Happens post coital or postpartum bacterial infections
Limited to the endometrium
Happens in mares
Inflammation of all layers of the uterus
May be fatal
Inhibits bacterial adhesion to mucosa and activate complement
Good drainage (open cervix), increased leukocytes, estrogen may inc phagocytosis, progesterone reduces NT activity
WHen is the best time to overcome infection in the female and why?
Stimulate the syntehsis of PF2a following progesterone priming
Premature regression of CL and short estrous
What happens w/ acute inflammation in the female?
Reduced mucosal surface and PF2alpha production
WHat happens w/ chronic inflammation in the female?
In the cow, where is pyometra limited to?
What is pyometra in the bitch/queen like?
If the exudate in pyometra is viscid and brown, what is the causative agent?
If the exudate in pyometra is creamy yellow, what is the causative agent?
Excellent medium for bacterial growth
Debris discharged following parturition
Who are uterine hydrops most common in?
Marked fluid accumulation
Can be fatal in 3rd trimester
Insufficiencies in placentation
What does hydroallantois cause?
What does hydramnios cause?
Animal will present straining to defecate
Doesn't affect ability to get pregnant
MC in bitch
Tumor of uterus and vagina
Associated w/ hyperestrogenism
OFten firm, pink or white and pedunculated
Smooth muscle tumors; clinically significant when they obstruct gastric inflow or outflow
WHo will leiomyomas present most commonly in?
Happens in cows and does
Readily metastasizes to lung
MC in cow associated w/ BLV
Soft grey to tan nodular masses
May be diffuse
Stomach of the dog and cat, and bovine abomasum
Nodular or diffuse infiltrates of neoplastic lymphoid cells can infiltrate all layers of the stomach and may produce gastric ulcers
May be segmental or diffuse and infiltrarte all layers of the I and LI. Seen in many species. Villous atrophy, malabsorption and ulceration are common
Contagious Equine metritis
Caused by Taylorella Equigenitalis
Associated w/ endometritis or vaginitis
Non-specifically associated w/ postparturition
Trauma and bacteria and viral and tumefaction/swelling
4 general causes of vulvovaginitis?
If vulvovaginitis is due to trauma, when does it occur?
Mycoplasma and ureaplasma
What causes bovine granular vulvovaginitis?
Bovine granular vulvovaginitis
Hyperemic mucosa w/ 2 mm raised granules
Seen in bovine
Due to mycoplasma and ureaplasma
What kind of vulvovaginitis dues herpesvirus cause?
Cow, ewe, mare
Who does pustular vulvovaginitis occur in?
Pigs that eat moldy corn (mycotoxin zeralenone)
Both cause hyperestrogenism
What causes vulvovaginitis in pigs and ewes that is hormonal?
Squamous cell carcinoma
Happens in the vulva in cows, ewes, and mares
Lack of pigmentation>solar radiation
Locally invasive, slow to metastasize
Squamous cell carcinoma
DDX for TVT
Squamous cell carcinoma
MC in the horse, secondarily in the dog
Invasive (locally), necrotic, slow growing, slow to metastasize
Treatment: amputate penis
Squamous cell carcinoma
MC cancer of the oral cavity in cats
Squamous cell carcinoma
Large cauliflower like or ulcerated mass in the squamous part of the stomach in the horse. Transmural infiltration w/ implantation of the periotnoneal surface is common. Often metastasize widely before detection
Transmissible venereal tumor
Dorsal junction b/t vulva and vagina
MC in tropical and subtropical regions
Transmissible venereal tumor
MC on the penis but may occur on the prepuce
Few mm to 10 cm across
May regress spontaneously
Occurs at the base of the penis
Most common disorder of the testis and sexual development in the dog
Who is testicular torsion common in?
In the horse, which testicle is most likely to be abdominal in a cryptorchid?
Where should you look for a cryptorchid's undescended testis?
Percheron, saddlebred, QH
Which breeds of horse are most likely to be cryptorchids?
Testicular atrophy, infertility, and neoplasia
What can be associated w/ cryptorchidism?
Puberty - went to full development and then regressed
When does testicular atrophy happen?
WHy does testicular atrophy happen w/ cryptorchidism?
Sertoli in abdomen
Seminoma in inguinal area
What kind of neoplasias are associated w/ cryptorchidism?
Both can be
Is one or both testes affected by neoplasia caused by cryptorchidism?
4 things that can cause testicular hypoplasia
Swedish red and white
Who is testicular hypoplasia genetic in?
Reduced LH > Leydig cells
Reduced FSH> Sertoli cells
What endocrine abnormalities can cause testicular hypoplasia?
Puberty (don't use this term in an immature animal)
When does testicular hypoplasia become apparent?
Swollen and soft> small, firm testicle
How do atrophied testicles change?
What can atrophy of testicles occur w/?
Heat, obstruction, Amphotericin B, Gentamicins, chemotherapeutic, LH or FSH, estrogen, Vitamin A deficiency, Zn deficiency, General malnutrition
Causes of testicular atrophy (10)
What is a spermatocele?
