Do injected live mice harm snakes?

Question
QUESTION: I need to feed my ball python, and have bought a live mouse from petsmart. after i bought it i was informed that the mice were injected with medicine to help the snake's immune system and that they may be harmful to the snake.  i need to know how long it takes the medicine to wear out of the mouse's system or if it is safe to feed my python with this mouse.  thanks!

ANSWER: Hi Wesley, Who told you that?  Was it an employee of Petsmart or someone not associated with the store? Did they imply that Petsmart was injecting the mice or that they arrived that way from the supplier?  Many (but not all) of the reptile employees at the large chains have little knowledge about what they sell. Over the years I have heard some pretty outrageous and wildly inaccurate things that they have told customers but (if that is from an employee) that might be the strangest!
Regardless of who told you that, I can't imagine what they could have been talking about. None of it makes any sense. Rodent-eating snakes need well-fed, healthy prey to be healthy themselves. The rodents do not need to be artificially enhanced in any way. Individually injecting mice would be expensive, time-consuming and labour-intensive, not something any Petsmart or any large scale rodent supplier is going to do.

Check the source of this info. If it was an employee I would speak to someone higher up at the store about it. Don't be afraid to ask them what wholesaler they get their live rodents from. If this was told to you by someone not associated with the store then I would just pass it off as one of those strange rumours that sometimes get passed around.




---------- FOLLOW-UP ----------

QUESTION: Thanks for the advice!  I called Petsmart and found out that the person who bought the mouse got one that was recommended for a pet. the pet mice are given antibiotics to deal with stress before they were shipped to the store. I asked them about the time it takes for the antibiotics to wear off, and the manager and the small pet salesperson had no idea.  i've located a pet store where i will buy non- medicated mice, but still need to know if the mouse i have will be safe for my snake to eat.  Thank you for clearing that up.

Answer
Hi Wesley, O.K that makes a little more sense. The stress of shipment can cause diarrheal problems in small rodents, hamsters in particular. We never experienced any such problem with our shipments of live feeder rodents but perhaps the various coloured/fancy mice bred and sold as pets are not quite as hardy.

Most antibiotics used for mice or dosed orally, only a few by syringe. Some antibiotics take a bit longer to clear the system then others but frankly I would not be overly worried about that. Antibiotics are dosed by weight so only a very small amount of drug would have been administered to a mouse and that would not affect your much heavier snake.