Antibiotic Resistance in Multi-Rabbit Situation

Can someone give an 'idiot proof' explanation as to how abx resistance can become a problem within a colony as opposed to 'just' within one Rabbit ?

Please 'speak' slowly as I am extremely dim

Ta in advance

I'll have a stab at it Jane. BTW it's up to me to communicate effectively -nothing wrong with your brain.:lol:

OK there's a carpet of bacteria all over the outside world, & this includes the upper respiratory tract & gut. :shock::shock: Most don't cause disease (non pathogenic) but some can do so in the right circumstances (pathogenic).

Whether pathogens cause disease or not also depends on many factors, the numbers around the host, physical integrity of these barriers, whether the bodys' natural mechanism for keeping bacterial populations low has broken down, & the internal immune reponse etc. Bunnys immune systems are very fragile, & can be markedly lowered by stress. even the pain (of stasis) can cause a low WBC.

So there is a situation of pathogens spreading from host to host & being exchanged between them without causing disease, but living in wait for a failure of the defense mechanisms. - a living time bomb.

Bacteria multiply very fast about every 20 mins in favourable conditions. So when we introduce ABx = adverse environment it's like watching ordinary evolution at a very fast rate indeed.
The other factor withABx is that some actually kill the bacteria ="cidal" whereas others only stop them multiplying = "static"

OK with 1 sick rabbit /host the battle ground is confined to 1 animal, if it lives even if some resistance has ocurred to the ABx it isn't passed on. If it dies -end of story. The problem with a colony is the gradual accumulation & rabbit-rabbit transference of resistant strains throughout the rabbits but we don't know about it.
This shows so clearly with Maizey's MRSA problem in her contis. MONTHS would elapse before another fell ill.

I'll try to find an old TED TAlk for you which demonstrates how we are causing the evolution of resistant bacteria in humans.

Does that make ANY sense whatsoever?

From my dim and distant memory: antibiotic resistance can acquired due to genetic changes in eg. gut bacteria. The bacteria themselves adapt to survive the antibiotics and can pass this resistance on to other bacteria. I would therefore suggest that in a colony situation, acquired immunity to antibiotics is either due:

1. to ingestion of another's faeces / caecotrophs (deliberately or eg from grooming feet which have picked up the bugs) where the other individual has been treated and is passing bacteria with some antibiotic immunity, or:

2. there is an already resistant strain of a particular bacterium which is being passed round the colony (eg respiratory disease) either passively in the environment (from normal excreta / sneezing, etc), or being 'carried' by otherwise well individuals, or as an active infection.


Hope this makes sense. It's been 20 yrs since I was a proper microbiologist.

Absolutely right Shimmer. I forgot about that bit!

Thank you both. I think I understand.

So in a multi-Rabbit situation the use of abx needs to be done with extra care and the course definitely needs to be long enough to try to insure eradication of all the pathogenic bacteria ??

Given that Baytril is the most common abx prescribed for Rabbits is it more likely,for example, that a Rabbit from a multi-Rabbit situation who develops a RTI may well have a poor response to Baytril treatment if Baytril were to have been previously used for a similar bacterial infection in other Rabbits from the colony ?

If so, is there a way to reduce the impact of this occurrence ?

Does that make sense ? I know what I mean but I am hopeless at expressing it

I can't give you a proper answer Jane. I don't know enough about the bacteria which affect buns & how they transmit them.
A good principal in choice of ABx is to know what the causative organism is & it's sensitivity, THEN of those available select the AB which is of narrowest spectrum & has good penetration to the infection site.

Baytril has a bad reputation on RU. Lilbun says that the difference in dose between toxic & therapeutic levels is relatively small.
Failure to reach optimum blood levels could be one problem. Poor penetrance into certain tissues could be another.
With URTI in particular, I suspect that a major issue, is poor drainage of the sinuses etc & that we are not seeing true resistance but reinfection from an inadequately treated 1st. episode.
Trouble is that no one knows what the normal anatomy of the rabbit post nasal space should look like. :shock:
In fact very little is known specifically about rabbits. :shock: It's often extrapolation from other species.

Every doctor is taught "if there's pus let it out", before even thinking about which ABx to use. Of course rabbit pus doesn't liquify. I think this is one of the big problems treating bunny infections. Also over reliance on ABx without helping to reduce swelling (reduces blood supply) & simple means to liquify secretions containing large populations of bacteria eg - steam nebulisation for URTI.

A prescribed course of antibiotics should ALWAYS be completed, especially if the individual seems 'better' before the end of treatment. The risk is that the bacteria have time to be weakened but not eradicated, so enabling them to build up resistance to the antibiotic and then for the resistance to become embedded in the general environment - this is happening in many bacteria - and making it more difficult to treat the next susceptible individual. You are not just treating the animal - you are eliminating the bad bugs.

