Path outline final (KP) Flashcards
What is a severe case of diffuse destruction of brain w/ no cerebral hemispheres called?
Hydranencephaly
Is the stroma destroyed in Hydranencephaly?
Yes
What is Congenital Hydranencephaly associated with?
Examples?
Cerebrum
Fetal viral infxns
Ex: Calves BVD & prego Sheep (Blue Tongue) vax at day 50-58
What is a typical lesion of hydranencephaly?
Absence of Telencephalon w/ complete or almost complete absence of cerebral hemispheres
Hydrancephaly: On necropsy what would you see in the cranial cavity?
Membranous sac of CSF made up of enclosed leptomeniges inside a complete cranial cavity
Hydrancephaly: What would the skull look like?
Mostly normal but could have mild doming & thickening of cranial bones
Is there an epindymal lining with Hydranencephaly?
NO
What viruses are associated with Hydrancephaly?
Akbane Bluetounge RVF Wessel-bron BVD Border Dz
If Porencephaly occurs prenatal what will the brain look like?
Focal destruction of White Matter w/ caveated cysts in the cerebral hemisphere
What is Porencephaly?
A congenital anomaly that effects the White Matter of the Cerebrum
How do the the cysts in Porencephaly appear and what are they filled with?
Smooth walled & filled with clear fluid
Associated viruses of Porencephaly?
Border Dz
BVD
What deficiency is associated with Porencephaly?
CU deficiency
What is Internal Hydrocephalus?
Abnormal accumlulation of CSF ventricles
What is External Hydrocephalus?
Abnormal accumulation of CSF in the Subarachnoid Space
Is Stroma present in Hydrocephalus?
YES
What can cause Congenital Hydrocephalus?
Idiopathic
Viral
Nutritional Deficiency
What are the lesions of Congenital Hydrocephalus? TQ
Lateral ventricular distention w/ domed shaped, thin boned ENLARGED cranium
What animals are more prone to congenital hydroencephalus?
Dogs-Brachycephalic
Calves
Foals
Pigs(familial)
What can cause Acquired Hydroencephalus?
Anything that Obstructs the flow of CSF leading to pressure atrophy.
Progressive dz
What are the lesions of Aquired Hydroencephalus? TQ
Lateral ventricular distention with NO cranial malformation
Lipping is present
What is Acquired Hydroencephalus a sequele of?
Bacterial meningitis Granulomatous meningitis (TB) FIP Cryptococcosis Intracranial Neoplasms Parasitic cysts Cholestratoma (horse)
What is Abiotrophy?
“Cerebellar Atrophy”
Premature apoptosis of Cerebellum
What is the primary metabolic defect/degeneration of the Cerebellum? TQ
Abiotrophy
Happens after the cerebellum has reached full size
Where are the lesions seen in Abiotrophy?
Cerebellar Cortex - basal ganglia
What are the lesions of Abiotrophy?
Loss of Perkinje cells & granule cells
How does Cerebellar Hypoplasia occur?
Inherited or Intra Uterine viral infection
What are the lesions of Cerebellar Hypoplasia?
loss of purkinje cells & granular cells
What viruses are associated with Cerebellar Hypoplasia?
Feline Panleukopenia
BVD-calves
Herpesvirus- dogs
What is Syringomyelia?
Inhereted dz causing a syrnx (tubular cavity) of cavitation in Grey Matter of the lumbar spine
What breed would you most likely see Syringomyelia in?
Apparently Weimaraners but really in CKCS
Leads to bunny hopping
What is a Prion Dz?
Abnormal protein causing spongiform changes in the brain
What are the lesions of Prion Dz?
No inflammation
Cytoplasmic vacuolation
Astrocytosis
How do you DX a Prion dz?
Examine the obex and use IHC
What are some examples of Prion dz?
Scrapie
BSE
Chronic Wasting Dz Deer,
Transmissible Mink Encephalopathy
What is Sphingolipidoses?
