Title: Cerebellar hypoplasia (non-human)

{{short description|Underdevelopment of the cerebellum in animals}}
{{for|the condition in humans|Cerebellar hypoplasia}}
{{Multiple issues|
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{{how-to|date=March 2021}}
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'''Cerebellar hypoplasia''' is a neurological condition in which the [[cerebellum]] is smaller than usual or not completely developed.&lt;ref&gt;{{Cite web|url=https://www.ninds.nih.gov/health-information/disorders/cerebellar-hypoplasia|title=Cerebellar Hypoplasia Information Page }}&lt;/ref&gt;  It has been reported in many animal species.&lt;ref name=&quot;:1&quot;&gt;{{Cite web|url=https://www.merckvetmanual.com/nervous-system/congenital-and-inherited-anomalies-of-the-nervous-system/congenital-and-inherited-cerebellar-disorders|title=Congenital and Inherited Cerebellar Disorders - Nervous System|website=Merck Veterinary Manual|language=en-US|access-date=2019-02-20}}&lt;/ref&gt;

== Function and development of the cerebellum ==
The cerebellum is the brain's main control center for planning, adjusting, and executing movements of the body, the limbs and the eyes. It plays a major role in several forms of motor learning, including balance and posture.&lt;ref&gt;{{Cite web|title=Neural - Cerebellum Development|url=https://embryology.med.unsw.edu.au/embryology/index.php/Neural_-_Cerebellum_Development|url-status=live|archive-url=https://web.archive.org/web/20150518084330/https://embryology.med.unsw.edu.au/embryology/index.php/Neural_-_Cerebellum_Development |archive-date=2015-05-18 }}&lt;/ref&gt;

In the past, the evidence for a role for the cerebellum in cognitive functions was rather weak.&lt;ref&gt;{{cite journal | vauthors = Glickstein M | title = What does the cerebellum really do? | journal = Current Biology | volume = 17 | issue = 19 | pages = R824-7 | date = October 2007 | pmid = 17925205 | doi = 10.1016/j.cub.2007.08.009 | s2cid = 14683993 | doi-access = free | bibcode = 2007CBio...17.R824G }}&lt;/ref&gt;  However, investigations into the cognitive neuroscience of the cerebellum are rapidly advancing, extending far beyond the traditional view. For humans, current theories support the theory that what the cerebellum does to [[Sensory-motor coupling|sensorimotor]] and [[Vestibular system|vestibular control]], it also does to cognition, emotion, and [[Autonomic nervous system|autonomic function]].&lt;ref&gt;{{cite journal | vauthors = Schmahmann JD | title = The cerebellum and cognition | journal = Neuroscience Letters | volume = 688 | pages = 62–75 | date = January 2019 | pmid = 29997061 | doi = 10.1016/j.neulet.2018.07.005 | s2cid = 51623392 }}&lt;/ref&gt;&lt;ref&gt;{{cite journal | vauthors = Basson MA, Wingate RJ | title = Congenital hypoplasia of the cerebellum: developmental causes and behavioral consequences | journal = Frontiers in Neuroanatomy | volume = 7 | page = 29 | date = September 2013 | pmid = 24027500 | pmc = 3759752 | doi = 10.3389/fnana.2013.00029 | doi-access = free }}&lt;/ref&gt;{{Clarification needed |date=October 2025}} How it functions in cognition, emotion, or autonomic function in animals is still largely unknown. In 2012, a  study in mice provided direct evidence that subtle disruptions in cerebellar architecture can have pronounced effects on behaviors typically associated with &quot;autistic-like&quot; behavior.&lt;ref&gt;{{cite journal | vauthors = Tsai PT, Hull C, Chu Y, Greene-Colozzi E, Sadowski AR, Leech JM, Steinberg J, Crawley JN, Regehr WG, Sahin M | title = Autistic-like behaviour and cerebellar dysfunction in Purkinje cell Tsc1 mutant mice | journal = Nature | volume = 488 | issue = 7413 | pages = 647–51 | date = August 2012 | pmid = 22763451 | pmc = 3615424 | doi = 10.1038/nature11310 | bibcode = 2012Natur.488..647T }}&lt;/ref&gt;

