Ch 8 - Juvenile Flashcards
How does neutering affect physeal closure times in cats?
It causes delays; Castrated males have delayed physeal closure times when compared to entire males.
Castrated females in one study had delayed closure of the distal radial physis.
What is the primary source of vitamin D in dogs and cats?
diet
What is the most common clinical outcome of physeal disruption?
angular limb deformity, due to partial or complete premature closure of the growth plate
All physes contribute to bone growth equally - T or F?
False; certain physes contribute more, e.g. distal ulnar physis contributes 85% of total ulnar growth potential.
The distal ulnar physis contributes ___% of the growth potential of the ulna.
85
Why is the distal ulnar physis the most commonly affected location for premature closure i.e. injury, in dogs, but not in cats?
It is largely due to the conical shape of the physis in dogs, which is not the case in cats.
Describe the main findings and the cause.
Premature closure of the distal ulnar physis
Which of the following is NOT a radiographic feature of premature closure of the distal ulnar physis?
a) Shortened ulna relative to the radius
b) Carpal varus deformity
c) Craniomedial subluxation of the distal radius
d) Proximal displacement of the styloid process of the ulna
b) Carpal varus deformity
Explanation: The typical deformity observed is carpal valgus, not carpal varus.
Which of the following is a typical radiographic feature of premature closure of the distal ulnar physis?
a) Shortened radius relative to the ulna
b) Cranial bowing of the radius
c) Proximal displacement of the accessory carpal bone relative to the styloid process of the ulna
d) Narrowed humeroulnar joint space
b) Cranial bowing of the radius
What is the common result of premature closure of the distal ulnar physis in relation to the radial cortex?
a) Caudal bowing of the radius
b) Cortical thickening of the cranial radial cortex
c) Cortical thickening of the caudal radial cortex
d) Lateral displacement of the radial cortex
c) Cortical thickening of the caudal radial cortex
Which of the following is true regarding the anconeal process in cases of premature closure of the distal ulnar physis?
a) It may undergo accelerated fusion
b) It may fail to fuse, but it is difficult to determine if this is related to the physis injury
c) It never fails to fuse and is unrelated to the injury
d) It causes lateral subluxation of the radius
b) It may fail to fuse, but it is difficult to determine if this is related to the physis injury
In premature closure of the distal ulnar physis, which of the following is displaced proximally?
a) Accessory carpal bone
b) Trochlear notch of the ulna
c) Styloid process of the ulna
d) Distal radius
c) Styloid process of the ulna
Which of the following is associated with radial deformities seen in premature closure of the distal ulnar physis?
a) Distal radial subluxation
b) Medial bowing of the radius
c) Cortical thickening of the cranial radial cortex
d) Craniomedial subluxation of the distal radius
d) Craniomedial subluxation of the distal radius
Which part of the radius is most commonly affected by premature physeal closure?
a) Proximal radial physis
b) Distal radial physis
c) Mid-shaft of the radius
d) Both proximal and distal physes equally
Answer: b) Distal radial physis
What percentage of longitudinal growth of the radius is contributed by the distal radial physis?
a) 50%
b) 70%
c) 30%
d) 90%
b) 70%
Which of the following is NOT a typical radiographic feature of symmetrical premature closure of the distal radial physis?
a) Shortening of the radius relative to the ulna
b) Widened humeroradial joint space
c) Angular limb deformity with carpal valgus
d) Widened humeroulnar joint space
c) Angular limb deformity with carpal valgus
What clinical outcome is commonly associated with symmetrical premature closure of the distal radial physis in canines?
a) Carpal varus with inward rotation of the manus
b) Carpal valgus with outward rotation of the manus
c) Carpal varus with outward rotation of the manus
d) Angular limb deformity with no rotation
a) Carpal varus with inward rotation of the manus
Which species is more likely to experience carpal joint incongruity due to premature closure of the distal radial physis?
a) Canine patients
b) Feline patients
c) Both species equally
d) Neither, it’s not species-specific
b) Feline patients
Which of the following is a key radiographic feature of asymmetrical premature closure of the distal radial physis?
a) Widened humeroradial joint space
b) Sloping of the distal radial articular surface
c) Shortening of the ulna relative to the radius
d) Proximal subluxation of the radial head
b) Sloping of the distal radial articular surface
What is a common angular limb deformity resulting from asymmetrical premature closure of the distal radial physis?
a) Carpal valgus
b) Carpal varus
c) Either varus or valgus, depending on the site of closure
d) No angular deformity occurs
c) Either varus or valgus, depending on the site of closure
Premature closure of which part of the radial physis typically results in more severe clinical signs?
a) Proximal radial physis
b) Distal radial physis
c) Both result in equally severe signs
d) Proximal ulna
Answer: b) Distal radial physis
Explanation: The distal radial physis contributes 70% of radial growth, making its premature closure more severe than the proximal radial physis.
