12/28/2025
I strongly believe this!
Let’s Talk About Pasteurella, Carriers, and Culling
One of the most common myths in rabbit circles is this:
“If a rabbit has Pasteurella, you have to cull it. Once they have it, they always have it.”
The fact of the matter. Most rabbits already carry Pasteurella long before they ever show symptoms. They don’t “become” carriers because they got sick, they got sick because they were already a carrier, and something weakened their immune system.
This is echoed in the Textbook of Rabbit Medicine, which notes that Pasteurella is an endemic in many rabbit populations, and that disease often results from stress or co-infection not from a new exposure.
Once symptoms subside, they return to their original state, asymptomatic carrier, just like the majority of your herd.
According to the Merck Veterinary Manual, rabbits are usually exposed to Pasteurella shortly after birth, and colonization increases until about 5 months of age. Many remain asymptomatic carriers for life.
And the Journal of Exotic Pet Medicine confirms that Pasteurella is “frequently isolated from the nasal cavity of clinically normal rabbits,” reinforcing that carrier status is common and not inherently dangerous.
So what does that mean?
• A rabbit can carry Pasteurella in its nasal passages without showing any symptoms.
• The real risk is during active infection. Sneezing, nasal discharge, or eye issues. That’s when a rabbit is most contagious.
• Stress, another illness, or poor husbandry can trigger flare ups in carriers but that doesn’t mean they “caught” something new.
It’s important to understand that culling known carriers of Pasteurella is not only unnecessary but it’s often not beneficial. Unless a rabbit is in active infection it does not pose a meaningful risk to your herd. In fact, culling based solely on carrier status can weaken your herd, reduce herd resilience, and create a false sense of control. Lack of early microbial exposure can impair immune development in rabbits, and culling asymptomatic carriers may actually reduce herd resilience by disrupting microbial diversity and immune training. The focus should be on managing stress, supporting immune health and maintaining clean, well ventilated environments, not eliminating animals for something that’s already present in most of the population.
📚 Sources:
• Merck Veterinary Manual
• Textbook of Rabbit Medicine, Frances Harcourt-Brown
• Journal of Exotic Pet Medicine, via ScienceDirect
💡 Wondering about the role of genetics in immune strength? I’ve got a separate post that breaks that down because spoiler, resilience is built, not just bred.
https://www.facebook.com/share/p/1APrykFCzV/?mibextid=wwXIfr