The paratyphoid organism found in pigeons is usually, but not always, Salmonella typhimurium variety copenhagen. In fact, in the experience of Dr Gerry Dorrenstein of Holland, 94% of the strains of paratyphoid organisms his group has recovered from pigeons, are variety copenhagen. This variety seems to be almost specific for pigeons, although occasionally, it has been found to cause disease in chickens.
Like other birds and animals, most pigeons exposed to paratyphoid infection recover completely, either through treatment or natural defensive mechanisms, but as in the case of other species of birds and animals, the occasional bird is unable to clear the infection, and becomes a permanent carrier. As Dr Dorrenstein points out, it is still not known just where the paratyphoid organisms hide in the body of a carrier, but he suggests that this hiding place could be within certain patrolling defensive cells called macrophages where they are protected from the immune system. (Note: "macro"means "large"; "phage" is from the Greek word "phagein", meaning "to eat"-- hence, these are large, mobile defensive cells that engulf foreign material, such as invading bacteria, parasites, yeasts etc..) It is obvious that not all engulfed foreign invaders are killed by these large cells, but in some way, the invaders remain alive and isolated within the cells that engulfed them, and here they are protected from other defensive mechanisms in the body. As a result, during periods of stress, the immune system becomes depressed and less vigilant, as a result of which, the paratyphoid organisms can escape from their hidden locations. Once they have escaped, they begin to multiply and then to be shed in droppings from which they are readily spread to other susceptible birds in the loft.

In my experience, variety copenhagen can be sensitive to an unusually wide variety of antibiotics, except in cases in which fanciers have misused these products and have induced antibiotic resistance in these organisms by underdosing the birds in the first place, or by treating for a shorter time than recommended, or both. For this reason, it is often practical to have laboratory tests run to determine the most suitable antibiotics to use.
Treatment of E. coli and paratyphoid infections is best managed through laboratory assessments of antibiotic-sensitivity tests to choose the most effective antibiotic or other anti- bacterial product. Given the general misuse of anti-bacterial products, in some cases these organisms may have developed some level of resistance to antibiotics -- hence the value of laboratory cultures and antibiotic-sensitivity examinations to ensure use of the most effective product. According to Dr David Marx of Oklahoma, USA, all of his isolations of paratyphoid organisms from pigeons continue to be sensitive to Baytril (enrofloxacin), with more than 90% of these isolations also sensitive to Amoxicillin and Cephalexin.

By contrast, Dr Paul Miller of Pennsylvania, USA, reports that his laboratory has isolated some strains of paratyphoid organisms that have developed a great deal of resistance to antibiotics, and that only Baytril seems to be effective in treating these infections. This information points up, once again, the value of laboratory cultures and an accompanying antibiotic sensitivity examination.
In general, Salmonella species are notorious for their ability to transfer from one species of animal to another. However, in the case of variety copenhagen, it seldom ever transfers to other species, and this includes humans. So, in general, the fancier who is experiencing an outbreak of paratyphoid infection in his birds doesn't have to be overly concerned that he will contract the infection himself. However, individuals whose immune system is weakened or damaged should take extra precautions. Nevertheless, for the sake of general safety, fanciers should take normal precautions with sanitation and personal cleanliness while working with an infected flock.
As an advocate of the use of friendly bacteria, also called probiotics, and associated products for a more natural approach in attempting to prevent E. coli and paratyphoid infections in our birds, I have noted that some commercial supply houses are offering products containing the sugar lactose to aid in preventing paratyphoid infections in particular. I certainly support the use of such products and others, in the fight against paratyphoid organisms, but I would offer a few words of caution on the use of lactose when fanciers are dealing with, or trying to prevent, problems caused by E. coli, and even paratyphoid.