What is the most notable radiographic feature of premature closure of both the distal ulnar and radial physes?
a) Elbow joint degeneration
b) Shortening of the radius and ulna, more severe in the ulna
c) Shortening of the radius but normal ulna length
d) Lengthening of the ulna
b) Shortening of the radius and ulna, more severe in the ulna
Which of the following is NOT a radiographic feature of simultaneous ulnar and radial physeal disturbances?
a) Shortening of the length of the radius and ulna
b) Lateral bowing of the diaphyses
c) Secondary changes in the elbow joint
d) Angulation of the radiocarpal joint
c) Secondary changes in the elbow joint
Premature closure of both the distal ulnar and radial physes (together) is associated with:
a) Carpal varus
b) Carpal valgus
b) Carpal valgus
In simultaneous ulnar and radial physeal disturbances, which bone experiences more severe shortening?
a) Radius
b) Ulna
c) Both radius and ulna equally
b) Ulna
Asymmetrical disruption and premature closure of the lateral part of the physis of the distal femur leads to genu ______________.
Genu valgum
Which of the following growth plates, when disrupted, predisposes the patient to cranial cruciate ligament rupture?
a) Distal femoral growth plate
b) Proximal tibial growth plate
c) Proximal femoral growth plate
d) Lateral aspect of the distal tibial growth plate
b) Proximal tibial growth plate
Which physeal disturbance could lead to this appearance?
Premature closure of the proximal tibial physis
Which breed appears to be over-represented in the limited case reports of SCFE?
a) German Shepherds
b) Labradors
c) Beagles
d) Poodles
b) Labradors
In SCFE (Slipped capital femoral epiphysis), which part becomes detached - is the physis with the femoral head/epiphysis or with the neck/body?
It is with the neck/body.
In SCFE, what is happening histologically at the physis?
delayed endochondral ossification
osteochondrosis
The separation of the physis in conditions like SCFE occurs at which level of the physis?
a) Resting chondrocytes
b) Proliferative chondrocytes
c) Hypertrophic chondrocytes
d) Osteoblasts
c) Hypertrophic chondrocytes
Which layer of the physis is considered the weakest and most prone to separation?
a) Resting chondrocytes
b) Proliferative chondrocytes
c) Hypertrophic chondrocytes
d) Calcified cartilage
c) Hypertrophic chondrocytes
Which projection is best for diagnosing SCFE?
flexed VD
The most common physical manifestation of osteochondrodysplasia is:
a) Disproportionate dwarfism
b) Increased growth rate
c) Excessive limb length relative to the trunk
d) Proportionate dwarfism
a) Disproportionate dwarfism
Osteochondrodysplasia needs to be differentiated from which other type of dwarfism that results in proportionate dwarfism?
Pituitary dwarfism
8-month-old Weimaraner which presented with pelvic limb lameness without a history of trauma. There is bilateral displacement of the femoral heads relative to the proximal femoral physes and mottled radiolucency of the femoral heads. The diagnosis was slipped capital femoral epiphyses.
kitten with osteochondrodysplasia; widening of the distal radial, ulnar and metacarpal physes with metacarpal flaring
epiphyseal dysplasia in 10.5m Mini Dobermann
Osteogenesis imperfecta is caused by a structural defect in which of the following?
a) Collagen type I
b) Collagen type II
c) Collagen type III
d) Elastin
a) Collagen type I
Which of the following is a primary characteristic of osteogenesis imperfecta?
a) Bone overgrowth
b) Bone fragility and pathological fractures
c) Joint dislocations
d) Increased bone density
b) Bone fragility and pathological fractures
The onset of clinical disease in osteogenesis imperfecta is most commonly seen in puppies and kittens at what age?
a) 2-6 weeks
b) 10-18 weeks
c) 6 months
d) 1 year
b) 10-18 weeks
Osteogenesis imperfecta can be easily confused with which other condition due to similar clinical and radiographic findings?
a) Hip dysplasia
b) Osteosarcoma
c) Osteochondrosis
d) Nutritional secondary hyperparathyroidism
d) Nutritional secondary hyperparathyroidism
a) Generalized osteopenia and thinning of diaphyseal cortices
b) Increased bone density
c) Dislocation of the hip joint
d) Bone tumors
a) Generalized osteopenia and thinning of diaphyseal cortices
a) Softening of the bones
b) Translucent or pink discoloration of teeth
c) Overgrowth of enamel
d) Tooth fractures
e) B and D
e) B and D
Osteopetrosis is primarily characterized by:
a) Defective osteoclastic resorption
b) Increased osteoblastic activity
c) Decreased bone opacity
d) Loss of cortical bone
a) Defective osteoclastic resorption
Radiographically, osteopetrosis is often associated with:
a) Decreased bone opacity
b) Generalized increase in bone opacity
c) Normal trabecular bone pattern
d) Thin diaphyseal cortices
b) Generalized increase in bone opacity
Which virus is associated with medullary sclerosis and non-regenerative anaemia in growing cats?
