Transmissible mink encephalopathy (TME) is a rare sporadic

disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

that affects the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...

of ranch-raised adult

mink Mink are dark-colored, semiaquatic, carnivorous mammals of the genera ''Neogale'' and '' Mustela'' and part of the family Mustelidae, which also includes weasels, otters, and ferrets. There are two extant species referred to as "mink": the A ...

. It is a transmissible spongiform encephalopathy, caused by

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

called prions.

Clinical signs

This illness has a minimum incubation period of 7 months with a maximum of 12 months. This disease results in mortality of adult animals.

Clinical signs Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

of TME include behavioural changes such as confusion, loss of cleanliness, and aimless circling. An affected animal shows signs of

weight loss Weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat (adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other conn ...

, might develop matted fur, hindquarter

ataxia Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements. Ataxia is a clinical manifestation indicating dysfunction of ...

, and its tail arched over its back.

Seizures An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or neural oscillation, synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much o ...

may very rarely occur. Near-death stages include the animal showing signs of drowsiness and unresponsiveness.

Diagnosis

Currently, no tests are available to detect signs of this illness in live animals. However,

veterinary pathologist Veterinary pathologists are veterinarians who specialize in the diagnosis of diseases through the examination of animal tissue and body fluids. Like medical pathology, veterinary pathology is divided into two branches, anatomical pathology an ...

s can confirm this illness by

microscopic examination Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...

of the brain tissue in animals suspected to have died of this disease, where they expect to detect areas of distinct sponge-like formations, or by the identification of the prion protein in these tissue samples.

History

Transmissible mink encephalopathy was first noticed in 1947 on a mink farm in the United States, in Brown County, Wisconsin, but the disease was not reported in the scientific literature until 1965. Upon reviewing prior TME outbreaks in the U.S. and Canada, in all four cases which were not linked to a commercial feed plant and in which records were available, "downer" cattle were included in the mink diet. The most recent outbreak occurred in 1985, on a farm in the town of Stetsonville, also in Wisconsin. Outbreaks of TME have also occurred in Canada, Finland, Germany, and the former Soviet Union.

References

* Stanley B. Prusiner, Prion Biology and Diseases, second edition, 2004, United States of America {{Prion diseases Transmissible spongiform encephalopathies Mustelid diseases

Clinical signs

Diagnosis

History

See also

References