One morning while
doing your rabbit chores, you notice that your rabbit is shaking it's
head, or scratching it's years. Upon closer examination of the
rabbits ears you may notice small blisters and small areas of yellow
crusting scabs in the lower portion of the ears known as 'ear mange'
or 'ear canker'. At this point there is only culprit responsible for
this condition, the common ear mite. Ear mites are a member of the
Psoroptes or Chorioptes family. They are a blood
sucking parasite that burrow into the flesh of the rabbits ears and
lay their eggs in small tunnels as they suck blood from the skin. When
your rabbit feels the mites biting it's ears it begins shaking it's
head and scratching at it's ears which can cause more damage to the
ears.
The good news is
that by themselves ear mites are not deadly, however, untreated they
can cause significant damage and discomfort to your rabbit and they
can easily be spread from one rabbit to another unknowingly by you
the breeder. In worse case scenarios, the infestation can cause the
rabbit's immune system to weaken making it more susceptible to other
bacterial infections. If the inner or middle ear becomes infected the
rabbit(s) infected may develop wry neck (torticollis) which usually
results in the death of the rabbit.
So how did your
rabbits get infected with ear mites? There are many vectors that
could be responsible. Mites can be transported by a number of rodents
including mice and rats, as well as your barn cat if you have one.
They can live in straw and or the cracks of wooden hutches for a long
time and continue to re-infest your herd. They can be transmitted by
the breeder by unknowingly rubbing or scratching the head and ears of
a rabbit that has mites and then handling another rabbit without
washing their hands in between. Your rabbit can even acquire them
from any activity in which there are a large amount of rabbits
present such as a rabbit show, after all it only takes one newly
infected bunny to spread the mites to many others. However, the most
common way mites gain access to your rabbitry is when you bring a
newly infected rabbit into your rabbitry that has mites, but does not
yet show any signs or symptoms of the infestation. This is what
happened in our case. Fortunately, we soon discovered the problem and
because the rabbit was isolated, we were able to eradicate the mites
without any problem, and the rabbit involved is doing fine.
Now there are many
different ways to treat ear mites. The most common non-medication
treatment option is the use of mineral or olive oil (way to
expensive, keep it in your kitchen) to coat the scabs and drown the
mites. There are also a few different “off-label” medications
that can be used to effectively kill the mites as well as their eggs.
Each technique has it's advantages and disadvantages whether it be
cost, length of treatment time, or possible side effects. The goal of
this article is to share with you the many alternatives that you may
choose to eradicate the mites from your herd should you find that you
have a rabbit with ear mites.
Non-Medical
Treatment
The most common
non-medication type treatment for ear mites is called the 'triple 3'
or 3-3-3 treatment. This treatment involves coating all the scabs on
the ear with mineral oil once a day for 3 days to drown or smother
the mites. The easiest way to do this is to use a small medicine
dropper to place 3 or 5 drops of oil in ear year and then gently massage
the ear. If there are a significant amount of scabbing noted, then
dip a q-tip in the oil and gently coat the scabbed areas and
carefully remove as many of the scabs as possible without causing
further injury to the rabbit.
Then apply the
mineral oil every other day for three applications. By this point the
ears should be looking much cleaner. After three applications,
continue to apply oil to the ears once a week for a total of three
more weeks. Hence the name 'triple 3' or 3-3-3. This technique not
only kills any active mites that may be infesting the rabbits ears,
it will also kill any mites that may hatch from eggs that were still
in the ear.
This process works
by actually drowning the live mites with mineral oil causing them to
die, the reason you have to perform so many applications of the
mineral oil is that the initial application does not destroy any eggs
that may be in the tunnels of the skin in which they are laid. These
eggs incubate for a total of four days then new mites are hatched. So
while one dose of mineral oil may kill the adult mites, four days
later any eggs left in the ear will hatch and the process will
continue unabated. Therefore to be effective you most perform
multiple applications of mineral oil as directed.
Mineral Oil
Strength: Do not
dilute
Dose: 3 to 5 drops
(Enough to coat the scabs on the initial treatment)
Cost: $2.00 for 16
ounce bottle (more doses then I want to count)
Availability: Can be
purchased at any drug store or supermarket.
