The Maintenance of Race Form -
A Review of Worming
Control and Available Medications
By Dr. Colin Walker B.Sc. B.V.Sc. M.A.C.V.S (avian health)
As pigeon fanciers,
probably the first disease any of us became aware of was worms. We
all know birds and animals get worms and that it is necessary to
periodically worm them. Yet worms are still surprisingly common.
When doing investigations at the clinic into poor race performance
we often think of the more recently understood diseases and the
intricacies of diet and training but still find quite commonly that
the problem is just…worms. Why is this?
Part of the answer is the fact
that a pigeon with just a few worms can pass literally thousands of
eggs in its droppings everyday, that another bird only needs to
swallow one to become infected and that the worm life cycle can be
completed very quickly . The potential for disease build up and
spread is enormous. Another part of the answer is the use (and
misuse) of worming medications. Worms have also developed resistance
to many of the worming preparations on the market.
there are three different types of worms that pigeons get. These are
roundworms, hairworms and tapeworms. All worms because of their
parasitic effect weaken the birds and create a vulnerability to
are large enough to see and basically look like white earth worms.
They can be up to 3-4 cm long, 1-2 mm wide and are readily visible
when passed in the droppings. Their life cycle is very simple. The
adult worms live in the bowel. Here they breed and release
microscopic eggs that are passed in the pigeons droppings. Other
pigeons accidentally swallow these eggs when eating, drinking or
pecking around the loft floor or loft environment. Once swallowed
these eggs hatch and mature in the bowel of the newly infected
pigeon. It only takes three weeks for a swallowed egg to hatch, grow
into an adult and start producing eggs itself.
If a pigeon
has 6 roundworms, then on average half will be female. Each of these
females can produce up to 5000 eggs per day meaning that this pigeon
with only six worms can release approximately 15,000 eggs per day in
its droppings. Another pigeon only needs to swallow one of these to
At my clinic
we have seen pigeons with 300 or more roundworms. Using the above
figures these birds would release three quarters of a million eggs
every day. Once in the environment eggs remain viable for about 6
months. Very quickly therefore the environment becomes heavily
contaminated. Combining this with the very short life cycle of only
three weeks one can see how quickly worms can negatively impact on
the health of the loft.
birds once before the start of racing doesn’t really achieve a lot.
The treatment may kill the worms present but if the pigeon goes back
into the same loft and environment it is likely to swallow more eggs
the next day and in three weeks be infected again. At the very
minimum birds should be wormed twice, three weeks apart. Worming at
this interval means that the next lot of worms that the birds are
infected with are killed before they can, in turn, produce eggs
themselves. In this way the life cycle is broken. Each treatment
should be followed up by a particularly
clean of the loft to minimize the chance of re infection. Remember
that disinfectants do not kill worm eggs. Their thick shells protect
them. It really comes down to manual removal of all the droppings as
any droppings passed prior to treatment may contain eggs and have
the potential to re infect the birds. Torching with a flame is
however effective at killing eggs. Although normal cleaning and
torching are good I don’t think it is possible to eradicate every
last egg and so some re- infection is inevitable. In a contaminated
environment a good protocol to follow is to re worm every three
weeks for at east 6 months. Because round worm eggs only survive for
about 6 months, after this time all of the eggs in the environment
will have died and no longer be capable of infecting the birds.
are eradicated they can re-enter at any time with a stray or late
returning bird or indeed as some round worms are not species
specific [ and can infect many different types of birds], with wild
birds in particular doves. Ideally droppings should be regularly
checked under the microscope by your avian veterinarian for worm
eggs. During racing I recommend this be done at least every three
weeks. The on- going maintenance of dry hygienic conditions will
minimize environmental build up of eggs.
are microscopic worms. This means they cannot be seen with the naked
eye. Rather than live in the hollow tube of the bowel, like round
worms, they live in the wall of the bowel. This means that they do
much more harm.As they migrate through the bowel wall they damage
it. This means that not only can the bowel not digest and assimilate
its food properly but blood and tissue protein is lost through the
bowel wall. The hair worm life cycle takes longer (approximately 6
weeks) and they don’t lay as many eggs per day as round worms (about
500 per day). Birds can become infected directly by swallowing eggs
as with roundworms but sometimes the eggs hatch is the environment
and birds become infected by eating the free living larvae.
