Differential Diagnosis for Canine Immobile Mass
Single Most Likely Diagnosis
- Mycobacterial infection (e.g., Mycobacterium bovis, Mycobacterium avium): This is a common cause of immobile masses in dogs, particularly in regions where mycobacterial infections are prevalent. The infection can cause granulomatous lesions that may present as immobile masses.
Other Likely Diagnoses
- Fungal infection (e.g., Blastomyces dermatitidis, Histoplasma capsulatum): Fungal infections can also cause granulomatous lesions that may present as immobile masses in dogs. These infections are more common in certain geographic regions.
- Cutaneous or subcutaneous abscess: An abscess can cause an immobile mass, especially if it is located in a deeper tissue plane.
- Neoplasia (e.g., mast cell tumor, fibrosarcoma): Various types of tumors can cause immobile masses in dogs, depending on the location and type of tumor.
Do Not Miss Diagnoses
- Actinomycosis: This bacterial infection can cause severe, life-threatening disease if left untreated. It can present with an immobile mass, particularly in the cervical region.
- Nocardiosis: Similar to actinomycosis, nocardiosis is a bacterial infection that can cause severe disease and may present with an immobile mass.
- Sporotrichosis: This fungal infection can cause skin lesions and masses, particularly on the face, legs, or tail. It can be severe and life-threatening if left untreated.
Rare Diagnoses
- Algal infection (e.g., Prootheca): Algal infections are rare in dogs but can cause skin lesions and masses.
- Chronic foreign body reaction: A chronic foreign body reaction can cause an immobile mass, particularly if the foreign material is not easily identifiable.
- Parasitic infections (e.g., Leishmaniasis): Certain parasitic infections can cause skin lesions and masses, although these are relatively rare in dogs.