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Bones Developmental - Pathology (view source)
Revision as of 19:08, 18 August 2008
, 19:08, 18 August 2008New page: {{toplink |backcolour =CDE472 |linkpage =Musculoskeletal System - Pathology |linktext =Musculoskeletal System |maplink = Musculoskeletal System (Content Map) - Pathology |pagetype =Patholo...
{{toplink
|backcolour =CDE472
|linkpage =Musculoskeletal System - Pathology
|linktext =Musculoskeletal System
|maplink = Musculoskeletal System (Content Map) - Pathology
|pagetype =Pathology
|sublink1=Bones - Pathology
|subtext1=BONES
}}
<br>
==Generalised==
===Proportionate dwarfism===
*Miniature breeds
*Due to growth factor deficit
===Chondrodysplasia===
*Literally means “abnormal cartilage development”
*Defective cartilage growth at the physis
*Usually genetic cause
*Occurs in cattle, dogs, sheep, pigs and cats
*Leads to '''disproportionate dwarfism''' (contrast with miniature breeds)
**Generally, growth is disproportionate because only the growth of bones which form from cartilage models is retarded – growth of other bones is normal (i.e. long bones shorter than normal)
<u>In Dogs:</u>
*'''Localised''' forms occur in dogs (e.g. affecting skulls of Pekingese and Bulldogs or the limbs of Dachshunds and Bassett hounds)
*Occasionally seen in immature Beagles, Poodles, Alaskan Malamutes, Scottish Deerounds and Norwegian Elkhounds
<u>In Cattle:</u>
*'''Dexter cattle'''
**Are heterozygous for incompletely dominant gene
**When homozygous - lethal, producing 'buldog calf'
**Usually aborted prior to seven month of pregnancy
**Also occurs in Holstein, Jerseys and Charolais
**Grossly:
***Limbs and vertebral column are short
***Domed cranium
***Protruding [[Oral Cavity - Tongue - Anatomy & Physiology|tongue]]
***Absent hard palate
***Large umbilical hernia with eventrated abdominal organs
**Histologically:
***Proliferative and hypertrophic zones in the physes are irregularly separated by fibrovascular tissue
***Chondrocytes are not properly arranged
***Irregular ossification and mineralisation
*'''Telemark type'''
**Cattle of Norwegian origin
**Also seen in Jersey cows
**Calves born alive, unable to stand and die soon after birth
**Grossly:
***Domed cranium
***Brachygnatic face
***Protruding [[Oral Cavity - Tongue - Anatomy & Physiology|tongue]]
***Cleft palate
***Short neck and limbs
*'''Brachycephalic 'Snorter' type'''
**Hereford and Aberdeen Angus
**Show nasal dyspnoea and chronic rumenal tympany
**Grossly:
***Short, broad head
***Prominent, laterally displaced eyes
***Short and compressed vertebral column
***Distal long bones shorter than proximal
**Histologically:
**Physes appear normal
**Pallisading chondrocytes fewer in number
**Less hypertrophy
<u>In Sheep:</u>
*'''Ancon type'''
**Short limbs due to premature closure of growth plates
**Now rare
*'''Spider lamb'''
**Hereditary (autosomal recessive) in Suffolk and Hampshire breeds in North America
**Long, thin, angular limbs
**May be born alive or dead, aborted or develop symptoms within a month of birth
**Grossly:
***Fine bones, poor musculature, small heads, scoliosis
**Histologically:
***Abnormal centres of [[Bones - normal#Bone development|endochondral ossification]]
***Nodular cartilage hypertrophy
<u>In Pigs:</u>
*Occurs in Danish Landrace
*Autosomal recesive inheritance
*Dwarfs with short legs, forelegs shorter than hind legs
*Abnormal movement is noticable at weaning
*Sequel is [[Joints - degenerative#Degenerative joint disease (DJD)|arthrosis]]
===Osteopetrosis (Marble bone disease)===
*Occurs in sheep, dogs, cattle, horses
*Failure of resorption by osteoclasts -> failure of remodelling of [[Bones - normal#Bone organisation|cancellous bone]]
*Bones become thickened and dense but brittle
*Marrow cavites are full of unresorbed primary spongiosa
*Thickened intramembranous bones of skull -> altered shape of brain
