Diseases of the Nervous System

Chapter 67 Diseases of the Nervous System


Neurologic diseases are not common in sheep and goats, but they can be devastating to the animal and its owner. Many neurologic conditions carry a poor to grave prognosis. When determining the cause of a condition, signalment, history, and mental status are all important factors. A thorough neurologic examination is then performed to localize the lesion and provide a better idea of what condition is affecting the animal.



SCRAPIE


Scrapie is a reportable disease in the United States. It is a member of the group of diseases known as transmissible spongiform encephalopathies. It is a progressive, degenerative disorder of the central nervous system seen mainly in sheep but occasionally in goats. The exact cause of scrapie is unknown. The method of transmission is likewise unknown.




CLINICAL SIGNS



• Seen most commonly in Suffolk sheep

• Mild apprehension, fixed gaze, aggressiveness

• Exercise intolerance and ataxia

• Intense pruritus

• Recumbency

• Blindness, seizures, death


DIAGNOSIS



• It is difficult to make an antemortem diagnosis because no specific lesions or laboratory test results are specific to the disease.


TREATMENT



• No effective treatment exists.


RABIES


Rabies is a zoonotic disease that has many of the greatest public health implications. Most states have laws mandating the vaccination of dogs and cats, and some states mandate the vaccination of horses. No laws exist regarding the vaccination of sheep and goats. Currently, no rabies vaccines have been approved for goats; if goats are vaccinated, they are usually vaccinated with a product approved for sheep. The vaccine is available only through licensed veterinarians. Any animal that is showing neurologic signs, especially if there is a known history of having been bitten by another animal, should be suspected of having rabies.


The infectious agent is a Lyssavirus. An infected animal, usually a raccoon, skunk, fox, or bat, bites the victim and passes the virus in the saliva. The virus migrates through body and the nervous system and localizes in the central nervous system. The virus may affect the cerebrum, brainstem, or spinal cord.




CLINICAL SIGNS



• If the virus settles in the brain, extreme behavior changes, often aggressive, are seen.

• If the brainstem is affected, behavior changes with animal becoming more subdued and quiet are seen.

• If the spinal cord is affected, the animal exhibits ataxia that progresses to paralysis.

• Signs are rapidly progressive, and animal usually dies within 5 to 10 days of the onset of signs.


DIAGNOSIS



• Examination of the brain tissue


TREATMENT



• No treatment currently exists for rabies.


INFORMATION FOR CLIENTS



• If an animal is bitten by a rabid animal and has been vaccinated, the animal should be revaccinated and observed for 45 days.

• If an unvaccinated animal is bitten by a suspected rabid animal, it should be euthanized. If the owner is unwilling to perform euthanasia, the animal needs to be watched closely for 6 months and HANDLED WITH EXTREME CAUTION.

Related posts:

  1. Hematologic and Immunologic Diseases
  2. Hematologic and Immunologic Diseases
  3. Diseases of the Cardiovascular System
  4. Hematologic Diseases

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Aug 31, 2016 | Posted by in GENERAL | Comments Off on Diseases of the Nervous System

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