a) Feline immunodeficiency virus (FIV)
b) Feline leukaemia virus (FeLV)
c) Feline calicivirus
d) Feline herpesvirus
b) Feline leukaemia virus (FeLV)
In adult cats with idiopathic acquired osteopetrosis, what radiographic findings are typically observed?
a) Thickening of cortical bone
b) Increased bone opacity
c) Increased joint flexibility
d) Thickening of diaphyseal cortices and vertebral bodies
d) Thickening of diaphyseal cortices and vertebral bodies
In which of the following dog breeds is diffuse osteosclerosis observed due to anaemia from erythrocyte pyruvate kinase deficiency?
a) Beagles
b) Dachshunds
c) Basenjis
d) Golden Retrievers
c) Basenjis
tibia of a cat with osteosclerosis. Note the marked diffuse increased radiopacity in
the medullary cavity of the tibia.
Retained endochondral cartilage cores are most commonly found in:
a) Small-breed dogs
b) Medium-sized dogs
c) Large- and giant-breed dogs
d) Cats
c) Large- and giant-breed dogs
Which condition can retained endochondral cartilage cores radiographically mimic?
a) Osteochondritis dissecans
b) Hip dysplasia
c) Traumatic premature closure of the distal ulnar physis
d) Elbow luxation
c) Traumatic premature closure of the distal ulnar physis, because it also leads to a reduction in the overall growth in length of the ulna
leading to cranial bowing of the radii and carpal valgus.
Which part of the skeleton is MOST commonly affected by retained endochondral cartilage cores?
a) Distal radius
b) Distal ulna
c) Distal femur
d) Proximal humerus
b) Distal ulna
also distal tibia, femur and radius
antebrachium of a skeletally immature dog with a retained
endochondral cartilage core in the ulna showing the typical flame-shaped radiolucency extending from the physis into the metaphysis. Note the sclerotic rim surrounding the radiolucency.
What histological component accumulates in retained endochondral cartilage cores?
a) Osteocytes
b) Fibroblasts
c) Osteoclasts
d) Physeal hypertrophic chondrocytes
d) Physeal hypertrophic chondrocytes
At what age are clinical signs of retained endochondral cartilage cores typically observed?
a) Between 4 and 7 months
b) Between 10 and 12 months
c) Between 2 and 4 months
d) Between 1 and 2 years
a) Between 4 and 7 months
Which of the following factors may contribute to the development of retained endochondral cartilage cores?
a) Inadequate calcium supplementation
b) Excessive exercise in young dogs
c) Overnutrition and excessive calcium supplementation
d) Genetic factors in small breeds
c) Overnutrition and excessive calcium supplementation
Besides the distal ulna, retained endochondral cartilage cores may also be seen in:
a) The carpus and metacarpus
b) The distal tibia, femur, and radius
c) The scapula and humerus
d) The skull and mandible
b) The distal tibia, femur, and radius
Some dogs with retained endochondral cartilage cores may:
a) Remain asymptomatic with incidental findings
b) Develop life-threatening complications
c) Require immediate surgical intervention
d) Present only in their adult years
a) Remain asymptomatic with incidental findings
What type of dysostosis is this?
Ectrodactyly - (lobster claw deformity) separation of the medial and lateral portions of a limb. the separation is at least metacarpal level, but can be more proximal (varying levels)
Which dysostosis is this?
Hemimelia (longitudinal, intercalary form) in 10w kitten (heritable in DSH, Siamese, Chihuahua), absence of all or part of the distal limb
Pre-axial polydactyly means…
extra digit(s) on the medial side
In which breeds/species is polydactyly heritable?
Australian shepherd (also syndactyly)
Pyrenean Mountain dog
Collies
St. Bernard
cats
This is a condition described in humans, and rarely reported in dogs and cats. What is it?
Proximal femoral focal deficiency (proximal femoral dysplasia) - unilateral or bilateral absence (agenesis) of the femoral head/neck, can range from mild (lack of epiphysis) to severe (lack of entire proximal femur.
What is the predilection site of hematogenous osteomyelitis?
the metaphyses of long bones
What is the incidence of hematogenous osteomyelitis?
2.8 - 10%, mostly in young animals
9-month-old DSH with suspected proximal femoral focal deficiency. Left coxofemoral subluxation and a shallow acetabulum are evident. The left femoral head and part of the neck are absent (aplasia). The left femur is also markedly shorter than the right and is atrophied.
puppy with haematogenous
osteomyelitis. Note the moth- eaten lysis in the distal metaphyseal region of the ulna and the subtle immature periosteal reaction along the caudal cortex of the distal ulnar diaphysis.
