Exotics MSK diseases Flashcards
List your differentials for a falcon presented with swelling of the foot
- Bumblefoot
- Gout
- Neoplasia
- Foreign body
- Abscess
What factors need to be investigated in a bird with a swelling of the foot?
- Need to ask about the diet
- Need to ask about the perch
- Previous injury/illness
- Any concurrent signs
List the investigations needed in a case of suspected bumblefoot and justify
- Individual investigation of each individual toe
- Radiography (assess presence/degree of damage to the bone)
- Swab for culture, sensitivity and cytology (needed for treatment)
- Surgical debridement samples (ensures demonstration of infective agent rather than just commensal skin microbes)
- Blood tests (haematology, biochem - may be systemic disease, look for underlying cause that can be treated)
- Palpate origins of tendons
What is the notarium of a bird?
The fused thoracic vertebrae
Explain why the great vessels of older parrots may be visible on radiography
Atherosclerosis, either as a cause or result of cardiovascular compromise
Which skeletal structures need to be assessed in particular in a case of bumblefoot and why?
- Spine and HL
- May show evidence of abnormal weight bearing
What may be seen radiographically in severe cases of bumblefoot?
Progression of skin infection into the bone, which may be seen as lysis or fracture of the bone
How many phalanges are normal in the first, second, third and fourth digits of birds?
- First and second: 2 phalanges + claw
- Third: 3 phalanges + claw
- Fourth: 4 phalanges+ claw
Discuss the prognosis for a case of bumblefoot
- Guarded, with treatment ~80%
- Poor outcome usually related to owner not revealing underlying cause, or not addressing underlying case
- Commonly concurrent diseases
List concurrent diseases that are commonly identified in cases of bumblefoot
- Obesity
- Nutritional
- Aspergillosis
- Amyloidosis
- Heart disease
- Anything affecting circulation
- Anything affecting the immune system
Outline the treatment for early stage bumblefoot
- No surgery required
- Improve husbandry
- Meticulous cleaning of perches to prevent infection
Outline the treatment of bumblefoot if infection is present
- Topical or systemic antibiotics based on C+S, 1 week minimum, but usually requires several weeks treatment
- Amoxyclav, marbofloxacin can be used, avoid gentamycin systemically
- Clindamycin good bone penetration
- Fluoroquinolones can be used if needed, good penetration
- Metronidazole if Clostridia
Outline the treatment of bumblefoot lesions with deep infection and granulomatous material
- Surgical debridement
- Protective dressings after surgery, regular changes
- NSAIDs/analgesia
- if unable to grasp food or perch, prognosis poor, consider euthanasia
Outline the general approach to a lameness case in an exotic species
- Same as dog/cat
- History, clinical examination, radiography, cytology, biopsy, joint fluid analysis
- Endoscopy/arthroscopy possible in some, coelioscopy to look at internal organs esp. kidneys
- Sedation/GA often needed
What are the categories of lameness in exotics?
- Metabolic and nutritional
- Traumatic
- Degenerative
- Infection
- Neoplastic
Discuss traumatic causes of lameness in exotics
- Common from cage mates, other pets, owners
- Most reptiles should be kept alone, owners commonly think should be in pairs
Outline pododermatitis in rabbits
- No pads on feet, hair only
- Overgrown claws, overweight, DJD increase risk
- Most rabbits have degree of pododermatitis
Where does degenerative joint disease most commonly occur in rabbits?
- Stifles and spine most common
- Cranial cruciate disease common
What spinal deformity commonly occurs in older rabbits?
Spondylosis
Which spinal deformities commonly occur in rabbits generally?
- Spondylosis
- Kyphosys
- Lordosis
- Scoliosis
What factors are risk factors for spinal deformities in rabbits?
- Small cages
- Lack of exercise
What do spinal deformities commonly occur as a result of in younger rabbits?
Breeding/husbandry
Outline the potential consequences of spinal deformities in rabbits
- May interfere with locomotion, caecotrophy, urination, grooming
- May result in faecal soiling, urine scald, unkempt co, Cheyletiella, facial dermatitis
- Pain may lead to aggression, depression, GI stasis
What is kyphosis?
