Pathology Semester 2 Flashcards
What does VITAMIN D stand for?
Vascular, Inflammatory, Trauma, Autoimmune, Metabolic and hormonal, Idiopathic, Neoplastic, Developmental and Degenerative
What are the layers in skin histologically?
Basal lamina and basal layer of cells. Melanocytes in epidermis. Stratum spinosum with Langerhans cells, stratum granulosum at top with superficial keratin. Superficial and deep dermis, then hypodermis.
2 glands associated with hair follicle?
sebaceous and apocrine
3 phases of hair growth?
Anagen and catagen and telogen
acantholysis v acanthosis
loss of keratinocyte adhesion, increase in thickness of stratum spinosum
ballooning degeneration
intracellular oedema
bullae
collection of fluid
folliculitis v furunculosis
inflm of mural, luminal or perifollicular follicle. perifollicular inflammation due to hair follicle rupture - a pyogranulomatous reaction
hyperkeratosis
increase in keratin thickness. can be with (para) or without (ortho) keratotic.
pigmentary incontinence
melanin granules and melanophages in dermis.
seborrhoea
increase scale formation with or without greasiness
spongiosis
epidermal intercellular oedema
vesicle v pustule
fluid filled blister <1cm. Pustule is cavity filled with inflammatory cells.
Vascular GROSS skin lesions
multifocal, target shaped, deep red colour due to infarctions
Vasculitis skin lesions CAUSE
Endotheliotropic organisms (R. rickettsia), immune complex deposition, septic emboli (E. rhusopathiae).
Predilection sites for vasculitis lesions
ears, lips, tail
HISTO of vasculitis skin
karyorrhectic cell debris and fibrinoid necrosis of vessel wall with fibrin and haemorrhage. If chronic, faded vessel outline.
3 types of vasculitis
neutrophilic, lymphoplasmacytic, eosinophilic
Types of superficial bacterial pyoderma?
impetigo, exudative epidermitis, dermatophilosis
impetigo synonym, severity and gross
superficial pustular dermatitis, least severity, erythematous papule (pustules)
exudative epidermitis synonym, organism, patho
greasy pig, S. hyicus, exotoxin cleaves btw stratum corneum and granulosum.
dermatophilosis synonym, organism
rain scald, D. congolensis, continuous invasion, inflammation and regeneration
Deep pyoderma organisms
staph spp, strept spp, corynebacterium spp, pseudomonas spp
Deep pyoderma GROSS
papules and pustules, crusts and coalescing ulcers with alopecia. dark red nodules with fistulae. lymphadenopathy, fever and epidermal acanthosis.
deep pyoderma HISTO
neutrophilic folliculitis and furunculosis
Abscess and cellulitis GROSS
focal, non-specific suppurative inflammation of deep dermis, assoc with fever and LNadenopathy. can progress to necrotising fasciitis
Abscess and cellulitis HISTO
circumscribed core of necrotic material and degenerative Np with granulation tissue. Cellulitis poorly circumscribed extensive suppurative or pyogranulomatous inflammation with oedema, haemorrhages and thrombosis
Cutaneous bacterial granulomas organisms and type of inflm
Actinomyces and Nocardia spp also Mycobacterium bovis and tuberculosis - pyogranulomatous dermatitis and panniculitis
Gross of cutaneous bacterial granulomas
fibrotic and ulcerative nodules with draining fistulae
3 viral family causes of inflammatory dermatitis - diff btw the inclusion bodies?
pox and herpes and papilloma. Pox is intracytoplasmic, Herpes is Intranuclear. papilloma proliferative squamous disease.
general viral infection histo
spongiosis and eosinophilic cellular inclusion
2 pox virus skin organisms, gross
Orf parapoxvirus, Cowpox orthopoxvirus. cause vesicular and proliferative lesions
cowpox
felids, face and forepaws, ulcers, papules and pustules, fibrinonecrotic exudate
orf
‘CPD’ - lambs and kids. from lips, muzzle and sometimes legs. mf-to-c raised, flat, grey crusts
feline herpes cause and gross and histo
Felid herpes virus 1. nasal planum and face skin, recurring crusts and ulcers. ulcerative and necrotising dermatitis, mixed dermal infiltration
cutaneous fungal infections
Malessezia, dermatophytosis
WHWT skin condition common
M. pachydermatitis. face, ears, neck, legs. erythema, alopecia, greasiness, lichenification and hyperpigmentation. Histo parakeratotic hyperkeratosis, epidermal hyperplasia with spongiosis. yeasts in aggregates in stratum corneum.
dermatophytosis
Ringworm, Microsproum or Trichophytan. Non-pruritic. Fungi cause furunculosis and folliculitis.
Kerion
mycotic pyogranuloma
Histo of dermatophytosis
ortho and parakeratotic hyperkeratosis and acanthosis, with luminal folliculitis and furunculosis.
subcutaneous fungal dermatitis
eumycotic mycetoma (disease name). tumour-like lesion with tumefaction, fistula and grains in discharge. caused
eumycotic mycetoma organism and histo
Actinomyces spp. Focal chronic suppuration with numerous granules of fungal hyphae with prominent fibrosis
systemic fungal dermatitis
haematogenous dissemination of… Cryptococcus, Blastomyces or Coccidiodes spp
2 skin-affecting protozoa
Leishmania and Besnoitiosis
2 forms of leishmania
alopecic (Th1 response) and nodular (Th2 response)
GROSS leishmania
head, limbs and dorsal midline - nodules, alopecia, ulcers or pustules.
leishmania histo
hyperkeratotic nodular to diffuse superificial and deep granulomatous dermatitis, with variable plasma cells
Parasites affecting skin
myiasis, sarcoptic mange, demodectic mange
Myiasis inflm type and organisms
eosinophilic and lymphocytic. Cuterebra spp (rabbit, rodent, cats). Hypoderma bovis/lineatum (cattle). Lucilia calliphora (sheep).
