Bone Pathology - some taken from Linde's deck (AH) Flashcards
Other names for Osteopetrosis
aka: Metaphyseal dyslasia, Marble bone dz.
Spp. associated with Osteopetrosis?
Angus cattle = inherited
Pathology of Osteopetrosis?
Failure of osteoclasts to resorb the primary spongiosa –> accumulation of bondy spicules in marrow spaces.
What can Osteopetrosis lead to?
Aplastic anemia
Other name for Congenital Cortical Hyperostosis?
Diaphyseal dysplasia
Spp. associated with Congenital Cortical Hyperostosis?
Inherited in pigs
Patho of Congenital Cortical Hyperostosis?
Perioteal bone formation on long bones. Deposition on radiating trebeculae –> increase in diameter.
What other condition is associated with Congenital Cortical Hyperostosis?
Edema due to blockage of lymph
Other names for Craniomandiblar Osteopathy?
Scottie jaw, lion jaw, westie jaw.
Spp. associated with CMO?
inheritied in west highland white terriers = dogs
Path of CMO?
Abnormal periosteal bone formation, irregular resportion –> irregular thickening of mandible/occipital/temporal bones. Tympanic bullae often severely affected. Less so in the limbs. Appears at 4-7 mo. Can regress, self limiting.
Where is the primary lesion of Chondrodystrophy?
1* lesion in growth cartilage.
Where else can lesions of Chondrodystrophy be found?
Physis (epi/meta). Articular epiphyseal complex. Epiphyseal cartilage.
What spp. is associated with disproportionate dwarfism resulting from Chondrodystrophy?
Calves - get short legs with normal head.
Types of Disproportionate Dwarfism?
Deter type (bulldog claves) Telemark type. Short headed type.
What are the lesions of Telemark type Disproportionate Dwarfism?
Bracygnathia, cleft palate, protruding tongue, short neck.
Are the lesions associated with Osteiochondrosis focal or multifocal?
focal and or multifocal . Both can be observed.
Path of Osteochondrosis?
Failure / delay of endochondral ossification = cartilage retention –> increase in cartilage.
Etiology of Osteochondrosis?
secondary to anything that decreases vascular flow to cartilage (infarct). Idiopathic. Increase in Zn –> decrease in Ca. Increased calcium.
Lesions of Osteochondrosis?
dyplasia, wedge shaped, necrosis, hemorrhage, mineral debris.
Are lesions of Osteocondritis dessecans (OCD) focal or multifocal?
Non Focal. Multifocal dysplasia only.
Path of Osteochondritis Dessecans?
Dysplasia at the AE complex –> fracture of articular cartilage –> cartilage/ osteochondral flap –> breaks off –> “mouse joint”
What is cervical verterbral myelopathy (CVM) also known as?
Wobbler syndrome
What is cervical verterbral myelopathy (CVM) secondary to?
Compression/ irritation of the spinal chord.
2 types of spinal chord compression?
Static or Dynamic (both lead to CVM)
What animals are affected by static compression?
Horses 1-4yrs = Cervical static stenosis. Dogs = ccervical spondylomyelopathies.
Where do horses get static compression? What does this cause?
C5-7. Hypertrophy of the ligamentum flavum
What animals get Dynamic compression?
Horses 8-18mo = cervical vertebral instability
Where do horses get Dynamic compression?
C3-5
With what is Dynamic compression associated?
Rapid growth. Genetic
what is another name for Hemivertebrae?
Butterfly vertebrae
Path of Hemivertebrae?
partial development of vertebrae –> compression of spinal chord.
In what spp. is Hemivertebrae desired?
Bulldogs, Pugs, Boston Terriers.
Etiology of Growth Arrest Lines?
Viral (BVD, Canine distemper) Lead Toxicit (lead line)
Pathogenesis of Osteoporosis?
Atrophy → Increased resorption or decreased formation
Causes of Osteoporosis?
- Low Ca → high PTH
- Low Cu
- High Vit A.