*Associated with severe viral infections, e.g. '''FeLV''', [[Oral Cavity - Cavity & Gingiva#Bovine Viral Diarrhoea / Mucosal disease|BVD]]
*Hereditary in Angus cattle
===Lysosomal storage disease===
*Excess accumulation of metabolites in lysosomes
*Affects mainly nervous system
*Also affects growth of cartilage
===Osteogenesis Imperfecta===
*Cause of fragile bones in humans, very rarely in animals
*Reported in Holstein and Charolais calves
*Poor mineralisation of bones and teeth
*Fractures are often present at birth
===Congenital hyperostosis of pigs===
[[Image:Hyperostosis.jpg|right|thumb|100px|<small><center>Hyperostosis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
*Rare, genetic
*Diaphysial dysplasia
*Excessive periosteal intramembranous bone, particularly in long bones
*Grossly:
**Greatly thickened long bones
**Tense, shiny skin, closely adherent to tissues below
*Born dead or die soon after birth
===Retention of elongated primary trabeculae===
*Happens due to impaired osteoclastic activity
*Primary trabeculae do not transform into secondary and tertiary
*Continue to elongate
*Form a dense band beneath growth plate - growth retardation lattice
*Dense spikules apparent on radiographs
*Can be caused by [[Paramyxoviridae#Canine Distemper Virus (CDV)|distemper virus]], [[Flaviviridae|bovine viral diarrhoea virus]]
==Localised==
*'''Hemimelia''' - abscence of one of limb bones
*'''Syndactylia''' - fusion of toes
*'''Polydactylia''' - increased number of digits
*'''Ecterodactylia''' - cleft in paw extending to metacarpus of dogs and cats
===Cervical Vertebral Stenotic Myelopathy (Wobblers)===
*Equine disease
*Narrowing of the vertebral canal due to malalignment or maldevelopment of the vertebrae
*Fast growing male TBs ranging from 8 months to 4 years
*Hind limb ataxia due to cord compression
===Angular limb deformity===
*Lateral deviation of distal portion of limb (valgus)
*Medial deviation of distal portion of limb (varus) - more rare
*Most common in foals
**Carpal joint
**Tarsal joint
**Fetlock joint
*Congenital or acquired
*Due to:
**Malpositioning in utero
**Excessive joint laxity
**[[Thyroid Gland - Pathology#Hypothyroidism|Hypothyroidism]]
**Trauma
**Overnutrition
**Defective endochondral ossification
**Poor conformation
**Disruption of blood supply to one side of bone
**Secondary to [[Bones - developmental#Physitis|physitis in horses]]
*Usually resolves spontaneously in one to two weeks of life
*More severe cases exceding compensatory capabilities will persisist
*[[Bones - normal#Bone development|Cartilage development]] is affected
===Fibrous dysplasia===
*See [[Bones - hyperplastic and neoplastic#Fibrous dysplasia|Bones and Cartilage - hyperplastic and neoplastic]]
===Physitis===
*In horses
*Often associated with [[Bones - developmental#Angular limb deformity|angular limb deformity]]
*Also called '''epiphysitis''' and '''physeal dysplasia'''
*Problem of [[Bones - normal#Bone development|endochondral ossification]]
*Two age groups
**Weanlings
**Yearlings in early training and two-year-olds
*May cause contracted tendons and flexural deformities
*Factors probably involved in its development:
**Genetically fast growth rate
**Large quantities of imbalanced, high energy feed
**Imbalanced weight-bearing on joints
**Excessive activity
**Growth spurts
*Histologically: (appearance similar to [[Bones - developmental#Angular limb deformity|angular limb deformity]])
**Lateral aspect of radius
***Thickened metaphyseal part of physeal cartilage
***-> Delay or disturbance of endochondral ossification
***Compression
**Central part
***No obvious deformity
**Medial aspect
***Tension
***-> Transverse [[Bones - fractures|fractures]] and repair
**Laxity of periarticular attachements in young foals allows [[Bones - developmental#Angular limb deformity|angular limb deformity]]; not occuring in older foals and young horses
**(Sustained trauma produces similar lesions)
[http://www.omafra.gov.on.ca/english/livestock/horses/facts/info_congenital.htm#musculoskeletal Developmental abnormalities]