Sarcoptic mange gross and histo
inner pinna, head neck and legs. sever acanthosis, ortho and parakeratosis, spongiosis, leukocyte exocytosis and eosinophilic pustules
demodectic mange gross and histo
alopecia, sacling and comedones (squamous form). pustules, folliculitis, furunculosis (pustular form). ears, lips, eyes and extremitis. severe suppurative folliculitis and furunculosis
3 types of trauma/chemical damage to skin
physical (hot/cold/burn), chemical, actinic (direct solar effect)
which cells are present after a bruise has occurred?
haemosiderin laden macrophages
name the order of haemorrhages in size
petechiae, purpura, ecchymosis, haematoma
2 broad classes of ‘immune’ disease of skin
autoimmune (pathological self reaction) and hypersensitivity (exaggerated reaction to foreign matter)
MOA for hypersensitivity reaction?
IgE produced in response to antigens, if linked to membrane then eosinophils release lytic granules, causes histamine release, VD, oedema.
Urticaria Gross, Histo and Path
type 1 hypersensitivity, acute. oedematous skin lesions. localised or widespread. circumscribed erythematous oedematous lesions. non-specific and variable histo.
Atopic dermatitis gross, histo and path
intense pruritus, excoriations, papules, pustules, hyperpigmentation and lichenifiction secondary to trauma to self. perivascular to interstitial lymphoplasmacytic dermatitis with oedema, eosinophils, macrophages and some epidermal hyperplasia.
specific regions for insect allergy? histo
lumbosacral. eosinophil dominated dermal perivascular to diffuse dermatitis with lymphocytes and low M*
3 broad classes of autoimmune skin disease?
phemigo-complex disease, lupus erythematosus, erythema multiforme
phemigo-complex classes?
bullous phemigus, phemigus foliaceus, phemigus vulgaris
bullous phemigus target?
BPAG1 and 2
phemigus foliaceus target and gross?
desmoglein-1. skin only, starts from periocular and nasal skin, ears neck and ventral abdomen. erythematous maculae, pustules and erosions and crusts
phemigus foliaceus and histo?
acantholytic subcorneal or intragranular pustular dermatitis
phemigus vulgaris target? common or not? where are lesions?
Desmoglein-3. most severe and rare form. lesions on mucous membrane and mucocutaneous junctions, ulcerations and vesicles.
phemigus vulgaris histo?
spongiosis, vacoulation of suprabasilar layer, vesicles and bullae above basal layer. mild dermatitis.
types of lupus erythematous?
systemic, discoid
sytemic lupus erythematous (SLE) gross, histo and pth
skin around eyes, mouth, nostrils, genitalia and perineal area aswell as many organs. B cell hyperactivity, autoantibodies against nuclear contents. histo lichenoid interface dermatitis with hydropic degeneration of basal cells and lymphohistiocytic to plasmacytic infiltrate of dermo-epithelial junction.
discoid lupus gross, histo and path
skin only, photosensitised nasal dermatitis. nasal planum, eyrthema, depigmentation, scaling, crusting, alopecia, ulcers. Histo similar to SLE but more epidermal hyperplasia, denser infiltrate of lymphocytes.
erythema multiforme gross histo and path
uncommon, type 3+4 hypersensitivity. immune complexes in vessels and basal membrane. EM minor (symmetrical bilateral target lesions), EM major (widespread mucosal leisons, necrotising and vesiculobullous skin lesions and systemic illness). histo necrotic keratinocytes and satellitosis and epidermal necrosis.
3 vitamin responsible dermatoses?
vit A, Vit E, Vit B
Vit A hypovitaminosis
squamous epithelial hyperkeratosis (follicular keratosis)
Vit E hypovitaminosis
panniculitis due to steatonecrosis (lack of antioxidant protectant)
Vit B hypovitaminosis
dry sebborhoea with alopecia
Skin related mineral deficiency?
zinc. important in pigs and ruminants for DNA/RNA repair
zinc skin deficiency gross and histo
symmetrical and bilateral on distal legs and around eyes, ears and tail. erythematous maculae, papules covered in dark thick crust. histo acanthosis and epithelial hyperplasia with parakeratotic hyperkeratosis and prominent basal cell mitotic activity
dermatoses related to hormonal imbalances (3)
cushings, hyperoestrogenism, hypothyroidism
cushings synonym and gross/histo for skin
non pruritic, calcinosis cutis often. bilateral and symmetrical hypotrichosis and alopecia of trunk. skin thin and less elastic. hyperpigmented and comedones. cutaneous atrophy with orthokeratotic hyperkeratosis and follicular keratosis
'’red white blue’’ disease?
superficial necrolytic dermatitis (hepatocutaneous syndrome)… chronic hepatic disease. alternating parakeratotic hyperkeratosis (red), spongiosis and oedema spinous layer (white), and basal layer hyperplasia (blue). Assoc with glucagonoma and liver disease
hepatocutaneous syndrome gross/histo
symmetrical and bilateral on lips, periocular skin, pinna and distal extremities. histo erythema, erosion, ulcer and crust
general endocrinopathy skin histo
follicular atrophy, orthokeratotic hyperkeratosis, follicular keratosis with lumen distension. epidermal hyperpigmentation and dermal atrophy.
idiopathic skin diseases (2)
eosinophilic diseases and eosinophilic nodular diseases
two classes of eosinophilic diseases?
feline and equine
feline eosinophilic diseases?
eosinophilic plaques, granulomas and indolent ulcer.
eosinophilic plaque (feline)
pruritic lesions of haired skin of inguinal/axillary and lateral thigh areas. diffuse and perivascular eosinophilic dermatitis with epidermal acanthosis and spongiosis
eosinophilic granuloma (feline)
raised, pink pruritic nodular lesions on both haired and oral mucosa. diffuse eosinophilic inflm with granulomas centred around degenerated collagen bundles with degenerate degranulating eosinophils (flame figures)
indolent ulcer
uni or bilateral ulcerated-plaque lesion on UPPER lip only. non painful and non pruritic
2 equine eosinophilic skin diseases
Eosinophilic granuloma and multisystemic eosinophilic epitheliotropic disease (MEED)
nodular eosinophilic diseases of equines? (3)
Collagenolytic granuloma, axillary nodular necrosis, unilateral papular dermatosis. mainly all have coagulative necrosis and eosinophilia
3 types of tumour of skin (broad classes)?
epithelial, mesenchymal, round cell
non-neoplastic lesion of skin
epidermal cyst (lamellar keratin lined by continuous squamous epithelium).
