I wanted to
write a follow-up post to my NPIP post. I wanted to talk specifically about the
diseases that the NPIP testing covers. I understand that not all states tests
for all four of these diseases but I am sure that if you ask they will, it may
cost a little more though. Here in Georgia they test for Pullorum, which is
what all states that test for NPIP test for, but they also test for Avian
Influenza, M.
Gallisepticum, and M. Synoviae. I personally feel that it is very
important for any person owning chickens, whether for pet, show or food, to
have the NPIP testing done. It just
gives you a little more peace of mind knowing that you have a healthy flock.
The
following is just a brief explanation of the diseases and how they affect our
birds and what can be done to treat them.
Pullorum
Disease is caused my Salmonella pullorum.
It has very high mortality rates for young birds and can also kill adults. It
was once very common but has nearly been eradicated. Transmission is through
the egg, direct and indirect contact. If the egg has been infected, via the hen
having the disease, then death usually occurs within the first few days of life
and up to 2-3 weeks after hatching. Affected chicks seek and huddle under a
heat source, don’t eat, appear sleepy and will have whitish colored droppings
caked up around the vent. Any that survive will become carriers and can pass
the disease to their offspring. There are currently no antibiotics approved to
treat infected flocks.
Avian
Influenzas (Bird Flu) are caused by orthomyxoviruses. This disease is zoonotic,
meaning that some forms are transmissible to humans. Many wild birds carry this disease in a form
that does not cause illness. Domestic birds can contract the disease from wild
birds and get extremely sick, to the point of death. Some forms have a
mortality rate of nearly 100% and can kill an entire flock in as little as 48
hours. For more information you can visit
the CDC’s page on Avian Influenza.
M.
Gallisepticum and M. Sunoviae are both Mycoplasmas. They are bacteria but they
are very unique in that they lack a cell wall and must have a rich medium containing
serum to grow. This can make them different to treat as most antibiotics work
by destroying the cell wall. They do not
live very long outside of their hosts; usually no more than a few hours or
days. They are vulnerable to most disinfectants.
M.
Gallisepticum is a chronic respiratory disease in chickens and an infectious
sinusitis in turkey. Other avian species are also susceptible to infection. It
is the most pathogenic of the Avian Mycoplasma. It is found worldwide. It can
be transmitted via direct and indirect contact as well as through the eggs of
infected individuals. The infection may be dormant in the infected, hatched
chick for days to months, but when the flock becomes stressed aerosol
transmission occurs rapidly and infection spreads through the flock. The
infection can also be carried on the clothing or boots of a person from an
infected flock to a clean flock. This is why Biosecurity is very important. In
many flocks the source of infection cannot be determined. Once infected, birds
remain carriers for life. Infected birds may show no apparent symptoms or have
varying degrees of respiratory distress, slight to marked rales, difficulty
breathing, coughing and or sneezing. Infection rates are high, but death rates
are low in uncomplicated cases. There may be nasal discharge along with
frothiness in the eyes. The disease is generally
more severe in turkey than in chickens. Infected birds may fail to reach peak
laying ability, while broilers may not gain weight as normal. Treatment with
tylosin, oxytetracycline or erythromycin is affective, among other antibiotics.
Antibiotics are usually given via the feed or water for 5-7 days. There is a
vaccine, but it must be approved for use by the state veterinarian.
M.
Synoviae occurs most frequently as a subclinical infection of the upper
respiratory track. Chickens and turkeys are the primary carriers but ducks,
guinea fowl, geese, parrots, pheasants and quail are susceptible. It can be transmitted through the egg, but
the rates are very low. The risk of transmission via eggs is greatest the first
few weeks after infection of the hen. Transmission via direct and indirect
contact is rapid. Symptoms can include slight rales, but generally no signs are
seen. Outbreaks generally occur in young birds, those about 4-6wks. The disease
can cause tendonitis and bursitis, and some birds may sit, become depressed and
generally stay close to the feeders and waterers. Swelling of the hocks and
foot pads may be evident. These symptoms are generally only seen in severely
affected birds. The mortality rate is very low, less than 10% in most cases.
Treatment is with one of the tetracycline antibiotics.
Both
M. Gallisepticum and M. Sunoviae are respiratory diseases of chickens. I wanted to point out that they have the
possibility of being transmitted through the egg, in the embryo. So you can buy
chicks or hatching eggs and possibly bring these diseases into your flock. Your
birds will be carriers for life once they have contracted these diseases. There
is a chance that when your birds become stressed they will develop the symptoms
of these respiratory diseases. There is also a chance that when you bring new
birds into your flock they will contract these diseases and may become sick.
The only way to know you are buying birds or eggs that are free of these
diseases is to purchase from those who have had the NPIP testing and come back
clean of all of these diseases. The
testing is very easy and is not expensive; I feel it should be done by anyone
interested in keeping a healthy flock.
