Brucellosis

Root Cause


A zoonotic disease of the reproductive tract which may cause abortion in females, infection of the sexual organs in males, and infertility in both sexes. The disease can also cause non-reproductive problems. It is caused by the bacteria Brucella canis, facultative intracellular gram-negative cocco-bacilli, non spore forming, non-mobile and non-capsulated.



Affected Organs


It targets reproductive or steroid sensitive tissue mainly but other body systems can be affected by the bacteremia such as the intervertebral disks, and kidney or form antigen–antibody complexes in the anterior uvea of the eye.
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Historical Backgorund


Brucellosis was first known as Malta fever, the disease and was discovered by British medical officers in the 1850s in Malta during the Crimean War. The relationship between organism and disease was first recognized in 1887 by Dr. David Bruce. Then, In 1897, DanishveterinarianBernhard Bang isolated Brucella abortus as the agent; and the additional name Bang's disease was given to the disease. In 1905, Maltese doctor and archaeologist Sir Themistocles Zammit discovered that unpasteurized milk was as a major source of the pathogen. The disease has since been found in cattle, sheep, humans, goats, pigs, elk and canines and is now known to be contagious and causes spontaneous and infectious abortions. In the 20th century, the disease was named after Dr. Bruce as brucellosis but over the years has been referred to by many different names. It’s a worldwide disease and is considered a re-emerging zoonosis (Wilkinson, 1993).

Common Symptoms


Clinical signs may vary from asymptomatic to mild. Fever is uncommon because there is no endotoxin to induce a fever and a CBC is usually normal but lymphadenopathy can be present because of the reticuloendothelial cell stimulation and can result in some spleen and liver enlargement. Signs may include weight loss, dull coat, and lethargy. More severe symptoms include thoracic or lumbar diskospondylitis, endopthalmitis and uveitis caused by immune complex deposits in the eye. In female dogs, abortion usually happens 30-50 days of normal-partly autolyzed pups, or stillborn pups. In male dogs, include infertility as well as epididymitis, orchitis, and scrotal dermatitis that results from scrotal licking due to orchitis. In addition, testicular atrophy and azoospermia may be seen and up to 90% sperm abnormalities, head to head sperm agglutination, sperm phagocytosis, and PMN's and monocytes in the semen.

Standard Treatment


Brucellosis can be tested for using serology tests such as rapid slide agglutination or RSAT tests, tube agglutination, indirect fluorescent antibody test (IFA), agar gel immune-diffusion and enzyme-linked immunsorbent assays (ELISA). Due to intracellular localization of Brucella, it can easily adapt to environmental conditions and therefore extremely hard to treat. The most successful current treatment protocols include a combination of a tetracycline drug, like tetracycline hydrochloride, doxycycline, minocycline, and

streptomycin over a three month time span. Also proper sanitation of the environment and spaying and neutering infected dogs has been recommended for the best control methods. Euthanasia of infected dogs is also recommended depending on the situation. In some dogs, the disease seems to be self-limiting.

References

Medicine, I. S. (2012). Canine Brucellosis: Brucella canis. The Center for Food Security and Public Health Iowa State Univeristy , p.1-4.
Megid, J., Mathias, L. A., & Robles, C. A. (2010). Clinical Manifestations of Brucellosis in Domestic Animals and Humans. The Open Veterinary Science Journal , vol 4, p. 119-126.
Seleem, M. N., Boyle, S. M., & Sriranganathan, N. (2010). Brucellosis: A re-emerging zoonosis. Veterinary Microbiology , vol 140, p. 392-398.
Wilkinson, Lise (1993). "Brucellosis". In Kiple, Kenneth F. (ed.). The Cambridge World History of Human Disease. Cambridge University Press).