2 main aet assoc with epithelial tumours (skin)
UV and viral
2 broad types of epithelial tumour (skin)
papilloma and squamous cell carcinoma
papillomatosis types (2)
cutaneous and fibro
cutaneous papilloma gross and histo
filiform exophytic and hyperkeratotic epidermal projections with thin dermal stalks. histo solitary benign and exophytic proliferations, mature fibrovascular stalk. Koilocytes present (eccentric pyknotic nuclear and peripheral clear halo due to ballooning degeneration in keratinocytes). sometimes intranuclear inclusions.
fibropapillomas and assoc cause
plaque-like lesions with predominent dermal proliferation . aet = feline fibropapilloma and equine sarcoids)
idiopathic squamous papilloma (skin)
gross similar to squamous papilloma but no cytopathic effects, higher prev in older animals
squamous cell carcinoma in skin
locally invasive and destructive. UV-light involved and also viral papillomatosis. single expansile hyperplastic ulcerated or nodular skin lesions. mainly on head. Invasive islands/cords of neoplastic cells within dermis. Anisocytosis, anisokaryosis and high mitotic index. keratin pearls present. inflm and desmoplasia. neutrophilic pustules due to abnormal keratin formation and necrosis.
3 types of cutaneous adnexa tumours
follicular tumours, sebaceous gland tumours, ceruminous gland tumours
follicular tumours types
infundibular keratinising acanthoma, tricholemmoma, pilomatricoma, trichoepithelioma, trichoblastoma
3 classifications of sebacious gland tumours
adenoma, epithelioma, adenocarcinoma
ceruminous gland tumour location, species and gross
ulcerative, nodular, pedunculated masses with yellow cut surface in ear canal of cats mainly.
4 types of skin mesenchymal tumour
fibrous tissue, haemangiopericytoma, vascular tissue, muscle tissue
fibroma/fibrosarcoma
skin and subcutis of cats and dogs. often reoccur. solitary palpable masses, soft to firm, grey to white. poorly demarcated with central necrosis. Histo bands of fibrous tissue with high mitotic index, fibroblasts interlaced with multinucleated cells.
cats fibroma/fibrosarcoma
viral or vaccination related
post-vaccinal fibrosarcoma
locally invasive spindle cell sarcoma at injection site. time between injection and development is extremely variable. histo lymphocytic infiltration and multinucleate giant cells at periphery of neoplasia.
equine sarcoid
type of fibrous tissue tumour. locally aggressive fibroblastic skin tumour in horses. factors are bovine papilloma virus 1/2, genetic and trauma. does not metastasise but reoccur following surgery.
equine sarcoid gross
variable. verrucous to occult. biphasic tumour both epidermal and dermal component although CT is mainly proliferative tissue involved.
equine sarcoid histo
resemble fibroma/fibrosarcoma
haemangiopericytoma
common in boxer, GSD, springer spaniel. rarely ulcerative. whirling histology
epitheliotropic cutaneous lyphoma (mycosis fungoides)
pautrier’s microabscesses.
non-epitheliotropic cutaneous lymphoma (NECL)
more aggressive, systemic involvement.
lipoma
benign tumour of adipose tissue. encapsulated with fibrous tissue
melanoma
common in dark pigmented skin. occur often on face, trunk, gums, palate, lips. common metastasis site is to the mouth.
calcinosis cutis
mineralisation of dermal collagen and BM of adnexa. occurs in cushings commonly
calcinosis circumscripta
‘tumoural calcinosis’… solitary, dermal lesions of young large dogs or horses. localised bony prominences or repeated trauma. chalky white lakes stain with von kossa surrounded by inflm and fibrosis. in chronic lesions osseous or cartilagenous metaplasia can occur.
anopthalmia
absence of eye
micropthalmia
reduced size of eye
cyclopia
central eye instead of two
synopthalmia
fusion of two eyes into one
dermoid/choristoma
ectodermal skin on cornea
coloboma
failure of optic fissure to close
retinal dysplasia
imperfect retinal development
aphakia
absence of lens
Veratum calcifornicum assoc with what eye conditon
cyclopia. Day 14-15 gestation of ewe.
blepharitis is…
inflm of eyelid
tarsal inflammation 2 types
internal hordeolum (purulent) or chalazion (granulomatous)
lacrimal gland inflammation
dacryoadenitis
inflm of zeis/moll glands
external hordeolum (purulent)
Bacterial/Viral causes of conjunctivitis
IBR/FHV/Chlamydiophyla psitacci/Mycoplasma felis
IBR/FHV eye gross
serous to purulent with possible fibrin conjunctivitis
Mycoplasma eye gross and histo
pseudo-dyphteric fibrin. histo erosions and presence of coccoid bacteria
Chlamidyophila eye gross and histo
unilateral usually. Np, M* Lymphocytes and inclusion bodies
FHV/IBR eye condition often assoc w/
keratitis and upper resp disease
3 examples of non-infectious conjuncitivitis
dissication, allergy, idiopathic
eosinophilic conjunctivitis gross and histo
ulcerative marginal blepharitis. histo hyperplasia/squamous metaplasia of epithelium/eosinophils and lymphocytes
Parasitic conjunctivitis
larval Draschia megastoma, Habronema microstoma via Musca fly vector. in horses. medial canthus, ulcerative, oozing, viable larvae. Histo granulomatous inflm with eosinophils and larvae.
keratitis definition
inflm of cornea
non-infectious keratitis causes
trauma, sunlight, tear film lack
how can trauma cause keratitis
trauma -> stromal imbibition -> ulcer -> secondary bacs (streps) -> neovascularization -> restitutio ad integrum
pannus keratitis histo
lymphocytes, plasma cells, M*, granulation tissue and epithelium is intact.
cheratitis sicca
hyperplasia of corneal epithelium, squamous metaplsia of conjunctiva.
descemeocele
hernation of descemets membrane
anterior staphyloma
protrusion of uvea through ulcer
Infectious keratitis causes
FHV1, Moraxella bovis, Aspergillus, Alternaria, Penicillium
Mycotic keratitis common if on what treatment
long term AB/corticosteroids
FHV1/Moraxella bovis gross
ulcerative keratitis
mycotic keratitis gross
deep ulcerative with purulent exudate, keratomalacia
FHV1 keratitis histo
eosinophilic intranuclear inclusions
mycotic keratitis histo
fungal hyphae within corneal stroma, neurophils
moraxella bovis keratitis histo
stromal oedema and neovascularisation
2 diseases of the lens?
cataracts and lens luxation
how is a cataract formed?
imbalance between nutrition of lens and enzymatic activity, loses hydration, denatures lens fibrous proteins
histo of a cataract?