Foreign body granuloma
Occurs when sperm gets out of testicular tubule and mounts an immune response. Treated like foreign body by body
Bulls and stallions
Who gets nonspecific orchitis?
No gross lesions
Lymphocytic foci b/t tubules and around vessels
Poorly defined yellow foci> firm and white
Uroliths can cause what in the testicles?
What is a DDX for periorchitis?
Intratubular or hematogenous
2 origins of orchitis
Caseous mass, may fistulize
Gray brown, soft or firm
often becomes granulomatous
Physical description of orchitis
Most common in bulls
Associated w/ abortion
Causes of prostatitis?
Older animals, especially bulls
Neoplasms of testes are most common in?
Teratoma and seminoma
2 kinds of germ cell neoplasms of the testis
Leydig or sertoli cell tumor
2 gonadal stromal testicular neoplasms
MC testicular tumor in aged stallion
2nd MC testicular tumor in dogs
Tumor more prevalent in cryptorchids
Do NOT produce hormones
Locally invasive, white, pink-gray, and bulging
White soft and bulging testicular tumor
Of males, what animal is most likely to get a teratoma?
Leydig/Interstitial cell tumor
MC testicular tumor of the dog, cat, and bull
Rare in the cryporchid stallion
Leydig cell/interstitial tumor
Tan-orange, w/ hemorrhage
Leydig cell/interstitial cell tumor
Well demarcated, non-invasive, encapsulated
Almost always benign
Questionably hormonally active
Sertoli cell tumor
3rd MC testicular tumor of the dog
Occurs in stallions and shorthorn bulls
Rare in others
Sertoli cell tumor
MC in cryptorchid testicle
Sertoli cell tumor
Firm, white, fibrous, really hard
Invades spermatic cord
May metastasize to iliac l/n
Sertoli cell tumor
White, firm, and fibrous
Are sertoli cell tumors hormonally active?
1/3 of sertoli cell tumors produce estrogen and causes?
Mammary enlargement in male animals: duct dilation due to estrogen
Usually in mature dogs
Associated w/ feminizing effects of Sertoli cell tumor
Due to high estrogen levels in the male, usually in mature dogs
Myelotoxicity, hypothyroidism, alopecia, hyperplasia/metaplasia of prostate
Sertoli cell tumors can cause what because they are hormonally active?
Sex cord stromal tumors
Both Sertoli and Leydig cell components in the same mass. Tell client that it could metastasize
Kinds of hyperparathyroidism that lead to bone resorption and fibrosis and therefore cause fibrous osteodystrophy
Led poisoning, vitamin D deficiency, vitamin C deficiency, vitamin A toxicity
Nutritional and toxic diseases of bone
Vitamin c deficiency
Lack L-gulonolactone oxidase, impaired hydroxylation of pro collagen> improper cross linking of collagen fibrils > hemorrhage, thin physis w/ inadequate synthesis of cartilage and osteoid Relevant in guinea pigs
Vitamin C deficiency
DOES NOT cause widening of ribs
Does causeimpaired hydroxylationof procollagen, hemorrhage, thin physis, inadequate synthesis of cartilage and osteoid
Gly x y triplets w/ hyp in the y position. Need vitamin c for hydroxylation
Why is vitamin c necessary?
Enriched grains, sweet potatoes, liver
What foods does vitamin A toxicity come from?
Vitamin A toxicity
Causes closure of growth plate prematurely, affects hind limbs across species, premature closure of growth plate in distal femur and proximal tibia, Femoral head and greater trochanter are spared, growth plate invaded by trabecular bone
Seeing in young growing toy breeds unilateral, vascular compromise to the proximal femur epiphysis, necrosis of the trabeculae and marrow tissue vascular disturbance disease, bone necroses, Anything that causes vascular disturbance to femoral head and neck may result in this condition.
Infarction of an extremity needs to coagulative necrosis then mummification. Lack of blood supply.
Abnormal periOsteal proliferation of bone
Exostosis on the distal limbs of animals with*intrathoracic masses*example lung tumorSee mild chronic hypoxia may be altered vagal regulation increased parosteal blood flow to the extremities. Exostosis goes away when cause removed.
Infectious osteomyelitis and noninfectious osteomyelitis
Two types of infectious bone disease
Most commonly seen in young large animals and caused by bacteria
Umbilical infection plus failure of passive transfer leads to sepsis.Then see embolization to blind capillary loops. Normally subjacent to growth plate.
