Friday, December 4, 2015

The Truth About Getting Sick with Salmonella

"People get sick from Salmonella because they have no immunity to it. Getting Salmonella will help build my immunity to Salmonella so in the future I won't get sick from it."  - Statement posted as a reply to a post on the Chicken Whisperer Facebook page on October 17, 2015.

Getting an infection with Salmonella does not mean you will never get an infection with Salmonella again. Some immunity may be formed after infection with the germ, but it may not be effective if you subsequently receive a high dose of the germ and immunity may not last your whole life.  Also, there are many different types of Salmonella that can make you sick, so it is possible you may not get infected by the same type. Salmonella can cause serious illness or even death. Children younger than age 5, people older than 65, and those with weakened immune systems are at a higher risk for serious infection. Advice from CDC to help prevent getting sick with Salmonella can be found at:

Answer provided by Megin Nichols, DVM, MPH, DACVPM
Enteric Zoonoses Team Lead
Outbreak Response and Prevention Branch
Division of Foodborne, Waterborne and Environmental Diseases
National Center for Emerging and Zoonotic Infectious Diseases

U.S. Centers for Disease Control and Prevention

Thursday, December 3, 2015

The Truth About Pumpkin Seeds

"Pumpkin seeds are a natural dewormer in chickens." AND/OR "Pumpkin seeds prevent worms in chickens."  - Statement(s) found on multiple Facebook chicken groups posted on November 28, 2015.

After a search of the literature and talking to other veterinary colleagues, I can definitively state that there is no scientific evidence to support this claim.  While anecdotally one or more people may have noticed an effect, it is important to recognize that in order to definitively determine the beneficial effect of any potential medication or supplement controlled scientific trials are essential to determine their efficacy.  Specifically, we would need a controlled flock of birds with worms; half of the flock would be given the pumpkin seeds and the other half of the flock a sham or placebo.  Next, the worm load would be determined and if there was a significant difference between the two groups you could start to consider the potential beneficial effects.

Obviously, people observe things anecdotally and draw conclusions from their observations.  However, we need some level of scientific rigor to validate anecdotal claims.  Science is slow and tedious.  Things like repeatability, dose effect, and other types of "confounding" factors make results challenging to interpret.  Simply stating that pumpkin seeds are a natural dewormer is not good science or medicine in my opinion.

Answer provided by Maurice Pitesky DVM, MPVM, DACVPM
Veterinarian/Assistant Specialist in Cooperative Extension
Poultry Health and Food Safety Epidemiology
School of Veterinary Medicine
University of California

Wednesday, May 6, 2015

The Truth About the Withdrawal Period for Wazine

"The egg withdrawal period for Wazine is two weeks."  - Statement found on a Facebook chicken group posted on May 5, 2015.

The two-week Food and Drug Administration approved label withdrawal time for Wazine® is specifically for meat, not eggs, and only for chickens (and turkeys) to which the drug is administered according to label instructions. There are two main reasons why this withdrawal time cannot be directly extrapolated to eggs from backyard chickens.

1. The disposition of the active ingredients, i.e. the rate at which they distribute to and deplete from meat and eggs, may differ. This can result in higher drug concentrations in eggs, requiring a longer withdrawal time.

2. The length of a withdrawal time is proportional to the dose administered to the chicken (the higher the dose, the longer the withdrawal time needed).  The actual dose of Wazine® that a backyard chicken receives may be higher or lower than the dose on which the label withdrawal time is based. This is because the product is administered through the chicken’s water or food. When determining the label withdrawal time, the source and amount of water and food can be tightly controlled to ensure a specific dose. But backyard chickens can obtain food and water from different sources, and their intake varies depending on several physiological, environmental and behavioral factors.

The use of a product like Wazine® in backyard egg producing chickens constitutes extra label use, and should therefore occur under the guidance of a veterinarian, who is responsible for ensuring that the withdrawal time is adequately extended to account for differences in drug dose and disposition.

Answer provided by scientists at the Food Animal Residue Avoidance Databank (FARAD)

Monday, May 4, 2015

The Truth About Salmonella

"You only get salmonella from chickens that are sick with it themselves. You would typically notice a salmonella problem in your flock."  - Statement found on a Facebook chicken group posted on April 30, 2015.

Salmonella can come from multiple sources, not just chickens.  You can get it from fruits and vegetables, as well as from your flock.  Cross-contamination in the kitchen is also another way to get sick with Salmonella, or any other bacteria for that matter.  If you do not keep certain foods refrigerated and then undercook the food,  then that is yet another way to get sick with Salmonella.  The blame is not always on the chickens!  Salmonella has lots of ways to get into us if we do not know how to safely handle foods in the kitchen.

Now that that is out of the way, let’s talk about the chickens.  You said “"You only get salmonella from chickens that are sick with it themselves.”  That statement is correct.  Salmonella on the inside of chicken eggs typically comes from the chicken that is sick with the organism.  However, you can get Salmonella on the outside of the egg if the coop that the egg is kept in contains Salmonella.  That means another chicken could be sick with Salmonella and be spreading it around in the coop.  Dirty bedding, dirty nest boxes, dirty egg collections baskets, or other surfaces in the coop can be a source.  We all know that our chickens tend to share nest boxes, so think about it.  If the infected chicken uses the same nest box as a healthy chicken, then the outside of a good egg can be contaminated just through contact.  That is why we wash our eggs, so that the bacteria does not work its way in through the eggshell’s pores to contaminate the inside (or our hands as we crack open the eggs).

You also said “You would typically notice a salmonella problem in your flock."  This is not as accurate as your previous statement.  Salmonella has several hundred different serotypes, very few of which cause the chickens to show symptoms of illness.  Instead the chickens can become carriers of Salmonella.  That means that they randomly shed the bacteria in their feces, and their eggs, without showing signs that they were ever sick.  Salmonella is famous for this feature in humans too.  Ever heard of Typhoid Mary?  Same bacteria, just in humans rather than chickens.  The only way we know if our chickens have Salmonella is to test them regularly, because if we lapse in our biosecurity, then our chickens can pick up Salmonella at any given time.

Response provided by Dr. Brigid McCrea, Ph.D.
Associate Professor and Extension Poultry Specialist

Delaware State University