Globoid Cell Leukodystrophy
Etiology of Sphingolipidoses?
Lysosomal storage dz = Microglia cells –> Giant Globoid cells
What does Sphingolipidoses cause?
How is it Dx?
White Matter Degeneration
PAS stain
What is focal malacia?
Softening & necrosis of CNS tissue associated with specific toxins
What causes FSE (focal symmetrical encephalomalacia)? TQ
Hemorrhages from Clostridium perfringins D infection in sheep
What causes Equine leukoencephlomalacia?
Toxins from eating moldy corn
What causes Equine Nigropallidal malacia?
Yellow star thistle toxicity
What causes Avian encephalomalacia?
Hypovitaminosis E
What is laminar malacia? TQ
softening of cerebrocortical grey matter in a layered laminar pattern based on how susceptible the cells are to hypoxia
What are the two types of laminar malacia? TQ
Cerebrocortical Necrosis (CNN) Polioencephalomalacia (PEM)
What is the susceptibility of cells to laminar cortical necrosis from greatest to least? TQ
- Neurons
- Oligodendrocytes
- Astrocytes
- Microglial cells
What is the eitiology of laminar malacia/laminar cortical necrosis?
Lead poisoning-chronic → Cattle → CNN
Salt poisoning → Pigs → PEM
Selenium poisoning (acute) → Pig → Bilateral PEM
Thiamine depletion/deficiency → Rumi/Cats → CNN/PEM
Active Hyperemia to the brain is what?
Increased arterial blood flow
Passive congestion to the brain is what?
Increased venous flow
How does hypoxemia/Ichemia kill neurons?
Leads to hypoglycemia → energy depletion → increased Glutamate → neurotoxicity → neuronal death
Which type of animal is more resistant to hypoxemia?
Neonates
How does the brain get reprofusion injury?
Lactic acidosis
Calcium influx
Oxygen free radicals
Glutamate release
What are examples of causes hypoxemia/ishemia in Horses, Dogs, and Cats?
Horse: Anesthesia related
Dog: Fibrocartilaginous Embolic Myelopathy (FCEM)
Cat: Feline Ischemic Encephalopathy (Cuterebra)
What is the most important change that accompanies all Intracerebral lesions?
Cerebral edema
What is the etiology of Cerebral Edema? TQ
Increased ICP due to: Inflammation Hypoxia Ishcemia Toxins
What is a differentiating finding of cytotoxic intracellular cerebral edema?
No oozing blood on cut surface
What is a differentiating finding of Vasogenic cerebral edema?
Blood oozes on cut surface
Lesions of inflammation of the CNS?
Pronounced vascular response Perivascular Cuffing w/ Mononuclear cells Neuronal Degeneration Gliosis Demyelination (rare)
What causes CNS inflammationin dogs and cats?
Dogs: Idiopathic inflammatory brain disorders
Cats → Infectious meningoencephalitis
What is Thrombotic Meningoencephalitis (TME)? TQ
Acute Suppurative/Purulent inflamation caused by histophilus somni
What are the gross & microscopic lesions of TME?
Gross: hemorrhagic foci
Microscopic: Vasculitis w/ thrombosis & septic infarction (hallmark)
What does listeria monocytogenes cause in Adult ruminants? TQ
Encephalitis or meningoencephalitis
What does listeria monocytogenes cause in young ruminants & monogastrics? TQ
Septicemia & hepatic necrosis
How does listeria monocytogenes get into the brain? TQ
Affinity for brainstem: Ascends trigeminal nerve to the medulla & pons causing severe lesions (multifocal microabcesses)
What does clostridium perferingens type D cause? TQ
Focal Symmetrical Encephalomalacia (FSE) from the epsilon toxin causing vasculitis
What are the lesions of FSE in the Basal ganglia and the white matter? TQ
Basal Ganglia: Hemorrhage & softening (malacia)
White Matter: lysis & liquefacation
What causes edema disease of pigs and what does it cause?