Excessive curvature of the spine
What are the most common sites of fracture in rabbits?
- Spine and limbs
- Jaw also common
- Tibia most common
Discuss the development of nutritional secondary hyperparathyroidism in rabbits
- Common due to feeding of muesli mix, lack of UV-B
- Cause of dental disease in rabbits
- Indoor rabbits or outdoor rabbits shielded from sunlight
What are the most common sites of luxation in rabbits?
Hip, elbow and tarsus
What is the most common tumour that may cause metastatic musculoskeletal disease in rabbits?
Uterine adenocarcinoma
Explain the relationship between renal failure and musculoskeletal disease in rabbits
Leads to hypercalcaemia (normally excess excreted in urine), leading to soft tissue calcification and bone hypercalcification
How is musculoskeletal disease secondary to renal failure diagnosed in rabbits?
- Biochem and haematology may be normal
- If see hypercalcification and calcification of soft tissues on radiography is enough for diagnosis
What are the 3 main causes of muscular weakness in rabbits?
- Floppy bunny syndrome
- Splayleg
- Nutritional muscular dystrophy
Describe floppy bunny syndrome (presentation, cause, treatment)
- Generalised flaccid paralysis but rabbit often still very alert with good appetite
- Exact cause unknown: hypokaalemia, hypoMg, plant toxicity, myasthenia gravis, E. cuniculi suggested
- E. cuniculi most likely
- Majority recover within 3-4 days with supportive care
Describe splayleg in rabbits (presentation, cause, treatment)
- HL or FL affected, usually one or two rather than all 4
- Usually younger rabbits
- Poor prognosis vs. floppy bunny, often will not resolve
- Treatment: supportive +/- euthanasia
Describe nutritional muscular dystrophy in rabbits (presentation, cause, treatment)
- Mostly commercial units, unlikely to be seen in pets
- Similar to sheep/cattle (Se deficiency)
Describe the general treatment of musculoskeletal disorders in rabbits
- Analgesia essential (opioids/NSAIDs)
- Ensure soft, clean bedding
- Ensure clean wounds, perineum, face, ears
- Casts and splints contraindicated generally
- Cage rest and pain relief effective
Why are casts/splints generally contraindicated in rabbits?
- Bones are wide proximally, thin distally - difficult to place
- Often exacerbate injury due to pendulum effect
What is the preferred treatment for fractures in rabbits?
External fixation for most fractures
What are the main risks associated with surgical fixation of fractures in rabbits?
- Rabbit bone has thin cortices, shatters easily
- Osteomyelitis significant risk with open wound, poor surgical technique, difficult to manage
What are the main complications of hindlimb amputation in rabbits?
- Contralateral pododermatitis
- Ipsilateral otitis
- But usually do well if generally well
Which species of rodent in particular are prone to pododermatitis?
- Guinea pigs
- Chincillas
- Rats
What commonly leads to degenerative joint disease in guinea pigs?
- Metastatic calcification
- Can occur in lung/joints
- Older guinea pigs usually, cause poorly documented
What are key differentials for a ferret presented with HL paresis?
- MSK disease
- Hypoglycaemia
- Cardiomyopathy
- Generalised lymphooma
- Generalised disease
- Abscessation of spine
Identify the common MSK diseases of ferrets
- Spinal abscesses
- Trauma
- Long bone fracture
- Elbow luxation
- Vertebral disc prolapse and spinal neoplasia reported
What is the most common cause of lameness and fractures in many exotic mammal species?
Nutritional secondary hyperparathyroidism (NSHP)
Outline the general treatment of MSK disorders in exotic mammals
- Cage rest
- Analgesia
- Supplement calcium and vit-D
- Correct diet
- UV-B provision
Describe the clinical signs of lameness disease in birds
- Can be very subtle
- Abnormal stance +/- reduced grip on perch
- Using beak/ipsilateral wing for support
- Affected leg may be warmer
- Bumblefoot on contralateral limb
List orthopaedic causes of lameness in birds
- Fractures
- Bumblefoot
- Luxation
- Spinal injury
- Growth deformities
- NSHP
- Septic arthritis
- Osteomyelitis
- Osteoarthritis
- Tendon injury
- Tenosynovitis
Describe state of fractures in birds
Commonly compound and contaminated, esp. wild birds
Which cause of lameness are waterfowl, raptors and budgies especially prone to?