Which of the following does not occur in dogs with haematogenous osteomyelitis?
a) Infection spreads into the diaphysis
b) Transphyseal vessels allow infection to reach the epiphyses
c) Subperiosteal scalloping may develop
d) Medullary sclerosis can be present
b) Transphyseal vessels allow infection to reach the epiphyses;
What radiographic feature is typically seen in haematogenous osteomyelitis?
a) Uniform bone thickening
b) Patchy metaphyseal radiolucent areas
c) Complete destruction of the bone cortex
d) Cartilage overgrowth
b) Patchy metaphyseal radiolucent areas
n which species is osteochondroma more likely to have a heritable component?
a) Dogs
b) Cats
c) Horses
d) Rabbits
a) Dogs
(in cats, there is a possible viral component)
Osteochondromas are generally considered to be benign/malignant.
Benign
In which part of the bone do osteochondromas typically occur in long bones?
a) Diaphysis
b) Epiphysis
c) Metaphysis
d) Articular surface
c) Metaphysis
but diaphysis of femur/tibia has been reported
How are osteochondromas classified?
Based on their number;
solitary vs. multiple (multiple cartilaginous exostoses)
young Labrador Retriever; There is a smooth broad-
based bony lesion on the cranial aspect of the proximal radius, with a relatively radiolucent centre. The diagnosis was osteochondroma.
osteochondroma
In dogs, when do osteochondromas typically stop growing?
a) After skeletal maturity
b) After the age of 2 years
c) Never, they grow throughout life
d) At birth
what about in cats?
a) After skeletal maturity
in cats, they grow throughout life.
Osteochondromas can transform into osteosarcomas or chondrosarcomas - true or false?
True; older dogs may present as a result of this.
Why might you not see the extent of an osteochondroma radiographically?
The lesions are characterized by cartilage-capped bony protuberances, and the size of the lesion visible radiographically depends on the degree of mineralization of the cartilage cap. Hence, the lesion can be larger than radiographically noted, owing to a large cartilaginous component, especially in younger dogs.
A smooth bony protuberance with a broad base and a narrow tip. A well defined cortex and medulla may be differentiated, of which the cortex is continuous with the underlying cortex - this describes one appearance of which condition?
osteochondroma
What is endochondroma, histologically?
degenerative and necrotic chondrocytes
In which scenario will an osteochondroma of the ulna cause clinical pain?
Lesions appearing in the distal antebrachium, and in particular the medial or craniomedial cortex of the distal ulna, can impinge on the adjacent radial cortex and cause radial lysis and clinical pain.
Where is an enchondroma typically located?
a) In the epiphysis of long bones
b) In the diaphysis of short bones
c) Within the metaphyses of long bones
d) On the periosteal surface of flat bones
c) Within the metaphyses of long bones (but can spread and affect the diaphysis)
If endochondromas are benign, why would patients present?
Pathological fractures
Which of the following is a synonym for enchondromatosis?
a) Ollier’s disease
b) Paget’s disease
c) Ewing sarcoma
d) Chondromyxoid fibroma
a) Ollier’s disease
At what age is polyostotic lymphoma most commonly diagnosed in dogs and cats?
a) Between 5 and 15 years
b) Less than 2 years of age
c) After 10 years of age
d) After skeletal maturity
b) Less than 2 years of age
In which areas are polyostotic lymphoma lesions typically found in juvenile cats?
a) Proximal joints of the limbs
b) Cranial bones
c) Pelvis and shoulder joints
d) Distal joints of the carpi and metacarpi/metatarsi
d) Distal joints of the carpi and metacarpi/metatarsi
What are the typical radiographic features of polyostotic lymphoma?
a) Diffuse osteosclerosis with bone thickening
b) Diffuse osteopenia with multifocal circular lucencies in the metaphyses of long bones
c) Complete complex destruction of the cortex and medulla
d) Sclerotic lesions in the diaphyses of long bones
b) Diffuse osteopenia with multifocal circular lucencies in the metaphyses of long bones
Where are changes from metabolic bone disorders usually most noticeable?
a) In the skull and mandible
b) In the distal radius, ulna, and tibia
c) In the vertebrae
d) In the metacarpals and metatarsals
b) In the distal radius, ulna, and tibia - areas where bone activity is greatest
Which of the following is a typical radiographic feature of metabolic bone disease?
a) Double cortical line
b) Cortical thickening
c) Increased bone width
d) Cortical sclerosis
a) Double cortical line or cortical thinning;
The double line is due to loss (resorption) of intra-cortical bone.
In metabolic bone disorders (CHOOSE or FILL IN):
* Changes tend to be unilateral / bilateral and a/symmetrical
* Generalized osteopenia/osteosclerosis may be observed
* Cortical thinning/thickening may be observed, or a ______________.
* Pathological fractures are common / uncommon.
* Changes are usually most noticeable in areas where
bone activity is the greatest, such as ________
* Physes may be widened/narrowed.
* Metaphyses may be ___________.
- Changes tend to be bilaterally symmetrical
- Generalized osteopenia may be observed
- Cortical thinning may be observed, or a double cortical
line due to intra-cortical bone resorption - Pathological fractures are common
- Changes are usually most noticeable in areas where
bone activity is the greatest, such as in the distal
radius, ulna and tibia - Physes may be widened
- Metaphyses may be abnormally flared.
