An Introduction to Gordon Chalmers

I trained in veterinary medicine at the Ontario Veterinary College, University of Toronto, from which I graduated in 1961. I entered private veterinary practice as an assistant to practitioner for about a year, after which I joined the Alberta gov't (Dep't of Agriculture) in its veterinary diagnostic service, conducting post mortem examinations on domestic poultry and other livestock, wildlife, fish and zoo animals. the Doc, email is gacdvm@telus.net

Coccidiosis By Gordon Chalmers 

Coccidiosis is mainly an important infection of youngsters after weaning, likely because their immune system is not yet as fully developed as it will be later. Like worm eggs, the coccidial form (called an oöcyst) that is passed in droppings isn't yet at an infective stage, and requires, cool, damp conditions for development to the infective stage. Depending on the species of coccidia, microscopically, an oöcyst looks very much like a boiled egg cut in half or lengthwise. Under ideal conditions for the species of coccidia involved, the oöcyst undergoes what is called sporulation, to produce 4 or 8 banana-shaped structures called merozoites.

If a pigeon picks up a sporulated oöcyst and swallows it, within the intestines, these 4 or 8 structures break out and each one enters a cell where it divides to produce more merozoites, that in turn, break out of the cell and enter more cells. This process of repeatedly entering and breaking out of cells causes in the intestines, a great deal of damage and irritation that results in diarrhea. At some point, the process just described changes a bit, and the result now is the production of many oöcysts that break out of cells and pass out with the droppings, ready to start the whole cycle again.

In the past, the common treatment of coccidiosis was the use of sulfa drugs, notably Sulmet. One of our modern drugs, also a sulfa-based product is Vetisulid which is useful against coccidia and bacterial infections as well. One of the best modern drugs to use is Amprol (Amprolium). Another very effective drug is Baycox. After using Amprol (not while you are using it), give your birds a day or two of a multi-vitamin mix in the drinking water.

6. E. coli Infections

E. coli (short for Escherichia coli) is a very common bacterial organism in the intestines of humans, birds and animals and can be cultured from droppings almost all the time. For this reason, the isolation of this bacterium from a sample of droppings sent to a laboratory should not be surprising. If a culture of droppings reveals many E. coli, it is possible that these increased numbers may signify a problem. If the sample was fresh and held chilled until it reached the laboratory, high numbers of organisms are likely meaningful, especially if there was a related history of illness in the birds the sample came from. However, a high count may mean little if the sample wasn't refrigerated right after collection and wasn't sent chilled to the laboratory. Under conditions of little or no refrigeration, bacteria begin to multiply in the warmth, and can create a false picture of events happening in the birds. So don't read a lot into culture results that show high numbers of E.coli, unless you can eliminate warm shipping conditions, and can tie these high numbers to an illness that is compatible with E. coli infection.

If a post mortem examination and culture of a number of organs from sick birds reveals a high number of E. coli in these organs, these E. coli are likely to be significant in terms of the illness occurring in the birds. Also, if sick birds are vomiting, have mucoid diarrhea that has an odd odor, such findings are highly suggestive of a significant E. coli problem. E. coli can complicate other diseases by moving in as secondary invaders, a common finding in adenoviral and other infections, for example. Sometimes pathogenic strains can invade the bloodstream and, like the paratyphoid organism, can result in infections in joints, testes and ovary (which can produce dead-in-shell embryos -- black eggs), "going light", sudden death in youngsters or old birds, etc.. Some of the more useful treatments of E. coli infections include Baytril, amoxicillin, cephalexin, and trimethoprim/sulfa. Vetisulid seems to be much less useful than it used to be, likely because of overuse.