Morganian globules and ‘bladder cells’
lens luxation aetiology
tumour compression or increase in pressure
how does lens luxation associate with glaucoma?
can cause or be caused by glaucoma
uveitis infectious agents?
FIP, CAV1, MCF. Cryptococcus spp, parasitic larva migrans of Toxocara canis.
what is phacoclastic uveitis?
lens rupture and release of lens proteins causes inflm reaction
FIP/CAV1/MCF path of eye
haematogenous spread of agent and autoimmunity
Cryptococcus uveitis histo
yeasts present, soap bubble appearance of choroid/retina. pyogranulomatous reaction.
FIP uveitis histo
pyogranulomatous and vasculitis
Lens rupture histo
lymphocytes, plasma cells and fragments of lens
Equine recurrent uveitis
immune mediated reaction to Leptospira interrogans var Pomona - overproduction of Ab causes inflammation. grossly thickening of iris, with pigmentation and change in shape.
histo of equine recurrent uveitis
neutrophils (acute) followed by lymphocytes with lymph follicle formation in ciliary body. hallmark is formation of hyalinised membrane in the inner ciliary body (amyloid).
Retinal dysplasia is common in what breeds
samoyed, collie, labrador
Agent that can cause retinitis
toxoplasma
glaucoma, Vit A/C/E/taurine deficiency and bracken fern toxin can all cause what eye condition?
retininal degeneration/atrophy
gonodiodyegenesis
imperforate pectinate ligament in eye or trabecular hypoplasia (loss of trabecular network)
uveitis and posterior sinechia can cause what condition?
secondary causes of glaucoma
bupthalmia is..
enlargement of the globe
2 epithelial tumours of the eye
meibomian gland tumour, conjunctival squamous cell carcinoma
intraocular melanomas can develop from…
iris, ciliary body, choroid
cats get what type of eye melanoma?
diffuse iris melanoma
adenoma or adenocarcinoma in eye arise from…
non-pigmented epithelium
feline tumour with complete bulb destruction and never metastases
feline primary intraocular sarcoma
retrobulbar tumours examples
adenoma, fibrosarcoma, neural tumours, lymphoma
what are the 4 conducting systems of ventricles in teh CNS?
lateral, third, aqueduct, fourth, lateral apertures and spinal canal
cells originating from neuroectodermal origin? (4)
neurones, astrocytes, oligodendrocytes and ependymocytes
cells originating from mesenchymal origin in CNS (3)
microglia, BV, cells of meninges
Nissl substance…
RER of neurones,
astrocyte role
BBB integrity. Uptake NTs recycling. Maintain pH and osmotic pressure.
oligodendrocytes role
small cells picnotic nucleus. Interfascicular and satellite type. produce myelin within CNS. halo on histo (lipid).
microglia
M* like cells. ameboid shape after activation (rod cells).
3 layers of meninges?
dura mater (collagen rich), arachnoid (fine trabecules with vessels), pia mater (thin contact layer).
spheroids
cross section of enlarged axons present in acute to subacute degeneration
neuropil
dense unmyelinated sheaths of many axons
why are neurones susceptible to damage?
highly metabolic, large span, cannot proliferate, metabolic limitations
excitotoxicity and hypoxia of neurones causes
red hypoxic neurones
oxidative stress and lack of antioxidants in neurones cases
chromatolytic neurones
other effects of damage to neurones histologically?
apoptosis, intracytoplasmic accumulations, vacuolation, intranuclear and intracytoplasmic inclusions
astrocyte response to damage
astrogliosis (+ in number) and astrocytosis (+ in size). cell swelling and cell hypertrophy (become gemistocytes, reactive astrocytes). alzheimer type 2 astrocytes, scar tissue formation…
oligodendrocyte damage response
impaired myelin formation and myelin destruction phagocytosis.
leukodistrophy
primary or congenital oligodendrocyte dysfunction causing abnormal myelin formation
microglia damage response
neuronophagic nodules, gitter cell formation, rod cell proliferation.
4 reasons for oedema in CNS
1) cytotoxic type (intracellular accumulation of fluid). 2) vasogenic type (vascular barrier injury). 3) hydrostatic type (elevated ventricular pressure). 4) hypo-osmotic type (imbalance of osmotic pressures).
main signs of a vascular CNS lesion
focal/MF, malacic/haemorrhagic, acute development of lesions
why is CNS susceptible to vascular damage
high metabolic rate, cannot store glycogen, occurs below 60% normal blood flow.
penumbra
area of local reduced blood flow round a central core of ischaemia in CNS.
consequences of ischaemic brain infarcts
pale centre with red neurones, spheroids and penumber of hyperaemia and astrocytosis. chronically would see liquefactive necrosis in centre with astrogliosis, penumbra of glial scar formation.
inflammatory routes to brain infection
deposition of immunecomplexes (FIP), direct infection of endothelial cells (CSF), trojan horse (viruses), retrograde axonal transport (Listeria, Rabies, Herpes virus).
CNS inflammatory hallmarks
focal (abscessation) mf or disseminate. malacic, haemorrhagic, firm (granulomatous). No clinical or diagnosit hallmark!!
encephalitis
brain/encephalon inflammation
myelitis
spinal cord inflammation
polioencephalitis
grey matter inflammation
polioencephalomyelitis
grey matter and spinal cord inflammation
leucoencephalitis
white matter inflammation
leucoencephalomyelitis
white matter and spine inflammation
meningoencephalitis
leptomeninges and brain inflammation
pachimeningitis
dura mater inflammation
choroiditis
choroid plexus inflammation
perivascular cuff
presentation of inflammation in Virkow-Robin Space due to inflammation
viral CNS inflm pattern
non-suppurative with neuronophagic nodules
viral CNS inflm distribution
selectively targeting neurons or specific sub-populations
Rabies virus CNS inflm
mild, non-suppurative polioencephalomyelitis. eosinophilic round intracytoplasmic inclusion bodies (Negri bodies)
Pseudorabies (Aujesky disease) and clinical signs
DNA, Suid Herpes Virus 1. Non-supp meningo-polioencephalomyelitis with glial nodules and neuronal necrosis with neuronophagia. Pruritus and head mutilation
Swine polioencephalomyelitis (Teschen disease)
Picornaviridae enterovirus. Non-supp polioencephalitis with neuronal necrosis, glial nodules and neuronophagia. tropism for lower motor neurones in spinal cord. mainly piglets <10w
Canine Distemper CNS
Morbillivirus, Paramyxoviridae. De-myelinating leukoencephalomyelitis. Acute gliosis and macrophages and if chronic then non-supp inflm with cavitation.
