This
title implies failure of squabs to survive early in
their lives. The earliest we can consider is when they
are still in the shell. Death can occurr early on in
development, or at-or-near hatching time. The other
failure to survive occurrs in the first few days of
life after hatching.
These
deaths, when other than random, suggest an infection
which overcomes the chick. These infections can occurr
in the egg, where the developing squab becomes infected
either by bacteria incorporated in the egg, or more
commonly from bacteria penetrating the egg shell.
The typical black egg which when opened shows some
decomposing fetal material, is typically from an early
overwhelming infection. Other infections occurr when
the egg becomes infected later in development or when
the infection progresses slower, not overcoming the
developing squab, but weakening it severely.
In the latter, the squabs die just before or during
the pipping. The hatching requires a large effort
by the encased baby. When weakened by infection, it
becomes unable to put forth this effort and dies.
These babies, when examined closely, are seen to have
not absorbed all of their egg sacs; this being another
clue to a retarded development.
Squabs
that die after hatching frequently appear to have
been trampled by their parents. They have been trampled,
but only because they have perished first. They are
unable to vigorously feed or otherwise thrive.
When
we see an inordinate number (an epidemic) of this
we suspicion paratyphoid because of the statistical
odds that salmonella is the pathogen. We also know
that other bacteria can cause similar syndromes.
These other bacteria, in what I believe is the frequency
of occurrence, are Pseudomonas spp., Proteus spp.,
E.coli, Klebsiella spp., and Citrobacter spp. Of these
Pseudomonas can be the most difficult to treat because
it is notoriously resistant to many antibiotics.
When
it becomes pandemic, i.e. involvolving virtually all
of the babies one must think of loft contamination.
Loft contamination implies that the numbers of bacteria
in the loft environment has become so high that it
is virtually impossible to escape infection, especially
by the most susceptible.
This happens because of prolonged periods of high
humidity and mild to warm temperatures. This allows
the bacteria to flourish in the enriched environment.
We all know that dryness and very cold work against
bacterial growth, and the opposite promotes their
growth. With any infection an infective dose of bacteria
is needed, so the higher the numbers of bacteria in
the environment the easier it becomes for the infective
dose to be achieved.
So
what can one do? If one suspicions paratyphoid it
is frequently necessary to break up the couples and
treat vigorously (with Baytril or Saraflox) for at
least 10 days and vaccinate the breeders WHILE they
are on the antibiotic.
For the other bacteria, look first at loft contamination.
If this does not seem to be a reasonable cause, then
treat as with paratyphoid. If it appears that we may
be dealing with loft contamination, remove all litter
and nesting material, clean the loft thouroughly and
disinfect it. Use only clean dry nesting material
and work to eliminate dampness.
If the birds are to continue to feed babies and reproduce
during treatment, do not vaccinate (this will make
them neglect their eggs and babies), and treat with
an antibiotic which is safe to use during reproduction
such as Amoxicillin or Cephalexin.
Ideally,
cultures can be done on these casualties before further
contamination. Here we can determine what we are dealing
with and which antibiotic will give us success. Several
specimes to culture reveal much more information than
culturing a single one.
Dr.
David E. Marx D.V.M.