Prevention, Control & Treatment of Salmonella
The Prevention,Control,& Treatment Of Salmonella (Paratyphoid) Infections In Racing Pigeons
Author: John Kazmierczak,D.V.M. West Trenton, New Jersey
Salmonella (Paratyphoid) infections are one of the most frustrating and difficult problems encountered in pigeons and often occur in the best managed lofts.
The signs pigeons exhibit can be subtle, dramatic, chronic or acute (sudden).
Some of the signs are sudden death, swollen painful joints, crop stasis (fluid filled crop) weight loss, lethargy, decreased fertility, sterility, failure of eggs to hatch, dying in the shell, clear eggs, black eggs, laying erratically or just one egg, abnormally shaped eggs, blindness in one or both eyes, anemia, young birds dying in the nest, neurological signs, failure to thrive, mucousy droppings, unhealthy feel of the pigeon’s muscles (soft, weak), pigeons that smell bad, susceptibility to other diseases, loss of performance, droppings and clumps of feces stuck to the rectal area, etc.
Additional clinical signs that should be added pertaining to eye diseases with salmonella are glaucoma, uveitis (Inflammation of the colored part of the eye), cloudy eye, secondary cataracts, blepharospasm (squinting or sensitivity to light or a painful eye).
Sometimes the eye will change color after recovering to a dull or more pale color. This maybe a permanent change.
Basically, clinical signs reflect whatever organ system the salmonella bacteria invade. Post mortem examination can reveal abscesses In whatever organ system has been invaded. Typical sites are liver, spleen, bowel, pancreas, brain, and reproductive organs. These abscesses (and occasionally the salmonella organism) can be seen either gross (to the naked eye) or under the microscope (histopathology).
Finding and identifying the salmonella organism can be difficult, but some of my best results have been through culture of the blood, bone marrow, spleen, and liver. Sometimes one will culture E.coli, but the true source maybe an underlying salmonella infection.
It appears here in New Jersey most commonly during the cold damp months (possibly related to rodent activity). Often, It occurs in hens, but both sexes and any age can show signs. It can have a waxing and waning course whereby, it may disappear then return after a season or two. My clinical Impression is that certain families of racing pigeons appear more hardy or resistant to infection and conversely, others seem more prone to infection. Inbred families that are hybridized (again my clinical impression) with other inbred families, appear to me, to be more disease resistant.
The continual movement of pigeons throughout the country and the world may aggravate the problem. My experience has been that it takes time and some cost to solve or control the problem and one has to be eternally vigilant. It seems that one needs to work through the
problem, by a series of measures that added together help considerably in control and treatment of outbreaks. In severe cases, it may take months or years to really control the problem.
Treatment and control measures mentioned have been:
Improved management to reduce stress, such as reducing numbers of pigeons, dry, sunny lofts, cleanliness, etc… The application of sodium acid sulfate and other safe acidifying agents to the loft floors, nests, and perches. Baytril (Enrofloxacin-a Fluoroquinolone antibiotic) and other antibiotics. Isolation and treatment of new pigeons with appropriate antibiotics. The use of Mannan Oligosaccharide (BioMos(r)) or fructooligosaccharide. These prevent salmonella from binding to the intestinal wall and entering the body of the pigeon. Probiotics. Water Acidification (4-WayAcid Pak(r)), apple cider vinegar, lactose (whey), etc. Selecting and breeding for disease resistant stock Rodent Control – mice and rats carry and spread salmonella
A recent article In Avian Pathology (Taylor & Francis, Issue: Vol. 31, Number 4/Aug. 01, 2002, pgs. 393-397) discusses the prevalence of antimicrobial resistance among pigeons isolates of various bacteria (salmonella typhimurium), stated;
“Thirty-three Streptococcus gallolyticus, 60 Eschericha coil and 18 Salmonella enterica serotype Typhimurium var. Copenhagen strains isolated from homing pigeons (Columba livia) were tested for susceptibility to the antimicrobials most commonly used to treat pigeons. Minimal inhibitory concentrations were determined using the agar dilution technique. Aminoglycosides (gentamicin and kanamycin), trimethoprim and flumequine were relatively inactive against the streptococci tested. Acquired tetracycline resistance amounted to 85%, and lincomycin and macrolide (erythromycin) resistance to 48 and 45%, respectively. Fluoroquinolone (enrofloxacin) resistance was found in four S. gallolyticus strains. All strains were susceptible to ampicillin. With the E. coli strains, resistance was found to all antibiotics tested. Over one-half of them were resistant to tetracycline and to broad-spectrum penicillins (ampicillin); however, none showed extended spectrum b-lactamase activity, implying that the cephalosporins (ceftiofur) remained active. Resistance to trimethoprim, aminoglycosides and fluoroquinolone ranked next. In contrast to the S. gallolyticus and E. coli strains, the S. enterica strains were susceptible to all antimicrobials tested.”