Bumblefoot
Where do spinal injuries most commonly occur in birds? Why?
At the vertebral synsacral junction - this is the only moveable part of the spine
Name 2 common orthopaedic growth deformities in birds
- Luxated gastrocnemius tendon
- Juvenile osteodystrophy
When does juvenile osteodystrophy most commonly occur in birds?
- Hand rearing (too much space, move too much, excessive strain on bones too soon)
- Parents with inappropriate diet
How do tendon injuries most commonly occur in birds?
- Bites from companions/prey
- Equipment on legs e.g. rings
- Extension of skin infection
Name the causative agent of tenosynovitis in birds
Mycoplasma synoviae
Identify the non-orthopaedic causes of lameness in birds
- Nephritis
- Renal and testicular neoplasia
- Gout
- Mass effect in cloaca e.g. egg binding
- Lead poisoning
- Viral
Explain how nephritis can cause lameness in birds
- May be bacterial, parasitic, coccidial, fungal
- Kidney swells, presses on nerve, causes sciatica type pain
- Presents as paresis of limb
Describe the lameness that may occur with renal and testicular neoplasia in birds
- Most common in budgie
- Unilateral lameness
What does gout in birds often occur secondary to?
Renal disease
Describe the common presentation of lameness as a result of a cloacal mass effect
- Pushes against kidney, leading to pain or lameness
- Budgie, cockatiel, ducks most common
- May have regurgitation
Explain how lead poisoning may lead to lameness in birds
- Neuro and renotoxic
- Leads to limb weakness
- Raptors may be seen holding own feet i..e one on top of the other
Outline viral disease as a cause of lameness in birds
- Marek’s disease in chickens
- Young birds presented with progressive lameness, death
- No MSK injury, one leg and one wing outstretched
What are the key considerations for fractures in birds?
- Lifestyle: wild need perfect restoration, caged can cop with less aggressive treatment
- Compound fractures or close to joints carry poor prognosis for return to normal function
- Ocular damage in 80% of impact injuries, damage to pecton probably PTS
- Surgical repair only once patient stable for at least a day
What is the pecton and explain its significance in birds?
- Black segmented patch in eye of bird
- Provides nutritional supply to the retina
- Must be visualised prior to release, minor damage can do well, significant damage means euthanasia
When do tibiotarsal fractures of birds most commonly occur?
In newly-jessed falconry birds
Discuss the tethering of falconry birds
- Should be short tether
- Prevent bird getting up too much speed before being held back
Describe the treatment of fractures in birds
- Immobilisation of joints more than 3-5 days may lead to permanent disability
- Casts and splints generally contraindicated
- Supportive body sling if trouble standing
- Ex-fix and IM pin most useful
- Must anaesthetise for each bandage change
- Need physiotherapy
What fractures in birds can have casts/splints applied?
- Distal tarsometatarsal
- Tibiotarsal in very small birds
List the factors that predispose to the development of bumblefoot
- Poor perching surfaces
- Trauma
- Excessive weight bearing
- Hypovitaminosis A
Describe the clinical signs of lameness in reptiles
- Can be very subtle even with severe fractures
- Abnormal stance/gait +/- reduced grip
- Often may just seem lethargic
- Deformity of spine/limbs +/- generalised limb swelling may indicate metabolic bone disease
Identify the orthopaedic causes of lameness in reptiles
- Fractures
- Luxation
- Tendon/ligament injury or infection
- Spinal injury(trauma, NSHP, burns)
- Septic arthritis/osteomyelitis (solid pus)
Identify the non-orthopaedic causes of lameness in reptiles
- Gout and pseudogout
- Pre- and post-ovulatory oostasis (POOS)
- Urolithiasis
- Hypocalcaemia
- Viral (herpes in tortoise)