Non-supp polioencephalitis with inclusion bodies present in which post-vaccine disease?
distemper
Borna disease CNS
borna virus. Non-supp polioencephalomyelitis with neuronal degeneration and neuronphagia. Patomniomonic inclusion bodies but rarely seen. affect hippocampus (horse) and brainstem (cat).
West Nile Encephalitis
Flaviviridae (Arbovirus group). Non-supp polioencephalomyelitis. grey matter of thoraco-lumbar spinal cord and brainstem
Visna
maedi-visna virus (lentivirus, retroviridae). granulomatous leucoencephalomyelitis. Chronic lymphoplasmacytic infiltration that gives granulomatous appaearance. cavitation and malacia with choroiditis and meningitis.
FIP CNS condition
feline coronavirus. Ag-AB complexes in vessel walls, immune mediated aggression, diffuse pyogranulomatous meningo-chorio-subependemitis. can cause pyogranulomatous eye lesions too.
Louping ill
flavivirus from ticks. non-supp polioencephalitis with neuronal necrosis, glial nodules and neuronophagia. tropism for purkinje cells, gliosis and leptomeningitis.
4 viral vasculitis CNS causes
Classical Swine Fever, Rubarth’s Disease (CAV1), Malignant Catarrhal Fever, Herpetic encephalomyelitis
classical swine fever CNS
pestivirus, disseminated non-supp meningoencephalitis
hepatitis contagiosa canis (Rubarth’s disease)
rubarth’s disease. canine adenovirus 1. amphophilic inclusion bodies in endothelium with mixed vasculitis and haemorrhages
malignant catarrhal fever CNS
ovine herpes virus 2 + alcephaline herpes virus 1. Mononuclear necrotising vasculitis.
Herpetic encephalomyelitis
equine herpes virus 1. petechial or ecchymotic haemorrhages in white and grey matter or spine. vasculitis, with thrombosis, suppurative myelitis and haemorrhages.
general CNS bacterial infection findings
suppuration, tissue lysis and gliotic reaction. disseminated or focal/multifocal. with pyrexia and other organ invasion.
thrombotic meningoencephalitis (TME/Sleeper syndrome).
Histophilus somni. Young cattle post-pneumonia commonly. Fibrinopurulent meningitis, multifocal haemorrhagic and necrotising encephalitis.
Listeria monocytogenes CNS condition
haematogenous spread, can be from otitis media. retrograde axonal flow. MF-C microabscesses. oral cavity, cranial nerves and brainstem transmission. small leukomalcic areas.
mycotic encephalitis examples
Aspergillus spp, Mucor spp, Absidia spp.
mycotic encephalitis (yeasts)
Cryptococcus neoformans, Candida, Coccidiodes immitis, Blastomyces dermatididis. Necrotising nad suppurative granulomatous meningoencephalitis or myelitis. also necrotic vasculitis and thrombosis.
3 protozoal cns infectious agents
Neospora, Toxoplasma, Encephalitozoonosis
Encephalitozoonosis CNS
E. cuniculi (Microsporidia). Rabbits, rodents and dogs. Disseminated granulomatous encephalitis. compact epitheliod macrophages. Mf to massive dissemination throughout encephalon
Toxoplasmosis/Neospora CNS
T. gondii. Coupled with myocarditis/myositis. non-supp polioencephalitis with glisois. in adult causes necrotizing an granulomatous encephalitis
Granulomatous meningo-encephalitis (GME)
usually female young dogs. anti-GFAP antibodies? mf-to-c granulomatous meningoencephalitis. perivascular cuffs frequent.
CNS Trauma injury examples
Hansen 1 (extrusion of disc material) and Hansen 2 (protrusion without rupture of AF).
2 neural tube closure defects
cranium bifidum and spina bifida
holoprosencephaly
lack of cerebral hemisphere development, agenesis of corpus callosum
agyria, pachygyria and polymicrogyria are a result of
neuronal migration disorders and sulcation defects.
cerebellar agenesis and hypoplasia result from
malformation of caudal fossa
diff btw SB Occulta and SB aperta
occulta is covered by skin, aperta is open
meningocele v meningomyelocele
fluid filled hernial sac v fluid filled hernial sac containing some neuroparenchyma
hydrocephalus is an increase in
CSF volume.
syringomelia
fluid filled cavity within spinal cord following rupture of ependymal covering
syringobulbia
fluid filled cavity within brainstem following rupture of ependymal covering
hydromelia
fluid filed cavity within spinal cord, lined by ependyma
metabolic/toxic general path features CNS
symmetrical, malacia, specific cell necrosis, spongy state. progressively worsening condition affecting any age and sex.
Polioencephalomalacia (CCN corticocerebral necrosis)
of cortical structures or deep nuclei. thiamin deficiency related in carnivores and sulfur intoxication. Acute = oedema, red hypoxic neurones, swollen brain. chronic = cavitation, gitter cell proliferation, glial scar formation.
aspartate excitotoxicity commonly related with what CSN condition?
CCN. due to hypoglycaemia
leukoencephalomalacia
equine LEM, swayback
encephalomalacia
focal symmetrical encephalomalacia, oedema disease
Carnivore thiamin deficiency CNS…
often food with thiaminases or chronic deficiencies
chastek’s paralysis
foxes and minks, form of neuronal and axon/myelin degeneration due to thiamin deficiency
Focal Symmetrical Encephalomalacia
Cl. type D in ruminants. Microvascular damage and neuronal excitotoxicity. Chronically severs symmetrical encephalomalacia. Also caused by STEC in swine.
Equine leukoencephalomalacia (mouldy corn disease)
Ingestion of Fusarium moniliformis. Yellow-brown haemorrhagic malacic foci that progress to fluid-filled cavities (corona radiata). Toxin fumonisin B1 -> vascular necrosis and microthrombi -> leukomalacia -> vasogenic oedema, gitter cells and mild inflammation.
