CHLAMYDIA IN CATTLE REPRODUCTION

Abstract

Well-run reproduction, both in beef and dairy herds, determines the profitability of
production. Knowledge of the factors affecting the reproduction of cattle allows you to
undertake procedures to prevent or reduce their adverse impact. In addition, in the case of
disease agents with zoonotic potential, knowledge about them determines the safety of
personnel working with cattle on a daily basis – breeders, veterinarians. An example of such a
factor is bacteria from the Chlamydiaceae family, gram-negative microorganisms found in
many animal species as well as in humans. For cattle, the most pathogenic are C.abortus,
C.pecorum and C.pistici. The disease has been known for a long time, but its role in cattle
breeding is still underestimated. The results of monitoring studies conducted in different
countries differ quite significantly from each other, and the obtained results indicate
prevention from 0.4% through 4.44% up to 100% of the examined herds. Different species of
Chlamydia cause different forms of disease. Chlamydia abortus is mainly associated with
pathologies in the genital organs, abortions, embryonic death, metritis and mastitis. In
addition to abortions, it can cause dead calves to be born at the right time or weak newborns
that die within a few days for unspecified reasons. In the subclinical form, it may be
responsible for lower fertility rates and high somatic cell counts. Epididymitis and alveolar
gland inflammation may occur in bulls. Chlamydia pecorum, in turn, is more pathogenic for
calves, causing inflammation of the intestines, brain and spinal cord, joints, lungs, cornea and
conjunctiva, and kidneys. However, this division is not very rigid, as there are cases of
obtaining positive results from vaginal swabs towards Ch. abortus of several-week-old calves.
Ch. psittaci is extremely rare in cattle, but it can be responsible for abortions and pneumonia.
Long-term antibiotic therapy with the use of tetracyclines, macrolides and fluoroquinolones
brings some results in the form of alleviation of clinical signs associated with the presence of
chlamydiosis in the herd. However, it does not reduce shedding and may lead to latent
infections. In order to reduce the disease, the focus should be on maintaining an appropriate
standard of hygiene and biosecurity. Separating infected animals, removing aborted fetuses
and quarantining newly introduced animals are the basic elements of the fight against this
disease entity. Unfortunately, there are no vaccines against chlamydia registered for cattle
available on the Polish market. However, when using a pharmacological cascade, a
preparation available for sheep, providing protection against Ch. abortion. The combination
of vaccination, appropriate maintenance and hygiene conditions, and biosecurity make it
possible to control chlamydiosis in dairy and beef cattle herds.