E.coli → shigella toxin → vasculitis → bilateral symmetrical encephalomalacia of the brain stem
What histological changes would you see with Viral inflammation of the CNS? TQ
Vascular - perivascular cuffing of PMN cells
Neuronal - degeneration
White matter - Gliosis & demylination
Meningitis - Lyphocystic +/- plasmacystic
Inclusion Bodies
What histological changes would you see in the brain with Canine Distemper Virus? TQ
Gliosis & Demylination of White Matter
Intranuclear inclusion bodies
What inclusion bodies would you see with rabies and herpes?
Herpes - IntraNuclear
Rabies - IntraCytoplasmic (Negri)
How does Cuterebra cause Feline Ischemic Encephalopathy? TQ
Larvae migrate to brain via nasal cavity causing vascular lesions
What does cerebral nematodiasis cause in the brain?
Malacia
Hemorrhages
Migratory tracts
Space occupying lesions
How does Oestrus ovis cause cerebral nematodiasis?
Penetrates ethmoid bone and makes cysts in the cranial vault
How does hypoderma bovis cause cerebral nematodiasis?
Pentrates spinal canal during migration making cysts
What causes equine protozoal encephalomyelitis?
CS?
Sarcocystosis (Sarcocystis neruona) Horse is dead-end host –> affects spinal cord, focal liquafactive necrosis
CS: ataxia & CNS signs
How do you Dx EMP?
Biopsy of spinal accessory nerve and see Wallerian degeneration
Neoporosis is caused by Neospora caninum. What does it cause in Horses, Dogs & Cattle?
Horses (DH) → meningoencephalomyelitis
Dogs (DH) → Polyradiculoneuritis & polymyositis
Cattle (IH) → Multifocal necrosis +/- abortion
How does cryptococcus neoformans cause dz in dogs?
Infects meninges & paranasal sinuses → granulomatous meningioencephalitis (soapy looking lesions)
How does cryptococcus neoformans cause dz in cats?
Infects Nasal cavity & Pharynx → non-supurative meningioencephalitis (soapy looking lesions)
What causes polioencephalomalacia (CNN of cerebral cortex) in ruminants? TQ
Vit B deficiency from Brackenfern or Horse tail ingestion
What is the pathophysiology of Vit B deficiency in ruminants?
Grey matter degeneration & bilateral symmetrical edema due to increased thiaminase levels
What is the pathophisiology of avian encephalomalacia?
Hypovitaminosis E → Focal necrosis Cerebellum → exudative diathesis & muscular distrophy
What causes bilateral cerebral cortical necrosis (CNN) in Lambs & kids?
CU defeciency affecting both grey & white matter → axonal degeneration If present at birth = sway back Delayed onset (upto 6mths) = enzootic ataxia
What does NaCl toxicosis do?
Affects grey matter of cerebral cortex
CS: blindness, deafness & convulsions
What are THE PATHOGNOMONIC lesions of NaCl toxicosis?
Eosinophilic meningioencephalitis + encephalomalacia (pigs) & polioencephalomalacia
What are your ddx for NaCl tox?
CNN
But CNN → laminar necrosis
NaCl tox → Eosinophilic meningitis + laminar necrosis
What causes leukoencephalomalacia in horses?
Ingestion of Fusarium moniliforme from moldy corn
What is the pathophysiology of leukoencephalomalacia in horses? TQ
Mycotoxin fumonisin B1 → focal necrosis of white matter of cerebral hemispheres via vascular damage → infarction lipid per-oxidation inhibiting DNA synthesis
Where would you see the hemorrhagic lesion of coup?
At the site of impact
moving object hitting stationary head
Where would you see the hemorrhagic lesion of Countrecoup? TQ
Opposite the site of impact
moving head hitting stationary object
What is hansen type 1 V disc degeneration?
Degeneration of annulus fibrosis involving multiple discs (acute dz)
Nucleus protrudes & puts pressure on spinal cord
Who is predisposed to hansen type 1 V disc dz?
