Which of the following has multiple vessels?

Periportal

Central

midzonal 

Hypoxia will affect what area of the liver lobule first?

Hypoxia will affect centrilobular first. 

o   Increased production

§  Hemolysis

§  Congenital defect in bilirubin conjugation

o   Decreased excretion

§  Hepatic dysfunction

§  Cholestasis

• Random pattern-hematogenous bacteria, neoplasia
• Centrilobular-hypoxia, toxins
• Midzonal-rare, corticosteroid administration
• Pericordal-direct hepatotoxins
• Massive-entire lobule, dog-bluegreen algae, tyler’s disease in horses

opposite direction to blood

(canaliculi around central vein, portal vein, bile ductules, gall bladder)

contain large amounts of mitochondria

primarily responsible for purifying blood

separated from endothelial cells by space of Disse

fixed macrophages attached to endothelial cells of sinusoids

phagocytic, toxin degradation, iron accumulation

lipocytes within space of Disse

store vitamin A

produce collagen

important in hepatic fibrosis

highest concentraiton of oxygenated blood and nutrients

more resistant to toxic injury and hypoxia

necrosis uncommon

susceptible to direct hepatotoxins that do not require P450 (e.g. ferrous sulfate), ascending GI infections, and feline cholangiohepatitis

degeneration and necrosis uncommon, though reported in pigs and horses due to aflatoxins

intermediate oxygen and nutrient concentration

susceptible to corticosteroids

lowest oxygen concentration

most susceptible to hypoxia or toxic injury

area of greatest cytochrome P450 oxidase activity

necrosis more common (e.g. right sided HF, chronic passive congestion)

anemia, hemolysis, congestion

CCl4, chloroform

NOT alcohol or Hepatitis B, C.

Phenobarb, NSAIDS (carprofen in labs)

functional reserve only requires 10% of total capacity. 

66%

• metab of carbs, fats, ammonia, vitamins, proteins
• production of albumin, fibrinogen, globulins, factors V, VII, IX, X
• metab of drugs, toxins, steroids
• conjugation of bile

• jaundice/icterus (due to bilirubin)
• hepatic encephalopathy (due to ammonia)
• edema/ascites (due to increased pressure or oncotic pressure)
• cutaneous lesions (due to failure of chlorophyll breakdown)
• clotting abnormalities (due to lack of synthesis)
• abdominal pain

• intrahepatic- failure of bile secretion due to abnormal conditions in liver due to hepatocellular damage or damage to canaliculi (cirrhosis)
• extrahepatic- due to bile duct obstruction due to gallstones, neoplasia, pancreatic disease, fibrosis, etc.

false, due to nature of hepatic blood supply (dual)

cay be due to neoplasia, arteritis, or sepsis

• affected animals usually stunted
• hepatic encephalopathy
• angiography best method of diagnosis
• congenital: small liver with sharp edges, lobular atrophy, reduplication of arterioles and small blood vessels, lipogranuloma formation
• acquired: primary or secondary due to portal hypertension. chronic hepatic injury with secondary fibrosis, many small-caliber venous shunts between portal vein and other intraabdominal veins. large portal veins and larger, more dense muscular arteries. hepatocyte atrophy and lipidosis
• increased liver ALP, ALT, ammonia, BSP retention, bile acids, decreased BUN and albumin

• portal vein atresia
• more common in small breed dogs
• identical to PSS histologically, but no detectible shunt

• dilation of group of sinusoids
• dark red, irregularly shaped areas in liver
• unknown etiology
• in humans, after chronic steroid or contraceptive therapy

• lepto
• babesia
• acetaminophen
• snake venoms
• transfusion reaction
• RBC fragmentation
• hypoosmolarity
• phosphofructokinase deficiency