Swayback
congenital copper deficiency in lambs. Present from birth. Blind/ataxic, immobile and leads to death. Ventricular distension with bilateral rarefaction of periventricular grey matter.
Enzootic ataxia
post-natal dietary deficiency of copper. Bilateral symmetrical demyelination and axonal damage of spinal funiculi and motor neuron chromatolysis.
Hepatic encephalopatbhy
moderate/chronic or severe/acute. provoke a toxic encephalopathy. Astrocytes overwhelmed by +NH3, metabolised glutamine, cytotoxic oedema. severe spongy state of white matter. also assoc with CKD.
6 primary tumours of CNS
astrocytoma, oligodendroglioma, meningioma, choroid plexus papilloma/carcinoma, ependymoma
astrocytoma
common in brachycephalics, supratentorially, white, undemarcated. Can be malignant, see neoangiogensis and necrosis.
Oligodendroglioma
brachycephalic breeds common. induce angiogenesis and intratumoral haemorrhages. Well circumscribed, gelatinous. areas of necrosis, cystic appearance and honeycomb appearance on histo
meningioma
lobulated, granular, white to tan. Can contain mineralised centres (Psammoma bodies).
Choroid plexus papilloma/carcinoma
mainly in 4th ventricle. large, granular with rough texture. carcinomas induce haemorrhage in ventricle wall.
ependymoma
arise from ependyma lining the ventricles, assoc with obstructive hydrocephalus. large well demarcated tan solid mass. on histo can get pseudorosettes.
degeneration CNS characteristics
symmetrical, bilateral, with microanatomical focus. usually start at young age and become slowly progressive.
histo degeneration of CNS
depletion of neuron subpopulations, intracellular accumulation of material, white matter degenerations
5 degenerative CNS diseases
motor neuron disease, cerebellar cortical abiotrophy, degeneration of myelin (CNS+PNS), storage diseases, prion diseases
motor neuron disease CNS
neurons die from oxidative stress (Free radical damage). Neuronal chromatolysis, neuronal depletion and gliosis.
cerebellar cortical abiotrophy
familial. loss of purkinje cells first, slow progressive onset of worsening cerebellar signs. finally atrophy of cerebellar folia, transneuronal retrograde degeneration of functionally connected cells (granular cells e.g.)
Degeneration of myelin (2)
leukodystrophies and myelin dysgenesis
myelin dysgenesis (hypomyelinogenesis)
shaking puppy syndrome (X-linked defect of PLP protein) causing abnormal myelin and grossly diffuse grey translucent white matter.
storage diseases CNS
enzymatic defects causing intracytoplasmic storage of non-degradable catabolites > neuron degeneration. classified on nature of compound accumulation.
neuronal ceroid-lipofucsinoses… .
accumulation in neurons with lipofucsin followed by degeneration. Can be mitochondrially linked instead of lysosome defect.
prion diseases (6) and their histo appearance
Kuru, vCJD, Scrapia, BSE, CWD, TME. Neuronal vacuolation, neuropil vacuolation, astrogliosis and NO inflammatory signs.
terms for inflm of spinal ganglia, spinal ganglia and related nerves, nerves only
ganglionitis, ganglineuritis, neuritis
Wallerian degeneration (PNS), histo
axonal segmental degeneration caudally to site of insult. Many spheroids, necrosis, schwann cell proliferation. not the consequence of ischaemia/trauma, caused by lack of conduction.
Vascular PNS disease
ilio-aortic thromboembolism (saddle thrombus). sudden paraperesis or paraplegia with painful hard muscle lacking femoral pulse.
acute polyneuritis/polyradiculoneuritis
autoimmune inflm of PNS, including ganglia. E.g. coon hound paralysis (Raccoon bites in USA). Non-supp inflm of proximal motor nerves. Transient ascending paresis/paralysis.
cauda equina neuritis
pyogranulomatous inflm of cauda equina of horse. chronic and progressive with paralysis of sphincter and tail.
neuropraxia
structurally intact nerve, temporary impairment, but do fully recover
axonotmesis
axon damaged, basal lamina intact, can regenerate over long time depending on distance from organ.
neurotmesis
entire nerve truncated, no regeneration possible
caudal compression of cauda equina
assoc w/ stenosis of lumbosacral spinal canal, chronic axonal degeneration.
dysautonomia (2 types) PNS
Equine dysautonomia (Equine) and Feline dysautonomia (Key-Gaskell syndrome).
equine dysautonomia PNS and histo
grass sickness. can be chronic or acute. grazing animals only. Cl. botulinum type C. Histo see shortened intestinal villi, inflm and accum of mucus.
3 forms of grass sickness histologically
acute (plexuses marked chromatolysis), subacute (plexuses reduced number of neurones but proliferation of non-neuronal elements), chronic (plexuses reduced severely in neurons and overcome with non-neuronal cell proliferation).
Key-Gaskell syndrome
feline dysautonomia. sporadic worldwide. Possible Cl. botulinum type C involved.
Metabolic neuropathy (4) PNS
Salinomycin poisoning, canine hypothyroidism, diabetic polyneuropathy, paraneoplastic neuropathy
salinomycin poisoning PNS
primary axonal degeneration of both sensory and motor nerves
canine hypothyroidism PNS
partially inconsistent reports of degeneration and demyelination
diabetic polyneuropathy PNS
rare in dogs. plantigrade posture of hindlimbs.
paraneoplastic neuropathy PNS
autoimmune inflm response, degeneration and regeneration.
difference between lamellar and woven bone
woven is immature, lamellar is mature. lamellar can be compact or spongy.
embryologically bone is dervied from
mesoderm, either cartilage or connective tissue
two types of ossification
endochondral or intramembraneous
zones in the endochondral growth plate
resting zone, proliferating zone, maturation zone, calcification zone, woven bone formation, capillary invasion…
osteoprogenitor cells can produce which cell types
osteoblasts or osteoclasts.
which cells are precursors to osteoblasts
peritrabecular stromal cells
osteoid is made up of what and what is its fate?