Things that cause direct inoculation osteomyelitis
Most common cause of inoculation osteomyelitis
Hypertrophic osteodystrophy or metaphyseal osteopathy
Happens in young growing large breeds, bilateral, self-limiting suppurative inflammation in metaphysis, necrosis and hemorrhage, good prognosis, Spontaneously regresses, manage the pain and the lesion will go away, Happens in metaphysis of long bones also see osteomyelitis with infarction
Canine hypertrophic osteodystrophy, canine pan osteitis, craniomandibular osteopathy
Three poorly characterized developmental orthopedic conditions and dogs
Only young, growing large breeds, 75% in both German shepherds, self-limiting, bone marrow replaced by finrovascular tissue with woven bone, increased activity of osteoblasts and fibroblasts, inflammation may or may not be present,
West Highland white, Scottish, Cairn terriers
Dogs that get crania mandibular osteopathy or lion jaw
Cause of cranial mandibular osteopathy
Cranial mandibular osteopathy or lion job
Exostosis on skull, usually mandibular bone is most affected.Bilateral self-limiting good prognosis, usually confined to the skull, usually recognized at 4-7months, self-limiting by 11 to 13 months, pain discomfort while chewing, have bone pain and soft tissue pain some owners choose to euthanize due to pain
Malignant tumor, most common bone tumor***, does not cross the joint space several types but all make osteoid*
In dogs more than 80% of primary bone tumors, most common in large breeds, more common in appendicular skeleton, poor prognosis with frequent metastatic this, should be top differential, will happen away from elbow toward knee, happens a lot in proximal humerus distal radius distal femur and proximal tibia
Benign tumor, rare, most common in the jaws of horses and cattle,
Second most common primary bone tumor, 10% of primary bone tumors in dogs, most common in large breeds, flat bones often affected, locally invasive but slow to metastasize, better prognosis,
Most common in chondrosarcoma platforms but also trachea because of Hyaline cartilage, similar to normal cartilage tissues, very rare benign bone tumor, neoplasm composed of well-differentiated cartilage
Multilobular tumor of bone
Mainly affects skull or other flat bones in dogs, locally invasive, metastatic to lumg, known to undergo more malignant, transformation to osteosarcoma and chondrosarcoma. Similar prognosis to chondrosarcoma important to know that this transfers more malignant tumors
Malignant tumor of intramedullary plasma cells, Multifocal ostial lysis, moth eaten pattern, like a plasmacytoma in intramedullary cavity
In dogs can involve bone in maxillary area, mesenchymal tumor arising from bone, can arise from connective tissue anywhere in body including bone, most likely in maxillary area, rare, invasive
Arises from the CT of the oral cavity
Often on the palate in dogs and the gingiva in cats
Metastasis is seen occasionally
Immobile bone joints, dense fibrous connective tissue, sutures of the cranium connections between Radius and ulna, tibia and fibula
Bones united by Hyaline and or fibrous cartilage, intravertebral discs, pelvic synthesis, sternum
A joint cavity lined by a synovium, typical mobile joints such as elbow, shoulder, knee and hip
Bilayer structure, produces joint fluid, and provides nutrients to articular Cartilage
Acts as a shock absorber, provides joint surfaces with low friction very important one cell type chondrocytes no vascular no lymphatic supply poor healing potential very important with disease
Plasma dialysate plus hyaluronic acid
Compressive stiffness to articular cartilage, core protein with lots of sugar, negative, pulls water molecules, provides cushion
Most prevalent joint disease across species, affecting more than 20% of the canine population older than one year, have angry synovium, synovial hyperplasia, have Fissure, have thickening of subchondral bone and pseudocyst formation
Common endpoint from any joint problems, including osteochondritis dissecans, hip dysplasia, CR CLX, meniscal tear, Valgus or Cary's deformity. See more inflammatory cytokines, proteolytic cytokines. Currently no cure
Total loss of articular cartilage with exposure of underlying bone, happens when chronic, very painful
Also known as bone spurs, formed by endochondral ossification the margins of the OA in nonweightbearing zones
Increased catabolic, IL –1, tnf, mmpDecreased anabolic col2, proteoglycan
What causes osteoarthritis to happen?
One of the main path ologies of osteoarthritis.
Whole joint disease
Osteoarthritis is a partial or whole joint disease?
Cranial translation of tibia with respect to the femur, excessive internal rotation, hyperextension
CRC who is a main stabilizing structure and stifle and prevents what?
Cranial translation of tibia w/ respect to femur, excessive internal rotation, hyperextension
Cranial cruciate ligament prevents
Is cranial cruciate ligament injury trauma caused or spontaneous in dogs?
Dogs get cranial cruciate ruptures by biological?
Dog develops osteoarthritis
End result of cranial cruciate ligament injury
Rheumatoid factor are produced in response to an unknown stimulus and attacks the synovial membrane
Systemic lupus erythematosus
Antibody against wide targets are produced leading to systemic immune complex and then arthritis and vasculitis
Bacterial, tickborne, viral
Types of infectious arthritis
Penetrating wounds leading to direct inoculation, extension of infection from adjacent tissues (osteomyelitis, panniculitis, myositis)
What causes bacterial arthritis?
Most common in neonatal large animals, umbilical infection due to failure of passive transfer leads to sepsis then synovial fluid and then causes arthritis.
Which synovial fluid is less viscous, normal arthritis?