Chondrodysplastic breeds
What is hansen type 2 V disc dz?
Bulging of disc, fewer discs involved (gradual dz)
Nucleus puts pressure on annulus which puts pressure on spinal cord
Who is susceptible to hansen type 2 V disc dz?
Any Breed Old dogs
What is the most common tumor of the CNS? TQ
Meningiomas → well circumscribed & encapsulated w/ streams & whorls of fusiform CT
Who gets Glial tumors most commonly? TQ
Brachycephalic breeds
What is the most common glial tumor? TQ
Astrocytoma –> Not well demarcated
What is the 2nd most common glial tumor? TQ
Oligodendrioma –> well demarcated
If a dog has a metastatic (2dary) CNS neoplasm what is your highest rule out?
Mammary carcinoma –> most common mammary tumor of dogs
What is cyclopia and what is it’s etiology?
A single medial globe (eye ball)
From Ingestion of Veratrum californicum ( veratrum alkaloid) at day 14 of gestation
What is Synophtalmia?
Incomplete separation or early fusion of globes
What is Coloboma?
Failure of choriod fissure to close (optic cup)
Normally found at the optic disc
What is Scleral ectasia?
Cavity of choroid lined by retinal layer & associated with CEA –> retinal degeneration or detachment
Who gets collie eye anomoly (CEA)? TQ
Inherited in collies & shelites
What is the pathology of Collie Eye (CEA)? TQ
Coloboma –> incomplete closure/development of the optic cup –> ABNORMAL Choriod & Retina –> retinal degeneration or detachment
What are the lesions of CEA? TQ
Chorio-retinal dysplasia/hypoplasia
Ectasia of optic disc/sclera
Abnormal retinal vessles
+/- Vision
What is suppurative focal blepharitis?
Hordeolum (stye): suppurative adenitis (inflammation)
What is External Hordeolum?
Suppurative adenitis of adnexal galnds: Moll- apocrine or Zei- sebaceous
What is Internal Hordeolum?
Suppurative adenitis of melbomian gland
What is sterile Blepharitis?
Chalazion: sterile granulomatous inflammation of internal melbomian gland
What is the most common neoplasm of the canine eyelid?
Melbomian Gland adenoma
What is the 2nd most common neoplasm of the canine eyelid?
Melanocytoma
What is a Dermoid? TQ
A congenital teratoma tumor on the conjuctiva with at least 2 embryonic layers. Contains Skin & hair!
Where do dermoids occur on dogs & cattle?
Dogs: Lateral canthus & limbus
Cattle: Medial canthus, eyelid & 3rd eyelid
What animals get infectious conjunctivitis more commonly?
Cattle & Cats
What are the viruses that can cause infectious conjunctivitis?
Feline Herpes & IBR (BHV-1)
Infect the eye and make it more susceptible to 2dard bacterial infection
What bacteria is associated with pink eye in cattle? TQ
Moraxella
What other bacteria can cause infectious conjunctivitis?
Mycoplasma
Chlamydia psittaci
What parasites can cause infectious conjunctivitis? TQ
Thelaziasis (cattle/horse)
Habronema (horse)
Oestrus ovis (sheep)
Who gets idiopathic eosinophilic conjunctivitis?
Horses & Cats
What are the lesions of Idiopathic eosinophilic conjunctivitis?
Ulcerative
Epithelial hyperplasia
Cellular infiltrate of lymphs & eos
What is Non-infectious conjuctivitis?
Nodular granulomatous episcleritis (NGE) –> nodules in lamina propria made up of macrophages, fibroblasts & lymphcytes
What is the most common neoplasm of the conjunctiva?
SCC
Cattle > Horse > dog & cat
What predisposes animals to SCC on their conjunctiva?
IBR (BVH-1)
Genetic –> Herefords
Actinic irradiation
Hypomelanosis
What in an infectious cause of ulcerative dz of the cornea?
