Canker and routine treatments

What routine treatments do I have to do in my team of racing pigeons.  When do I do it and what should I use? By David Palmer B.V.Sc, M.R.C.V.S

Racing pigeons “carry” many diseases which need treatment to keep them under control. They also carry several diseases which can be lived with quite happily, can flare up into clinical disease under conditions of stress e.g. racing, overcrowding. Molting, dampness, concurrent disease, breeding, rearing, moving loft.  In other words, living the life of a racing pigeon!  All these “carried” diseases need looking out for, as when they flare up they produce noticeable signs, which need treating appropriately.

CANKER

Like coccidiosis canker is caused by a protozoan parasite and so it is not responsive to any kind of therapeutic drug apart from a flagellicide antiprotozoan.  Thus, even the coccidiostats that deal with the protozoan parasite of coccidia, antibiotics that kill bacteria and vermicides that kill worms will have absolutely no effect on trichomonas, the casual pathogen of canker.  Trichomonas , the protozoan that causes canker differs from the cocci bug in it has a set of flagella and is consequently motile.  It is this property that is also associated with the specific nature of its therapeutic susceptibility.  There are many different strains of trichomonas about in the pigeon world, each capable of producing disease of varying severity and yet looking the same on cursory microscopical examination, and so a case of canker one year may cause little inconvenience, whereas a similar looking canker lesion next year may be responsible for a high mortality.

If we start by assuming that all pigeons carry some degree of canker and like all ‘carried’ diseases it flares up and causes clinical disease when the bird is stressed.  An inevitable stress and consequential flare up occurs when the birds (cocks and hens) are feeding the squeakers, and from the trichomonads point of view this is quite handy, since not only do the trichomonads live in the crop and throat and thus easily ‘enrich’ the crop milk that is being produced but they are also very conveniently transported to a new susceptible host in the milk - the young pigeon.  Thus we have two canker problems:

1. All birds carrying canker without much trouble - usually.
2. Young birds catching it from their parents and going down with classic canker i.e listlessness, ruffled feathers, thirst, loose droppings, weight loss and cheesy white/yellow lumps in the throat that cause pain in eating and may even choke the bird.  The ‘cottage cheese’ like lumps in the throat are easily removed with a damp cotton bud leaving no damage to the underlying mucosa, in contrast to pox lesions, which may appear similar and can only be removed with difficulty and usually result in damage and bleeding to the mucosa.  Any bird with loose droppings as the result of canker will pass the infective organism in its droppings.  Less common forms of canker include death from internal organ involvement and umbilical canker, where youngsters get a swollen naval through trichomonas getting in at that point.  A lump will be seen and the internal organ disease usually follows.

CONTROL: Trichomonads survive longest outside of the bird in damp environments so it is essential to keep a loft floor dry and to change the drinking water frequently.  

Medicate all birds when the hens are sitting on eggs.  

Medicate again after about six months.

Diagnosis by observing motile organisms in a damp throat or crop swab under the microscope is relatively straightforward.

Canker is common, variable in its effect and is often present as a secondary complicaton of another problem e.g young bird diseases, herpes virus.

Dont forget that the cocks feed the youngsters as much as the hens and so are just as likely to pass on infection.

As a vet I have access to many products and can use unlicensed products if I feel they are superior to the licensed products.  Thus it might be that I dispense some ‘Emtryl Soluble’ for use in a pigeon because I have some on the shelf, it is identical to ‘Harkanker’ and I feel the bird needs treating urgently or, if neither is to hand I might need to dispense some ‘Flagyl’ tablets which contain metronidazole (only a ¼ tablet daily for 10 days) a close relative to the dimetridazole in ‘Harkanker’ and ‘Medicanker’.  Ronidazole now available from Meditech.

Extract from British Homing World (June 4th, 1999) Veterinary Corner with David Palmer.