13. 6. Foal
• Bone, Multifocal
necrotizing
osteomyelitis
and physitis
with sequestra
• E coli, Strep spp,
Salmonella,
Klebsiella,
Rhodococcus
equi,Arcanobact
erium pyogenes,
Actinobacillus
equuli
14. 6. Foal
• Sequestra- large necrotic
bone separated from
blood supply
• Involucrum- Granulation
tissue or reactivebone
around the sequestra
• Foals most commonly in
secondary ossification
centers, and can cause
articular cartilage
defects
15. 7. Dog, Mdx
• Spine,
intervertebral
disc
degeneration
and prolapse
with spinal
cord
compression
• Vertebral
osteosclerosis
26. Rickets/Osteomalacia
• Anything that • Phosphorus
interferes with deficiency-
mineralization uncommon
(Cattle >Sheep >
• Vit D Deficiency- Horses)
Sunlight,
ingested , • Calcium
depressed by deficiency-
carotenoids rapidly corrected
serum calcium
not likely to be
cause of faulty
mineralization
27. Rickets
• Inherited errors of • Type 2 - Vit D
Vit D metabolism Resistant
Rickets- Defect in
• Type 1- Vit D 1,25
Dependent dihydroxycholeca
Rickets- defect in lciferol receptor
renal alpha-1-
hydroxylase • cant use D2,
and D3 is
• treat with present in
1,25 (OH)2 D3 high amounts
without
hypercalcemi
28. Hypophosphatemic
rickets
• Vit D resistant
• hypophosphatemia
(impaired renal
resorption and
intestinal
absorption),
normocalcemia,
skeletal
deformities
• Plasma 1,25
Dihydroxy D3
levels are low
30. 17. Aborted calf
• Thought this might be a
growth retardation lattice
(BVD), but histolgically
normal primary and
secondary spongiosa with
local band of reduced
hematopoiesis
31. 18. Bovine
• Synovial fossae in the
elbow joint, normal non-
weighbearing surfaces
develop as a
consequence of joint
modeling
• found in horses, cows,
and pigs
50. Terms
• Spina bifida- absence of the • Spinal dysraphism (raphe=
dorsal portions of the suture)- term applies to the
vertebrae (secondary to neural tube- Applies to spinal
failure of the neural tube to cord and may have vertebral
close completely) abnormalities
• occulta- skin overlying • Myeloshisis (“marrow”=
the defect is normal, and fatty=spinal cord/bone
spinal cord may be grossly marrow+ cleft)-same as
normal dysraphism
• cystica- a cystic swelling • Dermoid sinus- congenital in
protrudes through the Rhodesian ridgebacks-
vertebral defect incomplete separation of the
neural tube from the overlying
• Meningomyelocele- dorsal midline ectoderm
spinal cord is missing
segments
51. Arthrogryposis
• AM- Arthrogryposis multiplex- Angus
cattle, AR- Front and rear legs affected
• BVD/Akabane virus infection in utero
• Toxic- Lupins (crooked calf disease),
Veratrum californicum (day 29
gestation), Conium maculatum (pigs,
cows), Jimsonweed, Wild black cherry,
locoweed (Astragalus and Oxytropis),
Hybrid sorghum and Sudan grass in foals
71. Nutritional Disorders
Rickets (bending of the tibiotarsus, distortion of the ribs and enlargement of the costocondral junctions)
Manganese deficiency Tibial chondrodystrophy, displacement of gastrocnemius tendon (Perosis)
Riboflavin (B2) deficiency Curly toe paralysis
Nutritional Etiology
• Calcium or phosphorus deficiency or an imbalance in these nutrients
will result in rickets in immature birds or osteomalacia in mature
breeders and commercial egg-production flocks.
• Vitamin D3 (cholecalciferol) deficiency results in rickets in immature
flocks housed in controlled environment units.
• Thiamine (vitamin B1) deficiency results in an abnormal gait
progressing to recumbency and paralysis with hyperextension of the
neck.
• Riboflavin (vitamin B2) deficiency results in a deformity of the feet
termed “curled toe paralysis”.
• Pyridoxine (vitamin B6) deficiency results in abnormal gait and
convulsions. This condition can also occur following administration
of toxic levels of nitrofurans to immature flocks.
• Manganese deficiency results in chondrodystrophy. This occurs in
growing chicks due to decreased formation of bone below the growth
plates of the tibiotarsus and tarsometatarsus. Mildly affected chickens
show stunting and enlargement of the hock joint with reduction in the
length of the leg bones. The lesion progresses to severe deformation of
the hock joint culminating in displacement of the gastrocnemius
(Achilles) tendon (perosis). Chondrodystrophy is characterized by a
high prevalence in the flock, bilateral involvement of the hock joints
and reduction in length of the long bones. Confirmation of the diagnosis
requires analysis of feed to determine manganese content. Dietary level
should range from 80 to 120 ppm for optimal growth.
• Choline and pyridoxine deficiency may result in bilateral enlargement
of hock joints, sometimes with displacement of the gastrocnemius
tendon.
• Chondrodystrophy should be differentiated from valgus-varus
abnormality of genetic origin.
76. Layer chicken
• Cage Layer Fatigue
• Osteoporosis-fractures
of limbs, with
osteomalacia
histologically
• Muscle weakness also
a feature
• Occurs in animals in
cages, but resolves if
on the ground
• Relative calcium
deficiency (below 2:1
ratio)
104. Hereditary
chondrodysplasia
• Multiple irregular ossification
centers in long bones- hypertrophic
cartilage forms nodules thatf ail to
develop normally, lack of
subchondral bone predisposes to
degenerative arthropathy- bone
growth in utero is normal
• Suffolk and Hampshire sheep
• Long limbs, necks, kyphosis/
scoliosis, sternal deformity, valgus
deformities below the carpus,
roman nose, deviated nasal
septum, shortening of maxilla,
elongation of the occipital
condyles- affects all endochondral
bones and
106. Holoprosencephaly
• Failure of the rostral • V.
cerebrum to divide californicum-
normally antagonism of
sonic
• Arhinencephaly- hedgehog
aplasia of the gene- involves
olfactory bulbs the rostral
and tracts extremity of
the notochord
• craniofacial and the
abnormalities- surrouding
cyclopia mesenchyme
(synophthalmus)