Infectious Bovine Keratoconjunctivitis - (Moraxella bovis)
What are dendritic ulcers of the cornea?
Branching tracts of necrosis
What is a viral cause of dendritic ulcers?
FeHV-1: neutrophils infiltrate & release enzymes –> descemetocoele
What is a melting ulcer? TQ
Suppurative keratomalcia
What is the pathology of melting ulcers? TQ
Neutrophils infiltrate & release Proteases/collagenases liquify stroma (keratomalcia) –> descemetocoele –> perforation
What is Equine keratomuycosis (mycotic keratitis)?
Opportunistic infection of Aspergillus in corneal wounds
Why does Equine keratomycosis cause descemtocoeles?
Aspergillus has high affinity for descemet membrane
What can predispose a horse to keratomycosis?
Long term use of antibiotics or corticosteroids
What is pannus?
A non-ulcerative superficial lesion of the cornea with marked pigmentation
What is the etiology of pannus?
Sun alters antigen in the cornea –>cell mediated response –> cell membrane grows across cornea
What is canine pannus keratitis?
Uberreiter’s syndrome/superficial stromal keratitis
typically bilateral vascularized opacity of cornea
What is the etiology of eosinophilic keratitis?
Idiopathic in cats
What is primary KCS?
congenital lack of lacrimal secretions or caused by old age (dry eye)
What is secondary KCS?
More common form of dry eye that arises from anything that destroys the lacrima lduct
What is dacryodadenitits?
autoimmune inflammation of the lacrimal gland –> eptithelia hyperplasia –> metaplasia of cuboidal to squamous cells –> dry eye
What is the etiology of anterior uveitis?
toxic damage, hematogenous infections or extention of deep corneal ulceration alters formation of aqueous = decreased IOP
What are the lesions of anterior uveitis?
Hyperemia & congestion of cilliary body & iris
Aqueous flare–>exudate
Hypopyon –> white/pink/yellow flocculant sediment in aneterior chamber
Hyphemia –> blood in Ant. Chamber
Glaucoma
Keratitis punctate
What is hyphemia? TQ
Blood in anterior chamber
What is keratitis punctate?
adherence of inflammatory cells to posterior corneal endothelium
What is the sequele of anterior uveitis?
Anterior synechia
Posterior synechia
Iris bombe
What is anterior synechia? TQ
Iris adhering to cornea
What is posterior synechia? TQ
Iris adhering to lens
What do both forms of synechia lead to ?
Glaucoma
What is an Iris bombe?
Complete posterior synechia (360) –> blocks papilary flow –> increases Posterior chamber pressure –> iris bulges –> & can attatch to anterior cornea
What can dz conditions can have the sequele of iris bombe?
Ulcerative keratitis
Hematogenous Infection
Anterior Uveitis
What is the etiology of posterior Uveitis (chordidits)?
Direct or hematogenous infection
What are the lesions of posterior uveitis (chorditis)?
Hyperemia of cilliary body & choroid –> retinal detachment & degeneration
What is staphyloma?
When Iris is incorporated into corneal stroma.
Most common w/ posterior uvitis but can happen with anterior.
How is Stapyloma different from coloboma?
Lesion is off center of optic disc while it occurs at the optic disc with coloboma
What are two sepcific examples of posterior uveitis (chorditis)?
Equine recurrent Uveitis (ERU) - moon blindness from repeated episodes of chroditis
Feline Idiopathic Lymphonodular uveitis
What is the etiology of ERU/moonblindness?
Leptospira or onchocerca antigens have delayed reaction –> neutrophilic uveitis –> eosinophilic hyaline membrane on non-pigmented cilliary epithelium (resembles amyloid)
What is the most common histological patter of uveitis in cats & what can cause it?
Feline Idiopathic lymphonodular uveitis
Lymphoplasmatic pan uveitis, FIP, FIV, FeLV, toxo & choroidal hypoplasia
What causes primary glaucoma?
