Bones 1
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Transcript of Bones 1
Some bone disorders of ‘medical’ interest
Richard A. Squires
Lecture 1 of 317 Aug 09
We are not going to consider the bone marrow
at this stage…
From: Ettinger & Feldman Textbook of Veterinary Internal Medicine – Diseases of the Dog and Cat. 6th Edition. Chapter 279.
Associated Clinical Problems
• Lameness: owners wont notice lameness if bilat symetrical/all 4. Will notice discomfort, getting up slowly
• Exercise intolerance: sometimes think CHF, then its bone
• Bone pain: Elicit pain when pressing on bone many of the bone diseases
• Fever: inflammatory going into multiple organ failure and die
• Pathological fractures: secondary to weakness of bone leading to it breaking
• Deformity / Small stature: swellings at metaphysis; varus/valgus; small stature
From: Ettinger & Feldman Textbook of Veterinary Internal Medicine – Diseases of the Dog and Cat. 6th Edition. Chapter 279.
Andrew will cover bone disorders associated with angular and other
obvious deformities…
Ruth will cover most of the causes of small stature
The Biggies…
• Osteomyelitis (bacterial, fungal)
• Bone cancers• Malignant or benign
• Primary, metastatic or ‘multifocal’
• ‘Metabolic’ bone diseases– Well balanced diets don’t see as much
– Feeding carnivores just meat masses too much phosphorous stops Ca being absorped nutritional hypoPTH
– Dx it right can help animals quality of life : EXAM
Weirdies you also need to know a bit about…
• Panosteitis (=enostosis)– Something inside the bone
• Metaphyseal osteopathy• Craniomandibular osteopathy• Secondary hypertrophic osteopathy
– Maries Dz periosteal new bone formation
• Hypervitaminosis A CATS• Various inherited disorders
(e.g., mucopolysaccharidoses)
Some others…• Bone cysts• Bone infarcts• Multiple cartilaginous exostoses
• Others
D A M N I T - V
Bone disorders can be confused with…
• Disorders of joints
• Disorders of muscles
• Neurological disorders
• Some metabolic disorders
General diagnostic approach
Signalment
• Age: usually older
• Breed: little vs big dogs: terriers vs Large breeds
• Sex: 2/3 panosteitis male
• Neutering status : D + C dont live long enough to show neutering status effect
History
• Duration / Onset• Intensity / Progression– Intermittent –Constant– Shifting shifts from leg to leg (lameness)–Worsening bone cancers get worse over time
• Better with exercise? After rest?– Some joint diseases will help with exercise
History
• Diet? • Any supplements?• Vaccinations?• Siblings / Parents? Some Dz are familial affected
same time by same disease
• Previous illnesses? Trauma?• Therapy? Response to therapy?
– Can give idea on kind of Dz process
Physical examination
• Distance exam (gait, attitude)
• Bones• Muscles• Joints
• Assess for pain, lack of symmetry, crepitus
Diagnostic imaging
• Radiology• Computed tomography• Magnetic Resonance Imaging
• Nuclear imaging
From: Ettinger & Feldman Textbook of Veterinary Internal Medicine – Diseases of the Dog and Cat. 6th Edition. Chapter 279.
Haematology / Serum biochemistry
• Leukogram• Anaemia of inflammatory disease
– Can happen quickly
• Calcium– Ionized Ca in blood drops detected and PTH pumped out to bring
isonized Ca back to normal– Hypercalcemic : some bone tumours release Ca into system
• Phosphorus• Alkaline phosphatase : normally higher in adult in large breed dogs
growing quickly
• Globulin– Multiple myeloma can prod immunoglobulin light chains
• Creatine kinase (muscle)
+/- Other blood tests
• Ionized calcium• PTH / PTHrP• Vitamin D metabolites• Serum protein electrophoresis
• FeLV / FIV
Bone biopsy / histopathology
• Can achieve definitive diagnosis• Grading of some tumours helps with
prognostication– How aggressive it looks– Some tumours grading can give Px
• Prone to operator error: inappropriate sampling of reactive bone instead of cancer– Jim sheedy needle ... Need to get into middle...the more luscent centre
Cytology / Microbiology
• Osteomyelitis• Aerobic & anaerobic• Not recommended to culture pus from externally
draining tracts Why?–Osteomyelitis can drain from sinuses
sinus tract open to outside world becomes colonised with skin bacteria : <50% of time org you culture from sinus is the one you want.
D A M N I T - V
D A M N I T - V
Infectious, inflammatory, idiopathic, immune-mediated, iatrogenic, inherited
D A M N I T - V
Infectious, inflammatory, idiopathic, immune-mediated, iatrogenic, inherited
From: Ettinger & Feldman Textbook of Veterinary
Internal Medicine – Diseases of the Dog and Cat.
6th Edition. Chapter 279.