• cytauxzoon
• mycoplasma
• IMHA
• neoplasia
• RBC fragmentation

midzonal

Cushing's, iatrogenic steroids

weakness, depression, hepatomegaly, stunted growth

• late pregnancy, lactation
• increased synthesis of fatty acids, triglycerides
• increased lypolysis and uptake of FFA
• decreased fatty acid oxidation
• decreased apoprotein synthesis
• decreased lipoprotein excretion

idiopathic

obese cats with recent bouts of anorexia

hepatic failure, icterus, hepatic encephalopathy

consequence of other diseases that may have resolved at time of lipidosis

abyssinian, siamese, oriental shorthair cats

Shar-pei dogs

large and friable with chronic inflammation

chronic response of liver defined as bridging fibrosis and nodular regeneration

can cause portal hypertension, leading to ascites and acquired portosystemic shunting and biliary obstruction adn decreased liver function

causes: pyrrolizidine alkaoid toxicosis, chronic NSAIDS and anticonvulsants, or chronic right sided heart disease

rumenal acidosis (from intake of hi energy feed)

ulceration

rumen to portal vein bacteria dumped in liver

adenovirus (look for intranuclear inclusions on histo)

corneal edema from vasculitis

intrinsic toxins (pyrrolizidine alkaloids, aflatoxins)

idiosyncratic toxins (NSAIDS, anesthetics, anticonvulsants)

biotransformation-toxins processed in liver

bioactivation-activation rather than inactivation of toxins in liver

contain cycasin which is converted to methlazoxymethanol by bacteria in GI tract.

sings: vomiting, weakness, lethargy, liver failure, coagulopathy

• canine adenovirus type I- acute hepatic necrosis, hepatitis, corneal edema
• FIP-pyogranulomatous inflammation, vasculitis, icterus, ascites, vomiting, fever
• canine herpesvirus-neonatal puppies affected. hepatic necrosis

what are the types of injury the following cause? acute or chronic?

a. CCl4 and mycotoxins

b.pyrrolizidine alkaoids, aflatoxins

c. steroids

d. nitrofurantoin, copper

e. anticonvulsants, antineoplastic drugs

a. necrosis (acute)

b. fibrosis/cirrhosis (chronic)

c. degeneration (acute)

d. chronic active hepatitis (chronic)

e. lipidosis (acute)

fibrosis

cirrhosis

carcinoma

carcinomas-aflatoxins, nitrosamines

adenomas-many carcinogens

sarcomas-vinyl chloride-induced hemangiosarcoma

•  produced by Aspergillus and Penicillium on stored grain and feed
• B1 is most toxic substance produced
• anemia, icterus, ecchymotic hemorrhages, ascites
• chronic, low-level toxicity, with moderate liver damage, poor weight gain, decreased milk production
• feed analysis best way to diagnose

• acute hepatic failure, coagulopathy in dogs
• clinical within 30 min
• depression, stumbling, lack of coordination, seizures
• causes of sudden drop in blood glucose

enlargement due to glycogen accumulation and hepatocellular damage

increases ALT, GGT

autosomal recessive gene

hepatocytes accumulate copper, hit threshold, cells rupture, release copper to surrounding cells

hepatocellular-usually one massively enlarged liver lobe

biliary-multiple nodules scattered throughout liver

• German shepherds
• maldigestion/malabsorption before end of first year of life
• small numbers of hypoplastic or atrophied exocrine acini
• steatorrhea

pregnancy

diabetes

starvation

• usually dogs, female
• obese, older than 2 years
• vomiting, abdominal pain, anorexia, lethargy, dehydration
• occurs after fatty meal
• trypsinogen activated to trypsin. phospholipase A causes necrosis of fat and elastase and causes vasculitis-->DIC, thrombosis
• hemorrhage and edema in pancreas, areas of saponification of fat, fibrin adhesions

chronic

trypsin-like immunoreactivity

nodular hyperplasia and adenomas of pancreatic acini

pancreatic ductal or acinar adenocarcinoma

ependymal cells line _________

choroid plexus produces

ventricles

CSF

Oligodendrocytes form ______ that wraps around axons in CNS. Same as _________ in PNS

myelin

Schwann cells

BBB

fibrous (white matter), protoplasmic (grey matter)

pia mater

leptomeninges (arachnoid here)

dura mater

increase in size and number of astrocytes in response to injury

repair after CNS injury is largely the job of astrocytes

what are the 3 types of hydrocephalus?