|backcolour =CDE472
|linkpage =Musculoskeletal System - Pathology
|linktext =Musculoskeletal System
|maplink = Musculoskeletal System (Content Map) - Pathology
|pagetype =Pathology
|sublink1=Bones - Pathology
|subtext1=BONES
}}
<br>
==Generalised==
===Proportionate dwarfism===
*Miniature breeds
*Due to growth factor deficit
===Chondrodysplasia===
*Literally means “abnormal cartilage development”
*Defective cartilage growth at the physis
*Usually genetic cause
*Occurs in cattle, dogs, sheep, pigs and cats
*Leads to '''disproportionate dwarfism''' (contrast with miniature breeds)
**Generally, growth is disproportionate because only the growth of bones which form from cartilage models is retarded – growth of other bones is normal (i.e. long bones shorter than normal)
<u>In Dogs:</u>
*'''Localised''' forms occur in dogs (e.g. affecting skulls of Pekingese and Bulldogs or the limbs of Dachshunds and Bassett hounds)
*Occasionally seen in immature Beagles, Poodles, Alaskan Malamutes, Scottish Deerounds and Norwegian Elkhounds
<u>In Cattle:</u>
*'''Dexter cattle'''
**Are heterozygous for incompletely dominant gene
**When homozygous - lethal, producing 'buldog calf'
**Usually aborted prior to seven month of pregnancy
**Also occurs in Holstein, Jerseys and Charolais
**Grossly:
***Limbs and vertebral column are short
***Domed cranium
***Protruding [[Oral Cavity - Tongue - Anatomy & Physiology|tongue]]
***Absent hard palate
***Large umbilical hernia with eventrated abdominal organs
**Histologically:
***Proliferative and hypertrophic zones in the physes are irregularly separated by fibrovascular tissue
***Chondrocytes are not properly arranged
***Irregular ossification and mineralisation
*'''Telemark type'''
**Cattle of Norwegian origin
**Also seen in Jersey cows
**Calves born alive, unable to stand and die soon after birth
**Grossly:
***Domed cranium
***Brachygnatic face
***Protruding [[Oral Cavity - Tongue - Anatomy & Physiology|tongue]]
***Cleft palate
***Short neck and limbs
*'''Brachycephalic 'Snorter' type'''
**Hereford and Aberdeen Angus
**Show nasal dyspnoea and chronic rumenal tympany
**Grossly:
***Short, broad head
***Prominent, laterally displaced eyes
***Short and compressed vertebral column
***Distal long bones shorter than proximal
**Histologically:
**Physes appear normal
**Pallisading chondrocytes fewer in number
**Less hypertrophy
<u>In Sheep:</u>
*'''Ancon type'''
**Short limbs due to premature closure of growth plates
**Now rare
*'''Spider lamb'''
**Hereditary (autosomal recessive) in Suffolk and Hampshire breeds in North America
**Long, thin, angular limbs
**May be born alive or dead, aborted or develop symptoms within a month of birth
**Grossly:
***Fine bones, poor musculature, small heads, scoliosis
**Histologically:
***Abnormal centres of [[Bones - normal#Bone development|endochondral ossification]]
***Nodular cartilage hypertrophy
<u>In Pigs:</u>
*Occurs in Danish Landrace
*Autosomal recesive inheritance
*Dwarfs with short legs, forelegs shorter than hind legs
*Abnormal movement is noticable at weaning
*Sequel is [[Joints - degenerative#Degenerative joint disease (DJD)|arthrosis]]
===Osteopetrosis (Marble bone disease)===
*Occurs in sheep, dogs, cattle, horses
*Failure of resorption by osteoclasts -> failure of remodelling of [[Bones - normal#Bone organisation|cancellous bone]]
*Bones become thickened and dense but brittle
*Marrow cavites are full of unresorbed primary spongiosa
*Thickened intramembranous bones of skull -> altered shape of brain
*Associated with severe viral infections, e.g. '''FeLV''', [[Oral Cavity - Cavity & Gingiva#Bovine Viral Diarrhoea / Mucosal disease|BVD]]
*Hereditary in Angus cattle
