Salmonellosis in pigeons or paratyphoid is an infection caused by the bacteria Salmonella typhimurium variety Copenhagen. This disease of pigeons fundamentally affects pigeons or immunocompromised adults, which may suffer a clinical picture with variable signs depending on the affected organ. Birds that recover spontaneously often become asymptomatic carriers that intermittently excrete the bacteria and are a source of infection for the rest of the loft.
If you are interested in learning more about the symptoms of salmonellosis in pigeons and their treatment, don't miss the next article in our site where we explain the most important aspects of this disease.
Symptoms of salmonellosis in pigeons
Salmonella in pigeons enters the body orally On reaching the intestine, it colonizes the epithelial cells or enterocytes, provided that the microbial flora allows it, since on many occasions the flora acts as a barrier preventing the colonization of Salmonella. Once inside the enterocytes, the bacteria multiply and pass into the blood (bacteremia) to reach other organs.
Adult birds and immunocompetent develop some degree of immunity against Salmonella, which means that the disease evolves chronically in these individuals, remaining as reservoirs or asymptomatic carriers of the infection.
However, in immunocompromised chicks or adults that are unable to mount an effective immune response, an acute illness may occur. Depending on the affected organ, the clinical signs will vary, being able to differentiate 4 possible forms of salmonellosis in pigeons:
- Digestive Form: Characterized by enteritis with signs such as diarrhoea, anorexia, weight loss and, in severe cases, death of the bird. This presentation is frequent in pigeons.
- Joint shape: characterized by the appearance of purulent arthritis. Affected joints are hot, swollen, and painful, leading to lameness and difficulty flying. In chronic cases, the disease progresses to joint degeneration or osteoarthritis.
- Nervous form: birds show nervous symptoms characterized by tremors, paralysis and torticollis.
- Septicaemic form: this is the most serious presentation. Depending on the affected organ (lungs, liver, spleen, pancreas, sexual organs, etc.) the animals will present some signs or others. In this form of the disease it is common to see episodes of sudden death in pigeons.
Pigeons that manage to recover spontaneously from the disease, become asymptomatic carriers of the infection As we have mentioned before, the birds expel the bacteria in the form of excretion and intermittently, which is a source of infection for the rest of the loft.
Check this post about Pigeon Diseases to have more information on the subject.
Contagion of salmonellosis in pigeons
As we have already explained, Salmonella enters the body through the oral route and is eliminated through the faeces. Therefore, the main source of Salmonella infection in birds is the faeces of infected individuals. Generally, outbreaks are associated with the presence of asymptomatic carrier pigeons, which they act as a reservoir of infection in the loft.
Said c can be vertical or horizontal. Next, we are going to see them in more detail.
Transmission of vertical salmonellosis
It is the transmission of salmonellosis that occurs from mothers to chicks. It can be produced in two ways:
- Before the eggs hatch: Salmonella is capable of passing through the eggshell and causing the death of the embryo before hatching. birth or a few days after birth.
- After hatching: by feeding the chicks the mush from the crop of infected parents.
Transmission of horizontal salmonellosis
In turn, horizontal transmission can be of two types:
- Direct: by direct contact with infected animals.
- Indirect: by ingestion of water or food contaminated by faeces of infected birds or from dust in poorly ventilated lofts. Sometimes, it is the own keepers who are responsible for spreading the infection through the loft, by handling sick birds without maintaining adequate biosecurity measures.
If you are thinking of having a pet pigeon, we recommend this post on Pet pigeons: care and behavior that may interest you.
Diagnosis of salmonellosis in pigeons
The clinical diagnosis of salmonellosis is hardly relevant, since a high percentage of birds remain asymptomatic during infection. For this reason, the diagnosis is usually based on laboratory analysis, whose objective is to detect carrier birds in order to separate them from the group and prevent them from acting as a permanent source of infection.
Laboratory diagnosis includes:
- Isolation by microbial culture: the samples of choice are feces. However, it must be taken into account that Salmonella is a very poor competitor, so if a direct culture of the stool sample is performed, it is likely that the rest of the bacteria present in the stool will inhibit the growth of Salmonella. For this reason, before sowing, enrichment media that favor the growth of Salmonella should be used, so that the bacterium is in better conditions to compete with the rest of the bacteria once it is sown in the culture.
- Identification: through the biochemical profile, to find out the specific genus, species and serotype of Salmonella.
Treatment of salmonellosis in pigeons
Treatment against Salmonella in pigeons involves a major problem. Salmonella is a bacteria capable of producing multiresistance, that is, resistance to the action of antibiotics from different families, so that an inappropriate use of antibiotics can favor selection of multi-resistant strains and make it even more difficult to eliminate the infection in the loft. To avoid the appearance of antibioresistance, the antibiotic should be selected based on the results of an antibiogram Only in this way can it be guaranteed that the administered antibiotic is sensitive to the Salmonella strain isolated in microbial culture.
The infected pigeons must be kept isolated from the rest of the birds in the loft during antibiotic treatment. They will only be able to return to the loft if, after a month of treatment, the analyzes are repeated and it is verified that the treated pigeons are free of Salmonella.
In addition to antibiotic treatment, it is advisable to administer vitamin complexes and immunostimulants to accelerate the recovery of the birds.
Prevention of salmonellosis in pigeons
The prevention of this pigeon disease is based on the following points:
- Vaccination: using an inactivated vaccine. In general, vaccination is only recommended in those lofts that suffer continuous outbreaks of salmonellosis, since adverse reactions may occur after inoculation (nodules at the point of injection, decreased sporting or productive performance, even death of the birds at 24 hours). of inoculation). Only he althy adult pigeons should be vaccinated, preferably before or after molting and outside the breeding period.
- Cleaning and disinfection of the lofts: a high level of hygiene must be maintained in the lofts, carrying out good cleaning practices and applying DDD (disinfection, disinsection and rat extermination) programs. Facilities that are well ventilated, sunny and isolated from other animals that may be reservoirs of the disease are essential factors to keep the loft free of salmonellosis.
- Water and feed control: it is convenient to analyze the water inlet and outlet of the loft to check that the water supply and the flock of birds are free of Salmonella. Likewise, bacteriological controls must be carried out on the feed to ensure that it is not contaminated. Additives such as propionic or formic acid can also be used, which prevent the colonization of the feed by Salmonella.
