FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Vet Med (Auckl) / Seizures in horses: diagnosis and classification.
Veterinary medicine (Auckland, N.Z.)2015; 6; 301-308; doi: 10.2147/VMRR.S62078

Seizures in horses: diagnosis and classification.

Abstract: Seizures are a diverse and very common set of chronic neurologic disorders in humans and dogs but are less common in horses. Seizures refer to a specific clinical event (described as sudden and severe) regardless of the etiology, which includes both intracranial and extracranial causes. Therefore, after briefly reviewing some definitions, this article aims to describe the use of a standardized classification, which could facilitate a logical approach for the clinician to establish a diagnosis, as well as to use a consistent mode of communication. For instance, seizures can be classified by type (ie, focal vs generalized) or etiology (ie, reactive, symptomatic, cryptogenic, idiopathic). In particular, epilepsy, a brain disorder characterized by recurrent seizures can be classified as primary (ie, genetic origin) or secondary (ie, acquired). This review further discusses the limitations associated with the clinical workup of horses with seizures. This is germane to the fact that the identification of the underlying cause remains challenging due to the technical limitations of imaging the equine adult brain. Indeed, as in man and dogs, epilepsies of unknown cause (ie, cryptogenic) account for the majority of all epilepsies. Therefore, although electroencephalography and advanced brain imaging techniques (eg, computed tomography and magnetic resonance imaging) are becoming increasingly available, information obtained from the history, physical, and neurologic examinations and progression of clinical signs and response to treatment remain essential in the workup of horses with seizures.
Get Full Text
Publication Date: 2015-10-05 PubMed ID: 30101115PubMed Central: PMC6067615DOI: 10.2147/VMRR.S62078Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article
  • Review

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article discusses the complexity of diagnosing and classifying seizures in horses. It emphasizes the challenge in identifying the underlying causes because of limitations in imaging equipment for adult horses. However, the authors suggest a standardized classification for seizures, which could help to establish a diagnosis and a consistent mode of communication between clinicians.

Definitions and Classification of Seizures in Horses

  • The article begins by outlining the basic concept of seizures, which it describes as sudden and severe clinical events. This can be due to various causes, both intracranial (within the brain) and extracranial (outside the brain).
  • The authors propose that seizures can be categorized by the nature of their presentation (focal vs generalized) or by their cause (reactive, symptomatic, cryptogenic, or idiopathic).
  • Epilepsy is presented as a brain disorder characterized by recurrent seizures, and according to the article, it can be classified as primary (originating from genetics) or secondary (acquired).

Issues in Diagnosis

  • The research indicates a challenge in diagnosing seizures in large animals like horses, particularly when it comes to identifying the underlying causes.
  • This difficulty arises because of technical limitations in imaging the brains of adult equines. The researchers point out that in humans and dogs, most epilepsy cases are of unknown origin – termed as cryptogenic. This highlights the fact that similar challenges exist in diagnosing horses.

The Role of Advanced Imaging Techniques and Other Relevant Information

  • While noting the challenges, the research also indicates that advanced imaging techniques like computed tomography (CT) and magnetic resonance imaging (MRI) are becoming more accessible, offering some light in addressing the issue.
  • However, it is clear that history, physical and neurologic examinations, and observing the progression of clinical signs and response to treatment—remain essential tools in the diagnosis and classification of seizures in horses.

Cite This Article

APA
Lacombe VA. (2015). Seizures in horses: diagnosis and classification. Vet Med (Auckl), 6, 301-308. https://doi.org/10.2147/VMRR.S62078

Publication

Veterinary medicine (Auckland, N.Z.)
ISSN: 2230-2034
NlmUniqueID: 101724251
Country: New Zealand
Language: English
Volume: 6
Pages: 301-308

Researcher Affiliations

Lacombe, Véronique A
  • Department of Physiological Sciences, Oklahoma State University Center for Veterinary Health Sciences, Stillwater, OK, USA, veronique.lacombe@okstate.edu.

Conflict of Interest Statement

Disclosure The author reports no conflicts of interest in this work.