Development of the cerebellum starts in a fetus in utero and, depending on the species, may continue for some period after birth. Postnatal development periods vary by species including: dogs up to 75 days, cats to 84 days, calves up to six months.&lt;ref&gt;{{cite book|title=Veterinary Neuroanatomy and Clinical Neurology|last1=DeLahunta|first1=Alexander|last2=Glass|first2=Eric | name-list-style = vanc |publisher=Saunders Elsevier |year=2009 |isbn=978-0-7216-6706-5 | url = https://books.google.com/books?id=pEWbeIU9-7QC&amp;pg=PA5 |pages=348–350}}&lt;/ref&gt;

== Cerebellar hypoplasia in cats ==

=== Symptoms ===
Symptoms of cerebellar hypoplasia in cats include swaying, head tremors, uncoordinated walking, and [[Dysmetria|hypermetria]].{{Citation needed |date=October 2025}}

=== Overview ===
The severity of the condition is dependent upon the time of infection and the portion of the cerebellum that is affected. The condition is not usually diagnosed by a test, but rather by observation of characteristic symptoms in the cat's behavior. There is no treatment for this because of how it arises,{{Clarification needed |date=October 2025}} but it may be prevented by vaccinating mothers against [[Carnivore protoparvovirus 1 |panleukopenia]] (a white blood cell infection) before becoming pregnant.&lt;ref&gt;{{Cite journal |last1=Schatzberg |first1=Scott J. |last2=Haley |first2=Nicholas J. |last3=Barr |first3=Stephen C. |last4=Parrish |first4=Colin |last5=Steingold |first5=Samantha |last6=Summers |first6=Brian A. |last7=de Lahunta |first7=Alexander |last8=Kornegay |first8=Joe N. |last9=Sharp |first9=Nicholas J.H. |date=2003 |title=Polymerase Chain Reaction (PCR) Amplification of Parvoviral DNA from the Brains of Dogs and Cats with Cerebellar Hypoplasia |journal=Journal of Veterinary Internal Medicine |language=en |volume=17 |issue=4 |pages=538–544 |doi=10.1111/j.1939-1676.2003.tb02475.x |pmid=12892305 |issn=1939-1676|doi-access=free }}&lt;/ref&gt;

=== Differences in lifestyle ===
There are very minor differences to a cat's life caused by cerebellar hypoplasia.&lt;ref name=&quot;vca 2025&quot;&gt;{{Cite web |title=Cerebellar Hypoplasia in Cats |website=VCA Animal Hospitals |url=https://vcahospitals.com/know-your-pet/cerebellar-hypoplasia-in-cats |access-date=2025-04-20 |language=en}}&lt;/ref&gt;  Usually, they are more prone to falls and being attacked. A simple solution is keeping them indoors. The condition is not infectious in any way. Some accommodations that might be needed are easier access to the litter box or higher food and water bowls.

== Cerebellar hypoplasia in dogs ==

=== Symptoms ===
Symptoms of cerebellar hypoplasia in dogs include goose-stepping, stumbling, eye flicking, stiff and wide-set legs, and a curved spine.&lt;ref name=&quot;Johnstone 2024&quot;&gt;{{Cite web |date=April 5, 2024 |author=Gemma Johnstone |title=Cerebellar Hypoplasia in Dogs: Signs, Symptoms, Treatment |url=https://www.akc.org/expert-advice/health/cerebellar-hypoplasia-in-dogs/ |access-date=2025-04-20 |website=American Kennel Club |language=en}}&lt;/ref&gt;

== Causes ==
A hereditary link to cerebellar hypoplasia has been established in some animals, including certain breeds of cows&lt;ref name=&quot;:1&quot; /&gt; and dogs.&lt;ref&gt;{{Cite web|url=https://www.petmd.com/dog/conditions/neurological/c_dg_cerebellar_hypoplasia|title=Brain Tissue Undervelopment in Dogs|website=www.petmd.com|access-date=2019-03-01}}&lt;/ref&gt; 

