Page 9 - Sep302021

Understanding Anaplasmosis Risk The Midwest Cattleman · September 30, 2021 · P9

By Bob Larson DVM
Dr. Bob Larson is Professor, Production Medicine at Kansas State University’s College of
Veterinary Medicine and Executive Director, Veterinary Medical Continuing Education.

Anaplasmosis is a serious the disease are likely to die.
disease that affects cattle in If infected cattle are able to
an increasing larger area of survive, they are not likely to
the country. A tiny organism have severe problems due to
called Anaplasma margina- the disease in the future, but
le attaches to red blood cells they remain as carriers for the
which leads to destruction of rest of their life. In some cases,
those cells and a decrease in these carrier infections can be
the ability of affected cattle continued on page 31
to carry oxygen in their blood.
If more red blood cells are de-
stroyed than the animal can
replace with new cells – the
blood becomes watery, the ani-
mal becomes anemic, and other
signs of infection can occur,
including: fever, depression,
dehydration, rapid or difficult
breathing, and yellow discolor-
ation of the mucus membranes
of the gums, around the eyes,
and the vulva.
Sometimes affected animals
become excited and aggres-
sive when not enough oxygen
reaches the brain. Young ani-
mals are often able to recover
because they can make new
red blood cells very quickly,
but older animals do not pro-
duce new cells very fast, and
they can quickly become very
anemic and have very low oxy-
gen levels in the blood leading
to severe illness or death.
Anaplasmosis is primarily
carried from cattle to cattle
by ticks, but the movement
of blood from infected cattle
to susceptible cattle can also
be accomplished by biting
flies such as horseflies, or by
human activities such as via
blood-contaminated needles,
dehorning instruments, tat-
too pliers, or palpation sleeves.
The disease has historically
been a problem in the south-
ern parts of the United States
but has now spread north so
that cattlemen in many im-
portant beef-producing areas
need to be aware of the prob-
lem. In herds that become ex-
posed to the organism, cattle
of any age can become infect-
ed, but the severity of illness
is usually mild in young cattle
and increases with age.
In cattle that become in-
fected when they are 3 years
of age or older, 30% to 50%
of animals showing signs of