| Line 1: |
Line 1: |
| − | {{review}}
| + | #REDIRECT[[:Category:Bones - Developmental Pathology]] |
| − | | |
| − | {{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 [[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 [[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 - Pathology#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''', [[Bovine Viral Diarrhoea Virus|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
| |
| − | *'''Ectrodactylia''' - 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 - Pathology#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 - Pathology#Fibrous dysplasia|Bones and Cartilage - hyperplastic and neoplastic]]
| |
| − | | |
| − | | |
| − | ===Physitis===
| |
| − | | |
| − | *In horses
| |
| − | *Often associated with [[Bones Developmental - Pathology#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 - Pathology#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 - Pathology|fractures]] and repair
| |
| − | **Laxity of periarticular attachements in young foals allows [[Bones Developmental - Pathology#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]
| |
| − | | |
| − | | |
| − | ==Test yourself with the Bone and Cartilage Pathology Flashcards==
| |
| − | | |
| − | [[Bones_and_Cartilage_Flashcards_-_Pathology|Bones and Cartilage Flashcards]]
| |