90% collagen (type1) plus chondroitin and osteocalcin). after 10d, undergoes primary mineralisation, then after few months secondary mineralisation. at the beginning it is unmineralized matrix. creates the osteoid seam.
type 1 and type 2 collagen are found mostly where
bone type 1, cartilage type 2.
what is howships lacunae
where osteoclasts erode the bone (proteolytic enzymes and low pH).
3 actions of peritrabecular stromal cells
produce EPO, progenitor cells, react to PTH, act as strain gauge and activate remodelling
RANK-L and OPG regulate which cells?
RANK-L ++ osteoclats, OPG – osteoclasts
which cells are inhibited by calcitonin and promoted by IL1 + TNFa
osteoclasts
osteoblast activation occurs by? inhibition?
osteoclasts producing matrix bound ground substance. inhibited by PTH.
what signs are assocaitd histo with bone injury?
resting and reversal lines
sirenomelia
lack of hind limbs
peromelia
lack of distal part of limbs
scoliosis, lordosis, kyphosis and kyphoscoliosis
lateral divert, ventral divert, dorsal divert
chondrodysplasia is a defect in which process? mainly assoc with what cause?
endochdonral ossification. genetic.
3 examples of BOVINE chondrodysplasias
bulldog calf, telemark lethal, snorter
bulldog calf
dexter/holstein. born dead w/ small limbs, short jaw and domed head. on histo lack growth plates, disorganised chondrocytes
telemark lethal
telemark breed. chondrodysplasia. born alive but die soon.
snorter
hereford/angus genetic chondrodyplasia. not lethal. short legs and broad head. irregular columns of hypertrophied chondrocytes on histo.
ovine chondrodysplasia
arachnomyelia. fibroblast growth factor receptor 3 defect. semi-lethal. Suffolk and hampshire breeds. small ossification centres in nodules on histo. hypertrophic cartilage. assoc with fracture.
osteogenesis imperfecta
defect in collagen type 1 gene. brittle bones. calcified cartilage spicules in primary spongiosa. pink teeth, joint laxity blue sclera.
osteopetrosis/marble bone disease
in angus, hereford, simmental. osteoclastic resoprtion/remodelling of primary spongiosa. long bones are short and fragile. no marrow cavity, avascular metaphysis and medulla occupied by cartilage matrix. assoc anaemia.
congenital hyperostosis
pigs, stimulation of extracortical bone production. stillborn or dies after birth, radius and ulna commonly. woven bone.
craniomandiublar osteopathy/lion jaw
dogs, WHWT commonly. bilateral bone ankylosis and tympanic bullae filled with new bone. histo see bone formation and resorption (resting and reversal).
hypertrophic osteopathy/marie’s disease
linked to neoplastic or thoracic inflm masses. changes in forelimb circulation causes increases periosteal bone production. hyperaemia and oedema on histo with fibrovascular periosteal proliferation.
bone pigmentations
icterus, porphyria, melanosis, tetracycline
Osteonecrosis
lack of bone blood supply, necrosis of osteoclasts, inflm reaction against dying bone. dry periosteum with tan bone. in histo see empty lacuna with pyknotic nuclei.
Claviceps purpurea can cause what bone condition
osteonecrosis
Legg-Calve Perthes Disease
genetic autosomal recessive. ischaemic episodes, delayed incorporation of vessels in femoral head. weight bearing leads to infarcts and necrosis. fracture, collapse of necrotic bone and femoral head.
osteoporosis common causes. what is the pathogenesis?
old age, calcium deficiency, starvation, GI parasitism, inflm bowel disease, corticosteroids, disuse of bone. Happens because increase osteoclastic activity but can occur through various mechanisms.
4 mechanisms of osteoporosis
starvation, parasitism (reduced calcium absorption), corticosteroids (collagen synthesis inhibition), disuse (reduced weight bearing, increase OC activity).
gross appearance of osteoporosis and histo
reduced bone quantity, quality of bone is normal. on histo see smaller trabeculae with normal calcification
Rickets and osteomalacia cause and pathogenesis and histo
hypovitaminosis D and hypophosphataemia. defective mineralisation at sites of bone growth or remodelling. newly formed osteoid is poor quality. on histo see tongues of cartilage extending into the metaphysis. common in chickens
fibrous osteodystrophy causes (4) and pathogenesis
primary PTH secreting tumour, secondary renal hyperparathyroidism, low ca/high P diet, PTH-like secreting tumour. huge increase in PTH causes stromal cells to mass produce collagen, which cant be absorbed by OCs.
fibrous osteodystrophy gross and histo
bone enlarged, fractures, floppy texture. on histo see bone resorption (OC activty) with fibrous proliferation.
process of fracture to repair
haemorrhage, haematoma, proliferation of collagen, ossification or chondrification (if O2 low), remodelling or endochondral ossification.
terms for inflm of outside of bone, of bone, of bone and marrow, of all structures of the bone
periosteitis, osteitis, osteomyelitis, panosteitis.
common causes of bacterial osteomyelitis in all species. where and why do they infect?
Actinomycosis, tuberculosis, brucellosis, yersiniosis, salmonellosis. capillary loops due to fenestrated endothelium, lack of phagocytes and blood flow turbulence.
bacterial osteomyelitis foal
e. coli, strept, salmonella, rhodococcus, klebsiella.
bacterial osteomyelitis calf
actinobacterium pyogenes, salmonella.
bacterial osteomyelitis dog/cat
secondary to penetration injury… staph intermedius, streps, proteus, e.coli
coccidiodes immitis (dog) causes…
mycotic osteomyelitis
viral osteomyelitis
distemper virus
bovine mandibular osteomyelitis
actinomyces bovis. pyogranulomatous osteomyelitis. purulent exudates and splendore-hoepplie figures.
metaphyseal osteopathy (hypertriohic osteodystrophy)
large young dogs. bilateral and symmetrical periosteal proliferation in radius and ulna. on histo see suppuration in cartilage tongues at physis.
canine panosteitis (juvenile osteomyelitis)
giant young dog. possible distemper link. only see Xray changes - radiodensity in medulla near nutritional foramen. on histo no inflm but some inflm cells, fibrovascular tissue and woven bone in bone marrow.
chondrosarcoma
nodular, expansile usually in ribs. infiltrative but not metastasising. on histo well differentiated chondrocytes with abundant matrix. disorganised in physis.
osteosarcoma
destructive and proliferative. often in weight bearing bones. poorly differentiated osteoblasts with high mitotic activity on histo.
