Title: Feline spongiform encephalopathy

{{Short description|Feline brain disease}}
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'''Feline spongiform encephalopathy''' ('''FSE''') is a neurodegenerative disease that affects the brains of [[felidae|feline]]s. This disease is known to affect domestic, captive, and wild [[species]] of the family Felidae.&lt;ref name=&quot;german&quot;&gt;{{cite journal | vauthors = Eiden M, Hoffmann C, Balkema-Buschmann A, Müller M, Baumgartner K, Groschup MH | title = Biochemical and immunohistochemical characterization of feline spongiform encephalopathy in a German captive cheetah | journal = The Journal of General Virology | volume = 91 | issue = Pt 11 | pages = 2874–2883 | date = November 2010 | pmid = 20660146 | doi = 10.1099/vir.0.022103-0 | doi-access = free }}&lt;/ref&gt; Like [[bovine spongiform encephalopathy]] (BSE), this disease can take several years to develop.&lt;ref name=Hilbe09/&gt;

== Causes ==
Like other forms of [[transmissible spongiform encephalopathy]] (TSE), FSE is caused by contact from a misfolded form of the [[prion protein]] (PrP&lt;sup&gt;Sc&lt;/sup&gt;) which causes normal prion protein molecules (PrP&lt;sup&gt;C&lt;/sup&gt;) to become misfolded.&lt;ref name=Kim22&gt;{{cite journal | vauthors = Kim YC, Kim HH, Kim K, Kim AD, Jeong BH | title = Novel Polymorphisms and Genetic Characteristics of the Shadow of Prion Protein Gene (''SPRN'') in Cats, Hosts of Feline Spongiform Encephalopathy | journal = Viruses | volume = 14 | issue = 5 | page = 981 | date = May 2022 | pmid = 35632724 | pmc = 9148082 | doi = 10.3390/v14050981 | doi-access = free }}&lt;/ref&gt; Better-known examples of TSE include BSE in bovines, [[Creutzfeldt–Jakob disease|Creutzfeldt–Jakob disease (CJD)]] in humans, [[scrapie]] in sheep and [[chronic wasting disease]] in deer.&lt;ref name=Bencsik&gt;{{cite journal | vauthors = Bencsik A, Debeer S, Petit T, Baron T | title = Possible case of maternal transmission of feline spongiform encephalopathy in a captive cheetah | journal = PLOS ONE | volume = 4 | issue = 9 | article-number = e6929 | date = September 2009 | pmid = 19738899 | pmc = 2732902 | doi = 10.1371/journal.pone.0006929 | bibcode = 2009PLoSO...4.6929B | doi-access = free }}&lt;/ref&gt;

FSE was first identified in the UK shortly after the BSE outbreak. These cases are believed to be a result of felines ingesting bovine meat contaminated with BSE.&lt;ref name=Hilbe09&gt;{{cite journal | vauthors = Hilbe MM, Soldati GG, Zlinszky KK, Wunderlin SS, Ehrensperger FF | title = Immunohistochemical study of PrP(Sc) distribution in neural and extraneural tissues of two cats with feline spongiform encephalopathy | journal = BMC Veterinary Research | volume = 5 | issue = 1 | page = 11 | date = March 2009 | pmid = 19335885 | pmc = 2673214 | doi = 10.1186/1746-6148-5-11 | doi-access = free }}&lt;/ref&gt; Prions from human TSE as well as deer [[chronic wasting disease]] can also cause FSE under laboratory conditions.&lt;ref&gt;{{cite journal |last1=Mathiason |first1=CK |last2=Nalls |first2=AV |last3=Seelig |first3=DM |last4=Kraft |first4=SL |last5=Carnes |first5=K |last6=Anderson |first6=KR |last7=Hayes-Klug |first7=J |last8=Hoover |first8=EA |title=Susceptibility of domestic cats to chronic wasting disease. |journal=Journal of Virology |date=February 2013 |volume=87 |issue=4 |pages=1947–56 |doi=10.1128/JVI.02592-12 |pmid=23236066 |pmc=3571486 }}&lt;/ref&gt; However, [[scrapie]] prions from sheep cannot cause FSE in cats, indicating a difference between TSE prions from different species.&lt;ref name=&quot;Wells06&quot; /&gt;

Contact with FSE prions from sick cats (horizontal transmission) is assumed to spread the disease, but no laboratory research has been done into this topic as of 2006.&lt;ref name=&quot;Wells06&quot; /&gt; One suspected case of maternal (vertical) transmission was reported in captive cheetahs in 2009.&lt;ref name=Bencsik/&gt; FSE prions can infect TgOvPrP4 mice which produce large amounts of the sheep version of the prion protein.&lt;ref name=Bencsik/&gt;

==Symptoms and signs==
Clinical signs of FSE typically develop gradually in housecats, ranging from several weeks to months.&lt;ref name=&quot;Wells06&quot;&gt;{{Cite book | vauthors = Wells GA, Ryder SJ, Hadlow WJ | chapter = The Pathology of Prion Diseases in Animals | pages = 323–327 |title=Prions in Humans and Animals |date=2006-12-21 |publisher=Walter de Gruyter | doi = 10.1515/9783110200171 |isbn=978-3-11-018275-0 | veditors = Hörnlimann B, Riesner D, Kretzschmar HA }}&lt;/ref&gt; Initial signs of the condition include behavioral changes such as aggression, timidity, hiding, [[hyperesthesia]], loss of motor functions, and [[polydipsia]].&lt;ref name=&quot;Wells06&quot; /&gt; Other commonly observed motor signs include gait abnormalities and ataxia, which typically affect the hind legs first. Affected cats may also display poor judgement of distance, and some cats may develop a rapid, crouching, hypermetric gait. Some affected cats may exhibit an abnormal head tilt, tremors, a vacant stare, excessive salivation, decreased grooming behaviors, [[polyphagia]], and dilated pupils.&lt;ref name=&quot;Wells06&quot; /&gt; [[Ataxia]] was observed to last for about 8 weeks in the affected animals.