As far as preventing resistance in a closed colony, all I can suggest is good general hygiene and isolating animals under treatment as far as possible / practical. Not sharing equipment, washing hands, wiping down hard surfaces with disinfectant (bleach and washing up liquid in hot water is as good as anything for use at home), provision of sneeze barriers, proper waste disposal, etc would be good practice to stop the physical spread of bacteria or infected materials. Think MRSA practices in hospitals.

Isolating a bun is a bit extreme under normal circumstances. Not something I personally would want to try as it causes other issues (bonding, referred aggression, etc) on return to normal. I would, however, consider not putting a bun under treatment in an area which could not be properly cleaned (eg a run on grass) and may be shared by others.

Mostly it is common sense. Most buns are healthy and would not be routinely affected.

I have just had to isolate one of my cats for a week as she was very poorly with an intestinal inflammation and no specific diagnosis on initial examination. She was a potential risk to us and the other cats, so she had the box room to herself. I could also monitor all input & output. She is fine now and has the all-clear. My bank account is also cleared out - another effect of random bacterial infection and an after effect of antibiotic treatment.

I can't give you a proper answer Jane. I don't know enough about the bacteria which affect buns & how they transmit them.
A good principal in choice of ABx is to know what the causative organism is & it's sensitivity, THEN of those available select the AB which is of narrowest spectrum & has good penetration to the infection site.

Baytril has a bad reputation on RU. Lilbun says that the difference in dose between toxic & therapeutic levels is relatively small.
Failure to reach optimum blood levels could be one problem. Poor penetrance into certain tissues could be another.
With URTI in particular, I suspect that a major issue, is poor drainage of the sinuses etc & that we are not seeing true resistance but reinfection from an inadequately treated 1st. episode.
Trouble is that no one knows what the normal anatomy of the rabbit post nasal space should look like. :shock:
In fact very little is known specifically about rabbits. :shock: It's often extrapolation from other species.

Every doctor is taught "if there's pus let it out", before even thinking about which ABx to use. Of course rabbit pus doesn't liquify. I think this is one of the big problems treating bunny infections. Also over reliance on ABx without helping to reduce swelling (reduces blood supply) & simple means to liquify secretions containing large populations of bacteria eg - steam nebulisation for URTI.

Another thought. With basic hygeine I'm a frequent "soap & water" person not a disinfectant fanatic (unless there's a good reason). Aim -don't kill off the non pathogens cos they're physically stopping the pathogens from getting a foothold.

Shimmer said:

A prescribed course of antibiotics should ALWAYS be completed, especially if the individual seems 'better' before the end of treatment. The risk is that the bacteria have time to be weakened but not eradicated, so enabling them to build up resistance to the antibiotic and then for the resistance to become embedded in the general environment - this is happening in many bacteria - and making it more difficult to treat the next susceptible individual. You are not just treating the animal - you are eliminating the bad bugs.

Click to expand...

And rabbits seem to require a much longer course of antibiotics than other species (e.g. humans). My vet goes by the general rule of thumb for really stubborn bacterial infections in rabbits...treat with abx until there are no symptoms, and then treat for another month on top of that.

This is a really interesting thread, as I had three guinea pigs who passed a UTI between them for years, which became more and more antibiotic resistant. I only have one of the three left now, and the vet has recommended she doesn't have a friend, as she is likely to still be a carrier.

Thanks for all your help folks.
I have been tying myself up in knots trying to read about and understand this in various other sources. Last night I gave up and went to bed...............only to dream about it all :roll:

SarahP said:

This is a really interesting thread, as I had three guinea pigs who passed a UTI between them for years, which became more and more antibiotic resistant. I only have one of the three left now, and the vet has recommended she doesn't have a friend, as she is likely to still be a carrier.

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I'm so sorry Sarah P how heartbreaking for you.
Were repeated C&S done showing incremental ABx resistance by any chance?

I ask because the nose is lined with fine "hair cells" -ciliated epithelium which waft the mucus & all the bacteria stuck to the surface, up & into the throat.

The hairs do not regrow if there is sufficient damage to cause scar tissue. So the mucus builds up in a pool & the bacteria multiply just to become invasive again, until they even infect the cartilage & bone.

You may be surprised that even relatively non invasive & fully sensitive bacteria can pose very great difficulty in treatment once they get into bone or cartilage in humans, & we still fail.

