing from that summary that producers might find particularly interesting is the ability of EXCEDE for Swine to control S. suis. As I already mentioned, S. suis is a growing problem in our industry. In a previous comparison study, we found that pigs treated with EXCEDE for Swine experienced lower mortality rates and better control of secondary S. suis infection compared to pigs treated with Baytril^®. This is yet another reason producers might find advantages in utilizing EXCEDE for Swine.

Photo submitted by Zoetis

Photo submitted by Zoetis

IMPORTANT SAFETY INFORMATION: People with known hypersensitivity to penicillin or cephalosporins should avoid exposure to EXCEDE for Swine. Do not use in swine found to be hypersensitive to the product. Pre-slaughter withdrawal time is 14 days following the last dose. See full prescribing information at Excedeforswine.com/pi.

_References

¹_{Lutz, S. et al. Pharmacokinetics of ceftiofur crystalline free acid in the first hour after single dose intramuscular administration in swine. Proceedings of the Leman Swine Conference, St Paul 2023}

²_{Data on file, Study Report No. 1121R-60-04-215, Zoetis LLC.}

³_{Anadón A. Perspectives in Veterinary Pharmacology and Toxicology. Front Vet Sci. 2016 Sep 13;3:82. doi: 10.3389/fvets.2016.00082. PMID: 27679801; PMCID: PMC5020047.}

⁴_{Hibbard, B et al. Pharmacokinetics of ceftiofur crystalline free acid in swine. Proceedings of the International Pig Veterinary Society Congress, Hamburg, Germany 2004.}

⁵_{Data on file, Study Report No ORPORK2030, Zoetis Services, LLC}

⁶_{Bowersock, T.L., et al., Efficacy of Ceftiofur Crystalline Free Acid for the Treatment of Artificially-induce Pnemonia in an Actinobacillus Pleuropneumoniae Challenge   Model. Proceedings of the 18th International Pig Veterinary Society Congress, Hamburg, Germany, 2004.}

⁷_{Data on file, Study Report No. 1123C-60-08-315, Zoetis Services LLC}

⁸_{EXCEDE for Swine FOI Summary: 2004/06/18 Original NADA 141-235.}

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