4 types of joint
syndemosis, symphyses, diarthrosis, synsarcosis
types of cell in synovial membrane
macrophage like and fibroblast like
aggrecans has a role in
joint pressure maintenance
what is a chondrone and ebumation. what occurs before eburnation?
group of chondrocytes which form in response to injury, eburnation is loss of synovial surface so bone is exposed. fibrillation occurs first.
DJD proper names are
osteoarthritis or arthrosis
gross and histo of DJD
rough, yellow fibrillation, ulceration and eburnation. can get osteophytes and joint mice. histo villous hypertrophy, inflm cells and necrotic cartilage.
Osteochondrosis aetiology and common species
rapid growth, over nutrition, mineral imbalances, trauma, genetics. young pigs, male dogs elbow dysplasia, horses.
osteochondrosis pathogenesis, gross and histo
ischaemic damage to growing cartilage, necrosis, cyst and detachment. white foci lesions leading to cartilage ulceration. histo see cartilage cores, cysts, hypertrophic cartilage.
GSD lack of conformity btw femoral head and acetabulum…
hip dysplasia
congenital patellar luxation
common in toy breeds and horses. hypoplasia of femoral trochlea.
Intervertebral disc disease
age related or congenital. degeneration of nucleus pulposus, rupture of annulus fibrosus, herniation of nucleus pulposus. ventral or dorsal herniation. dorsal has 2 types (Hansen 1/2). chondroid metaplasia/mineralisation of the herniation.
spondylosis
seconary degeneration of ventral annulus fibrosus. formation of osteophytes at ventral/lateral margins of vertebral bodies.
wobblers syndrome proper name
cervical vertebral stenotic myelopathy
wobblers syndroms aet
malformation of vertebrae causing pressure on spinal cord. various grades.
bacterial arthritis agents
streps, staphs, e.coli, erysipelas, haemophilus parasuis, actinobacillus equuli
bacterial arthritis path, gross and histo
either penetrating wound or septicaemic spread. various exudative forms, mainly purulent. villous hyperplasia and inflm cell infiltration
erysipelas bacterial arthritis
serofibrinous exudate
mycoplasma species causing arthritis in pig, goat, sheep, cow
M. hyorhinis (pig), M. mycoides (goat and cow), M. capricolum (sheep)
mycoplasma arthritis gross, histo
serofibrinous arthritis with villous hypertrophy. Non-degenerate neutrophils and mononuclear infiltration
viral arthritis agents (2) and histo
caprine arthritis encephalitis virus (CAEV) or sheep maedi visna virus. non-supp inflm.
rheumatoid arthritis gros and histo
complement cascade attacking self synovium. polyarthritis. oedema, pannus. hypertrophy and hyperplasia of villi.
synovial sarcoma
large breed dog. often stifle/elbow. indistinct border, infiltrates along planes. polygonal to spindeloid cells, oval nuclei can have cleft or cavities with proteinaceous/mucoid material.
histiocytic sarcoma
tumour of dendritic (langerhan) cells near synovial membrane. nodular swelling on joint.
explain colours of type1/2 muscle types
white = lots of mitochondria, fatigue resistant, oxidative. red = relies on glycolysis.
myotube forms when
damage to muscle, segmental necrosis.
histo of muscle atrophy
reduced myocyte size, infiltration with fibrour or fat tissue.
congenital musclar hypertrophy
belgian blue cattle and callipyge sheep. myostatin gene defect.
splayleg
myofibrillar defect in pigs. reduced myofibre diameter with decreased myofibrils and cytoplasmic glycogen
muscular dystrophy/X linked muscular dystrophy
congenital defect in gene coding for dystrophin (sarcolemmal protein). get muscular atrophy and pale muscles streaks in dogs. in cats get muscular hypertrophy over neck and shoulders and oes/diaphragm.
malignant hyperthermia
pigs defect in ryanodine receptor, over excitation of contraction, over release of calcium, excessive contraction and heat production. PSE meat and rapid rigor.
myaesthenia gravis histo
can only be seen on electron microscopy. associated with thymoma and is caused by autoantibodies against AcCh receptors
nutritional myopathy aka white muscle disease
Vit E/Selenium deficiency. lack of anti-oxidant acitivty, rhabdomyolysis. bilateral symmetrical white streaks in muscle. histo see multifocal degeneration of contractile elements and adipose tissue necrosis (yellow fat disease in horses).
exertional myopathy/equine exertional rhabdomyolysis/monday morning disease
exercise without training. insufficient ATP production causes excess glyolysis, lactic acid production, rhabdomyolysis, kidney damage. mainly in gluteals, femoral and lumbar muscles
bacterial myositis types (2)
suppurative and chronic pyogranulomatous fibrosing nodular myositis
suppurative myositis
streptococcus zooepidemicus (horse), arcanobacterium pyogenes (cattle/sheep), corynebacterium pseudotuberculosis (CLA), pasteurella multocida (cats). often purulent exudates and abscesses in muscle
chronic pyogranulomatous fibrosing nodular myositis
actinobacillus ligneresii (wooden tongue in cattle) or staphylococcus auerus (botryomycosis in pig and horse). fibrosing, granulomatous inflm in muscle. central radiating clubs of amorphous eosinophilic material.
malignant oedema
clostridium septicum/perfringens/novyi. penetrate muscle through skin wound, produce toxins creating tissue damage. gas bubbly appearance.
blackleg
clostridum chauvoei. latent spore activation in muscles, colonised by previous ingesta, reactivation by stressors. muscle dark red, oedematous dry centre and porous pattern.
parasitic myositis
N. caninum, T. gondii, T. spiralis, Sarcocystic spp, Cysticercus spp
eosinophilic myositis
sarcocystis spp. cattle/sheep. reaction against the cyst. demarcated green focal stripes. on histo see eosinophil dominated inflm and granulomas.
immune-mediated myositis
autoimmune antibodies produced against myosin type 2 (only in masticatory muscles). atrophy of masticatory muscles, see eosinophilic myositis. chronically see fibrosis mutlifocal lymphocytes.
neoplasia of muscles (2)
rhabdomyoma and rhabdomyosarcoma
strap cells and sarcomeric differentation are common in
muscle tumours. elongated mutlinucleate cells and ‘racket cells’ are ovoid shaped.