References

This article includes 67 references
  1. Ghormley TM, Feldman DG, Cook JR. Epilepsy in dogs five years of age and older: 99 cases (2006–2011). J Am Vet Med Assoc 2015;246(4):447–450.
    pubmed: 25632819
  2. Chandler K. Canine epilepsy: what can we learn from human seizure disorders?. Vet J 2006;172(2):207–217.
    pubmed: 16154785
  3. Fisher RS, Boas WV, Blume W. Epileptic seizures and epilepsy: definitions proposed by the International League against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE). Epilepsia 2005;46(4):470–472.
    pubmed: 15816939
  4. Lacombe VA, Mayes M, Mosseri S, Reed SM, Fenner WR, Ou HT. Epilepsy in horses: aetiological classification and predictive factors. Equine Vet J 2012;44(6):646–651.
    pubmed: 22168451
  5. Beghi E, Berg A, Carpio A. Comment on epileptic seizures and epilepsy: definitions proposed by the International League Against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE). Epilepsia 2005;46(10):1698–1699.
    pubmed: 16190948
  6. Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989;30(4):389–399.
    pubmed: 2502382
  7. Commission on Epidemiology and Prognosis, International League Against Epilepsy. Guidelines for epidemiologic studies on epilepsy. Epilepsia 1993;34(4):592–596.
    pubmed: 8330566
  8. Engel J. A proposed diagnostic scheme for people with epileptic seizures and with epilepsy. Report of the ILAE task force on classification and terminology. Epilepsia 2001;42(6):796–803.
    pubmed: 11422340
  9. Lacombe VA, Mayes M, Mosseri S, Reed SM, Ou TH. Distribution and predictive factors of seizure types in 104 cases. Equine Vet J 2014;46(4):441–445.
    pubmed: 23888910
  10. Ferrie CD. Terminology and organization of seizures and epilepsies: radical changes not justified by new evidence. Epilepsia 2010;51(4):713–714.
    pubmed: 20394642
  11. Avanzini G. A sound conceptual framework for an epilepsy classification is still lacking. Epilepsia 2010;51(4):720–722.
    pubmed: 20394647
  12. Berg AT, Berkovic SF, Brodie M. Revised terminology and concepts for organization of seizures and epilepsies: report of the ILAE commission on classification and terminology, 2005–2009. Epilepsia 2010;51(4):676–685.
    pubmed: 20196795
  13. Berendt M, Gram L. Epilepsy and seizure classification in 63 dogs: a reappraisal of veterinary epilepsy terminology. J Vet Intern Med 1999;13(1):14–20.
    pubmed: 10052058
  14. Podell M, Fenner WR, Powers JD. Seizure classification in dogs from a nonreferral-based population. J Am Vet Med Assoc 1995;206(11):1721–1728.
    pubmed: 7782244
  15. Schriefl S, Steinberg TA, Matiasek K, Ossig A, Fenske N, Fischer A. Etiologic classification of seizures, signalment, clinical signs, and outcome in cats with seizure disorders: 91 cases (2000–2004). J Am Vet Med Assoc 2008;233(10):1591–1597.
    pubmed: 19014293
  16. Podell M. Seizures in dogs. Vet Clin North Am Small Anim Pract 1996;26(4):779–809.
    pubmed: 8813750
  17. Pakozdy A, Halasz P, Klang A. Epilepsy in cats: theory and practice. J Vet Intern Med 2014;28(2):255–263.
    pmc: PMC4857998pubmed: 24438024
  18. Berendt M. Epilepsy. .
  19. Lacombe VA. Seizures, narcolepsy and cataplexy. .
  20. van der Ree M, Wijnberg I. A review on epilepsy in the horse and the potential of ambulatory EEG as a diagnostic tool. Vet Q 2012;32(3–4):159–167.
    pubmed: 23163553
  21. Berendt M, Gredal H, Alving J. Characteristics and phenomenology of epileptic partial seizures in dogs: similarities with human seizure semiology. Epilepsy Res 2004;61(1–3):167–173.
    pubmed: 15451018
  22. Berendt M, Gredal H, Ersboll AK, Alving J. Premature death, risk factors, and life patterns in dogs with epilepsy. J Vet Intern Med 2007;21(4):754–759.
    pubmed: 17708395
  23. Viitmaa R, Cizinauskas S, Bergamasco LA. Magnetic resonance imaging findings in Finnish spitz dogs with focal epilepsy. J Vet Intern Med 2006;20(2):305–310.
