By Dr Colin Walker BSc, BVSc, MRCVS, MACVSc (Avian health)
The parasitic worms drain the birds’ of nutrition, in the
process compromising both health and race performance.
External parasites such as lice and mites directly damage the
feathers. Control of parasites is therefore vital to the
long-term success of the loft. At times, both the information
and the enormous array of products available to the fancier
can be a bit confusing and so what are the important parasites
and what are the current preferred medications available to
control them.
The important parasites are basically roundworms, hairworms,
tapeworms and lice and mites. Roundworms and hairworms live in
the digestive tract of the pigeon, releasing eggs, which are
passed in the droppings. After several days, they become
infective and, if then accidentally ingested by a bird, hatch
in the bowel and grow into a new worm. This new worm then
grows into an adult and then produces more eggs. This whole
lifecycle can be completed as quickly as 3 weeks. In both the
racing and breeding lofts, the number of round- and hairworms
should be absolutely zero. This can be achieved by worming
twice at a 3-week interval and each time following up with a
super-thorough clean of the loft. If it is not possible to
totally clean the loft, then worming should be repeated every
3 weeks for at least 6 months. Worm eggs cannot survive in the
environment for more than 6 months, and treating for longer
than this therefore means that there are no further infective
eggs in the environment to reinfect the birds. Worm infection
is diagnosed by microscopic examination of droppings.
Droppings should be regularly checked by a veterinarian or
animal technician. If reinfection occurs from introduced
birds, returning race birds or strays, the above protocol
should be repeated.
Tapeworms have a different and fascinating lifecycle. The
adults live in the bowel, burying their heads deep in the
bowel wall and feeding off body fluids. Behind the head
stretches a ribbon-like body that is divided into segments.
These segments are called egg packets or proglottids. As they
mature, one or more of these segments break off from the end
of the body and are passed in the droppings. Once in the
environment, the egg packets need to be eaten by an insect to
become infective. Pigeons, in turn, become infected by eating
one of these insects. Tapeworm infection does not require a
microscope to diagnose, as the egg packets in the droppings
are visible. Most are about the size of a grain of rice and
are white to pink in color. Often a fancier will notice that
a bird is a bit quiet and that its droppings are a bit loose.
Close examination will reveal the small white glistening egg
packets in the droppings. With tapeworm infection, the birds
just need to be treated once but the loft should be sprayed
with a safe long-acting insecticide (the preferred one is
Permethrin) to minimise the chance of the birds eating more
insects. The droppings in the loft should then be monitored
during cleaning to ensure that infection does not recur.
For roundworms and hairworms, these days there is no reason to
use anything else than an avermectin such as Ivermectin
(‘Ivomec’) or Moxidectin. These medications are just so safe
and effective and of course have the handy side-effect of also
killing all external parasites that suck blood. This includes
all mites. Do, however, watch your dose rate. Not all Ivomec
is the same. It comes in a variety of strengths. Some
large-volume bottles that seem really cheap are probably a
fairly dilute preparation. One needs 10 mg of active drug per
liter of drinking water for the medication to be effective. To
figure out how much to add to the drinking water, multiply the
strength on the label by what will become the dose to equal
10. For example, a common strength available is 0.8 mg/ml (0.8
g/liter). 0.8 x 13 equals approximately 10. So therefore, one
needs to add 13 ml to 1 liter to give an effective dose.
Similarly, a brand that is 5 mg/ml will only need 2 ml per
liter to be added to the drinker.
All avermectins are well tolerated and the birds can be fed
and loft flown routinely. These medications can also be used
safely during breeding, racing and molting. In overdose, the
birds will become quiet and some may vomit. However, with
withdrawal of the drug the birds become normal in 1 – 2 days.
Some fanciers will notice that some worming preparations
contain piperazine. This is an older drug that rarely gives
100% clearance of worms and because it has been used a long
time some worms are totally resistant to it. Products based on
levamisole – and a number of liquids and tablets are available
– have the strong disadvantage that food need to be withdrawn
for at least 12 hours before and 6 hours after treatment and
even then many birds will still vomit. This makes it very hard
to use during racing. Wormers based on fenbendazole and
mebendazole cause huge frets to form in the feathers if used
during molting and are not conveniently packaged for use in
birds.