To explain in a bit more detail, friendly bacteria such as those in yogurt or in commercially available probiotics, usually include Lactobacillus spp., along with certain species of Streptococcus, sometimes called Enterococcus, etc.. In the USA, commercial products such as PrimaLac and Benebac, among others, are available. No doubt, similar products are available in other countries around the world as well. Some of these products have been developed specifically for turkeys as well as for egg-producing and broiler strains of chickens. Dr Gary Davis of North Carolina State University, USA, has done a great deal of research on the probiotic called PrimaLac in quail, pheasants, domestic ducks, turkeys and laying hens. He reports that his results have been very positive, with the most significant effects being improvements in livability, egg size, body weight gains and immunity. The poultry grade of PrimaLac is available from Bob Adams of Star Labs (Email address : bobadams@siteone.net.)

Certainly, the best source of these bacteria for pigeons would be those derived from normal, healthy pigeons, if such products are commercially available. However, PrimaLac seems very promising indeed, especially because of the range of positive effects found by Dr Davis in several species of birds. It seems likely that pigeons would benefit similarly -- in fact, a colleague of Dr Davis, Dr Mike Wineland, has been using this probiotic on his own pigeons, and swears by it. The organisms in all of these products are believed to have at least two mechanisms of operation in the intestines. Firstly, they can multiply to very high numbers of organisms that form a protective physical barrier that may be up to 12 or more organisms deep, lining the inner surface of the intestines.

Secondly, in the low levels of oxygen in which these bacteria live in the intestines, they produce and release into their environment, lactic acid which of course shifts conditions in the intestines to the acid side of neutral. (As an aside, it is my understanding that, in some countries such as the USA at least, two basic kinds of yogurt are available, one a killed product, and the other containing live cultures of bacteria. Obviously, the product containing live cultures of bacteria is the one to choose. Check the label of the product you buy. As well, remember that because these products contain live bacteria, you must not combine them with antibiotics or any disinfectant, both of which will kill the bacteria you want to use in your birds.)

Now, E. coli and paratyphoid organisms much prefer to live and reproduce in slightly alkaline conditions, whereas in a hostile acidic environment, their numbers can drop drastically (in some studies, up to 97%). In promoting the use of such products, where practical, to reduce the heavy reliance on antibiotics to solve health problems in pigeons, I have been advocating not only the use of probiotics and a small amount of apple cider vinegar (5-10 cc per litre, or 1 - 2 teaspoons per US gallon [4 litres] of drinking water, as suggested by Dr Colin Walker of Austalia) to help acidify intestinal contents, and thereby create conditions that are hostile to the survival of E.coli and paratyphoid bacteria. While I visited Australia last year, I noted that one Sydney- based company had produced for use in pigeons, a powder containing a mix of organic acids that also would be ideal for this purpose. I am sure that other equally useful products exist also.

As well, in dealing with paratyphoid infections, I have also suggested the addition of some lactose to the drinkers, as a source of nutrient for friendly bacteria in their production of lactic acid. Lactose is the chief sugar found in cow's milk, and is available as whey powder from health food stores, cheese and milk factories, livestock feed companies, and commercial pigeon supply houses. As noted by Dr Paul Miller, one problem with the use of lactose is that birds lack the enzyme lactase, and so are unable to break down and utilise the lactose themselves. The presence of this lactose in the intestine can draw fluids from the bloodstream into the intestine, and may result in diarrhoea and dehydration that can add to that caused by the concurrent paratyphoid infection. Fortunately, paratyphoid organisms themselves aren't able to ferment lactose either, which means that they are unable to use this sugar as a nutrient in their life processes. Equally fortunate for us is the fact that the friendly species of bacteria mentioned earlier certainly will use lactose as a nutrient in their production of lactic acid.

Now here is the fly in the ointment, so to speak. It is important to understand that, although paratyphoid organisms are unable to ferment lactose, E. coli on the other hand are known to be lactose fermenters, that is, they actually use lactose as a nutrient in their life processes. For this reason then, it is my opinion that the use of lactose when E. coli infections are occurring should be avoided because this sugar simply aids these organisms to thrive and multiply in great numbers. For this reason, I would NOT recommend that lactose be used in drinkers when birds are affected with adenovirus + E. coli infections, or to help prevent E. coli problems. Yes, use lactose along with probiotics and organic acids,etc., to help prevent paratyphoid infections, but avoid the use of lactose when you are dealing with or trying to prevent E. coli problems.