All Cooped Up: Erysipelas
Erysipelas is found worldwide and most commonly affects turkeys.
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What is it? An acute zoonotic bacterial infection is seen most often in turkeys.
Causative agent: Erysipelothrix rhusiopathiae
Incubation Period: A few days.
Disease Duration: Short; infected birds will die quickly or recover.
Morbidity: Can be as high as 50%.
Mortality: Usually less than 15%, but it depends on vaccination status and how quickly interventions are made.
Signs: Sudden death, especially after artificially inseminating a flock. Other signs are listlessness and loss of balance, but there may be no clinical signs other than death.
Diagnosis: Must be done through a laboratory.
Treatment: Antibiotics with veterinary assistance and vaccination for prevention.
Erysipelas is found worldwide and most commonly affects turkeys. The bacteria live in areas high in nitrogen, so poultry droppings in bedding is an ideal breeding ground. Bacteria enter the bird through wounds in the skin or mucous membranes or ingestion. Fighting, picking, and artificial insemination in birds like broad-breasted turkeys are risk factors for contracting erysipelas because they potentially create lacerations.
Cannibalism may also lead to infection, especially if the birds eat a deceased bird carrying the bacteria. According to Merck Veterinary Manual, there is also some evidence that biting insects can serve as a vector for this infection. Red mites can carry this disease and may pass it between birds.
Erysipelas has a very sudden onset. After the pathogen enters the body, it frequently leads to septicemia, systemic infection in the blood. Once bacteria toxins enter the bloodstream, the bird may have diarrhea, weakness, and loss of appetite. Death generally follows shortly after. If the birds start showing clinical signs, they usually end up passing.
Sometimes the first sign that a flock has erysipelas is that individuals start suddenly dying. An assumptive diagnosis can be made if birds, particularly turkeys, start dying a few days after artificial insemination. Rarely, a flock can carry a chronic infection of this disease. It isn’t common, but the signs of this are swollen snoods and hocks, darkened areas on the skin, and lesions found during a necroscopy.
An official diagnosis of erysipelas requires a lab. Isolation and detection of E. rhusiopathiae, the causative bacteria, can be challenging, and the lab will need a sample of liver, spleen, cardiac blood, or bone marrow.
Once officially diagnosed, the remaining birds will need to be treated concurrently with vaccination and antibiotics. Since erysipelas can affect many different species, there are multiple types of vaccines available. For the health and safety of your flock, only use ones approved for turkeys.
Birds who already have contracted the disease and have recovered will have some level of immunity. However, the vaccine is still a beneficial booster and will reduce the chances of reinfection. Additionally, not every bird in a flock may currently be carrying the disease; therefore, mass vaccination will protect them from becoming infected.
Both live and inactivated vaccines are available. You can give individual birds injections if the flock is small enough or administer live vaccines in the drinking water with another dose given in two weeks. Inactivated vaccines for erysipelas don’t offer lasting protection and may require more doses every four weeks. Breeders in high-risk situations typically dose turkeys with the vaccine every four weeks until egg production begins.
Rapid-acting penicillin is the antibiotic of choice for an acute erysipelas outbreak. The bacteria are susceptible to the drug, and the birds need immediate intervention due to how quickly this disease kills. It is key to work with a veterinarian during antibiotic administration. Underdosing can cause spotty coverage and lead to increased losses.
The most effective route of antibiotic administration is via injection. A secondary route is dosing through the drinking water for four to five days. Giving the penicillin through water reduces its effect on the flock because it only reaches birds who are still interested in eating and drinking. It may not be administered in a high enough dose to be as effective as needed.
Prevention is important. Excellent biosecurity is vital for flock management, especially in high-risk areas or with birds requiring artificial insemination to reproduce. Keeping their living space clean from droppings and prophylactic vaccine administration will significantly reduce the risk of a flock contracting erysipelas.
If an outbreak occurs, attention to aftercare will help prevent future losses as well. Prompt removal of any carcasses is huge because healthy birds may become infected if they’re picking at the body. Equipment needs to be disinfected, and the living area should be tidy.
Erysipelas is a zoonotic disease; therefore, anyone who handles the infected birds or equipment is at risk of contracting the disease. Just like with turkeys, it enters the body through cuts in the skin. It is a common disease in people and often far less deadly, but it is painful and requires medical care.
In general, but particularly in the case of a known zoonotic disease, owners should wear gloves when handling sick birds, providing medical care for them, or cleaning and disinfecting the area. Any wounds need to be covered entirely, and hands must be washed thoroughly and frequently with soap and hot water. People with many breaks in the skin or those who are immunocompromised should not be handling sick animals.
All Cooped Up is a new feature, profiling poultry diseases and how to prevent/treat them, written as a collaboration between medical professional Lacey Hughett and University of Pennsylvania poultry specialist Dr. Sherrill Davison.
Originally published in the October/November 2021 issue of Backyard Poultry and regularly vetted for accuracy.