There are numerous potential causes for cerebellar hypoplasia. It is suspected that the most common cause is animal [[Parvoviridae|parvoviruses.]]&lt;ref&gt;{{Citation|last1=Pattison|first1=John R.|title=Parvoviruses|date=1996|url=https://www.ncbi.nlm.nih.gov/books/NBK7715/|work=Medical Microbiology|editor-last=Baron|editor-first=Samuel|edition=4th|place=Galveston (TX)|publisher=University of Texas Medical Branch at Galveston|isbn=978-0-9631172-1-2|pmid=21413262|access-date=2021-05-02|last2=Patou|first2=Gary}}&lt;/ref&gt; In dogs and cats specifically, it is thought to be most likely related to in utero viral infections, toxins or genetic disorders.&lt;ref&gt;{{Cite journal|url=https://www.vin.com/apputil/content/defaultadv1.aspx?meta=&amp;pId=11147&amp;id=3846241|title=Cerebellar Diseases of Dogs and Cats|website=Vin.com|last=LeCouteur|first=Richard A. | name-list-style = vanc |date=2002|others=WSAVA 2002 Congress }}&lt;/ref&gt;

In dogs, along with parvoviruses, the condition can be caused by canine herpes virus. The time frame during which a dog may be affected by cerebellar hypoplasia begins in the prenatal period and continues to the age of four weeks. Some non-infectious causes include injuries, heredity, and random events during development.&lt;ref name=&quot;Johnstone 2024&quot; /&gt;

In cattle, cerebellar hypoplasia is the most frequent result of bovine virus diarrhea virus.&lt;ref&gt;{{Cite journal |last1=Agerholm |first1=Jørgen S. |last2=Hewicker-Trautwein |first2=Marion |last3=Peperkamp |first3=Klaas |last4=Windsor |first4=Peter A. |date=2015-09-24 |title=Virus-induced congenital malformations in cattle |journal=Acta Veterinaria Scandinavica |volume=57 |issue=1 |page=54 |doi=10.1186/s13028-015-0145-8 |doi-access=free |issn=1751-0147 |pmc=4581091 |pmid=26399846}}&lt;/ref&gt; This happens because the virus destroys brain cells in the immature cattle fetus. Loss of cells specifically in the cerebellum of the cattle fetus results in lesions that reduce the size of the cerebellum and cause cerebellar hypoplasia.  

[[Feline panleukopenia]] ({{aka}} feline distemper&lt;ref&gt;{{Cite web |date=31 January 2025 |title=Feline Distemper Vaccine and Distemper Vaccine Cats: The Ultimate Guide to Keeping Your Cat Healthy |url=https://petawn.com/distemper-vaccine-cats-and-feline-distemper-vaccine/ |access-date=5 April 2025 |website=Petawn}}&lt;/ref&gt; or Feline Parvo) virus has long been known to cause cerebellar hypoplasia in neonatal kittens through in utero or perinatal infection.&lt;ref&gt;{{cite book |title= Veterinary Neuroanatomy and Clinical Neurology |url= https://archive.org/details/veterinaryneuroa00phda |url-access= limited |last1=De Lahunta |first1=Alexander |last2=Glass |first2=Eric | name-list-style = vanc |year=2009 |isbn=978-0-7216-6706-5 |pages=[https://archive.org/details/veterinaryneuroa00phda/page/n322 348]–388 |chapter=Cerebellum|doi=10.1016/B978-0-7216-6706-5.00013-5}}&lt;/ref&gt;  [[Uterus|In utero]], the virus can pass from the dam (mother) to the developing fetus and may then disrupt the development of its cerebellum by hindering cell division. This can happen when the dam is actively infected with the virus or given a modified-live feline parvovirus vaccine when pregnant.&lt;ref&gt;{{Cite web|url=http://www.abcdcatsvets.org/abcd-guidelines-on-feline-panleukopenia-2012-edition/|title=Feline panleukopenia|language=en-GB|access-date=2019-03-01|archive-date=2019-03-02|archive-url=https://web.archive.org/web/20190302024735/http://www.abcdcatsvets.org/abcd-guidelines-on-feline-panleukopenia-2012-edition/}}&lt;/ref&gt; Kittens are particularly vulnerable to cerebellar hypoplasia, in particular when the protective antibodies present in their mothers' milk are no longer present at four to twelve weeks of age. Unvaccinated adult cats are also prone to developing the condition.&lt;ref&gt;{{Cite web|title=Feline Parvovirus (FPV)|url=https://www.cats.org.uk/media/1034/vg05_feline_parvovirus_-fpv.pdf|url-status=live|archive-url=https://web.archive.org/web/20201028112220/https://www.cats.org.uk/media/1034/vg05_feline_parvovirus_-fpv.pdf |archive-date=2020-10-28 }}&lt;/ref&gt;