Bilateral decrease in drainage
What causes congenital glaucoma?
abnormal development of anterior chamber
What are the lesions of primary glaucoma?
goniodysgenesis - maldevelopment of trabecular meshwork where aqueous humor drains
What is secondary glaucoma, example?
Secondary Unilateral blockage
Ex. Iris bombe (form of papillary blockage)
What is retinal dysplasia?
failure to completely develop
What are the lesions of retinal dysplasia?
cells in rosettes & granules, retinal fold & undifferentiatied photo receptors
What is retinitis?
Systemic infection that causes vascularization and exudation leading to retinal degeneration
What can acguired retinitis lead too?
Choroidial infection –> retinal detachment
What infections can lead to retinitis?
CDV, MCF, FIP & toxo
What is retinal degeneration?
retinal atrophy–> loss of photoreceptors, formation of spaces in the retina & decreased thickness of retina
What is generalized progressive retinal atrophy (PRA)?
Photoreceptor dysplasia (inherited)
Rods and cones never reachmaturity
Loss of night vision leading to complete blindness
What is central progress retinal atrophy (PRA)?
Pigmented epithelia degeneration (later onset)
defective removal ofshed components –> accumulation of lipofuscin –> dark macules
What are the types of retinal detachment?
Congenital –> micropthalmia
Tractional –> shrinking vitreous
Exudatvie - accumulation in sub retinal space
Rhegmatougenous - peripheral sensory eptithelium tears away from ora ciliaris –> fills with exudate & looks like funnel from ora ciliaris to optic disc
What is the most common disease of the lens?
Cataracts
What can cause cataracts?
Hydration of lens stroma due to loss of osmoregulation from DM or congenital infection of BVD
What are the most common occular neoplasms?
SCC: Primary tumor hereford cattle, sun, bovine papilloma virus (locally invasive)
Uveal Tract Melanoma: Primary tumor most common intraocular tumor of dogs
Lymphosarcoma: secondary tumor associated w/ BLV & exopthalmos most common ocular tumor is Cats
What is otitis externa?
Most common ear dz. Irritation –> hyperplasia of ceruminous glands
What is the eitiology of Otitis Externa? TQ
Parasites BacT Fungi FB Metabolic Disorder Chronic Inflammation Autoimmune Dz
What can predispose and animal to Otitis Externa? TQ
Excessive Moisture Increased Cerumen Anatomy of canal Impeded Drainage FB Lipid rich environment Inappropriate Treatment
What causes auricular hematomas?
Trauma
What causes auricular necrosis?
Infarction
Vasoconstriction
Septic emboli in pigs
Frost bite - cattle
What is the most common neoplasm of the ear and what animal is it seen in most commonly? TQ
Ceruminous Gland Adenoma/Carcinoma
Cats
What can cause Otitis Media? TQ
Extension of otitis externa
Ascending URT infxn from nasopharynx (cat flu)
Causing nasopharyngeal polyps or hyperplastic glands
What is the sequele of otitis media in horses? TQ
Salpingitis/Eustachitis –> inflammation of eustachian tubes
What is the sequele of otitis media, empyma?
Accumulation of exudate in the gutteral pouch after URT Ifxn. Can involve the carotid artery by extension –> epistaxis
What causes otitis interna?
suppurative infection from extension of otitis media
What is the lesion of congenital deafness?
absence or degeneration of organ of corti
What is the most prevelant type of deafness in animals? And what is the pathology?
Congenital
Assoc w/ piebald & merle genes –> cochlea-saccular degeneration –> collapse of walls –> secondary neuronal degeneration
What does ototoxicity do?
Degenerates the vestibular sensory epithelium & organ of corti –> head tilt, atacia & nystagmus
What can cause ototoxicity commonly? TQ
Aminoglycoside antibiotics–> degenerate cochlear hair cells
What species is very susceptible to aminoglycoside antibiotic ototoxicity? TQ
Cats
What can cause peripheral vestibular dysfunction?
Uncontrolled otitis media destroys labyrinths of inner ear