in what breeds of dog is it common?

internal-in ventricles

external-in arachnoid space

communicating- in both

brachycephalic

______is an abnormally small brain

_________is  the near complete or complete absence of cerebral hemispheres

__________is cystic cavitation of the brain, usually involving cerebral white matter

________is a brain that lacks normal gyri and sulci

microencephaly

hydranencephaly

porencephaly

lissencephaly

neural tube closure defects are called ______

what is anencephaly?

prosencephalic hypoplasia?

• dysraphia
• absence of the brain
• absence of the cerebral hemispheres with preservation of the brainstem

what is a meningocele?

what is a meningoencephalocele?

herniation of meninges

herniation of meninges and brain/spinal cord

1.      BVD d100-170 of gestation

2.      Feline panleukopenia

3.      Hog cholera

4.      Canine parvo

5.      Border disease

• defective catabolism, resulting from a defect in lysosomal enzymes
• mostly autosomal recessive with neuro signs early in life. typically progressive and fatal

neurons and oligodendroglia

grey matter more sensitive than white matter

presumed to be due to ischemia and reperfusion during foaling. 

laminar neuronal necrosis, multifocal small hemorrhages

• hi sulfur intake
• deficiency in thiamine also implicated
• occasionally seen with water deprivation
• glows under blacklight

piscivorous  (foxes, cats, mink) (fish contain thiaminase)

horses consuming bracken fern and horsetail

• ataxia, neck ventroflexion, incoordination, mydriasis, convulsions
• hemorrhage, necrosis, neuropil vacuolation in periventricular grey matter

direct salt poisoning

(ingestion of excessive salt) mainly affects what species, and what are the signs?

cattle

v/d, paresis, blindness, abdominal pain

congestion of abomasal mucosa, dark watery intestinal contents. no CNS lesions

• ingestion of hi salt with restricted water
• blindness, deafness, head pressing, convulsions
• cerebral edema, laminar cortical necrosis, nonsuppurative and eosinophilic meningoencephalitis

• in horses
• neurotoxin: repin-sesquiterpene lactone-->glutathione depletion
• malacia in globus pallidus and substantia nigra

leukoencephalomalacis in horses

fumonisin by Fusarium moniliforme

circling, somnolence, visual impairment, weakness, pharyngeal paralysis

necrosis fo cerebral white matter

staggering, muscle tremors, convulsions, head pressing, blindness, hypersalivation, ruminal atony, recumbency, hyperesthesia, death

Lesions: laminar cerebral cortical necrosis in cattle if the disease has lasted a few days. white matter edema in brain and spinal cord, demyelination in dogs

• secondary to septicemia in young animals
• septic emboli with endocarditis
• abscesses from hematogenous spread or direct invasion
• through cribiform plate or from middle ear

• Listeria monocytogenes
• affects ruminants
• heavy feeding of silage
• head tilt, circling, confusion, depression, head pressing, unilateral facial nerve paralysis, masticatory muscle paralysis, purulent endophthalmitis
• lesions in brainstem
• spreads up trigeminal nerve
• microabscesses

what is infectious thrombotic meningoencephalitis? (ITME)

• Histophilus somni
• young cattle and sheep
• normally found in upper GI, resp, urogenital tract
• septicemia-->cerebral vasculitis with hemorrhage, necrosis, thrombosis

1. non-suppurative meningoencephalitis (+/-myelitis)
2. perivascular cuffing
3. gliosis
4. +/-viral inclusions
5. +/-neuronal degeneration/necrosis

can affect all mammals

skunks, foxes, raccoons, bats

CNS and salivary gland

• virus inoculated, replicates in muscle, spreads to sensory paravertebral ganglia, travels along peripheral nerves to CNS
• nonsuppurative encephalomyelitis, ganglioneuritis and parotid adenitis
• Negri bodies in hippocampus in carnivores and Purkinje cells in herbivores