This increasing antibiotic resistance emphasizes the need for proper and judicious use of these medications. Indiscriminate, random use without proper diagnosis and proper dosage and length of therapy, which is common In pigeon racing, is likely to result in greatly reduced efficacy of these drugs in the future.
Another approach is specifically the use of autogenous bacterin, which our vaccine is.
The use of Salgard(r) as a feed additive, may also be helpful. In addition to being less costly, it also provides for the possibility of broad-spectrum antimicrobial control without causing drug resistance.
This product is not approved for use in pigeons at the present time and has not been approved by the FDA. We can only hope it may be of help by drawing on work done in the poultry Industry. Limited use in my own loft has shown no side effects. However, since it has worked well in poultry, and because we often need to extrapolate pigeon medicine from the poultry industry; I feel that It deserves some consideration.
The following are excerpts taken from the manufacturer’s handout on Salgard(r). I would urge all pigeon flyers to review and consider its potential value. One would have to use it at his own risk. Discussion with a manufacturer’s representative revealed that it is unlikely to cause any problems with pigeons.
It could be of potential use in large breeding stations or for those individuals, who import large amounts of pigeons that need to be quarantined and medicated, prior to introduction into one’s colony. Since salmonella can persist a long time in the loft, Salgard(r) can also be applied to perches, nests, and loft floors to kill organisms in the local environment. Its low cost and probable (but not proven) safety may be of help in our continual struggle to keep our pigeons healthy.
Note: Anyone interested in more information regarding Salgard(r) may contact John Kazmierczak, DVM, at 609-771-0995.
“Avian Salmonellosis – A Review”by Dr. Kapucicals
Salmonellosis” is a term used to describe infection with any organism of the salmonella group other than S. pullorum (Pullorum Disease) or S.gallinarum (Fowl Typhoid. In some areas the name of the serotype is used, such as Typhimurum Infection.
There are over 2,000 serotypes in the Salmonella group, many of which have already been isolated in poultry, and new ones are being constantly identified. Different countries seem to have specific strains associated with their own poultry industry. These become established in an area, breeding flock or hatchery and give rise to a number of disease outbreaks.
Incidence and Importance
Many of the known serotype do not result in either humans or poultry. However, consumer pressure is such that any Salmonella is thought to be a major problem.
It is often difficult to assess the exact incidence of salmonellosis in poultry since, in most cases, mortality is so low that specimens are not submitted for veterinary investigation. In such cases it is easy to believe that there is no Salmonella infection at all. Mortality from the rarer and more exotic strains is usually only around 23%, but once other diseases become superimposed, a significant increase in mortality can take place.
The invasive nature of Salmonella organisms means that they may be absent from the gut, as assessed by routine cloacal sampling, even though they can be present in the liver, spleen, ovaries or egg contents.
Salmonella infection rarely causes clinical disease In chicks over 3 weeks of age and even then mortality may only be high when other adverse conditions are present. Unfortunately however, a high proportion of survivors are likely to remain as carriers and become “symptomless excretory.” If these birds are used as breeders, they will continue the cycle of Infection.
In Europe up to 20% of birds are known to be carriers of Salmonella organisms and the figure could be as high as 4o% in the USA. There is every reason to suspect that this is the case wherever poultry is reared intensively.
Cycle of Infection
In most cases, with the exception of the duck, infection is carried on rather than in the egg. Carriers are intermittent fecal excretory and the organism contaminates the outside of the shell either during the passage through the cloaca or by soiling with feces alter laying.
The organisms can then penetrate the pores of the shell (especially as the egg cools) and set up infection of the embryo with further infection being transmitted at hatching or during brooding. Most outbreaks of salmonellosis arise from infection via contaminated eggs of infected breeding stock.
Lateral infection does occur from other sources such as rats and mice and wild birds. However, the most common external sources of infection by exotic serotype are water, feeds and feedings stuffs entering the food chain.
Symptoms of Salmonellosis
In chicks and turkey poults symptoms are very similar to those of Pullorum Disease, i.e., sleepy appearance, huddling, loss of appetite. “pot bellied” appearance and white chalky diarrhea. The conditions can only be definitely differentiated by bacteriological examination. In ducklings a fairly common symptom is that immediately after drinking the birds keel over backwards. Hence it was once known as Keel Disease.” Mortality varies widely from only a few deaths to the majority of the chicks hatched.