The advantages of
this form of treatment is that it is extremely cheap and relatively
easy to perform. The disadvantages are that it is labor intensive,
and the process takes the longest time to eradicate the mites, and
you may have to perform the compete process more than once for severe
infestations. If you have a lot of animals it will take you along
time to treat them all.
Medical Treatment
Options
There are several
fifferent medications that can be used to treat ear mites in rabbits,
with the exception of 'Eradimite' all of them are considered
'off-label'. That is that the medication or treatment option is
effective for treating ear mites in rabbits, but that is not what the
original intended use of the medication was created for. Other than
Eradimite, the two most common forms of medical treatment used to
treat ear mites in rabbits is the use of the anti-parasitics
ivermectin and selamectin.
Eradimite
Is a topical ear
solution that uses pyrethrins (0.15%) and piperonyl butoxide (1.50%)
as it's active ingredients to kill the mites in dogs, cats, and
rabbits. Pyrethrins come from the chrysanthemum flower and have been
used in many insecticides since the 1950's, piperonyl butoxide is a
chemical that keeps the insects from being able to degrade the posion
therby enhancing the effectiveness of pyrethrins. The remaining
ingredients (98.3%) is essentially aloe vera. Pyrtethrins are a form
of nerve agent which excites the nervous system of any insect that
eats or touches it. This quickly leads to their paralysis and
eventually kills them. My research into this product indicates that
it does nothing to destroy the mites eggs, therefore it has to be
repeated several times in order to kill all of the mites in your
rabbits ears.
The recommended
dosage is to place 8 – 10 drops of the mediation in each ear, which
means that a 1 oz bottle will probably only be good for two to four
applications before you need to purchase another bottle. The
instructions for use state “Repeat every 2 days until the condition
has cleared up or as directed by your veterinarian.” As far as I
can tell, eradimate will kill mites in their various stages of
growth, but it does not effect the eggs which is why multiple
applications are needed.
I have read on may
forums that pet owners claim that 8 to 10 drops are way to many for
their dog, cat, and or rabbit and they usually recommend only 3 to 4 drops. As I have
never used this medication, and do not know of anyone who has done so, I cannot verify if the lesser dose is
effective or not. There appears to be no specific 'weight based'
instructions for this medication, the only caveat is that it is not
to be used on dogs, cats, and rabbits less than 12 weeks old.
Eradimite (Fort
Dodge)
Strength: Do not
dilute
Dose: 8 to 10 drops
per ear
Cost: $17 – $20
for a 1 ounce bottle (about two to four applications)
Availability: Can be
purchased on-line or at some pet stores.
Ivermectin 1%
(Anti-parasitic)
Some would say that the use of anti-parasitic agents is the easy way out, however it does require the purchase of medication as well as syringes, and you need to know the proper way to administer the medication to your rabbit. The medication of choice is Ivermectin (Stromectol). Ivermectin is a broad-spectrum anti-parasitic used to treat head lice, scabies, and ear mites among other things in both humans and animals. The effective dosage of ivermectin for rabbits is 0.018 to 0.025 ml of a premixed 1% sterile solution for each pound that the affected rabbit weighs. While a smaller dose may be effective, for rabbits with a severe mite infestation, it is recommended that the dose used be 0.025 ml's for each pound your rabbit weighs. Some of the brand names for ivermectin that you will find not only on the internet, but at retail farm supply stores such as Tractor Supply include: Ivomec 1%, Vetrimec 1%, and Agri-Mectin among others.
Name: Ivermectin 1%
Injectable
Strength: 10mg/ml
Dose: 0.018 –
0.025 ml per pound of rabbit
Cost: $25 – $35
for 50ml bottle (about 400 – 450 doses)
Availability: Can be
purchased on-line, or locally at Tractor Supply, or at almost any
farm and ranch supply store.