Joint pain and swelling or arthritis can be a clinical symptom of this
Tick associated with rickettsial arthritis and vasculitis
Arthritis is probably a result of persistence pure studies and or Union complex deposition. Kind of tick Born disease
Rocky Mount spotted fever, Ehrlichiosis, Lyme disease
Three arthritic tickborne diseases
Caprine retrovirus or CAE
Most important virus that causes arthritis
Caprine arthritis and encephalitis
Primary lymphoplasmacytic, proliferative synovitus secondary cartilage lesions, leukoencephalomyelitis in kids, interstitial pneumonia in kids and adults, synovitis or arthritis in adults, mastitis in adults.
Osteochondrosis and joint dysplasia
Two developmental joint disease types
Disturbance in the normal process of endochondral ossification, affecting articular epiphyseal complex and physis. See pain lameness and osteoarthritis
Failure of endochondral ossification, thickened carrilage, susceptible to mechanical stress, detached articular cartilage, not inflammatory, will see osteoarthritis with it.
Canine elbow dysplasia is thought to be a result of?
Separation of articular cartilage, disturbance in the normal process of enodhcondral ossification, thickened cartilage, susceptible to mechanical stress
Separation of articular cartilage, disturbance in the normal process of endochondral ossification - thickened cartilage - susceptible to mechanical stress
Failure of blood supply
Failure of endochondral ossification causes what
Ununited anconeal process, fragmented medical coronoid process, OCD of the medial humeral condyle, elbow incongruity
Four path ologies of canine elbow dysplasia
Most common large animals between four and 12 months, probably multifactorial involving genetics, rapid growth, mechanical stress, nutrition leading to join laxity which leads to join subluxation then laxation of the femoral head and finally osteoarthritis, Failure of endochondral ossification may contribute
Rare malignant mesenchymal cell tumor arising from Mesenchymal membrane or tendon sheath. Locally invasive with the moderate metastatic potential. Crosses the joint space**Surrounds synovial joint Arises from joint space
Histo cystic sarcoma
Rare malignant histiocyte tumor in dogs, coming in Bernese Mountain dog, primary lesion may involve various tissues including synovium, periarticular HS may encircle affected joint, metastatic in 91% dogs can cross joint space**
Rare mesenchymal cell tumor arising from synovial membrane or tendon sheath. Is considered a benign but sometimes locally infiltrative. Local recurrence is possible after incomplete surgical exit decision.
Neurons have an ____ function that requires intact cell processes, therefore gray or white matter damage causes dysfunction.
One cell extends a process near to and secretes a product that affects a target cell of the same type
Autocrine function is?
Provides metabolic support for cell processes
All structural components synthesized in here
Support and transport
Although the cell body is the metabolic hub of the cell, much of its metabolic efforts are directed to maintaining ______ and ______ of the axon
Supporting cells, about half the tissue volume, about 10x the number of neurons
Produce myelin in CNS
Make myelin in the brain for more efficient conduction
Take up NT and maintain ions
Regulate microenvironment, especially around the synapse: make glutamate from glutamine, GABA uptake. Regulate electrolytes
Aid or hinder axon growth
Scar - like support
Scar like support
Has some cilia and provides some movement for CSF
Simple ciliated epithelium w/ gap jxns
No barrier b/t brain and CSF
Another reason why CSF reflects brain pathology
4. Choroid plexus epithelium
4 types of glial cells
Schwann cells: PNS
Difference b/t schwann and oligodendrocytes?
If cells in the CNS could vote, neurons would never win an election against the glial party. T/F?
Some conditions affecting the neuron can affect only the axon and are at least theoretically reversible T/F?
A short time after brachial plexus avulsion you would expect to microscopic degeneration or loss of both axons and myelin
Fibrocartilagenous emboli of disc material affect the gray matter predominately. True or false
In what space is the tip of a needle placed to obtain CSF?
Blood brain barrier
Astrocytic foot processes
Restricted access to CNS
Regulated transport systems
One reason why CSF tends to reflect brain pathology
Virchow's Robin's space
Allows leukocytes to travel into subarachnoid space and CSF, reason why CSF reflects brain pathology
They accumulate in perivascular spaces that are connected to the SAS
Cells in CSF reflect the inflmmation in the brain because?
Diffusion acros ependyma into the ventricles (normal brain) and across damaged parenchymal vessels into the virchow robin space in a damaged brain
Increased interstitial fluid protein found in CSF can enter by which routes?
Via nasal lymphatics
Most CSF leaves the brain of dogs by what route?
Least frequent glial cell
Come from bone marrow
Stay in brain for long periods
Sentinels cells to detect tissue damage/infection
Divide and can develop phagocytic form and can draw new macrophages into brain after injury
Possesses blood nerve barrier w/ protective layers- no lymphatics
Which is more effective in Myelin sheath repair ? PNS or CNS
Post mitotic cells w/ specific irreplaceable funcitons
Susceptible to injury
The soft epithelial nature of the CNS makes it?
Is inefficient at draining fluid and CSF elaboration is not rapily controlled
Anencephaly and exencephaly
Anomalies of the CNS, lesions of defective neural tube, abnormal cranial closure
Meningocele or meningoencephalocele
Failure of focal cranial bone closure, frontal bone often involved
Failure of focal cranial bone closure, if cerebrum was in the lump, frontal bone often involved
Failure of dorsal vertebral closure
Aperta w/ meningocele w/ myelomeningiocele oculta
Just have neurons, can't tell ventral or dorsal horn
Occurs w/ or w/o boney defect, cord is disorganized,
Result from in utero necrosis
Healing by cavication. Often associated w/ blue tongue, border dz, or BVD. Common in people w/ cerebal palsy
Most are degenerations of the granular layer
Cerebellum too small.