Nutritional secondary hyperparathyroidism occurs with disruption of which minerals?
Ca and P (both are too low)
Which hormone is stimulated as a result of Ca/P disruption in nutritional secondary hyperparathyroidism?
PTH
What causes compensatory increased PTH synthesis in nutritional secondary hyperparathyroidism?
a) Excessive calcium in the diet
b) Balanced calcium and phosphorus levels
c) Chronic insufficient calcium intake or absorption
d) Vitamin D toxicity
c) Chronic insufficient calcium intake or absorption
What is the primary role of PTH in cases of nutritional secondary hyperparathyroidism?
a) Decrease bone resorption
b) Inhibit calcium absorption from the gut
c) Increase bone resorption to restore serum calcium levels
d) Prevent phosphorus excretion in the kidneys
c) Increase bone resorption to restore serum calcium levels
8m DSH with nutritional secondary hyperparathyroidism; poorly visible scapulae and dorsal spinous processes. diffuse osteopenia.
Which of these has delayed epiphyseal ossification?
Pituitary dwarfism
Congenital hypothyroidism
MPS
and some chondrodysplasias (cats, malamutes, english pointers)
in short, chondrodysplasias have many forms, and some of them will have features of metabolic bone diseases.
Which of these has widened physes?
Rickets
Pituitary dwarfism
MPS
and some chondrodysplasias
in short, chondrodysplasias have many forms, and some of them will have features of metabolic bone diseases.
Which of these can present with fractures?
Osteogenesis imperfecta
Nutritional secondary hyperparathyroidism
Which of the following conditions is associated with both delayed epiphyseal ossification and disproportionate dwarfism?
a) Osteogenesis imperfecta
b) Nutritional secondary hyperparathyroidism
c) Pituitary dwarfism
d) Congenital hypothyroidism
d) Congenital hypothyroidism
Which disorder does not typically cause widened physes or dwarfism but is associated with osteopenia and fractures?
a) Rickets
b) Osteogenesis imperfecta
c) Pituitary dwarfism
d) Hypervitaminosis A
b) Osteogenesis imperfecta
What metabolic disorder is characterized by flared metaphyses at the ribs and disproportionate dwarfism?
a) Rickets
b) Osteogenesis imperfecta
c) Mucopolysaccharidosis
d) Chondrodysplasias
c) Mucopolysaccharidosis
Which of the following changes is associated with hypervitaminosis A?
Osteopenia
Which biochemical changes occur with renal secondary hyperparathyroidism?
Hyperphosphatemia, consequently hypocalcemia
Simultaneously, reduced calcitriol (secreted by the kidney).
Both of these lead to increase in PTH secretion > osteoclast activity (they resorb bone / cause bone loss, in order to increase the serum Ca)
Why does rubber jaw occur?
In renal secondary hyperparathyroidism, the cancellous bone from the mandible/maxilla is resorbed, and the bones become soft/pliable.
Which condition may accompany renal secondary HPTH in immature animals?
Rickets, due to the kidneys’ inability to perform the final hydroxylation of Vit D, leading to hypovitaminosis D.
(this is rare)
Which types of rickets exist?
Diet-related (rare)
Heritable Type I (Vit D-Dependent)
Heritable Type II (Vit D-Dependent)
what’s the difference between Vitamin D-dependent rickets type I and II?
VDDR-II is much more difficult to treat because the issue lies in the receptor, not in the production of calcitriol. Type II results in high levels of calcitriol, while type I results in low levels of calcitriol.
young dog with rickets. There is
- widening of the physes of the distal
radius and ulna, and the distal metacarpi (arrowed),
- flaring of the metaphyses
- marked thinning of the metacarpal cortices.
Sometimes in rickets (especially dietary), there is generalised osteopenia.
Which breed is most affected by pituitary dwarfism?
GSD
How do you distinguish pituitary dwarfism from other types of of dwarfism (metabolic etiologies), and what are the other types?
Pituitary dwarfism is proportionate; congenital hypothyroidism and mucopolysaccharidosis and some chondrodysplasias, produce disproportionate dwarfism.
By what age can you recognise pituitary dwarfism?
2-3 months of age
In pituitary dwarfism, which bones are particularly affected by delayed physeal closure?
vertebral bodies, humerus, femur
(hence why they grow slowly, but retain near-normal body proprotions)
How is pituitary dwarfism confirmed?
