Hello Sara.
Hope you are safe and well.
You are right regarding the DDX for the pyrexia, the list for this is obviously quite extensive. You have indeed covered the main categories. I would probably say ‘immune-mediated’ (particularly in an exam). This means that you are covering yourself for primary or secondary disease:
• Infectious causes (bacterial, fungal, viral, protosoal and rickettsial)
• Immune disease
• Neoplasia
• Tissue damage
• Pharmacological agents (e.g. colchicine, tetracycline)
Distal limb swelling?
• Immune-mediated polyarthritis usually affects multiple joints, may be shifting in nature, and is often symmetrical. The joints are usually swollen and the severity of pain may be variable.
• Septic arthritis can result in severely painful swollen joints, often accompanied by non-weight-bearing lameness. Most cases are associated with a penetrating injury, though haematogenous spead of bacteria to the joints is more likely in cases of pre-existing OA (unlikely in this dog). Where haematogenous spread of infection is involved, multiple joints may be affected.
• Neoplasia (e.g. synovial cell sarcoma), though capable of causing swelling of the limbs, is unlikely to cause symmetrical disease with multiple limb involvement.
• Vasculitis mediated by immune complexes occurs in dogs. Lesions are most prevalent in the dermis of the distal limbs and mucous membranes of the mouth. Vasculitis is a feature of SEL in some animals, but is most often idiopathic. Drug-induced vasculitis has been well recognised in dogs.
Hypoalbuminemia could also be a possibility for causing the distal limb swelling. Your comment about the cardiac disease is interesting. I will maybe get Liz to comment on this.
How would you investigate the pyrexia and joint swelling?
