Deer hunters, dairy farmers and nonpasteurized milk drinkers can develop signs of bovine tuberculosis, a zoonotic disease (passed from animals) transferred mainly from cattle and white-tailed deer. A bacterium called Mycobacterium bovis passes from the unpasteurised milk of an infected cow or the undercooked meat of an infected deer to humans and causes the disease, states the Indiana State Department of Health. Modern eradication programs in the United States reduce the disease in domestic cattle, but pockets of tuberculosis are still seen in some wildlife populations. The symptoms of bovine tuberculosis resemble those of human tuberculosis, with a few noted differences.
Other People Are Reading
According to the Center for Food Security and Public Health at Iowa State University, "tuberculosis is usually a chronic debilitating disease in cattle, but it can occasionally be acute and rapidly progressive." The early phases of the infection are often asymptomatic, with clinical signs normally showing only in the latter stages of the disease; these symptoms may take several years to develop.
Typically, cattle will become increasingly emaciated and unwilling to eat. They may present with a low-grade fever and ongoing weakness. If the bacterium travels to the lungs, the cows may develop a moist cough that worsens after exercise or during cold weather. Their breathing may be laboured or faster than normal. When the digestive tract becomes involved, cattle will show symptoms of diarrhoea and intermittent constipation. Animals suffer extreme emaciation and respiratory distress as the disease enters the terminal stage. Some of the lymph nodes under the cow's jaws may become so inflamed that they rupture and drain. Enlarged lymph nodes will obstruct airways, some blood vessels and possibly the digestive tract before the animal succumbs to the disease.
Medical professionals label infections of bovine tuberculosis in humans either as "latent infection" or "active disease." The California Department of Health Services says that "people with bovine TB [tuberculosis] 'infection' have the germ that causes TB in their bodies, but they do not feel sick and they cannot spread the germs to anyone else." This is similar to the early stages of tuberculosis in cattle.
Once the infection develops into bovine tuberculosis "disease," patients begin to feel sick and can spread the disease to others. Symptoms include fatigue, low-grade fever, lack of appetite and unexplained weight loss. Patients may also experience chills and intermittent night sweats. Since tuberculosis normally affects the lungs, humans will cough up blood--sometimes for weeks at a time--and feel chest pain when breathing or coughing.
Other parts of the body may be infected, and symptoms vary according to which organ is involved. Tuberculosis of the kidneys might result in blood in the urine and lower back pain, while tuberculosis of the spine or brain can present as pain in the limbs and/or ataxia (inability to coordinate movement).
In Other Animals
Other animals, both domesticated and wild, can contract bovine tuberculosis. Iowa State reports that in the United States, bovine tuberculosis has been seen in white-tailed deer, sheep, pigs, dogs, cats, horses, ferrets, elk, foxes, coyotes and opossums. Disease symptoms in most animals include the same as seen in cattle: weight loss, lung involvement with coughing and painful breathing, and enlarged lymph nodes.
Domesticated cats present with different problems. Along with the respiratory and intestinal issues seen in other animals, cats have symptoms of ulcerous skin infections, usually on the neck and face. The ulcers may become draining fistulas (holes) and deformities on the bridge of the nose or forehead that devastate the facial bones. Tuberculosis sometimes travels to the eyes of the cat, causing retinal detachment and blindness. The iris thickens, the cornea becomes red and inflamed, and the cat will develop abscesses in the tissues around the eye.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for