Happens near birth.
BD, BVD, Border dz, panlekopenia
4 dz associated w/ cerebellar hypoplasia
It is mitotically active late in gestation
Why is the external cerebellar granular layer preferentially affected in viral infections?
White matter (gangliosidosis)
Storage diseases or lysosomal enzyme defects affect what?
Altered proprioception, doesn't know where feet are,
Lots of species affected
INherited/acquired vitamin E deficiency/aging
Axn not communicating w/ target
Equine laryngeal hemiplega
Distal axonal degeneration from the ends of longest nerves
Left recurrent alaryngeal nerves and others
Common in draft horses
Simultaneous degeneration of axon and myelin
WHat distinguishes WD from other axonopathies?
Blacnching of RNA or loss of RNA from near nucleus
Nonspecific rxn to injury to a liveing cell body reflects change
Such cells frequently lose synaptic contact w/ nes
Loss of nissl substance is visible 2d-6 wks after injury
What kind of viral inclusions do DNA viruses cause?
What kind of viral inclusions do RNA viruses cause?
RNA viruses usually have inclusions at what location in the cell?
1. Secondary lysosomes in storage dz
2. Viral inclusions
3. Insoluble products of proteosomal degratdation> unfolded protein response and cell deth
What have neuronal inclusions?
Neurons can be killed alone
If neurons are killed do other cells have to die too?
Neurophagia>neuronal loss> brain atropy
In temporal sequence, what is the correct order of microscopic events follwoing neuronal necrosis?
Increase glutamate release from ischemic excitatory neurons Excess glutamate in cleft and can't get out, ion pumps give up and flooded w/ Ca and undergoes metabolic failure
Why do neurons die after ischemia?
Cerebellar abiotrophy /systems degenerations
Affects purkinje cells, degeneration may occur at different intervals, incremental
Motor neuron dz
Genetically or idiopathically determined loss of previously normal neurons May be incremental over long period.
Cerebellar abiotrophy and systems degenerations and motor neuron dz
Chronic incremental neuronal loss and degeneration
Primary degeneration or loss of Purkinje cells, and sometimes neurons in other areas. Very orderly in givengroup of patients, very different b/t them. Looks wrinkled, always weigh less.
Spinal muscular atrophy
Genetically determined or idiopathic degeneration neurons, superoxide dismutase defun, cytoskeleton deficiency, vitamin E deficiency. Degeneration of motor neurons in ventral horn. Horse is weak, neck muscles will quiver because can't raise head. There are inherited tylpes. Spontaneous dz in horses, in dogs called old dog myelopathy and can reverse itself but this is really uncommon
Results in demyelination , Primary destruction of myelin sheath,
What does oligodendrocyte/Schwann cell injury result in?
Attack on myelin sheath, death of parent cell
Demyelination is due to?
Which fibers does random hit demyelination affect most?
Central pontine myelinolysis
Demyelination due to oligodendrocyte death
Happens when you correct hypernutrenia too quick.
Localized, sometimes animal will recover
Inflammatory demyelination of ventral roots, affecting peripheral and cranial nerves
Thought to be autoimmune dz, reversible
Usually from hunting dogs getting bitten by coon. Need to be put on respirator or will die.
1. Experimental allergic encephalitis
2. Experimental allergic neuritis
3. Multiple sclerosis
3 autoimmune demyelination dz
1:1 relationship w/ axon and Schwann cells divide readily
Why is the PNS so effective at repairing the myelin sheath?
While oligos can proliferate, one oligo goes to several axons. and they lack a basement membrane and secoondary axonal loss makes damage permanent
Why is repair of myelin sheath less effective in CNS than PNS?
In the PNS by Schwann cells
The repair of demyelination is most likely ?
Hypertrophy and hyperplasia
How do astrocytes react to injury?
Fibrillary and gemistocytic
2 types of astrocyte hypertrophy
Increase cell processes w/ more GFAP +/- vimentin
Enlarged nuclei w/ HE
What kind of astrocyte hypertrophy is most likely to happen in severe disease?
Astrogliosis and astroglial scar
2 kinds of astrocyte hyperplastic distribution?
Astrocytes Diffuse, mixed w/ surviving normal cells
What is astrogliosis?
Nothing but astrocytes; occurs at edge of severe injury, area of necrosis in middle
What is an astroglial scar?
2. Microglial nodules
3 microglial rxn to injury
May increase in number, no cytoplasm skinny arrangement
Focal, increase in number near an injury of micrglials sign to stop and look at middle of nodule
Does edema affect white or gray atter more?
