 What
YOU can do about chytrid
Chytrid is a cool
climate fungus so this is not a disease you need to worry about unless
your local daytime temps are consistently below 27 degrees C. If you are
in winter, then being extra watchful of your captive and/or backyard frogs
is important if you want to save them from chytrid fungus.
We are providing this
information to assist those who are unable to transport their frogs to
use for treatment. However, you should not be undertaking treatment
of frogs you find unless we have been able to discuss the symptoms with
you and reasonably determine that you have found a frog that is sick
with chytrid and not another disease problem which would be treated differently.
Prevention
for keepers
Preventing chytrid
from infecting your pets is far better than trying to recover them. Keep
in mind that chytrid is a winter problem and include some special procedures
in your pet care routine at this time.
- give all your
frogs a betadine bath for four minutes every few days as a preventative
(a betadine bath is 1 part "povidone 10% iodine" per 100 parts
water in a small bowl; sit the frog in the bath but avoid getting the
bath into its nostrils and eyes)
- use new disposable
gloves for each frog you handle
- avoid going out
to look for frogs in the field during this time
- avoid obtaining
or disposing of any pet frogs during winter but if you must, give those
frogs the betadine bath every day for at least a week before transfering
- if you are receiving
frogs, keep them separate from your other frogs; give them the daily
betadine bath described above for at least two weeks after arrival;
always use gloves to handle
Prevention
for pond owners
- Exchanging anything
with other pond owners is a great way to spread many problems, not just
chytrid. Avoid exchanging plants, snails, fish and tadpoles with other
pond owners.
- When you buy plants
from an aquatic nursery, you can try giving them a special bath in the
aquarium product "Rapid White-spot Remedy" before introducing
them to your pond. Use the directions on the bottle to mix up the bath
in a large bowl and let the plants soak in it for an hour or so before
adding to your pond. Check to see if any tadpoles are present before
you leave the shop as nursery troughs often attract frogs and then the
tadpoles get distributed with the plants. If there notice tadpoles after
you get home, you can return them to the nursery or you can raise them
in a separate container (our raising tadpoles
page will help you). If the nursery is further than 20 km from you,
the metamorphs should be returned to the nursery area for release.
- Another way to
ensure that chytrid can't possibly get into your pond and kill amphibians
is to drain the pond entirely each winter and only keep it filled during
the warmer months. Bird baths and other small containers can be provided
for backyard wildlife during the dry months and these can easily be
kept regularly cleaned and disease-free.
Terminal
Chytrid
As chytrid progresses
to the point of being irreversible, the attack on the nervous system becomes
more obvious. In the Common Green (White's/Litoria caerulea), the head
can tilt forward to the point that it becomes at a right angle to the
back; the toes can curl and the limbs can become paralysed even though
the frog is still alive. Both heart rate and breathing slow right down
and eventually just stop. The frog's posture becomes withdrawn in temperment
and it sits in such as way as to reduce the amount of contact between
its skin and the surface it is sitting on. The entire ventral surface
can turn a flaming red/orange colour which is quite different to the reddening
caused by the bacterial disease "Red leg". If you have found
a frog in this condition, you won't be able to save it but a frog disease
researcher might want the body as part of their research into this hideous
disease. If you don't know how to find a frog researcher, email us and
we can assist you.
Treating
captive frogs that have chytrid fungus
Essential supplies for treating chytrid are: povidone iodine 10%, Aqua
Master's Rapid White-spot Remedy (for fish), a fan-type heater, calcium
sandoz syrup from a vet, amphibian ringers solution which will need to
ordered through a vet, disposable gloves, an accurate thermometer (preferably
mercury), and a small room which is easy to heat. All four approaches
described below are required - just doing one or two of them might not
work.
First part
of treatment: Heating process
- Suspect frogs
can be placed in the small room with the heater running - the temp should
be kept at 35 degrees C for four hours, then return to ambient temp;
only exceed 36 deg. C if you have a tropical frog species (but do not
go any higher than 40C!) as such a high temperature might kill a sensitive
or cool climate species
- the daily four
hour heat treatment can be used until the skin symptoms clear and the
frog/toad stops excessive soaking in the water bowl (we've had one species
come in so far - Litoria gracilenta - that refuses to get into the water
bowl so there may be some species which avoid contact with water)
- If the majority
of captive frogs are affected, heat the frog room(s) instead so all
are treated simultaneously
Second part
of treatment: Special baths
- Mix up the White
spot Remedy at twice the dosage on the bottle and use this as the frog’s
normal water in its bowl; large frogs (> 7cm) can sustain a triple
dose but delicate species and small individuals (less than 35mm) should
be given only the normal dose rate for fish
- The same mixture
can be put in a spray bottle and the frogs and inside of the enclosure
sprayed daily
- Give each frog
a daily betadine bath (as described up top) after its heat treatment;
this is to remove all the dead skin material created by the heat treatment
and speed up the healing process for the new skin underneath
- Continue the special
baths until the frog is consistently eating normally again
Third part of
treatment: Electrolyte imbalance
- Chytrid causes
internal changes to the frog's chemistry and these changes get more
extreme the longer the frog has the disease. To reduce the imbalance,
you will need a solution called Amphibian Ringers (which will need to
be ordered from a veterinarian) and another product from the vet called
Calcium Sandoz. Do not substitute something else for these products
- they must specifically be Calcium Sandoz and Amphibian Ringers (although
Calcivet might be used only if you are treating adult frogs and no tadpoles
while Sandoz can be used for adults, juveniles and tadpoles).
- The Calcium Sandoz
is administered in drop form onto the frog's back at the rate of .08
ml per 10 grams of bodyweight (so you'll also need to be able to weigh
the animal on a digital scale). Normal calcium maintenance would require
one application per week but in chytrid, it might be acceptable to try
this treatment every few days until the fluid retention is reduced.
Do not overdose so if the bloating disappears after the first or second
application, then reduce further applications down to once per week.
- The frog ringers
is poured into a small bowl only to a shallow depth and then sit the
frog or toad in the bowl for at least 30 minutes. The soak in ringers
could also be repeated every few days until fluid retention/bloating
are reduced.
Fourth part
of treatment: Disinfection of enclosures:
- If frogs are normally
kept in large, well planted enclosures, they should be moved to pet
tanks during treatment and until cured
- Disinfect their
enclosures and anything they come into contact with - chytrid is easy
to disinfect for so washing tanks/bowls/perches with bleach is fine;
rinse very well with water
- Then pour betadine
straight from the bottle over all surfaces and keep spreading for several
minutes; rinse well and towel dry
- plants should
be discarded in plastic bags in the bin (trash) and new plants supplied
- wooden perches
can be soaked in 1 part betadine to 3 parts water for a day or two before
rinsing well and drying in the sun
Handling
chytrid for pond owners
It really depends
on how much you care about your backyard frogs as to whether you want
to intervene if and when chytrid arrives in your yard. What you do about
disinfecting your pond can be very involved if your pond is quite large.
If your pond is small, prevent a tragedy from occuring in the first
place by draining it for the winter. If the pond is large, then dosing
it with White spot Remedy may be sufficient if sick frogs are found but
this might not be enough. If you find sick frogs in your pond and decide
to help them by treating them, the instructions for keepers should be
used but this means that the frogs will have to be cared for indoors until
better. However, if the pond is still infected and you succeed in curing
the frogs, they will re-infect once outside.
If you believe that
you might have a chytrid problem and want advice on managing your particular
pond, you can contact us to describe your
setup and location.
Last updated: June 10th, 2006
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