• Pseudorabies (porcine herpesvirus 1)
• can affect all of the common domestic species
• carnivores infected by consumption of meat
• spreads up nerves to spinal cord, spreads within CNS and out into other peripheral nerves
• non-pigs: intense pruritus, hi mortal, fever, neuro signs
• pigs: mild fever, no pruritus
• young pigs: prostration, convulsions, twitching
• sows: abortion, stillbirth, mummified fetuses

• lymphohistiocytic and neutrophilic polioencephalomyelitis
• neutrophils may also infiltrate the grey matter
• gliosis, neuronal degeneration/necrosis, vasculitits, meningitis, and thrombosis

lentivirus

nervous system signs in kids 2-4 months old

hindlimb ataxia, paresis, paralysis, often death

non-suppurative leukoencephalomyelitis, demyelination

adults: arthritis, mastitis, pneumonia

• affects sheep over 2 years of age
• hindlimb ataxia, trembling lips, progressive hindlimb paralysis, death due to infection or starvation
• nonsuppurative meningoencephalitis, most severely affecting white matter, demyelination
• pneumonia, mastitis, arthritis

morbillivirus

affects canids, procyonids, mustelids, some large cats

look at paws

look for inclusions

Cryptococcus neoformans

cats, dogs, horses

enters brain via cribiform plate or hematogenously from pulm infection

• grey, gelatinous foci in brain, meninges
• inflammatory response variable
• non-staining mucopolysaccharide capsule which imparts "soap-bubble" appearance 

• affects horses
• encephalomyelitis
• gross lesions: none
• histo: hemorrhage, necrosis, perivascular cuffs of lymphocytes, macrophages, neutrophils, eosinophils, astrocytosis

New world monkeys and australian marsupials

immunosuppressed mammals

• gross: hemorrhage and necrosis
• histo: necrosis, hemorrhage, perivascular lymphohistiocytic cuffs, tachyzoites, cysts with bradyzoites

what causes transmissible spongiform encephalopathies? what is the pattern of transmission? 

what are some species affected?

abnormal isoforms of a normal cellular protein called a prion protein (PrPc)

horizontally via consumption of infected feed material

bovine, ovine, cervids, feline, mink

meningioma

cats, dogs, horses, cattle, sheep

astrocytomas are reported in what species?

what do they look like? where are they found?

• dogs (brachycephalic), cats, cattle
• poorly-demarcated, firm, grey-white masses in white matter and grey matter
• well-differentiated neoplasms difficult to differentiate from surrounding brain matter
• pyriform and temporal lobes

oligodendroglioma is found in what species? 

what does it look like and where is it found?

• dogs (brachycephalics), cats, cattle
• grey, pink-red soft to gelatinous in white matter or grey matter of cerebrum and brainstem

only left side develops

oviduct (shell gland, uterus) creates shell around ova during passage

accelerated passage yields soft shelled eggs

• anterior pituitary
• anterior pituitary
• ovary
• CL ,later by placenta to maintain pregnancy

what do the following become?

• paramesonephric ducts
• mesonephric tubules
• mesonephric ducts
• urogenital sinus
• external genital tubercle

• uterine tube/uterus/vagina
• tiny rete ovary
• regress
• vulva/vagina
• clitoris

male and female internal genitalia and gonadal tissue

testis and ovary

ovotestis

gonads fit gender, but do not match distorted external genitalia or accessory glands

male more common in pigs/goats

• testicular feminization
• male pseudohermaphrodite with female external genitalia and testes that produce testosterone
• bovine/equine

• 90-95% of female calves with male twin are born with masculinization of internal repro system
• sterile
• due to blood exchange between fetuses if placental circulation forms vascular anastamoses
• hormonal exchange=old theory
• hematopoietic cell theory (XX/XY chimera)=new theory

• congenital ovarian hypoplasia (streak hypogonadism)
• segmental aplasia (paramesonephric system)
• uterus didelphis (divided uterine fundus, double cervix, two vaginas)

A. cat

B. cow

C. horse

D. human

1.  germ cells (oocytes of follicle)
2.  granulosa (supporting cells)
3.  theca cells (supporting cells)
4.  interstitial cells (cats, endocrine)
5.  granulosa cells (dogs, tubular),
6.  outer epithelium
7. stroma
8. vessels
9. nerves

inflammation  of ovary (infectious or sterile)

rare

 in fimbria adjacent to ovary

common in mares

remnants of paramesonephric ducts

granulosa cell tumor 

dysgerminoma

benign teratoma

serous cystadenoma (rare)

what is the primary epithelial tumor of the ovary?

what is a secondary ovarian tumor?

• papillary adenocarcinoma
• often bilateral, implants into abdomen, causes ascites due to lymphatic blockage
• lymphosarcoma enlarges ovaries (cat, cow)

• granulosa cell tumor (80% of all ovarian tumors)
• unilateral, polycystic, many centimeters, enlarges ovary
• benign, surgical removal usually curative 
• usually produce estrogen--> nymphomania or bull-like behavior
• secondary cystic endometrial hyperplasia
• mares, cows, dogs

papillary ovarian carcinoma

seeds abdominal cavity

• bacterial associated with mating, may affect fertility
• Campylobacter fetus venerealis, Tritrichomonas foetus, Taylorella, Arcanobacter pyogenes 
• can affect glands (fibrosis) and affect pregnancy

·         Grade I- no lesions, good chance for successful preg

·         Grade II- mild to mod inflammation, minimal glandular nesting or fibrosis, mildly dilated lymphatics (doughy uterus) (a low and b high)

·         Grade III-prominent glandular nesting/fibrosis, dilated lymphatics (implies poor drainage), and inflammation; very poor prognosis for fertility

A.[image]B. [image] 

C. [image]

A. grade II (fibrosis and inflammation)

B. grade III (inflammation and fibrosis)

C. grade I

• hyperplasia of mucosa with formation of mucosal cysts
• followed by pyometra and secondary bacterial infections
• associated with excess estrogen due to follicular ovarian cysts, granulosa cell tumors, or iatrogenic

• mucosa of uterus and caruncles are exposed
• uterus swollen with dependent edema
• tissue becomes contaminated, dehydrated, traumatized

uterine subinvolution of placental sites (dog)

alternating striped pattern with inflammation, fibrin, necrotic debris

what are the placental structures of various animals?

cat

sow

primates

dog

ruminants

• cat, dog-zonary, endotheliochorial
• horse, sow- diffuse, epitheliochorial
• ruminants-cotyledonary
• primates-discoid, hemochorial

• amorphous, rubbery mass free in allantoic fluid
• formed by debris and dead cells
• incidental finding

amorphus globosus

incomplete twin found as round, hard cystic structures next to umbilical cord

adventitial placentation of chorion in a cow

red plaques of intercotyledonary placentation

common in older cows

• Endometrial cups, uterus, mare.  
• plaque‐like structures in the endometrium 
• trophoblasts invade the endometrium early in pregnancy.  
• 37-150 days of pregnancy  
• secrete equine chorionic gonadotropin.
• chorionic surface opposite each cup is called the chorioallantoic pouch and is avillous.

umbilical torsion

more likely if umbilicus is longer than your arm

Innate defenses

• Vaginal epithelium

• Cervical barrier

• Conformation

• Myometrial tone and contraction

• Drainage ofsecretions

• Neutrophils

• Macrophages

• Complement

• Cytokines

• Microbial recognition molecules

Adaptive defenses

• Humoral immunity including commonmucosal immune system

• Cellularimmunity

• stillborn
• memmy
• embryonic
• death
• infertile

fetal skin lesions

thickened, plaque-like

may be systemic

•  endometrium and placenta
• osteomyelitis, pneumonia, fibrinous inflammation of many other organs
• harbored in lymph nodes
• infection by ingestion of feed/water contaminated by uterine/placental fluids

what causes prolonged gestation?

what is needed to initiate parturition?

• pituitary aplasia-->failure of fetal pituitary-adrenal axis to initiate parturition
• fetus needs to release fetal adrenal glucocorticosteroids to initiate parturition

anasarca

generalized fluid accumulation

schistosomus reflexus

abdominal fissure and vertebral column retroflexion

mostly ruminants

perosomus elumbis

shortened body with loosely attached hind legs due to lack of vertebrae caudal to thoracic region

hydrocephalus

cerebral ventricular system fluid accumulation

doming of head

aquaductal stenosis or blockage due to inflammation, hemorrhage, tumor, etc.

fibropapilloma (bovine)

squamous cell carcinoma

vaginal polyp and fibroleioma

transmissible venereal tumor (canine)

uterine leiomyoma. 

can block lumen

• nurse cells for progenitor cells
• both in seminiferous tubules
• retained testicles can develop sertoli cell tumors-->estrogen-->feminization-->marrow suppresion, squamous metaplasia of prostate gland

between seminiferous tubules

produce testosterone

1. proliferation phase for spermatogonia
2. meiotic division (reduction in chromosome #)
3. spermatogenesis (haploid cells transform)

place the following in the correct order:

spermatocytes

spermatozoa

spermatogonia

spermatids

T or F: various factors affect the length of time for spermatozoal development

what are those factors?

seminal vesicles are absent in _________

bulbourethral (Cowper's) glands are absent in _________

and prostate glands are present in ________

dog and cat

dog

all male domestic mammals

1. seminal vesicles- thick liquid added
2. prostate-thin alkaline solution to neutralize urine and female system
3. Cowper's gland-lubrication and flushing or geltinous plug

• seminiferous tubules become small with only Sertoli cells remaining
• thickened basement membrane
• tubular and interstitial fibrosis
• inflammation secondary to tubular Ag leakage

[image]

what do both pictures depict?

• testicular degeneration
• interstitial fibrosis
• arrested spermatocyte stage
• vacuolated Sertoli cells
• wavy basement membrane
• multinucleated spermatids

• hypoplasia
• regular tubular circumference
• regular sertoli cell lining
• thickened, even basal lamina
• no inflammatory cells
• absence of lipofuscin
• degeneration
• irregular tubular circumferences
• lack of tubular lining and collapse
• thickened, wavy basal lamina
• secondary inflammation of interstitium
• presence of lipofuscin in tubular cells

trauma

infectious (bacterial)

[image]

what is the lesion, and what is it charcteristic of? what are the histo and gross lesions?

• granulomatous interstitial orchitis in ram testis
• pyogranulomatous inflammation
• spermatozoal aggregates and mineral typical of Brucella
• putty or clay-like gross accumulated material in enlarged epididymal tail

• gonadal-stromal
• Leydig cell
• Sertoli cell
• germ cell
• seminomas
• teratomas

• almost always benign
• most common testicular neoplasm in dog, cat, bull
• some produce estrogenic compounds
• grossly spherical, well demarcated, tan to orange
• microscopically in sheets
• spindle-shaped cells with vacuolation
• hemorrhage and necrosis

A. Sertoli cell tumor

B. Leydig cell tumor

• well-circumscribed firm white lobulated mass
• enlarged testis
• abundant fibrosis
• intratubular or diffuse pattern with tubular structure or palisading along fibrous strands
• produce estrogen or inhibin 

• grossly homogenous, white or pink-gray
• firm
• bulges when cut
• intratubular or diffuse pattern of large round cells

Seminoma

(bulging on cut surface)

• benign prostatic hypertrophy (BPH)
• secondary to hormonal imbalance
• symmetrically enlarged 

B[image]C

chronicity of prostatitis?