1. Falx cerebri
2. Tentorium cerebelli
3. Foramen magnum
3 sites of brain herniation
1. The brain lacks lymphatics
2. Flaps of dura and craniu limit the expansion of the brain
3. Herniation causes damage to additional tissue in the region
4. Herniation thru the en magnum injures respiratory centers
Why is brain edema a life threatening condition?
Called spongiform change
Irregular loose, vacuoles in parenchyma seen in microspcopic brian edema
3 types of brain edema
Breakdown of vascular integrity, Kind of brain edema
Arises from endothelial damage to brain blood vessels, vascular permeability increases, blood brain barrier function is lost, water proteins and electrolytes enter parenchyma
Intracellular brain edema
Intracellular edema of the brain, like that seen in hepato- encephalopathy, is referred to by which term?
What happens when you have hydrocephalus, start pushing fluid back into lining of parenchyma
Result of ventricular obstruction or blocked CSF absorption forces CSf between ependymal cells into the interstitium
Most concerning kind of brain edema
Vasogenic edema is an increase in
Begins with intoxication of cell membrane ion pumps intracellular water accumulation and swelling, reduces the brains extracellular volume,
What kind of edema happens in hepato- encephalopathy?
What kind of edema does salt poisoning or water intoxication lead to?
Vasogenic and cytogenic edema
Two types of brain edema that perpetuate each other in lesions
Toxins from intestine that can't be metabolized by the liver example ammonia and glutamine
Causes of hepato encephalopathy
Interference with CSF drainage,
Lesions due to increasing CSF pressureCauses more obvious lesions in immature animals, but kills mature animals much more rapidly
Tumors and mumps
2 causes of hydrocephalus
The ependyma is not separated from the brain by basement membrane
Hydrocephalus results in transependymal edema. Why?
In parenchyma around blood vessels
If dies injected intravenously before death into a dog that has vasogenic brain edema, where would the die be localized at postmortem exam?
Polio encephalomalacia or polio myelomalacia
Malacia that affects only the gray matter
Leuko encephalomalacia or Leukomyelomalacia
Malacia affects only the white matter
Tissue stains poorly and you may see edema or neuronal necrosis
What do you see in the earliest malacia
Liquefied tissue, phagocytes enter from viable blood vessels, astrocytes proliferate at the edge of viable tissue and go to Center.
What do you see in well-developed malacia?
Fluid filled cavity, infarct, cavitation, astrocytic scar at border
How does malacia resolve?
Polio encephalomalacia of ruminants
Laminar malacia of cerebral cortex in ruminants
Amprolium intoxication, thiaminolytic bacteria, lead intoxication, high dietary sulfur**
Causes of ruminant polio encephalomalacia
Malacia results in a cavity while neuronal necrosis resulting atrophy of affected brain
How does the resolution of malacia differ from the resolution of neuronal necrosis?
Moldy corn poisoning of horses leads to?
Name of corn toxin that causes leukomalacia in horses
Limited cranial volume, inability to significantly limits CSF production, poor regeneration of nervous tissue
Three reasons traumatic injury has a poor prognosis in the brain
Can produce permanent damage, neurotransmitter failure to death associated with diffuse axonal injury by stretching
Hemorrhage is on the brain surfaceCan occur without cranial fracture
Can occur at fracture sites
Physical disruption of tissue
Contusion Occur near the point of impact
Near point of impact; body at rest and hit by an object
Occurs opposite the point of impact
Opposite point of contact; head and body in motion and suddenly stopped
Do lacerations have a lot of hemorrhage?
Is vascular disease of the CNS common in animals?
Is neoplasia common in the esophagus?
Does osteosarcoma cross the joint space?
Trauma, bleeding disorders, thrombosis
Hematomas in the brain can be associated with what
Distal thrombi or emboli leading to endocarditis
Most common cause of impaired local vascular patency
Size and type of blood vessel blocked, number of and arteries involved, Rapidity and extent of the obstruction
Severity of brain infarcts depends on?
Mitral valve and left cardiac chambers for endocarditis, check carotid artery for injection sites, check for local vasculitis
Where should you look for lesions causally related to a brain infarct?
An example of in situ thrombosis following histophilis somni infection
Solitary, do not metastasize outside CNS, do implant along pathways of CSF flow
Primary brain tumors do what
Most common primary brain tumor you will see in dogs and cats. Occurs at the meningeal surface but can grow along vessels. Surgery prolong survival in cats but this can recur
The most common primary intracranial or intra-calvarial neoplasm of dogs and cats is
Occurs at meningeal surface
Olfactory region of dogs
Where do malignant meningiomas occur
Most common primary brain parenchymal tumor of dogsFirm, ill-defined tumors of well-differentiated astrocytes
Occurs in the parenchyma of the brain, usually centered in white matter, softer than astrocytomas and more prone to cystic changes
Choroid plexus tumors and ependymomas
Peri Ventricular neoplasms that are both soft crumbly masses
Rare tumor of cranial nerve roots
In peripheral nerves, expands and infiltrates pre-existing nerves malignant form is common
Spinal cord invasion
Malignancy of PN STS relates to?