Jack's-Jane said:

Thanks for all your help folks.
I have been tying myself up in knots trying to read about and understand this in various other sources. Last night I gave up and went to bed...............only to dream about it all :roll:

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Oh Jane you poor soul! I imagine you sitting in bed with a knotted handkerchief on your head like a monty python character groaning "my brain hurts". TBH so does mine when looking at the whole issue. :lol::lol:
It's bad enough looking at specific areas!

thumps_ said:

I'm so sorry Sarah P how heartbreaking for you.
Were repeated C&S done showing incremental ABx resistance by any chance?

I ask because the nose is lined with fine "hair cells" -ciliated epithelium which waft the mucus & all the bacteria stuck to the surface, up & into the throat.

The hairs do not regrow if there is sufficient damage to cause scar tissue. So the mucus builds up in a pool & the bacteria multiply just to become invasive again, until they even infect the cartilage & bone.

You may be surprised that even relatively non invasive & fully sensitive bacteria can pose very great difficulty in treatment once they get into bone or cartilage in humans, & we still fail.

Click to expand...

I think Sarah's Guinea Pigs had Urinary Tract Infections not Upper Respiratory Tract Infections

Not sure if this addition is any help:

One of the main issues with resistant bacteria is opportunism - most bacteria (except the incredibly virulent types) need some form of opportunity to cause disease, that doesn't occur on an everyday basis. Usually this is an opportunity to enter tissues e.g. microdamage to the lung epithelium, or a slight reduction in immune defences e.g. stress of environmental changes, travel, other illness etc.

Therefore, if you have a resistant bacterial strain in a colony, it is very easy to unwittingly spread that bacteria around the colony without knowing it, but no disease occurs. Then when one or more animals that are now carrying this bacteria get stressed and an opportunity occurs, they become very sick without any obvious cause because time has lapsed between infection and disease occuring. And of course, as this strain is resistant it won't respond to normal therapy and is more likely to be highly virulent.

So to prevent this occuring, hygiene and total isolation is essential with ALL infections from the very beginning, as you won't know its virulence or resistance to antibiotics unless it is cultured, and very often useful samples are very difficult to acquire.

IMO this is partly why there tends to be more sick animals in larger colonies and multi-animal households vs the same number of animals in separate environments. This doesnt make it wrong, but something people must consider if they have a lot of animals, including rescues and fosterers.

Jack's-Jane said:

I think Sarah's Guinea Pigs had Urinary Tract Infections not Upper Respiratory Tract Infections

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You're right Jane. My neurone just fell off the spirochete.:lol:

The talk I found has some interesting concepts. http://www.ted.com/talks/paul_ewald_asks_can_we_domesticate_germs.html

IMO this is partly why there tends to be more sick animals in larger colonies and multi-animal households vs the same number of animals in separate environments.

Would this mean that a colony would be more likely to have a variety of illness due to general weakness caused by an unseen bug which they have fought off but, in fighting it, they have reduced resistence of other problems? (Hope I am making sense).

My buns (12 of them) seem to have a lot of problems but every problem is completely different.... working my way through FHB's book with my own buns as the examples Often wondered why I seem to have an above average number of problems. The buns all come from resuces so I thougt also that their past lives and stresses may have contributed somehow.

bunnylover177 said:

IMO this is partly why there tends to be more sick animals in larger colonies and multi-animal households vs the same number of animals in separate environments.

Would this mean that a colony would be more likely to have a variety of illness due to general weakness caused by an unseen bug which they have fought off but, in fighting it, they have reduced resistence of other problems? (Hope I am making sense).

My buns (12 of them) seem to have a lot of problems but every problem is completely different.... working my way through FHB's book with my own buns as the examples Often wondered why I seem to have an above average number of problems. The buns all come from resuces so I thougt also that their past lives and stresses may have contributed somehow.

Click to expand...

Stress factors can dramatically reduce a bunny's immune system - even to the point of lowering the WBC.

There is also an increasing awareness that our companion animals of all species are contracting bacterial infections previously thought to affect humans only. The converse does not seem to be happening so much.
When there is sudden exposure to a new infection for the species, it is often more virulent. I do not know how much of the ABx resistance problem is coming from the human vector.
We just don't know enough really.

bunnylover177 said:

My buns (12 of them) seem to have a lot of problems but every problem is completely different.... working my way through FHB's book with my own buns as the examples Often wondered why I seem to have an above average number of problems.

Click to expand...

I suspect Jill that another reason for your higher number of problems is simply that you're a very observant owner with a very experienced and competent vet, so between you, you spot more things that an average "child's pet" bunny owner wouldn't...

I have made a mental note to read through this thread properly when my brain is working a bit better. My vet was always concerned about antibiotic resistance spreading through our bunnies and used to limit the duration of any course she prescribed. I had no idea what she was on about so this will make interesting reading :wave: