Multiple limb lameness Flashcards
(42 cards)
Types of multiple limb lameness (& their signalment, potential causes, etc)
- generalised osteoarthritis
- panosteitis
- septic arthritis
- Lyme dz (Borrelia burgdorferi)
- endocarditis and associated polyarthritis
- pulmonary osteopathy
- metaphyseal osteopathy
- rickets
- nutritional hyperparathyroidism
- osteogenesis imperfecta
- immune mediated arthritis
What is the most common cause of multiple limb lameness?
- immune mediated arthritis
Generalised OA - signalment, cause
- seen in the older dog
- little evidence of a genetically determined generalised OA
- hence this condition primarily arises in breeds which suffer from concurrent developmental dz such as elbow dysplasia, hip dysplasia or acquired dz such as cruciate rupture
-> this is secondary OA
Panosteitis - what is it? signalment
- inflammatory condition in multiple long bones
- most common in the young male (<2y) GSD
Septic arthritis - how can it occur? presentation in young vs older animals
- in the younger animal it occurs in multiple joints
- in the older animal a single joint
- may occur following surgery or via haematogenous spread
Pulmonary osteopathy - what is it? aetiology?
- a paraneoplastic syndrome with proliferative new bone on the limbs
- aetiology not clearly determined but may arise from vagal stimulation arising from arteriovenous shunting
Metaphyseal osteopathy - what is it?
- inflammatory condition seen in young dogs
- characteristic radiographic changes
- prognosis is good to far
Rickets - prevalence, what is it associated with?
- seen occasionally
- associated with poor diet as well as lack of sunlight
Nutritional hyperparathyroidism - cause, what does it cause?
- all meat diet (high in phosphorus, low in calcium) in young animal
- poorly mineralised bones with multiple folding fractures and collapse of vertebrae
Osteogenesis imperfecta - what is it?
- rare inherited dz which results in multiple fractures due to abnormal formation of bones
Multiple limb lameness - signalment and hx clues
Age
- e.g. young dogs are more prone to vaccine associated polyarthritis, panosteitis and viral causes such as calicivirus infection in the cat
Breed predilections
- e.g. Sharpei fever
- sulphonamide induced polyarthritis in the Doberman (Dobermans shouldn’t have sulphonamides due to high prevalence of developing polyarthritis after administration)
Recent vaccination or drug administration
- e.g. potentiated sulphonamides
Recent tick exposure
- although Borrelia infection may not become apparent for 2-5months
Recently imported from abroad
Clinical presentation
- generalised lameness in multiple joints sometimes with a shifting lameness
- may be worse in 1 limb but the animal should be seen to have poor movement generally with short stride lengths
- the joints may be visually or palpably swollen and painful on manipulation
- there may be accompanying muscle pain
- the animal may be systemically unwell with pyrexia
- there may be a hx of previous episodes
- other signs may accompany the lameness such as respiratory or GI signs
Further investigations
- radiography
- arthrocentesis
- serology
- echocardiography & blood culture
- CSF tap
- liver/kidney/muscle/skin biopsies
Radiography
- variable in its helpfulness e.g. rheumatoid arthritis will demonstrate a destructive pattern but systemic lupus erythematosus and idiopathic forms only soft tissue swellings
- radiograph other body systems such as lungs for pulmonary osteopathy and pulmonary adenocarcinoma in the cat
- radiograph all the joints showing CS and others
- radiographic and CS may not coincide in panosteitis
Arthrocentesis
- generally performed on the more distal joints i.e. carpus, elbow, tarsus and stifle
- these are the more commonly affected joints
- laying the pt on 1 side and tapping all those on the non-dependent side is an easy way to proceed
- joint fluid may be watery, have a low viscosity and be obviously turbid
- normal gross appearance doesn’t rule out the condition
- cytology for immune mediated dz shows increased white cells, predominantly neutrophils as would a septic polyarthritis or vector borne dz such as Lyme dz
- collect for cytology, protein estimation and culture
- bacterial culture is best achieved by collecting into blood culture medium
- make smears of the joint taps, air dry and examine in house
- if there is evidence of a polyarthritis collect samples for serology or PCR for infectious conditions (e.g. Borrelia burgdorferi (Lyme dz), Brucella, Leishmania and Ehrlichia in the imported dog and serology for rheumatoid and anti-nuclear factor
- joint taps are obligatory for the investigation of the pyrexic animal even if the CS are not suggestive of polyarthritis
Joint tap - how to
- aseptic skin preparation and technique
- collect into EDTA and plain tubes
- make smears and examine in house
- collect sample into blood culture media if suspect sepsis
Appearance of synovial fluid
Examine gross appearance and volume
- colour and gross appearance
- viscosity-stringing?
- protein mucin clot time
- cell count
- cell morphology
— activity foamy macrophages - consistent with degenerative joint dz
— neutrophils - consistent with sepsis or if multiple joints a polyarthritis
Always interpret the synovial findings in the light of clinical signs
Serology - use
RF, ANF, Borrelia, Brucella, Ehrlichia (RF and ANF are neither specific nor sensitive tests for rheumatoid arthritis or SLE)
Dx snap test can be used of the detection of Ehrlichia, Lyme, Dirofliaria and Anaplasma infections
Echocardiography and blood culture - use
- if suspect a polyarthritis secondary to an endocarditis
CSF tap - use
- if suspect concurrent immune mediated meningitis
Liver/kidney/muscle/skin biopsies - use
- if suspect more widespread immune mediated dz
Immune mediated polyarthritis - forms and their examples
Erosive forms
- rheumatoid arthritis
- Chronic feline erosive progressive polyarthritis
- more aggressive and serious form
Non-erosive forms
- immune-mediated polyarthritis (4 types)
- systemic lupus erythematosus
- feline non-erosive chronic progressive polyarthritis
- breed associated e.g. Sharpei fever and juvenile onset polyarthritis of Japanese akitas
- drug and vaccine associated polyarthritis’ e.g. sulphonamide and post-vaccinal
- polyarthritis/myositis and polyarthritis/meningitis syndromes
Types of immune mediated non-erosive polyarthritis
Type I
- no underlying dz detected
- idiopathic
- most common form
Type II
- associated with infection elsewhere e.g. respiratory or urinary tract infection
- may spontaneously resolve with tx of the underlying condition or require immunosuppression
Type III
- associated with GI dz
Type IV
- associated with neoplasia e.g. myeloproliferative dz
Non-erosive chronic progressive polyarthritis in cats
- may be the same condition as the erosive form just a different manifestation of the same dz process
All present similarly clinically
Types of non-erosive polyarthritis - vaccine reactions - what to do?
- may recur and benefits must be weight against potential risks when advising re subsequent vaccinations
- particularly after the calicivirus vaccine
