Clinical Presentation of Demodicosis in Dogs and Cats

Demodicosis presents with a wide spectrum of clinical manifestations in dogs and cats, ranging from mild, localized lesions to severe, generalized disease. Early recognition is essential for appropriate management. 

Forms of Demodicosis 

Localized Demodicosis 

Characterized by: 

• One to a few areas of alopecia 

• Mild erythema and scaling 

• Common involvement of the face and forelimbs 

This form is more common in juvenile dogs and may resolve spontaneously in some cases¹. 

Generalized Demodicosis 

Defined by: 

• Multiple lesions or widespread involvement 

• Pododemodicosis 

• Frequent secondary infections 

This form typically requires active treatment¹. 

Clinical Signs in Dogs² 

Common findings include: 

• Patchy or diffuse alopecia 

• Erythema 

• Scaling and crusting 

• Hyperpigmentation in chronic disease 

Pruritus is variable and often linked to secondary bacterial infection rather than mite burden¹. 

Secondary Complications¹ 

Secondary bacterial pyoderma is frequently observed and may present with: 

• Papules and pustules 

• Crusting 

• Draining tracts in severe cases 

These complications may increase disease severity and influence treatment decisions. 

Clinical Presentation in Cats 

Presentation varies by species: 

• Demodex cati: Often associated with systemic illness; presents with alopecia and scaling 

• Demodex gatoi: Frequently pruritic and may be contagious between cats¹ 

Distribution of Lesions 

Common sites include^1,2: 

• Face and periocular region 

• Limbs and paws 

• Trunk 

Pododemodicosis may be more resistant to treatment and require prolonged therapy. 

Clinical Relevance 

Recognition of clinical patterns assists in: 

• Selecting appropriate diagnostic tests 

• Assessing severity 

• Guiding treatment decisions 

Early identification of generalized disease and complications may improve prognosis. 

References  

1. Mueller RS, Rosenkrantz W, Bensignor E, Karaś‐Tęcza J, Paterson T, Shipstone MA. Diagnosis and treatment of demodicosis in dogs and cats: Clinical consensus guidelines of the World Association for Veterinary Dermatology. Veterinary dermatology. 2020 Feb;31(1):4-e2. https://ebvminpractice.org/wp-content/uploads/2025/09/veterinary-dermatology-2020-mueller-diagnosis-and-treatment-of-demodicosis-in-dogs-and-cats.pdf  
2. Salem NY, Abdel-Saeed H, Farag HS, Ghandour RA. Canine demodicosis: Hematological and biochemical alterations. Veterinary world. 2020 Jan 10;13(1):68. https://pmc.ncbi.nlm.nih.gov/articles/PMC7020110/pdf/Vetworld-13-68.pdf