MRI/CT of the pituitary gland - which shows hypoplasia or cysts
Which of the following breeds is NOT commonly associated with congenital hypothyroidism in dogs?
a) Boxers
b) Scottish Deerhounds
c) Giant Schnauzers
d) Labrador Retrievers
d) Labrador Retrievers
What is the primary role of thyroid hormones in bone growth in dogs and cats?
a) Stimulating osteoclast activity
b) Stimulating growth hormone production and promoting endochondral ossification
c) Reducing calcium absorption in the intestines
d) Inhibiting epiphyseal ossification
b) Stimulating growth hormone production and promoting endochondral ossification
Which of the following radiological features is characteristic of congenital hypothyroidism?
a) Flared netaphyses
b) Delayed epiphyseal ossification
c) Osteopenia
d) Widened physes
b) Delayed epiphyseal ossification
Flared metaphyses - rickets
Osteopenia - rickets, hyperPTH, hypervitA
Widened physes - pituitary dwarfism
abnormal at 14 weeks vs. normal at 12 weeks
kitten diagnosed with congenital hypothyroidism. Note the delayed epiphyseal appearance and retarded ossification of the carpal bones
Which of the following is NOT a radiological feature of congenital hypothyroidism?
a) Thickening of radial and ulnar cortices
b) Shortened vertebral bodies with scalloped ventral borders
c) Increased ossification of epiphyseal centers
d) Valgus deformities of the carpal and tarsal bones
c) Increased ossification of epiphyseal centers
What type of bone deformities are commonly seen in dogs and cats with congenital hypothyroidism?
a) Scoliosis
b) Valgus deformities of the carpal and tarsal bones
c) Fractures of long bones
d) Fusion of vertebrae
b) Valgus deformities of the carpal and tarsal bones
Which breed has NOT been described as having radiographic abnormalities similar to congenital hypothyroidism?
a) Beagles
b) Miniature Poodles
c) German Shepherd Dogs
d) Golden Retrievers
d) Golden Retrievers
a) Beagles - multiple epiphyseal dysplasia
b) Miniature Poodles - multiple epiphyseal dysplasia
c) German Shepherd Dogs - pituitary dwarfism
What is the most common cause of hypervitaminosis A in cats?
a) Ingestion of excess fish
b) Ingestion of a diet composed primarily of liver
c) Ingestion of raw bones
d) Ingestion of dairy products
b) Ingestion of a diet composed primarily of liver
Which age group is more commonly affected by hypervitaminosis A in cats?
a) Kittens
b) Adolescent cats
c) Older cats
d) Neonatal kittens
c) Older cats
In dogs, the “lead lines” from lead poisoning are most commonly seen in which of the following bones?
a) Femur and humerus
b) Radius/ulna, and metacarpals
c) Pelvis and vertebrae
d) Skull and mandible
B - in the metaphysis of long bones, in particular the distal radius and ulna and the distal meta- carpals
Which of the following radiographic features is associated with lead poisoning in immature dogs?
a) Radiopaque bands in the metaphysis of long bones
b) Radiolucent areas in the epiphysis of long bones
c) Osteoporotic long bones
d) Widening of the joint spaces
a) Radiopaque bands in the metaphysis of long bones, so-called “lead lines”
At what age do cats typically present with clinical signs of mucopolysaccharidosis?
a) Less than 1 year of age
b) 1 to 2 years of age
c) 2 to 5 years of age
d) Older than 10 years
a) Less than 1 year of age
What type of abnormality is commonly seen in both Type VI and Type VII mucopolysaccharidosis?
a) Coxa valga
b) Coxa vara
c) Bilateral hip luxation
d) Femoral head necrosis
c) Bilateral hip luxation
What spinal abnormality is typically seen in cats with mucopolysaccharidosis Type VI?
a) Fusion of cervical vertebrae
b) Scoliosis
c) Lordosis
d) Increased intervertebral spaces
a) Fusion of cervical vertebrae
Numerous types of mucopolysaccharidosis have been described in humans, with types __, __ and ___ reported in the cat. Classically, cats present at _______ year of age with __________________, __________, ___________ and ________-ism.
- I, VI and VII
- less than 1
abnormal facial features, an abnormal gait, diffuse neurological disease and dwarf(ism)
Bone cysts are typically seen in which group of dogs?
a) Young male large-breed dogs
b) Older small-breed dogs
c) Middle-aged female dogs
d) Young male small-breed dogs
a) Young male large-breed dogs
Which of the following is NOT a common characteristic of bone cysts?
a) Monostotic or polyostotic lesions
b) Involvement of the epiphyses and metaphyses
c) Geographic bone lysis with cortical thinning
d) Loculated or multicameral appearance
Answer: b) Involvement of the epiphyses and metaphyses
(Explanation: Bone cysts are typically limited to the metaphyseal and diaphyseal regions and do not extend into the epiphyses.)