- Adriamycin
- Fluoride
- Glucocorticoids
3 Lesions of Osteoporosis?
Cortical bone → decreased thickness, high porosity Trabecular bone → decreased thickness Medullary cavity → ENLARGED
Pathogenesis of Rickets (Rachitic Rosary)
- Young animals
- failure of mineralization of endochondrial ossification
- Excess osteoid @ epiphysis
3 Causes of Rickets?
Low Vit D
- Low P
- Low Ca
Pathogenesis of Osteomalacia?
- MATURE
- softening of bones after growth plate closure
- failure of mineralization
3 Causes of Osteomalacia?
Low Vit D → low Ca & P → high intestinal P absorption → lower Ca Chronic Renal dz → low calcitriol Chronic Fluorosis </ul
3 Lesions of Osteomalacia?
- Soft bones → limb deformities
- FX
- Excess UNmineralized osteoid → resistant to osteoclasts
Fibrous Osteodystrophy is a form of _______.
Osteopenia
Other names for Fibrous Osteodystrophy?
- Recklinghausen’s Dz
- Renal Rickets
- Big Head
- Bran Dz
- Rubber jaw
- Osteogenesis imperfecta
Pathogenesis of Fibrous Osteodystrophy?
abnormal bone quality → excess resorption “osteoclasts” w/ 2o fibrosis
* Disruptions in Ca:P homeostasis
Causes of Fibrous Osteodystrophy (Osteopenia)?
2° Hyperparathyroidism (most common) Nutrional → ingestion of high oxalate plants, HIGH P diets, or LOW Vit D3 diets Renal →
Pathogenesis of Vit A. Deficiency?
bone is laid down when resorption should be taking place
3 lesions of Vit. A Deficiency?
- Small brain case
- Increased ICP
- Blindness
Pathogenesis of Hypertrophic Osteodystrophy (HOD)?
- METAPHYSEAL osteopathy
- Bilateral, Symmetrical Physitis→ metaphysis
- Young, growing large/giant breed DOGS
Causes of HOD?
HIGH Ca2+ & Vit. D.
- LOW Vit C.
- Spontaneous
Pathogenesis of Hypertrophic (Pulmonary) Osteopathy (HOP/HPO
- Incr. blood flow → Incr. arterial pressure & pulmonary lesions → periosteal exostosis
- Exostosis → DYAPHYSEAL region of DISTAL limbs
- Bilateral, symmetrical
- New bone formation
Causes of HOP/HPO
- Rhabdomyosarcomas of Urinary Bladder → Dogs
* Ovarian Neoplasms → Horses
CS of Acute
- GI signs
* CNS signs
2 CS of Chronic Osteofluorosis?
- Dental abnormalities
* Osteodystrophy
Pathogenesis of Osteofluorosis?
F- BINDS Ca2+ → Ricket-like lesions F- REPLACES hydroxl radical in Hydroxyapatite → abnormal osteoid F- ACCUMULATES in
Pathogenesis of Vit. A Toxicity?
Excess Vit. A from liver consumption→ Decreased osteoblasts
- decreased chondrocyte proliferation
- decreased # of osteoblasts
- SPONDYLOSIS from periarticular osteophyets
Lesions of Vit. A Toxicosis?
- destruction of growth plates & cartilage
- Osteoporosis
- Ankylosing Cervical Spondylosis
Excesses of which 2 vitamins cause an INCREASED activity of
Vit. AVit. D
Pathogenesis of Vit. D. Toxicosis?
Acute massive Vit. D exposure excessive intestinal Ca2+ absorption→ widespread mineralizationChronic Vit. D exposure Per
What affect does Calcitonin have on osteoclasts?
SUPPRESSES osteoclasts
Pathogenesis of Lead Posioning?
DECREASED OSTEOCLASTS → decr. trabecular remodeling →retention of primary trabeculae (spicules)
Histologic Lesion of Lead Posioning?
Acid-fast inclusion bodies → osteoclasts & renal epithelial cells
Lesions of Necrosis (Osteosis)?
