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Les syndromes paranéoplasiques sont peu observés et très peu rapportés chez les NAC. De rares cas de dermatite exfoliative paranéoplasique associée au thymome sont rapportés chez le lapin. Encore plus rarement, des troubles sanguins et neuro-musculaires paranéoplasiques peuvent être observés. L’hypercalcémie maligne associée au lymphome peut s’observer chez le furet. La myasthenia gravis auto-immune a fait l’objet de rares publications chez le furet, mais son association au thymome n’a pas été rapportée comme chez le chien et le chat. Un cas de dermatite exfoliative associée à un thymome a été rapporté chez la chèvre. Les syndromes paranéoplasiques ne sont pas décrits chez les rongeurs de compagnie, les oiseaux et les reptiles.

Cutaneous paraneoplastic syndromes of the cat mainly include paraneoplastic alopecia and thymoma-associated exfoliative dermatitis, even though rare cases of paraneoplastic pemphigus and necrolytic superficial dermatitis have been reported. Paraneoplastic alopecia leads to progressing, extensive alopecia, which gives the affected skin a shiny and polished aspect due to its lack of stratum corneum. Lesions affect the ventral aspect of the body and can become infected, and they are caused by pancreatic, biliary, hepatic, or intestinal neoplasias. Thymoma-associated exfoliative dermatitis leads to erythema, alopecia, severe exfoliation sometimes with crusts, lichenification and seborrhea. Clinically undifferentiable from non-thymoma-associated exfoliative dermatitis, clinical imaging is paramount to reach the correct diagnosis and chose an appropriate treatment. In dogs, superficial necrolytic dermatitis, most often associated with hepatocutaneous syndrome, can be paraneoplastic, mostly due to glucagonoma. Clinically identical to the non-paraneoplastic version, lesions are composed of hyperkeratosis, crusts, erosions, ulcers, erythema of the paw pads and the mucocutaneous junctions, and sometimes haired skin. Clinical imaging is once again necessary to determine the origin of the dermatitis. Finally, paraneoplastic hypercortisolism and hyperestrogenism can be associated with cutaneous lesions.