===Lysosomal storage disease===
*Excess accumulation of metabolites in lysosomes
*Affects mainly nervous system
*Also affects growth of cartilage
===Osteogenesis Imperfecta===
*Cause of fragile bones in humans, very rarely in animals
*Reported in Holstein and Charolais calves
*Poor mineralisation of bones and teeth
*Fractures are often present at birth
===Congenital hyperostosis of pigs===
[[Image:Hyperostosis.jpg|right|thumb|100px|<small><center>Hyperostosis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
*Rare, genetic
*Diaphysial dysplasia
*Excessive periosteal intramembranous bone, particularly in long bones
*Grossly:
**Greatly thickened long bones
**Tense, shiny skin, closely adherent to tissues below
*Born dead or die soon after birth
===Retention of elongated primary trabeculae===
*Happens due to impaired osteoclastic activity
*Primary trabeculae do not transform into secondary and tertiary
*Continue to elongate
*Form a dense band beneath growth plate - growth retardation lattice
*Dense spikules apparent on radiographs
*Can be caused by [[Paramyxoviridae#Canine Distemper Virus (CDV)|distemper virus]], [[Flaviviridae|bovine viral diarrhoea virus]]
==Localised==
*'''Hemimelia''' - abscence of one of limb bones
*'''Syndactylia''' - fusion of toes
*'''Polydactylia''' - increased number of digits
*'''Ecterodactylia''' - cleft in paw extending to metacarpus of dogs and cats
===Cervical Vertebral Stenotic Myelopathy (Wobblers)===
*Equine disease
*Narrowing of the vertebral canal due to malalignment or maldevelopment of the vertebrae
*Fast growing male TBs ranging from 8 months to 4 years
*Hind limb ataxia due to cord compression
===Angular limb deformity===
*Lateral deviation of distal portion of limb (valgus)
*Medial deviation of distal portion of limb (varus) - more rare
*Most common in foals
**Carpal joint
**Tarsal joint
**Fetlock joint
*Congenital or acquired
*Due to:
**Malpositioning in utero
**Excessive joint laxity
**[[Thyroid Gland - Pathology#Hypothyroidism|Hypothyroidism]]
**Trauma
**Overnutrition
**Defective endochondral ossification
**Poor conformation
**Disruption of blood supply to one side of bone
**Secondary to [[Bones - developmental#Physitis|physitis in horses]]
*Usually resolves spontaneously in one to two weeks of life
*More severe cases exceding compensatory capabilities will persisist
*[[Bones - normal#Bone development|Cartilage development]] is affected
===Fibrous dysplasia===
*See [[Bones - hyperplastic and neoplastic#Fibrous dysplasia|Bones and Cartilage - hyperplastic and neoplastic]]
===Physitis===
*In horses
*Often associated with [[Bones - developmental#Angular limb deformity|angular limb deformity]]
*Also called '''epiphysitis''' and '''physeal dysplasia'''
*Problem of [[Bones - normal#Bone development|endochondral ossification]]
*Two age groups
**Weanlings
**Yearlings in early training and two-year-olds
*May cause contracted tendons and flexural deformities
*Factors probably involved in its development:
**Genetically fast growth rate
**Large quantities of imbalanced, high energy feed
**Imbalanced weight-bearing on joints
**Excessive activity
**Growth spurts
*Histologically: (appearance similar to [[Bones - developmental#Angular limb deformity|angular limb deformity]])
**Lateral aspect of radius
***Thickened metaphyseal part of physeal cartilage
***-> Delay or disturbance of endochondral ossification
***Compression
**Central part
***No obvious deformity
**Medial aspect
***Tension
***-> Transverse [[Bones - fractures|fractures]] and repair
**Laxity of periarticular attachements in young foals allows [[Bones - developmental#Angular limb deformity|angular limb deformity]]; not occuring in older foals and young horses
**(Sustained trauma produces similar lesions)
[http://www.omafra.gov.on.ca/english/livestock/horses/facts/info_congenital.htm#musculoskeletal Developmental abnormalities]