Sometimes the larvae are ingested by worms or beetles and pigeons
can also become infected by eating these in turn.
many different types of tapeworms. They vary tremendously in their
size. Some are almost microscopic while others are really large.
Some types can be 1cm wide and 10 cm long. The parasites head or
scolex is imbedded into the wall of the bowel where it feeds. Behind
the head, the body of the tape worm is made up of a segmented ribbon
of maturing packets of eggs called proglottids which trail down the
gut. As each egg packet matures it snap off the end of the body and
is the swept down the bowel and passed in the droppings. Pigeons
cannot become infected by eating these eggs (unlike roundworms and
hairworms). The eggs must be eaten by what is called an intermediate
host, usually a worm or beetle. The parasite undergoes several life
cycle changes in the intermediate host. Pigeon can only become
infected by eating these intermediate hosts. In Australia, the
common intermediate hosts are weevils and pigeons simply become
infected by eating these with their food
One of the
important decisions, as far as worm control is concerned, is which
wormer to use. These days there is really no reason to use anything
except a macrocyclic lactone and my preferred macrocyclic lactone is
moxidectin. Macrocyclic lactones are
new group of drugs that kill round and hair worms. They are very
effective., enormously safe in birds, do not effect race form, do
not effect the moult, food does not have to be withdrawn during
treatment, they do not cause vomiting, are readily drunk by the
birds, kill all life cycle stages (larvae and adults) and also have
the handy side effect of killing any external parasites that feed
off blood or tissue fluid. This means they kill all mites.
Macrocyclic lactones were initially used in dogs and cats where they
not only kill worms but also fleas.
lots of different macrocyclic lactone-ivermecton, doramectin,
abamectin and selamectin etc. Moxidectin is the one that is most
widely used in Australia. To treat a flock I use moxidectin 2mg/ml
at a dose of 5mls/1L of drinking water for 24 hours. Individual
birds can be wormed by giving 0.25ml (about five drops) of the nett
solution. Because lice live off feather debris and dandruff they are
hard to kill by giving moxidectin orally. However a common trick is
to put the moxidectin, one tenth strength i.e. 1/2ml/1L in the bath
water. Here it kills the lice by touch. This is so easy, the birds
simply dip themselves and it does not affect the feathers in any
way. The only restriction on the use of macrocyclic lactones is that
( like many drugs) they should not be used in the drinking water of
breeding birds feeding babies less than 3 weeks of age. During this
time the birds drink so much water that the chicks get a very high
dose of the drug and some may die.
is available by itself or combined with another drug, praziquantel,
under the brand name Moxidectin Plus. Praziquantel is the drug of
choice for tapeworms. This means that this drug combination
literally kills all worms and mites. Praziquantel is however a
bitter drug and altough the birds will drink it they do so
reluctantly. When using this I prefer to pick each bird up and give
0.25ml of the solution directly down the throat to ensure each bird
gets a full dose.
lots of different brands of wormers on the market but if you look at
their labels it is likely that they will contain one of the active
piperazine- a very old drug, used now for over 40 years, only kills
round worms, worm resistance to this is commonly seen.
levamisole- a useful drug but has the disadvantage that it can cause
vomiting, and when used in its tablet form, food needs to be
withdrawn for at least 12 hours making it hard to use during racing.
fenbendazole- a useful drug, has the disadvantage that it and other
drugs in the same group cannot be used during moulting otherwise a
‘fret mark’ will form in the feathers that were growing at the time
clinic when we are investigating potential health causes of a team
performing below expectations and we make a diagnosis of worm
infestation we think that this is pleasing. If birds have got to
have a health problem worms are probably a good thing for them to
have. This is because there are effective medications available and
response to treatment is usually very rapid. Having said that though
it is better if worms can be avoided in the first place.
the stock loft should be absolutely parasite free and maintained as
a mini quarantine station. Worms should be eradicated through repeat
worming and ongoing hygeiene as outlined earlier. All new birds
should be wormed prior to entry.
racing lost it is inevitable that the birds will be exposed in the
home environment or while away in race baskets. Ongoing hygiene,
regular dropping checks, strategic preventative wormings and a
complete worming program when the
identified will minimize their impact on race performance and health