Bone cysts can sometimes be confused with which other condition based on radiographic appearance?
a) Osteosarcoma
b) Osteochondrosis
c) Fibrous dysplasia
d) Giant cell tumor (osteoclastoma)
d) Giant cell tumor (osteoclastoma)
Which radiographic feature is typically associated with benign bone cysts?
a) Sclerosis of the affected area
b) Geographic bone lysis with cortical expansion and thinning
c) Periosteal reaction
d) Increased joint space
b) Geographic bone lysis with cortical expansion and thinning
What condition can mimic bone cysts but typically affects slightly older patients and extends into the epiphyses?
a) Osteosarcoma
b) Aneurysmal bone cysts
c) Giant cell tumor (osteoclastoma)
d) Osteochondritis dissecans
c) Giant cell tumor (osteoclastoma)
b) Aneurysmal bone cysts also similar and in older patients, but book doesn’t mention extending into the epiphysis
Which diagnostic tool is useful in distinguishing aneurysmal bone cysts from benign bone cysts?
a) MRI
b) B-mode ultrasonography
c) CT scan
d) Radiography
b) B-mode ultrasonography
What is the radiographic appearance of aneurysmal bone cysts that distinguishes them from benign bone cysts?
a) Narrowing of the nutrient foramen
b) Widening of the nutrient foramen
c) Decreased medullary opacity
d) Increased joint space
b) Widening of the nutrient foramen, owing to the increased blood flow to the medullary cavity.
Bone cysts are typically found in which regions of the bone?
a) Epiphysis and metaphysis
b) Diaphysis and epiphysis
c) Metaphysis and diaphysis
d) Joint spaces and periosteum
c) Metaphysis and diaphysis
Bone cysts are most likely to cause clinical symptoms when:
a) They become infected
b) They cause pathological fractures
c) They spread to the joints
d) They calcify
b) They cause pathological fractures
10-month-old Old English Sheepdog. A multilocular bone cyst is
present in the distal radial shaft
13mo dog. Which condition and which stage is this?
Early panosteitis
focal, well marginated medullary opacity (‘thumbprint’) in the right proximal femoral diaphysis
Which of the following is NOT a common clinical sign of panosteitis?
a) Shifting limb lameness
b) Pain on palpation of the diaphyses of long bones
c) Pathological fractures
d) Cyclical or recurrent pain
c) Pathological fractures
Which radiographic finding is associated with the early stage of panosteitis?
a) Increased medullary opacity near the nutrient foramen with a “thumbprint” appearance
b) Widespread osteosclerosis
c) Complete lucency of the bone
d) Thinning of the cortex
a) Increased medullary opacity near the nutrient foramen with a “thumbprint” appearance
What radiographic change is seen in the middle stage of panosteitis?
a) Bone marrow expansion
b) Coalescing medullary opacities and roughened endosteum
c) Hollowing of the medullary cavity
d) Formation of joint effusion
b) Coalescing medullary opacities and roughened endosteum
What characteristic radiographic feature is associated with the late stage of panosteitis?
a) Increased periosteal reaction
b) Complete bone lucency with no trabeculation
c) Resolved medullary opacities and relatively lucent medullary cavity
d) Persistent subchondral bone thickening
c) Resolved medullary opacities and relatively lucent medullary cavity
image: right humerus of an adult dog showing
evidence of previously healed panosteitis. Note the relatively empty-appearing medullary cavity with several horizontal radiopaque bands.
Which statement best describes the periosteal reaction associated with panosteitis?
a) It is a prominent feature in all stages of the disease
b) It is typically mild and more commonly seen in the femur during the middle stage of the disease
c) It results in extensive bone thickening in the early stage
d) It leads to significant joint deformation in the late stage
b) It is typically mild and more commonly seen in the femur during the middle stage of the disease
(although can persist in the late phase)
Which of the following is a potential cause of metaphyseal osteopathy?
a) Hypervitaminosis D
b) Overnutrition, Vitamin C deficiency, or canine distemper virus
c) Genetic predisposition to osteoporosis
d) Excessive calcium supplementation
b) Overnutrition, Vitamin C deficiency, or canine distemper virus
During the early stage of metaphyseal osteopathy, which radiographic feature is typically observed?
a) Complete cortical thickening of the diaphysis
b) An irregular radiolucent line in the metaphyses of long bones, parallel to the physis
c) Complete closure of the epiphyseal growth plates
d) Formation of periosteal bone spurs
b) An irregular radiolucent line in the metaphyses of long bones, parallel to the physis (“double physis”)
What histological changes are typically seen in metaphyseal osteopathy?
a) Acute suppurative osteomyelitis and defective bone formation in the primary spongiosa of the metaphysis
b) Increased osteoclastic activity with fibrous tissue proliferation in the metaphysis
c) Hyperplasia of the cartilage cells in the metaphysis with thickening of the trabeculae
d) Widespread necrosis of the cortical bone in the metaphysis with minimal inflammatory response
a) Acute suppurative osteomyelitis and defective bone formation in the primary spongiosa of the metaphysis
Young dog with early MO. The
arrow indicates an irregular radiolucent band in the distal radial metaphysis, running parallel to the physis.
7-month-old Bullmastiff with
advanced MO. Note the prominent metaphyseal enlargement and how the metaphyseal collar has fused with the underlying proximal and distal tibial cortex. The original cortex is still visualized and remodelling will eventually take place. The distal femur is also affected.
