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[[Image:Star-gazing_boa-1ed.jpg|300px|thumb|right|'''Typical "star-gazing" posture of a snake with neurological disease''' © RVC]]

[[Image:Star-gazing_boa-1ed.jpg|300px|thumb|right|'''Typical "star-gazing" posture of a snake with neurological disease''' © RVC]]

Neurological disease is relatively common in snakes. Viral infections may present with neurological signs and [[Snake Hypothiaminosis|hypothiaminosis]] is very common in [[Garter Snake|garter snakes]].

Neurological disease is relatively common in snakes. Viral infections may present with neurological signs and [[Snake Hypothiaminosis|hypothiaminosis]] is very common in [[Garter Snake|garter snakes]].

==Examination==

==Examination==

As with other problems of snakes, [[Lizard and Snake Taking a History|history-taking]] is critical for diagnosis. Signalment information can help determine the cause since many neurological diseases are more prevalent in certain taxa. Husbandry information will help to determine whether the nervous system is involved specifically or secondarily. Clinical signs of neurological disease in snakes vary from very subtle to severe. There may be only a mild decrease in activity and a drop off in appetite. More obvious signs include disorientation, incoordination, loss of righting reflex, paresis, paralysis, head tremors, opisthotonous and convulsions.

As with other problems of snakes, [[Lizard and Snake Taking a History|history-taking]] is critical for diagnosis. Signalment information can help determine the cause since many neurological diseases are more prevalent in certain taxa. Husbandry information will help to determine whether the nervous system is involved specifically or secondarily. Clinical signs of neurological disease in snakes vary from very subtle to severe. There may be only a mild decrease in activity and a drop off in appetite. More obvious signs include disorientation, incoordination, loss of righting reflex, paresis, paralysis, head tremors, opisthotonous and convulsions.

==Diagnosis==

==Diagnosis==

The aetiology of neurological disease can be suggested by signalment. [[Inclusion Body Disease|Inclusion body disease (IBD)]] is almost always seen in [[Boidae]]. [[Ophidian Paramyxovirus|Ophidian paramyxovirus]] (OPMV) occurs principally in [[Viperidae]]. Hypothiaminosis is common in fish-eating snakes such as [[Garter Snake|garter snakes]].   Disorientation and sluggishness may be attributed to a wide variety of causes but may be simply caused by an inappropriate environmental temperature. [[Snake Physical Examination|Physical examination]] may rule out cases of trauma. The use of diagnostic aids may identify the cause: [[Lizard and Snake Imaging|radiography]] may reveal fractures, [[Lizard and Snake Haematology|haematology]] may indicate an infectious cause, and serology may identify [[Ophidian Paramyxovirus|OPMV]]. Response to thiamine is diagnostic for [[Snake Hypothiaminosis|hypothiaminosis]]. However sometimes the aetiology is only found upon [[Snake Necropsy|necropsy]]. Perivascular cuffing in CNS issue may be associated with viral infections.

The aetiology of neurological disease can be suggested by signalment.  

*[[Inclusion Body Disease|Inclusion body disease (IBD)]] is almost always seen in [[Boidae]]. *[[Ophidian Paramyxovirus|Ophidian paramyxovirus]] (OPMV) occurs principally in [[Viperidae]]. *Hypothiaminosis is common in fish-eating snakes such as [[Garter Snake|garter snakes]].  

 

Disorientation and sluggishness may be attributed to a wide variety of causes but may be simply caused by an inappropriate environmental temperature. Stargazing in very suggestive of meningoencephalitis.

 

[[Snake Physical Examination|Physical examination]] may rule out cases of trauma. The use of diagnostic aids may identify the cause: [[Lizard and Snake Imaging|radiography]] may reveal fractures, [[Lizard and Snake Haematology|haematology]] may indicate an infectious cause, and serology may identify [[Ophidian Paramyxovirus|OPMV]]. Response to thiamine is diagnostic for [[Snake Hypothiaminosis|hypothiaminosis]]. However, sometimes the aetiology is only found upon [[Snake Necropsy|necropsy]]. Perivascular cuffing in [[CNS]] issue may be associated with viral infections.

==Causes of neurological disease==

==Causes of neurological disease==

There are many causes of neurological disease in snakes. Here’s a brief overview.

There are many causes of neurological disease in snakes. Here’s a brief overview.

*'''Viral''' - Two viral diseases have been reported to cause neurological problems in snakes – [[Inclusion Body Disease]] and [[Ophidian Paramyxovirus|OMPV]]. [[Ophidian Paramyxovirus|OPMV]] is primarily associated with [[Snake Respiratory Disease|respiratory pathology]] but can be associated with CNS disease. The clinical significance of infection with western equine encephalitis and Venezuelan equine encephalitis is unknown.