Gross
- soft, discolored bonesHisto.
- Empty lacunae
- resorption occuring
Sequelea of Osteosis?
Resportion → inflammation → Exostosis or scar No resorpotion → Sequestrum or involucrum
Legg-Calve-Perthes Dz refers to what?
ASEPTIC necrosis of the femoral head
Pathogenesis of Ischemic Necrosis
- decreased VENOUS outflow from bone
- increased BM pressure
- Empty lacunae
3 Routes of Infection for Osteitis/Osteomyelitis?
- Hematogenous → omphalophlebitis, swine spondylitis
- Local Extension
- Penetration
Term for Destruction Inflammation of Bone?
Osteolytic
Term for Productive Inflammation of Bone?
Sclerotic
Causes of Osteitis/Osteomyelitis in order of prevalance?
BacT > mycotic > viral > parasitic
Osteitis is inflammation of _______.
Bone
Osteomyelitis is inflammation of _______ & _____ _______.
- bone
* medullary cavity
Spondylitis is inflammation of the _____ ______.
Vertebral body
3 List the causes of Suppurative Inflammation?
Brucella → Swine spondylitis A. pyogens → vertebral abscesses R. equi → foals
2 Causes of Granulomatous Inflammation?
A. bovis → lumpy jaw, mandibular osteomyelitis
* Mycotic
3 Lesions of Osteomyelitis?
- Purulent exudate → medullary cavity
- Thrombosis/infarct
- Bone resorption
Sequelae of Osteomyelitis?(LOTS)
- Exudate
- Extension to adjacent bone
- Hematogenous spread
- Pathological FX
- Sequestration
- Fistulae
- Vertebral osteomyelitis
- Lysis of articular cartilage
Most common primary neoplasm of bone in Dogs & Cats?
OsteosarcomaAKAOsteogenic sarcoma
Where is the common site for Osteosarcoma to occur?
Metaphysis
3 Classifications of Osteosarcoma & location affected?
Simple → bone Compound → bone & cartilage Pleomorphic → anaplastic w/ only small islands of osteoid
Classification of Osteosarcoma?
- Cell type & activity
- Radiographic appearance
- Origin
Lesions of Osteosarcoma?
- Grey-white masses → hemorrhage & necrosis
- Reactive bone
- Pleomorphism
- Agressive w/ Pulmonary metastasis
8 responses of Joints to injury?
- Fibrillation
- Eburnation
- Joint mice
- Osteophytosis
- Villous hyperplasia of synovial membrane
- Pannus
- Capsular fibrosis
- Ankylosis
5 responses of Bone to Injury?
- Disruption of endochondrial ossification
- Bone modeling
- Altered mass
- Rapidily deposited bone
- Injured periosteum
What DZ is associated with pink teeth & disorganization of d
Osteogenesis imperfecta
Term for Chondrodysplasia in Suffolk/Hampshire lambs?
“Spider lamb”
Pathogenesis of Osteochondrosis dissecans (OCD/OD)?
DYSPLASIA @ AE complex → weak, retained cartilage → FX →cartilaginous or osteochondral flap
Lesions of OCD?
- Joint mouse/mice
* Interference w/ joint movement
Sequelae of OCD?
- DJD
- Ulcercation/exopsure of subchondrial bone
- Lameness
Common locations of OCD (by animal)?
Dog → humeral head Horse → ant. aspect of intermediate ridge of distal tibia Pigs → distal humerus
What is the only form of Osteochondrosis that Cats get?
Epiphysiolysis
Which animal can get Osteoporosis during lactation?
Gilts(young pigs)
Osteoporosis is abnormal ______ of normal bone.
QUANTITY
Rickets is due to abnormal ______ of bone.
QUALITY
Dogs & Cats get Fibrous Osteodystrophy most commonly due to
Renal dz.
Which 3 animals get Fibrous Osteodystrophy from improper nut
- Horses
- Reptiles
- Captive primates
Tell me about K9 Eosinophilic Panosteosteitis!
- young Male GSD
*