Other possible causes, if they occur during the development period of the cerebellum and thus inhibit its growth, include:&lt;ref&gt;{{cite web|url=https://www.vetstream.com/treat/felis/diseases/brain-cerebellar-disease|title=Brain: cerebellar disease |date=February 2019|website=Vet Stream| vauthors = Delauche A, Franklin R, Marsella R, Garosi L |issn=2398-2950 }}&lt;/ref&gt;
* [[Hypoxia (medical)|Hypoxia]]
* Malnutrition, either from a lack of adequate critical nutrients or an inability to absorb them
* [[Mycosis|Mycotic]] infection
* Protozoal infection (e.g. [[toxoplasmosis]])
* [[Rickettsia|Rickettsial infection]] (most are spread through ticks, mites, fleas, or lice)
* Traumatic brain injury
* Viral infection (e.g. [[feline infectious peritonitis]])&lt;ref&gt;{{Cite journal|last=Hartmann|first=Katrin|date=January 2005|title=Feline infectious peritonitis|journal=The Veterinary Clinics of North America. Small Animal Practice|volume=35|issue=1|pages=39–79|doi=10.1016/j.cvsm.2004.10.011|issn=0195-5616|pmc=7114919|pmid=15627627}}&lt;/ref&gt;

== Diagnosis ==
The veterinarian performs a physical exam and a neurological assessment to diagnose cerebellar hypoplasia. They will perform the physical exam to rule out other possibilities,&lt;ref name=&quot;Johnstone 2024&quot; /&gt; which include:
* Ataxia: [[Vestibular system|vestibular]] or [[Sensory ataxia|sensory]]&lt;ref&gt;{{Cite web |last=Wilson |first=Julia |name-list-style=vanc |date=7 March 2017 |title=Ataxia (Wobbly Gait) in Cats - Causes, Symptoms &amp; Treatment - Cat World – Cat Health, Cat Care &amp; Cat Advice |url=https://www.cat-world.com.au/ataxia-in-cats.html |access-date=2019-03-02}}&lt;/ref&gt;
* [[Feline infectious peritonitis]]&lt;ref&gt;{{Cite web |date=16 October 2017 |title=Feline infectious peritonitis |url=https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/vestibular-syndrome}}&lt;/ref&gt;
* [[Lysosomal storage disease]]s&lt;ref&gt;{{Cite journal |last1=Skelly |first1=Barbara J. |last2=Franklin |first2=Robin J. M. |date=2002 |title=Recognition and Diagnosis of Lysosomal Storage Diseases in the Cat and Dog |journal=Journal of Veterinary Internal Medicine |language=en |volume=16 |issue=2 |pages=133–141 |doi=10.1111/j.1939-1676.2002.tb02344.x |issn=1939-1676 |pmid=11899921 |doi-access=free}}&lt;/ref&gt;
If needed, an MRI can affirm the presence of the condition, though this is not always necessary due to the usual lack of severe impacts on quality of life with cerebellar hypoplasia.