When using avermectins to treat mites remember that all mites
that infect birds are not always found on them at any one
time. Many live in the nooks and crannies throughout the loft.
Unless the loft is also treated they quickly reinfect the
birds. At the same time as treating the birds with Ivomec or
Moxidectin, spray the loft to avoid this. Simply scrape the
loft out as you normally would and then spray a diluted
insecticide (Permethrin is best) on to the scraped surfaces
and into the cracks and crevices. Done on a warm day, the loft
will be dry in 1 – 2 hours and the birds can be called back
in. Try and do such a loft treatment in the morning so as to
ensure the loft is completely dry by night.
Tapeworms are best treated with praziquantel. This drug is
very safe and like the avermectins can be used at any time of
the pigeon year. During treatment the birds behave normally
and can be loft flown and fed normally. Praziquantel is
available in tablet form and also as a water-soluble solution
called Prazivet. Prazivet tends to be fairly bitter and so
often it is better to give each bird 0.25 ml of the neat
solution individually to each bird in the back of the throat.
Lice live off feather debris and so the avermectins have
limited effectiveness against them. When lice are a problem,
it is necessary to spray or dip the birds. As lice live always
on the bird, treating all birds simultaneously will rid the
loft of these. Whatever you do, do not use any of the older
preparations such as Malawash. These are based on
organophosphates. Organophosphates have a very narrow safety
margin in birds and accumulate in their system to their
detriment. Having a fancier ring the clinic in a panic after
using Malawash or a similar product, with birds dead or dying,
happens all too commonly. Organophosphates are absorbed
through the skin and as long as the birds remain wet continued
absorption will occur. Often fanciers have been lucky and have
earlier dipped on a warm day and have had the birds dry
quickly. Dipping on a cooler day means the birds stay wet for
longer and absorb more of the poison. This prolonged skin
absorption coupled with a narrow safety margin tips the birds
into a toxic dose range. If a drug company attempted to
register an organophosphate for use in birds these days they
would have no chance. The few such products that are on the
market are therapeutic dinosaurs. Birds with organophosphate
poisoning lose muscle control, start to salivate and vomit,
develop diarrhea, become unconscious and die. If overdose
occurs, it is important to prevent further absorption by
physically washing the birds. If the birds don’t start to
improve immediately, your veterinarian has an antidote
injection. Birds regularly washed in organophosphates
gradually accumulate the poison in their system. The drug,
although quickly absorbed, is only slowly released and tends
to be stored in the body, particularly in the body fat and
bones. From here, it is gradually released, interfering with a
number of metabolic processes. This is particularly so in
hens, in which reproduction is affected, leading to abnormal
ovulation and abnormal egg shell formation.
These days use a synthetic pyrethroid such as Permethrin.
These are very safe yet just as effective as organophosphates,
prevent reinfection for up to four months and do not take the
bloom off the feathers. To spray the birds, dilute (usually 10
–20 ml per liter ) into a handheld pump bottle and spray the
birds liberally. To dip the birds, pick a warm day, fill a
bucket with warm water, add Permethrin at the rate of 10 –20
ml per liter together with a wetting agent (e.g. some
children’s baby shampoo or a few shavings off a cake of pure
soap such as “Velvet”) and away you go. If done correctly, the
vane of the feathers will collapse back to their quills,
exposing pink lines of skin. The birds look like drowned rats
but after spreading in the sun and a bit of preening look
normal in about 1 – 2 hours.
Obviously there is no single way of effectively clearing the
birds of parasites, but the system preferred by me is:
Moxidectin, 2 mg/ml, 5 ml per liter for
24 hours
Dip birds in Permethrin
Thorough clean of loft and spray loft with Permethrin
In tapeworm areas or if tapeworm segments are seen in
droppings, Prazivet, 0.25 ml to each bird.
We are
a Loft that breeds strictly for performance. Our
birds are famous for their toughness and ability to
fly 100-600 miles in all types of conditions. After
over 30 years
of breeding I consider my bloodlines
the Best of The Best