    pubmed: 16594587
  24. Sogaro-Robinson C, Lacombe VA, Reed SM, Balkrishnan R. Factors predictive of abnormal results for computed tomography of the head in horses affected by neurologic disorders: 57 cases (2001–2007). J Am Vet Med Assoc 2009;235(2):176–183.
    pubmed: 19601739
  25. Furr M. Perinatal asphyxia in foals. Compend Conint Educ Pract 1996;18(12):1342–1351.
  26. Hardefeldt LY. Hyponatraemic encephalopathy in azotaemic neonatal foals: four cases. Aust Vet J 2014;92(12):488–491.
    pubmed: 25424762
  27. Manso-Diaz G, Dyson SJ, Dennis R. Magnetic resonance imaging characteristics of equine head disorders: 84 cases (2000–2013). Vet Radiol Ultrasound 2015;56(2):176–187.
    pubmed: 25139131
  28. Shorvon SD. The etiologic classification of epilepsy. Epilepsia 2011;52(6):1052–1057.
    pubmed: 21449936
  29. Aleman M, Gray LC, Williams DC. Juvenile idiopathic epilepsy in Egyptian Arabian foals: 22 cases (1985–2005). J Vet Intern Med 2006;20(6):1443–1449.
    pubmed: 17186863
  30. Lichter-Peled A, Polani S, Stanyon R, Rocchi M, Bar-Gal GK. Role of KCNQ2 and KCNQ3 genes in juvenile idiopathic epilepsy in Arabian foals. Vet J 2013;196(1):57–63.
    pubmed: 23182620
  31. Kube SA, Aleman M, Williams DC, LeCouteur RA. How to work up a horse with seizures. .
  32. Lyle CH, Turley G, Blissitt KJ. Retrospective evaluation of episodic collapse in the horse in a referred population: 25 cases (1995–2009). J Vet Intern Med 2010;24(6):1498–1502.
    pubmed: 21039868
  33. Wong D, Hepworth K, Yaeger M, Miles K, Wilgenbusch C. Imaging diagnosis-hypoglycemia associated with cholangiocarcinoma and peritoneal carcinomatosis in a horse. Vet Radiol Ultrasoun 2015;56(1):E9–E12.
    pubmed: 24103084
  34. Dunigan CE, Oglesbee MJ, Podell M, Mitten LA, Reed SM. Seizures activity associated with equine protozoal myeloencephalitis. Prog Vet Neurol 1995;6(2):50–54.
  35. Lacombe V, Andrews M. Electrodiagnostic evaluation of the nervous system. .
  36. Lacombe VA, Podell M, Furr M. Diagnostic validity of electroencephalography in equine intracranial disorders. J Vet Intern Med 2001;15(4):385–393.
    pubmed: 11467598
  37. Aminoff M. Electroencephalography: general principles and clinical applications. .
  38. Redding RW. Electroencephalography. .
  39. Grabow JD, Anslow RO, Spalatin J. Electroencephalographic recordings with multicontact depth probes in a horse. Am J Vet Res 1969;30(7):1239–1243.
    pubmed: 5815928
  40. Garner HE, Geddes LA, Amend JF, Rosborou JP, Ross JN. Electrodes for recording cortical electroencephalograms in ponies. Lab Anim Sci 1972;22(2):262–265.
    pubmed: 4337001
  41. Otto K, Short CE. Electroencephalographic power spectrum analysis as a monitor of anesthetic depth in horses. Vet Surg 1991;20(5):362–371.
    pubmed: 1962420
  42. Murrell JC, Johnson CB, White KL, Taylor PM, Haberham ZL, Waterman-Pearson AE. Changes in the EEG during castration in horses and ponies anaesthetized with halothane. Vet Anaesth Analg 2003;30(3):138–146.
    pubmed: 14498845
  43. Johnson CB, Taylor PM. Comparison of the effects of halothane, isoflurane and methoxyflurane on the electroencephalogram of the horse. Brit J Anaesth 1998;81(5):748–753.
    pubmed: 10193288
  44. Auer JA, Amend JF, Garner HE, Hutcheson DP, Salem CA. Electroencephalographic responses during volatile anesthesia in domestic ponies – comparative-study of isoflurane, enflurane, methoxyflurane, and halothane. J Equine Med Surg 1979;3(3):130–134.
  45. Haga HA, Dolvik NI. Electroencephalographic and cardiovascular variables as nociceptive indicators in isoflurane-anaesthetized horses. Vet Anaesth Analg 2005;32(3):128–135.
    pubmed: 15877659
  46. Dallaire A, Ruckebus Y. Sleep and Wakefulness in housed pony under different dietary conditions. Can J Comp Med 1974;38(1):65–71.
    pmc: PMC1319968pubmed: 4272959