Which of the following statements is true regarding the clinical significance of bone remodeling changes in young, growing Newfoundland dogs?
a) The changes are highly indicative of growth abnormalities and lameness
b) The changes were sometimes associated with significant clinical symptoms
c) The changes were not associated with any clinical signs and are believed to be incidental findings
d) The changes required surgical intervention in all affected dogs
c) The changes were not associated with any clinical signs and are believed to be incidental findings
A 7-month-old Newfoundland dog presents with mild lameness and radiographs reveal islands of reduced opacity outlined by thickened trabeculae in the distal radial and ulnar metaphyses. There is no other significant clinical history. Based on the findings from the study on bone remodeling in Newfoundland dogs, what should be the primary consideration regarding these radiographic changes?
a) The radiographic changes are incidental and should not be over-interpreted
b) The dog likely has osteosarcoma, and further diagnostic testing is required
c) Immediate intervention is needed due to severe growth abnormalities
d) The dog should be treated for infectious osteomyelitis
a) The radiographic changes are incidental and should not be over-interpreted
The radiographic changes in the distal radial and ulnar metaphyses of young growing Newfoundland dogs included:
a) Increased bone density throughout the skeleton
b) Islands of reduced opacity with thickened, radiopaque trabeculae
c) Widespread osteopenia
d) Irregular periosteal reaction with soft tissue swelling
b) Islands of reduced opacity with thickened, radiopaque trabeculae
Craniomandibular osteopathy (CMO) is a:
a) Neoplastic bone disease
b) Non-neoplastic proliferative disease
c) Infectious bone disease
d) Autoimmune disease
b) Non-neoplastic proliferative disease
Craniomandibular osteopathy (CMO) is most commonly reported in which dog breeds?
a) Labrador Retrievers and Golden Retrievers
b) German Shepherds and Boxers
c) West Highland White Terriers and Scottish Terriers
d) Beagles and Dachshunds
c) West Highland White Terriers and Scottish Terriers
What is the outcome of CMO?
Generally, the bone formation re- gresses when the puppy reaches maturity but the temporomandibular joint mobility may be severely affected
Which bones does CMO affect?
bilateral and symmetrical; and particularly affects the:
- occipital bone
- tympanic bullae
- mandible
The disease rarely involves LONG BONES but lameness or limb swelling can PRECEDE cranial involvement. Long bone changes include remodelling and enlargement of particularly the ULNA/RADIUS and TIBIA/FIBULA diaphyses and/or metaphyses due to proliferative new bone formation. Paracortical cuffs of new bone may be present and the disease resembles MO
dog showing fibrous dysplasia involving the
proximal radial and ulnar diaphysis. Note the lytic lesions within the adjacent cortices with extension of lysis into the radial medulla.
Canine Leucocyte Adhesion Deficiency (CLAD) is primarily reported in which breeds?
a) Golden Retrievers and Boxers
b) Irish Setters and Irish Setter cross-breeds
c) German Shepherds and Rottweilers
d) Poodles and Beagles
b) Irish Setters and Irish Setter cross-breeds
CLAD is a fatal inherited trait characterized by a defect in neutrophil adhesion and function. Skeletal changes range between MO, craniomandibular osteopathy and osteomyelitis.
Hypertrophic osteopathy most commonly occurs secondary to which type of disease process?
Thoracic neoplastic mass
What is another name for hypertrophic osteopathy?
Marie’s disease
Which radiographic feature is characteristic of hypertrophic osteopathy?
Brush-like to solid periosteal reaction extending from the distal limbs proximally
Which characteristic is true for hypertrophic osteopathy?
a) It involves a neoplastic process within the bone
b) Changes are usually unilaterally symmetrical
c) The periosteal reaction is usually bilaterally symmetrical
d) Changes are usually bilateral and asymmetrical
c) The periosteal reaction is usually bilaterally symmetrical
Which of the following is true regarding the radiographic findings of fibrous dysplasia?
a) The lesions are commonly found in the thoracic region
b) The lesions are expansive and may cause compression of adjacent structures
c) The lesions are typically malignant
d) The condition only affects the long bones
b) The lesions are expansive and may cause compression of adjacent structures
incorrect:
a) The lesions are commonly found in the thoracic region - RADIUS AND ULNA, BUT HAS BEEN REPORTED IN MANDIBLE OR MAXILLA
c) The lesions are typically malignant - NON-NEOPLASTIC, BUT CAN CAUSE BONE WEAKNESS
d) The condition only affects the long bones - REPORTED IN MANDIBLE/ULNA
REPORTED TO BE FAMILIAL IN DOBERMANN
In fibrous dysplasia, where are monostotic lesions most commonly reported?
a) Vertebrae and pelvis
b) Mandible and maxilla
c) Long bones
d) Ribs and sternum
b) Mandible and maxilla
What is fibrous dysplasia?
Developmental condition where bone (polyostotic/monostotic) is replaced by fibro-osseous tissue