==Diagnosis==
This disease can only be confirmed via a [[post-mortem]] examination, which includes identification of bilaterally symmetrical [[vacuole|vacuolation]] of the [[neuropil]] and vacuolation in [[neuron]]es. [[Lesion]]s are likely to be found in [[basal ganglia]], [[cerebral cortex]] and [[thalamus]] of the [[brain]].&lt;ref&gt;{{cite book |vauthors=Tipold A, Vandevelde M, Barber R, Sykes JE |year=2021 |chapter=Miscellaneous Infections and Inflammatory Disorders of the Central Nervous System |title=Greene's Infectious Diseases of the Dog and Cat |chapter-url=https://www.sciencedirect.com/science/article/abs/pii/B9780323509343001294 |pages=1710–1727 |editor-last=Sykes |editor-first=Jane E. |publisher=Saunders |doi=10.1016/B978-0-323-50934-3.00129-4 |isbn=978-0-323-50934-3}}&lt;/ref&gt;

FSE prions show some accumulation in the kidney and adrenal glands of an infected cheetah, which is unusual for prion diseases. This accumulation could allow FSE prions to be excreted in urine.&lt;ref&gt;{{cite journal |last1=Lezmi |first1=S |last2=Bencsik |first2=A |last3=Monks |first3=E |last4=Petit |first4=T |last5=Baron |first5=T |title=First case of feline spongiform encephalopathy in a captive cheetah born in France: PrP(sc) analysis in various tissues revealed unexpected targeting of kidney and adrenal gland. |journal=Histochemistry and Cell Biology |date=May 2003 |volume=119 |issue=5 |pages=415–22 |doi=10.1007/s00418-003-0524-5 |pmid=12783238}}&lt;/ref&gt; The detection was questioned in 2009 but reaffirmed in 2010. Similar detection has also been reported in domestic cats.&lt;ref&gt;{{cite journal |last1=Lezmi |first1=S |last2=Baron |first2=TG |last3=Bencsik |first3=AA |title=Is the presence of abnormal prion protein in the renal glomeruli of feline species presenting with FSE authentic? |journal=BMC Veterinary Research |date=4 August 2010 |volume=6 |article-number=41 |doi=10.1186/1746-6148-6-41 |doi-access=free |pmid=20684771 |pmc=2923130 }}&lt;/ref&gt;

==Treatment==
This is a [[Terminal illness|terminal]] condition and there is currently no specific treatment for the disease.&lt;ref name=&quot;provet&quot;&gt;{{cite web |date=October 2013 |title=Feline spongiform encephalopathy (FSE) |url=http://www.provet.co.uk/petfacts/healthtips/fse2.htm |access-date=2020-02-29 |website=Provet Healthcare Information}}&lt;/ref&gt; In most instances, infected felines die spontaneously within a few months to years, or are euthanized due to this condition.&lt;ref name=&quot;Wells06&quot; /&gt;

Any material from the infected cat should be carefully handled to eliminate the prion protein so as to not infect humans or other animals. General guidelines for prion inactivation apply (see {{section link|Prion|Sterilization}}). It may be very difficult to decontaminate a facility that has housed infected animals.&lt;ref&gt;{{cite web |last1=The Center For Food Safety &amp; Public Health |title=Feline Spongiform Encephalopathy |url=https://www.cfsph.iastate.edu/Factsheets/pdfs/feline_spongiform_encephalopathy.pdf |website=cfsph.iastate.edu |date=August 2016}}&lt;/ref&gt;

==Epidemiology==
This disease was first reported in domestic cats within the United Kingdom in 1990, only four years after the first reports of BSE.&lt;ref name=&quot;german&quot; /&gt;&lt;ref name=&quot;Wells06&quot; /&gt;&lt;ref&gt;{{cite web | url= http://archive.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/bse/othertses/index.htm#fse | title= BSE: Other TSEs | work = Department for Environment, Food &amp; Rural Affairs (DEFRA) | publisher = gov.uk | access-date=2012-09-02 | archive-url=https://web.archive.org/web/20120817003032/http://archive.defra.gov.uk/foodfarm/farmanimal/diseases/atoz/bse/othertses/index.htm#fse | archive-date=2012-08-17 | url-status=dead }}&lt;/ref&gt;  Since 1990, cases have been reported in other countries and other feline species in captivity, although most affected felines originated in the UK.&lt;ref&gt;{{cite journal | vauthors = Imran M, Mahmood S | title = An overview of animal prion diseases | journal = Virology Journal | volume = 8 | issue = 1 | article-number = 493 | date = November 2011 | pmid = 22044871 | pmc = 3228711 | doi = 10.1186/1743-422X-8-493 | doi-access = free }}&lt;/ref&gt;

The average age of felines that have been affected by this disease is 11 years of age, with the age range being roughly 2–10 years.&lt;ref name=&quot;Wells06&quot; /&gt; All breeds are equally affected.&lt;ref name=&quot;provet&quot;/&gt; Some genetic variation has been reported in the ''Prnp'' gene of domestic cats but no effect on the course of disease for these variations are known.&lt;ref name=Kim22/&gt;

== References ==
{{reflist}}

{{Prion diseases}}

[[Category:Cat diseases]]
[[Category:Transmissible spongiform encephalopathies]]
[[Category:Foodborne illnesses]]