== Treatment ==
===Special considerations===
In 2004, a study was published that linked [[ketamine]] to post-anesthetic cerebellar dysfunction in cats.&lt;ref&gt;{{cite journal | vauthors = Shamir M, Goonman G, Chai O | title = Postanesthetic cerebellar dysfunction in cats | journal = Journal of Veterinary Internal Medicine | volume = 18 | issue = 3 | pages = 368–9 | date = May–Jun 2004 | pmid = 15188828 | doi = 10.1111/j.1939-1676.2004.tb02562.x | doi-access = free }}&lt;/ref&gt; Eleven cats that did not have any indication of cerebellar deficits before surgery developed deficits post-surgery. All of these cats were Persian crossbreeds. Ketamine can cause erratic and spastic, jerky movements and muscle tremors and is slow to be metabolized out of the system.{{citation needed|date=August 2023}} The 2018 American Association of Feline Practitioner's Feline Anesthesia Guidelines&lt;ref&gt;{{Cite web|url=https://catvets.com/guidelines/practice-guidelines/anesthesia-guidelines|title=Anesthesia Guidelines|publisher=American Association of Feline Practitioners|website=catvets.com|access-date=2019-03-03}}&lt;/ref&gt; lists numerous alternatives. Gas anesthesia offers a number of advantages in many circumstances. In cats, rapid recovery is its primary advantage.{{citation needed|date=August 2023}}

=== Possible accommodations ===
For a house pet with cerebellar hypoplasia, accommodations for its condition may include limiting its access to stairs, using an animal wheelchair, installing carpets and rugs to prevent slipping, and improving the ease of access to food and water bowls.&lt;ref name=&quot;Johnstone 2024&quot; /&gt; The basis of care for these pets is making it easier and safer for them to move around and live as normally as possible. 

== Prognosis ==
The level of severity and mode of infection (if any) both play a role in determining the prognosis for animals that have cerebellar hypoplasia. At worst, the animal will not survive ex-utero; at best, the animal will live for the length of time that is considered normal for its species. If the root cause of the cerebellar hypoplasia impacted other parts of the developing brain and/or body, the overall health and life-span may or may not be impacted. For instance, feline fetuses infected in utero by FPLV that survive ex-utero, and kittens less than a few weeks of age that become infected with it, can also have [[retinal dysplasia]] and [[optic neuropathy]].The symptoms of cerebellar hypoplasia can also affect the prognosis of the animal. In severe cases, mobility issues can negatively affect the quality of life outcomes associated with the animal. In most cases, the symptoms of cerebellar hypoplasia can cause the animal to become more vulnerable to injuries or attacks.&lt;ref name=&quot;vca 2025&quot; /&gt; Most animals affected by cerebellar hypoplasia adapt to their disability but will need extra support and care to survive. 

== See also ==
* [[Cerebellar hypoplasia]] – the condition as it occurs in human beings

== References ==
{{Reflist}}

== Further reading ==
{{refbegin}}
* {{cite journal | vauthors = Schatzberg SJ, Haley NJ, Barr SC, Parrish C, Steingold S, Summers BA, deLahunta A, Kornegay JN, Sharp NJ | title = Polymerase chain reaction (PCR) amplification of parvoviral DNA from the brains of dogs and cats with cerebellar hypoplasia | journal = Journal of Veterinary Internal Medicine | volume = 17 | issue = 4 | pages = 538–44 | year = 2003 | pmid = 12892305 | doi = 10.1111/j.1939-1676.2003.tb02475.x | doi-access = free }}
* {{cite journal | vauthors = Sharp NJ, Davis BJ, Guy JS, Cullen JM, Steingold SF, Kornegay JN | title = Hydranencephaly and cerebellar hypoplasia in two kittens attributed to intrauterine parvovirus infection | journal = Journal of Comparative Pathology | volume = 121 | issue = 1 | pages = 39–53 | date = July 1999 | pmid = 10373292 | doi = 10.1053/jcpa.1998.0298 }}
{{refend}}

== External links ==

* [https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/vestibular-syndrome Feline vestibular syndrome]
* [https://lifewithchcats.com/ Life with cerebellar hypoplasia cats]
* [https://www.kittycatchronicles.com/cerebellar-hypoplasia.html Cerebellar hypoplasia] {{Webarchive|url=https://web.archive.org/web/20190302154005/https://www.kittycatchronicles.com/cerebellar-hypoplasia.html |date=2019-03-02 }}. Kitty Cat Chronicles
* [http://hpets.org/ The Handicapped Pets Foundation]

[[Category:Cat diseases]]
[[Category:Dog diseases]]
[[Category:Congenital disorders of nervous system]]
[[Category:Neurological disorders]]