When gray and white matter are affected in inflammation
Route of infection
Primary predictor of lesion distribution
Choroiditis and leptomeningitis
Smallest particles that enter Via hematogenous infection cause what
Encephalitis, microabscesses, and cerebritis
Kinds of inflammation caused by intermediate sized particles that enter In hematogenous ways
Septic infarct and brain abscesses
Large particles that enter via hematogenous infection cause what?
They often have specialized receptors from cell entry
The reason viral infections may affect only gray or white matter only is related to
Do you gram-negative or gram-positive bacteria cause more rapidly progressive disease in Cns
Most readily visible inflammatory lesion
In nearly all cases microscopic inflammation stops where
Less common than meningitis follows micro embolic shower, often from septic heart thrombus, the tiny foci of inflammation can coalesce over time and cause abscess
Most common type of CNS abscess and most dangerous because of potential rupturing can't wall them off
Focal pus in the subdural spaceBetween the Dura and arachnoid, localized
Lesions localized to the brainstem, cranial nerves five and six see ganglioneuritis of cranial nerve five affected brain has internal microabscesses, external lymphocytic meningitis
Host pathogen dialogue
The pathology of viral infections depends on
Viruses, rickettsia, ehrlichia
Endothelio tropic organisms name three
Death of cells, interference with luxury function, cytokine dysregulation and cell degeneration, infection without inflammation or degeneration
Possible outcomes of viral infection
Inherited human prion diseases
Results from germline mutations of cellular PRP Gene, these mutations make the PR PC protein less soluble, and they form a type of amyloid
Scrapie, mad cow dz, spongiform encephalopathies
Prion diseases of animals
Intraneuronal vacuoles and gliosis, no inflammation
Characteristics of prion diseases of animals
Have to have qq genotypeInfection orally from placenta Spreads to lymph nodes by one year
Elk genetic, all white tail
Who is at risk for CWD?
Leptomeningitis, encephalitis, mass lesions
What do yeastmycoses in the brain cause?
What do protozoa in the brain cause?
Guttural pouch, dehorning, fungemia, Aspergillus
Why would fungi have hyphae in tissue?
Wandering nematode larva, cestode cyst, Cuterebra, cause this?
High mitotic rate
Viral infections causeing cerebellar hypoplasia affect granular layer preferentially because of ?
Movement used in axonal repair
Eosinophilic cytoplasm, Neuronophagia, loss of dead neurons
Necrosis separate from ventricles
Neuronal necrosis morphological changes
Discoloration of white matter
Entire brain becomes necrotic * picture
Vasogenic brain edema
Arises from endothelial damage to brain vasculature
1. Increase pressure in brain tissue
2. Decrease arterial blood pressure
Decrease brain perfusion by?
Most common brain tumor
Fluid under dura mater looks cloudy and tan, bacterial infection, *picture
Nonsupperative inflammation of grey matter *case study
Intra-neuronal vacuoles, gliosis, lack of inflammation
CWD can occur ind deer from?
Metaphysis and epiphysis
Bacterial embolism in neonatal sepsis affects?
articular epiphyseal cartilage complex and physis
An animal grows longitudinally at the ?
Hematoma, inflammation, granulation, callus, bone remodeling
What happens in fracture secondary healing?
Type of chondroplasai, abnormal endochondral ossification
Type of chondroplasia
Abnormal endochondral ossification
Cortical hyperostosis in popeye pigs
Cortex is thickened by radiating proliferation of the periosteal bone in?
Not in large breed dog
Periosteum intramembranous ossification
Abnormally thick bone formation
Angular limb deformity
Occurs in the distal ulnar growth plate in dogs
Glass cages, advanced liver and renal disease, deficiency of protein and minerals
Decrease serum Ca (causes osteoporosis) can be caused by?
Does not cause widening of ribs, causes impaired hydroxylation of procollagen, hemorrhage, thin physis, inadequate synthesis of cartilage and osteoid
Failure of function because of damage of another endocrine gland or lack of needed substance to produce hormone
Lack of TSH from destroying pituitary -hypothyroidism, iodine deficiency causes goiter -hypothyroidism
2 examples of secondary hypofunction
Proliferation of cells of the organ that produce excessive amounts of the hormone and fail to respond to the feedback mechanism
Hyperparathyroidism: Too much PTH caused by tumor, Feline hyperthyroidism, Canine cushings caused by an adrenal tumor
3 primary hyperfunctions of endocrine organs
Excessive production of a hormone due to hypersecretion of a trophic hormone by a different and diseased endocrine organ in the feedback pathway due to derangement of the feedback mechanism
Bilateral adrenal cortical hyperplasia is an example of?