Panosteitis(=enostosis)
idiopathic
Panosteitis• Relatively common in medium to giant
breed dogs• 6 – 18 months• 2/3 are male• Acute onset intermittent lameness in
one or more limbs (no trauma Hx)• Each episode ~ 2 weeks. Can go on for 2
- 9 months• Worst of them need to be euthanised
Panosteitis
• Pain can be detected in long bone shafts (ulna, humerus, radius, tibia, femur)
• Lameness may be accompanied by anorexia, lethargy, pyrexia and weight loss. Can be quite ill.– Can have a fever
• A concurrent blood eosinophilia may be present
Panosteitis
• Aetiology unknown• Disease process begins in medullary
bone marrow, in vicinity of nutrient foramen– Why here? Swelling compromising blood flow in artery
going to foramen to feed bone?? We dont know!!!
• Genetic predisposition, certainly.– Viral (CDV)?– Dietary?
D A M N I T - V
Infectious, inflammatory, idiopathic, immune-mediated, iatrogenic, inherited
Metaphyseal osteopathy(hypertrophic osteodystrophy, HOD)
• Young, rapidly growing dogs of larger breeds
• Great Dane, Weimaraner, Boxer, Irish setter, GSD
• ~ 3 – 4 months of age• Metaphyseal swelling + pain,
+/- fever, inappetence• Usually resolves spontaneously
Metaphyseal osteopathy(hypertrophic osteodystrophy, HOD)
• Idiopathic acute, suppurative inflammation and necrosis of metaphyseal bone
• Trabecular microfractures and resorption leading to the lucent line
• CDV? MLV vaccine?
From: Ettinger & Feldman Textbook of Veterinary Internal Medicine – Diseases of the Dog and Cat. 6th Edition. Chapter 279.
Metaphyseal osteopathy
From: Ettinger & Feldman Textbook of Veterinary Internal Medicine – Diseases of the Dog and Cat. 6th Edition. Chapter 279.
Metaphyseal osteopathy
D A M N I T - V
Infectious, inflammatory, idiopathic, immune-mediated, iatrogenic, inherited
From: Ettinger & Feldman Textbook of Veterinary Internal Medicine – Diseases of the Dog and Cat. 6th Edition. Chapter 279.
Craniomandibular osteopathy
Craniomandibular osteopathy
• Young terriers, WHWT, Scottish, Cairn, Boston. Occasionally other breeds
• Autosomal recessive in WHWT, sporadic in other breeds. Predisposition rather than direct cause?
• 3 – 8 months• Swelling and pain of jaw, drooling, prehension difficulties,
pain on opening mouth – hungry...inflamed and sore if you palpate, might try bite you. If cant open mouth...muscles of mastication will atrophy: point on head occipital crest. Sometimes cant open mouth...might have to do surgery.
Craniomandibular osteopathy
• Self-limiting by about 1 year of age– Can use carprofen/meloxicam/soft food/small kibble
• Lesions regress but if petrous temporal bone / tympanic bulla is severely affected, jaw movements may be permanently affected and rostral hemi-mandibulectomy may be needed– Wont fully regress.
D A M N I T - V
D A M N I T - V
Neoplastic, nutritional
D A M N I T - V
Neoplastic, nutritional
Nutritional secondary hyperparathyroidism
From: Ettinger & Feldman Textbook of Veterinary Internal
Medicine – Diseases of the Dog and Cat. 6th
Edition. Chapter 279.
Nutritional secondary hyperparathyroidism
• Diets with excessive phosphorus, insufficient calcium, or both. Often exclusively, or nearly exclusively, meat / offal (Ca:P of 1:16 - 1:35 instead of 1.0-1.2:1)
• Osteopenia results from excessive bone resorption. Eventually, folding (pathological) fractures occur
• Costochondral junctions and metaphyses may appear swollen
Nutritional secondary hyperparathyroidism
• Confine / rest during first few weeks of dietary correction to avoid pathological fractures– Cage rest good idea: jump from furniture can break bones
• Feed a good quality diet with calcium carbonate supplementation to raise Ca:P to 2:1. Feed for 2 – 3 months then withdraw the supplement– Then carry on good diet
Hypervitaminosis A
From: Ettinger & Feldman Textbook of Veterinary Internal Medicine – Diseases of the Dog and Cat. 6th Edition. Chapter 279.
Hypervitaminosis A
• Typically mature, older cats fed a diet very rich in liver
• Osteopathy with fusion of cervical vertebrae due to confluent exostoses. May also involve long bones.
• Can be managed with dietary change, but vertebral fusion and neck stiffness will likely remain
Rickets
• Rare• Insufficient Ca or P ingestion or absorption• Hypovitaminosis D• Inborn error of Vitamin D metabolism
Renal osteodystrophy – ‘rubber jaw’
• Uncommonly seen• More likely in youngers than adults, so assoc
with familial renal diseases• Thickening and pliability of maxilla and
mandible. Jaw can sometimes be ‘sprung’ between fingers
• Renal 2y HyperPTHism and failure to synth 1,25 Vit D3