Of the three medical
treatment options, this is the cheapest as a 50ml bottle of
ivermectin will supply you with enough medication for about 400 –
450 doses for a 10lb rabbit making the cost around $0.065 per
application. The advantage of this treatment is that it 99.6%
effective after the administration of three doses. In addition to
killing ear mites, it also eradicates any fur mites the animal may
have. The disadvantages is that you need to also purchase insulin
syringes (which are relatively cheap) and you need to know how to give a
subcutaneous injection to your animal as you will need to administer this treatment once every two weeks for a total of six weeks.
Breeders Note: Using insulin syringes to administer ivermectin is just about the only accurate way to administer the correct dosage of medication to your rabbit. Insulin syringes are broken down into a scale known as units. There are 100 units in 1 ml (millileter). I have taken the original recommended doses from the chart in the book 'The Rabbit Problem Solver' and added a column to the chart indicating the number of units of medication you should administer to your rabbit based on the rabbits weight. If you want to perform your own calculations simply take the dose in ml's and multiply by 100 (0.25ml x 100 = 25 units), it that simple.
Ivermectin should be
administered subcutaneously once every two weeks for 6 weeks (total
of 3 doses). To administer a subcutaneous injection, pinch up the
skin over the shoulder blades of the rabbit and clean the area with a
q-tip dipped in alcohol, or with a cotton ball soaked in alcohol. Then inject the required amount of medication
into the tented area of the skin that you have just cleaned. Keep in mind that ivermectin is a thick and viscous medication and it takes a while to fill the syringe, and it will take a bit of pressure to inject it into to nape of your rabbits neck. Having a partner to hold the rabbit you wish to medicate is definitely an added bonus.
Breeders Note: There are a couple of other forms of ivermection such as pour-on, pastes, and even powders, none of which I have used. While there are a number of videos on YouTube from people who have given their rabbits ivermectin 1.87% horse de-wormer orally to treat ear mites, I cannot validate the effectiveness of the dose which is often described as "pea sized." I may delve into these other types of ivermectin in a future article, but for know, know that the subcutaneous route is safe and effective when administered correctly.
Breeders Note: There are a couple of other forms of ivermection such as pour-on, pastes, and even powders, none of which I have used. While there are a number of videos on YouTube from people who have given their rabbits ivermectin 1.87% horse de-wormer orally to treat ear mites, I cannot validate the effectiveness of the dose which is often described as "pea sized." I may delve into these other types of ivermectin in a future article, but for know, know that the subcutaneous route is safe and effective when administered correctly.
Revolution
(Selamectin 15mg topically)
Revolution for dogs
and cats can be used as an 'off-label' medication to treat ear mites
in rabbits. According the article 'Efficacy and safety of Selamectin
(Stronghold / Revolution) used Off-Label in Exotic Pets' in The
Journal of Applied Research in Veterinary Medicine (JARVM),
Stronghold and Revolution for puppies and kittens (5lbs and under)
can be used as an effective treatment for ear mites in rabbits.
In two independent
clinical trials a 15mg application of selamectin killed all of the
mites in rabbits whose ears were infested. In the first study, when
applied to the skin at the base of the neck either once or twice
after a single application of 15mg of selamectin (1 tube) no live
mites were recovered from day 7 through day 56. In the second case
study four 4-month-old dwarf rabbits who shared a cage all with ear
mites were treated with 15mg of selamectin, no mites were detected
after 7 days.
Revolution (Mauve
Colored Box)
Name: Revolution for
Puppies and Kittens < 5lbs (Mauve Colored Box)
Strength: 15mg per
tube, 3 tubes per box.
Dose: 1 15mg
application (3 doses per box)
Cost: $25 – $30
(about $10.00 per application)
Availability: Can be
purchased on-line, or locally from Pet supply stores such as
Petsmart, Petco, or from your local veterinarian.
Of the three medical
treatment options, this is the most expensive as one box contains
only 3 does (15mg per tube) of the selamectin making the cost about
$10.00 per application. The advantage of this treatment is that it is
99.5% effective after the administration of one to two doses. It is
easy to administer and takes no medical knowledge to do so. The
major disadvantage is the cost. If you are only treating one or two
animals this may be the route you want to go, but it is far to costly
to try and treat more than a few animals.