Canine cushings caused by pituitary tumore = too much ACTH
Example of a secondary hyperfunction
Tertiary endocrine dz
Dysfunction at the level of the hypothalamus
Very rare except in horses
PPI of horses
Example of a tertiary endocrine dz
PPI of horses
May see this w/ primary brain or pituitary dz which destroys hypothalamus as an innocent bystander
Anal sac tumor and lymphoma secretes PTH related peptide
Secretion of endocrine like hormone by non endocrine tumor examples
DI> renal, DM> insulin resistant type 2 diabetes
Failure of target cell response examples
Decreased/increased degradation of a hormone
1. Primary hyperfunction
2. Secondary hyperfunction
3 ways to get cushings
Parturition requires fetal endocrine signals
Secondary hypofunction of other organs
Ewes 12-14 days of gestation
CNS and hypothalamus malformations
Will stop developing, but will stay in utero as poorly developed fetus and either have to do C section or wait for fetus to die
Contains alkaloids that inhibit neural tube development
Failure of differntiation of Rathke's pouch
Results in pituitary dwarfism
Simple autosomal recessive trait
Small body size, immature hair coat, alopecia and hyperpigmentation
AKA pituitary dwarfism
Compress adjacent pituitary and brain tissue
Inactive tumor can be very large b4 causing signs
Variable clinical signs: decreased hormone secretion and CNS dysfunction/blindness
See secondary or tertiary endocrine dz
Adenoma and chromophobe
DDX for pituitary tumor
Intracranial germ cell tumor
Dwarfism due to lack of GH
May see decreased secretion of horones (2ndary or tertiary endocrine dz) and CNS dysfunction/blindness
Lack of production of ADH or lack of response by kidneys
See PU/PD w/ hypotonic urine
Compression and destruction of pars nervosa, infundibular stalk, or supraoptic nucleus in the hypothalamus
Kidneys lack ability to respond to ADH
May be acquired or transient
Inhibits ADH receptor
3. Increased Ca
3 reasons for nephrogenic DI
Causes insulin resistant diabetes mellitus in cats
ACTH -secreting Adenoma of the Pituitary gland
Classic dog dz
Most commonly from pars distalis
ACTH excess causes bilateral hypertrophy of adrenal glands and hypercortisolemia
Where is the ACTH-secreting adenoma most commonly from?
Abdominal distention (hepatomegaly and muscle atrophy)
Poor hair coat/alopecia
Clinical signs of cushings like syndrome
Adenoma of pars intermedia
MC in horses
Adenoma of Pars intermedia
Secretes ACTH in the dog
Hirsutism (failure to shed), PU/PD/PP, DI,DM due to secondary insulin resistance, obese/loss of muscle, insulin resistance, hyperhidrosis (sweating), laminitis, excercise intolerance, decreased fertility
Clinical signs of PPI adenoma in horses
Primary hypofunction of the pituitary, secondary hyperfunction of the adrenal, insulin resistant diabetes, blindness
What can happen w/ a pituitary tumor?
Mineral> aldosterone so salt regulation
Zona glomerulosa is responsible for?
Zona fasciculata is responsible for?
Zona reticularis is responsible for?
Immune mediated primary adrenal atrophy
MOst common natural form of Addison's
Happens in young FS dogs
Treatment for cushings like dz
When can Addison's be iatrogenic?
Weakness/bradycardia, sudden death, PU/PD, high K, low Na, lack of aldosterone, low glucose, high Ca-lack of cortisol,
Clinical signs of Addison's
Waterhouse - Friderichsen Syndrome
Bilateral cortical hemorrhage, secondary to overwhelming sepsis and endotoxic shock, classic lesion to find at necropsy in horse w/ endotoxemia, looks like adrenal gland is inside out, may cause acute hypoadrenocorticism or fatal blood loss in neonates
Idiopathic nodular hyperplasia
Common in older horses, dogs, cats
Multiple, bilateral, yellow
Most have no clinical signs
Secondary to pituitary tumor or cushings like syndrome
Diffuse bilateral hyperplasia can be due to?
More frequent in older dogs, well demarcated usually single nodule in one adrenal gland, yellow to red
Seen in cattle and older dogs
Larger, more likely to be bilateral, variated, yellow-red, friable, and invade surrounding tissue, wall of caudal vena cava, areas of mineralization and ossification
Responsible for 85-90% of cushings like dz
Adrenal cortical tumor (functional adenoma or adenocarcinoma)
Responsible for 10-15% of cushing's like dz
Bilateral adrenal hypertrophy
Pituitary tumor caused cushing's like dz is associated w/?
Bilateral adrenal atrophy
Iatrogenic cushings is associated w/?
Most common neoplasm of adrenal medulla
Light brown to red, invade into surrounding tissue, wal of caudal vena cava, may metastasize, neoplasm of adrenal medulla
May be asymptomatic- incidental finding, may see hypertension, tachycardia, edema, cardiac hypertrophy
Dogs and cattle
Pheochromocytoma is most frequent in?
Epi or NE secreting cells or both
What is pheochromocytoma composed of?
FS, middle aged, pure bred dog
Heat seeking, obese/lethargic, poor hair coat/alopecia, hyperkeratosis and seborrhea, low T4, high TSH, high cholesterol, atherosclerosis
Clinical signs of hypothyroidism
Multifocal nodular hyperplasia of thyroid
Old cats, horses, dogs
Inactive except in cat
Multiple white to tan nodules of variable size
Non-neoplastic, incidental finding
Older cats, can be seen in addition to hyperplastic nodules