As in Pullorum Disease, postmortem examination reveals no constant nor characterized lesions, although in older chicks of 2-3 weeks the liver may be enlarged and show area of congestion and possible hemorrhage. The caecal tubes are often filled with yellow discharge. Diagnosis can only be done by isolation and identification of the causal organisms by bacteriological examination
However well this is done, there is always the risk of reintroducing infection through infected feeding stuff. Much can be done to minimize this by feed manufacturers using only reputable sources of feed ingredients and by contact monitoring of their quality. Pelleting at high temperatures has been shown to eliminate Salmonellae from
previously infected feeds. However, this is not always possible or desirable (such as for breeder feeds).
Feed mills present many areas for harboring Salmonellae such as storage silos, conveyors, elevators, coolers and packing lines. Even after taking all possible precautions within the feed mill to avoid
Contamination, once the feed leaves the premises; there are many opportunities for reinfection to take place, such as bulk delivery vehicles, storage silos, sacks and feeding systems.
As previously described, birds can easily become infected from their environment, primarily because of picking up contaminated feces from other carriers who may not be showing symptoms of infection.
Treatment & Prevention
The fact that Salmonella species are found in all areas of animal production means that total elimination Is almost impossible and the main objective should be minimization.
Because of its invasive nature, once a Salmonella infection is firmly established within the bird, the only successful treatment to-date has been to medicate with furazolidone to its soluble counterpart furaltadone for a period of 7 days or so. This has been shown to reduce mortality if given early enough in the outbreak. However, surviving birds may become carriers and so must not be used as breeding stock.
Prevention is far better than cure. Through hygiene programs with the use of a long acting chemical treatment of the poultry feed is the only way to minimize the spread of the infection.
Organic acids are known to have a strong antibacterial effect. However, if the volatile free acids are used, these are likely to be lost through the heat of processing very quickly. Salts of these acids are more stable and are not lost so easily, but they do not have such a high initial kill rate of organisms. The salts do, however, dissociate over a period of time, given the correct conditions, so releasing the free, volatile acid to work over the long term. The ideal product would be a blend of free acids and acid salts on a suitable carrier that will protect the feeds from the point of mixing, through the feed mill, onto the farm and into the bird.
The ideal product is on the market at the moment – Salgard from Optivite. If used correctly in naturally contaminated feeds, Salgard begins to work immediately and gives a thorough bacterial kill in 48 hours and is the only product able to give continuous protection, thorough protection of the bird and so prevents reinfection by the methods described above.
Salgard offers the additional advantage of positive mold control to prevent mold growth, mycotoxin production and loss of feed value.
Salgard’s success has been based on laboratory trials using approved protocols and supported by large-scale animals trials. Most of the large integrated poultry concerns in the United Kingdom now specify the use of Salgard in their feeds ad currently around 750,000 breeders are protected by it.
Salgard kills over 50% of target organisms in 1 hour and achieves its full potential in 24 hours. Salgard is safe to use due to its neutral pH and is non corrosive to machinery. Salgard does not impair palatability or feed intake. Salgard protects feed nutrients and improves its energy value. This unique enhancement of feed value provides microbial control in the most cost effective way. Salgard is available in powder or liquid form giving complete flexibility. Both forms may be used on Optivite’s hygiene programs and the liquid can be used to spray into housing and onto litter.
Synergistic blend of carboxylic acids and their salts designed and processed for optimal antimicrobial activity.
Mode of Action
Free organic acids have a strong antibacterial and antifungal activity. The unique formulation ensures that the equilibrium favors the undissociated neutral molecule, which is most effective in traversing the electrical gradient across the cell wall.
Intracellular anion accumulation disrupts macromolecular synthesis and the ability of the organism to multiply.
The primary volatile components, benefiting from maximal synergy, give a very high initial kill rate of organisms within the feed or feed ingredient. Secondary volatile released over time ensure a long acting effect – important as feed travels through the feedmill, delivery
vehicles, silos and farm equipment – all potential areas of recontamination by pathogens.
Under simulated crop conditions, where Salmonellae are multiplying rapidly, Salgard acts quickly, killing 94% of the organisms in under 4 hours and completely eliminating Salmonellae in 24 hours.
Salgard did not render the mixture sterile, but allowed a profuse growth of other beneficial bacteria to develop.
Salgard completely sterilized the “crop” contents after 24 hours. This is undesirable since it can lead to digestive problems and cause feed rejection.
Salgard demonstrated an ability to selectively eliminate Salmonellae whilst allowing other bacteria to multiply. Hence, crop function is unlikely to be impaired.