Prevention
The old adage,
“prevention is always the best medicine” still applies to ear
mites. When bringing any new livestock into your rabbitry, the best
practise is to isolate them from the rest of your herd for a minimum
of two weeks, but four weeks is better. This will allow you to determine
not only if the animal has any ear mites that may have been
undetected by both the breeder and yourself when you initially examined the rabbit.
Keep in mind that no breeder that I have ever known intentionally
sold a rabbit infested with mites, but it does happen. After you
have treated your rabbits and they are mite free, you will need to
remove them from the cages and clean and disinfect your cages and any
plastic resting boards.
The following
instructions will demonstrate how we clean our cages here at TAP
rabbitry. We clean and disinfect our cages about every 6 months and
whenever necessary. We clean and disinfect our cages with both heat
and bleach. I use a butane torch and burn off any old hair from the wire
cage. Then I spray the cages with simple green and remove any
additional stuck on stuff with a plastic bristle brush. The cages are
then rinsed with the water hose and I spray the entire cage with a
1:10 bleach solution (1 part bleach, 10 parts water) and place the
cages in the sun to dry.
Make sure you also
clean and disinfect any plastic resting boards that may have been in
cages with infected animals. For this, I clean them with
simple green, and soak them in a container filled with a 1:10
bleach solution. Any wooden, sheet rock or other porous type resting
boards that cannot be disinfected with bleach should be thrown away
and not reused as the mites can live in the cracks and crevasses of
these items.
Conclusion
If you have the
time, and you are only treating a couple of rabbits, then the
non-medical treatment may be the choice for you. Of all the treatment
options it takes the most time and if you have a rabbitry of any size
it will take you some time to treat all your livestock. It will work,
but it has the lowest success rate, (most often due to human error)
and may need to be performed more than once. It is however the
cheapest option, and the only non-medical option that I am aware of
for treating ear mites. I am not so sure that the use of eradimite is
any more effective than simply using mineral oil as eradimite does
not kill the eggs and you still have to perform multiple applications
just as you would if you were using mineral oil. If these were my
only two choices, I would definitely try mineral oil first before
ponying up the money for eradimite, but this is just my humble
opinion. If you are not wanting to medicate your rabbits then the use
of mineral oil is definitely the only avenue you have other than
destroying the animal and or animals concerned.
If you do not mind
the use of anti-parasitics then Ivermectin is a good choice,
especially if you have to treat multiple animals. It is an
inexpensive solution when you figure the number of doses you can get
from one 50ml bottle, and with a 99.6% success rate it is hard to
beat. The downside is that you will have to wait for a minimum of two
months before you can butcher any treated animals for human
consumption to give the medication time to get out of their system.
Revolution (for dogs and cats) has about the same success rate as
Ivermectin, it is easier to administer, but is far more costly per
dose, but if you only need to treat a few rabbits, it is the easiest
of the three to administer. Like Ivermectin, a two month waiting
period is recommended to allow all of the medication to thoroughly
leave the rabbits system before butchering them for human
consumption.
It should be noted
that I am not a veterinarian, and I do not endorse any of the
products that are in this article regardless of whether I have used
them or not. Proper care should be taken whenever administrating any
medications to your rabbits and you do so at your own risk. I have
done my best to provide you with the necessary information so that
you can make an informed decision regarding how you may wish to treat
your rabbits if and when they become infected with ear mites. I
encourage you to do any additional research that you think may be
necessary regarding the side effects of he aforementioned medications. As
always, if you have enjoyed this article or have found it
informative, then please share it with your friends. Don't forget to
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Resources:
Bennett, Bob,
Storey's Guide To Raising Rabbits, (North Adams, MA: Storey
Publishing, 2009).
Fisher, Maggie DVM,
Beck, Wieland DVM, Hutchinson, Melanie J. DVM, “Efficacy and safety
of Selamectin (Stronghold / Revolution) used Off-Label in Exotic
Pets” in The Journal of Applied Research in Veterinary Medicine
(JARVM), 2007 (pp 87-96)
Patry, Karen, The
Rabbit Raising Problem Solver, (North Adams, MA: Storey
Publishing, 2014).