  47. Lapras M, Florio R, Joubert L. Normal electroencephalogram in the horse. Its pathological variations in West Nile viral meningoencephalomyelitis. Relations to clinical findings, virology and histopathology. Rev Med Vet (Toulouse) 1968;119:673–693.
  48. Knecht CD, Sorjonen DC, Simpson ST. Ancillary tests in the diagnosis of seizures. J Am Anim Hosp Assoc 1984;20(3):455–458.
  49. Williams DC, Aleman M, Tharp B. Qualitative and quantitative characteristics of the electroencephalogram in normal horses after sedation. J Vet Intern Med 2012;26(3):645–653.
    pubmed: 22489924
  50. Purohit RC, Mysinger PW, Redding RW. Effects of xylazine and ketamine-hydrochloride on the electroencephalogram and the electrocardiogram in the horse. Am J Vet Res 1981;42(4):615–619.
    pubmed: 7332120
  51. Borris DJ, Bertram EH, Kapur J. Ketamine controls prolonged status epilepticus. Epilepsy Res 2000;42(2–3):117–122.
    pmc: PMC2885610pubmed: 11074184
  52. Wijnberg ID, van der Ree M, van Someren P. The applicability of ambulatory electroencephalography (AEEG) in healthy horses and horses with abnormal behaviour or clinical signs of epilepsy. Vet Quart 2013;33(3):121–131.
    pubmed: 24111950
  53. Lacombe V. Seizure disorders. .
  54. Mysinger PW, Redding RW, Vaughan JT, Purohit RC, Holladay JA. Electroencephalographic patterns of clinically normal, sedated, and tranquilized newborn foals and adult horses. Am J Vet Res 1985;46(1):36–41.
    pubmed: 3970440
  55. Itabisashi T, Horino R, Hirano K, Maeda M. Electroencephalographic observation on sheep and cattle with experimental cerebrocortical necrosis. Jpn J Vet Sci 1990;52(3):551–558.
    pubmed: 2385036
  56. Berendt M, Hogenhaven H, Flagstad A, Dam M. Electroencephalography in dogs with epilepsy: similarities between human and canine findings. Acta Neurol Scand 1999;99(5):276–283.
    pubmed: 10348156
  57. Heath SE, Artsob H, Bell RJ, Harland RJ. Equine encephalitis caused by snowshoe hare (California Serogroup) Virus. Can Vet J 1989;30(8):669–671.
    pmc: PMC1681154pubmed: 17423397
  58. Hepburn RJ, Furr MO. Sinonasal adenocarcinoma causing central nervous system disease in a horse. J Vet Intern Med 2004;18(1):125–131.
    pubmed: 14765745
  59. Steiss JE, Cox NR, Knecht CD. Electroencephalographic and histopathologic correlations in eight dogs with intracranial mass lesions. Am J Vet Res 1990;51(8):1286–1291.
    pubmed: 2386329
  60. Noachtar S, Remi J. The role of EEG in epilepsy: a critical review. Epilepsy Behav 2009;15(1):22–33.
    pubmed: 19248841
  61. Lacombe VA, Sogaro-Robinson C, Reed SM. Diagnostic utility of computed tomography imaging in equine intracranial conditions. Equine Vet J 2010;42(5):393–399.
    pubmed: 20636774
  62. Gilman S. Medical progress – Imaging the brain – Second of two parts. New Engl J Med 1998;338(13):889–896.
    pubmed: 9516225
  63. Lacombe VA. Challenges associated with the diagnosis and treatment of parasitic encephalitis. Equine Vet Educ 2013;25(12):605–606.
  64. Jose-Cunilleras E, Piercy RJ. Advanced diagnostic imaging options in horses with neurological disease that localises to the head. Equine Vet Educ 2007;19(4):179–181.
  65. Porter EG, Werpy NM. New concepts in standing advanced diagnostic equine imaging. Vet Clin North Am Equine Pract 2014;30(1):239–268.
    pubmed: 24680215
  66. Tucker RL, Farrell E. Computed tomography and magnetic resonance imaging of the equine head. Vet Clin North Am Equine Pract 2001;17(1):131–144.
    pubmed: 11488040
  67. Krumholz A, Wiebe S, Gronseth G. Practice parameter: Evaluating an apparent unprovoked first seizure in adults (an evidence-based review) – Report of the quality standards subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology 2007;69(21):1996–2007.
    pubmed: 18025394
Subscribe to our newsletter
Join 99,357 horse owners like you who receive our email updates on horse health and nutrition.