B. acute prostatitis

C.  chronic prostatic inflammation with increasing fibrosis 

what neoplasia affects the prostate in the dog?

what is the prognosis? why?

• adenocarcinoma/carcinoma (small or enlarged, asymmetric with nodular areas)
• guarded prognosis
• aggressive, invasive, destructive
• locally metastasizes to iliac l.n., lumbar spine, adjacent soft tissues and can block pelvic canal or compress rectum or urethra
• can metastasize to lungs

A[image]B[image]

prostatic________?

A: prostatic carcinoma

B: prostatic hyperplasia

in bulls, occurs in combination with inflammation of other repro tissues

Arcanobacter pyogenes, Chlamydiophila, Mycoplasma, Ureaplasma diversum, Histophilus somus, Strep, Staph

corpus cavernosum

tunica albuginea

(after copulation)

eosinophils and granulomas with larvae in prepuce and penis 

grossly swollen

balanoposthitis due to bovine herpesvirus 1

hyperemia, swelling, vesicles, pustules, ulcers

painful lesion in young, sexually mature bulls

caused by  papilloma virus

• ulcerated to raised cauliflower mass extending into deeper tissues
• locally destructive and invasive
• can spread to regional lymph nodes

squamous cell carcinoma 

epithelial sheets wtih keratin forming swirled pearls

• cauliflower-like soft growths on genitals and face/nasal cavity
• 59 chromosomes vs normal dog (78)
• female more susceptible

stratum corneum

stratum granulosum

stratum spinosum

stratum basale

what is acanthosis?

what is acantholysis?

which causes lichenification?

• acanthosis: epidermal hyperplasia. causes lichenification
• acantholysis: loss of cohesion between keratinocytes due to cell to cell attachment breakdown

regular

irregular

papillated

pseudocarcinomatous

what is hyperkeratosis?

what are the two types?

• increased width of stratum corneum
• Orthokeratotic-normal epidermis, lots of keratin, nuclei are gone in keratinocytes
• Parakeratotic-keratinocytes have retained their nuclei, so keratin formation is abnormal, often due to hepatic disease.  (superficial necrolytic dermatitis)

premature keratinization of cells of epidermis

often seen with parakeratosis

A. orthokeratosis

B. parakeratosis

full thickness

apoptosis (single or cluster of cells)

what is mycosis fungoides?

what is the classic lesion on histology?

T cell lymphoma

Pautrier's microabscesses

• type II hypersensitivity
• enzymatic destruction

immune mediated

primary=vesicle

secondary=ulcer

damage to melanocytes or basement membrane zone

defects in formation of melanin or lack of melanocytes

calcinosis cutis

mineral deposition

1. thrombosis
2. ischemia
3. edema
4. hemorrhage
5. atrophy

perivascular dermatitis suggests what?

what can also be found? 

hypersensitivity

can have eosinophils, irregular epidermal hyperplasia, ortho or parakeratotic, ulceration

• Hydropic degeneration/apoptosis in basal layer
• Band of lymphs, plasma cells, macs at the epidermal/dermal junction
• Pigmentary incontinence
• cytotoxic T cell attack on keratinocytes or melanocytes or basement membrane
• non-immune mediated damage

in hypoplasia, the epididymis will be proportional to the testis. in atrophy, the testis will be small

 [image]

uveodermatologic syndrome

VKH

(akitas)

zygomycetes

acid fast bacteria

parasites

protozoans

pythium/lagenidium

algae

idiopathic

foreign material 

neoplasms

• Subcorneal – superficial pyoderma, pemphigus foliaceus
• Suprabasilar – pemphigus vulgaris
• Subepidermal – bullous pemphigoid, SLE, TEN, burns, EB

mammary fibroadenomatous hyperplasia

more common than mammary carcinoma in cats. 

spay and it may resolve

same agents as nodular to diffuse disease

part of systemic disease like pancreatitis