*'''Viral''' - Several viral infections have been reported to cause neurological problems in snakes – including [[Inclusion Body Disease]], [[Ophidian Paramyxovirus|OMPV]], reovirus and lentivirus infections. [[Ophidian Paramyxovirus|OPMV]] is primarily associated with [[Snake Respiratory Disease|respiratory pathology]] but can be associated with CNS disease. The clinical significance of infection with [[Equine Encephalitis Virus|western equine encephalitis and Venezuelan equine encephalitis]] is unknown.

*'''Bacterial''' - Bacterial infections, including Staphylococcus aureus and mycobacteria, have been reported to cause neurological disease and abscesses in the vertebral canal.

*'''Bacterial''' - Bacterial infections, including ''[[Staphylococcus aureus]]'' and [[:Category:Mycobacterium species|mycobacteria]], have been reported to cause neurological disease and abscesses in the vertebral canal.

*'''Fungal''' - ''Cryptococcus neoformans'' has been associated with neurological disease. Diagnosis can be confirmed by serology or isolation from CSF.

*'''Fungal''' - ''[[Cryptococcus neoformans]]'' has been associated with neurological disease. Diagnosis can be confirmed by serology or isolation from [[Cerbrospinal Fluid|CSF]].

*'''Parasitic''' - Protozoal neurological disease has been reported in snakes. Acanthmoebic encephalitis causes spasmodic opisthotonus and toxoplasmosis has been associated with meningoencephalitis.

*'''Parasitic''' - Protozoal neurological disease has been reported in snakes. Acanthmoebic encephalitis causes spasmodic opisthotonus and [[Toxoplasma gondii|toxoplasmosis]] has been associated with meningoencephalitis.

*'''Nutritional''' - Thiamine deficiency is the most common nutritional cause of neurological disease in snakes. Snakes fed incorrectly prepared fish are at risk. Hypobiotinosis may develop from feeding raw egg whites containing avidin, which has anti-biotin activity.

*'''Nutritional''' - [[Snake Hypothiaminosis|Thiamine deficiency]] is the most common nutritional cause of neurological disease in snakes. Snakes fed incorrectly prepared fish are at risk. Hypobiotinosis may develop from feeding raw egg whites containing avidin, which has anti-biotin activity.

*'''Trauma''' - Trauma neuropathies may occur after direct trauma to the head and vertebral column.

*'''Trauma''' - Trauma neuropathies may occur after direct trauma to the head and vertebral column.

==Therapy==

==Therapy==

Treatment of neurological disease involves both supportive care and aetiology related therapy. Some forms of neurological disease such as trauma may require up to one year of supportive care before snakes will begin to take prey spontaneously. Months of supportive care are often required for neurological deficits to repair but in many cases they may never be restored to full function. In some cases [[Lizard and Snake Euthanasia|euthanasia]] is probably the most humane act. Aetiology related therapy may not be possible in many cases.

Treatment of neurological disease involves both supportive care and aetiology related therapy. Some forms of neurological disease such as trauma may require up to one year of supportive care before snakes will begin to take prey spontaneously. Months of supportive care are often required for neurological deficits to repair but in many cases they may never be restored to full function. In some cases [[Lizard and Snake Euthanasia|euthanasia]] is probably the most humane act. Aetiology related therapy may not be possible in many cases.

'''For more information, see''' [[Snake Supportive Care]].

'''For more information, see''' [[Snake Supportive Care]].

==Prevention==

==Prevention==

'''For further information, see''' [[Snake Feeding and Digestion]] '''and''' [[Snake Housing]].

'''For further information, see''' [[Snake Feeding and Digestion]] '''and''' [[Snake Housing]].

==Literature Search==

[[File:CABI logo.jpg|left|90px]]

|flashcards = [[Reptiles and Amphibians Q&A 10]]

|full text = [http://www.cabi.org/cabdirect/FullTextPDF/2009/20093118384.pdf '''Neurologic examination in reptiles - Part I: Cranial nerve examination.''' Bennett, R. A.; The North American Veterinary Conference, Gainesville, USA, Small animal and exotics. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 17-21 January, 2009, 2009, pp 1766-1767 - '''Full Text Article''']

 

[http://www.cabi.org/cabdirect/FullTextPDF/2009/20093118385.pdf '''Neurologic examination in reptiles - Part II: Localizing neurologic dysfunction.''' Bennett, R. A.; The North American Veterinary Conference, Gainesville, USA, Small animal and exotics. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 17-21 January, 2009, 2009, pp 1768-1769 - '''Full Text Article''']

[[Category:Snake_Diseases]]

[[Category:Snake_Diseases]]