SYMPTOM
Unexplained bleeding
Owners may observe unexplained bleeding in their pet.
Various conditions
This symptom can occur in multiple conditions and warrants further assessment.
Why timing matters
Early observation
Early recognition allows prompt assessment and intervention if needed.
Later presentation
Persistent or worsening signs may indicate progression requiring attention.
The significance of this symptom depends on its context, duration, and associated findings.
Conditions commonly associated
Angiostrongylus (Lungworm)
Coagulopathy causes bleeding that may manifest as bruising, prolonged wound bleeding, or internal haemorrhage.
Lymphoma in Dogs
Lymphoma can disrupt normal blood clotting mechanisms when it involves the bone marrow or causes secondary clotting abnormalities, leading to bleeding that may appear without obvious injury. In some cases, the tumour itself can erode into blood vessels or cause platelet dysfunction.
Alabama Rot (CRGV)
Alabama rot involves damage to small blood vessels in the skin and kidneys, which can manifest as skin lesions with bleeding or ulceration, often appearing on the limbs or body. The vascular injury underlying this condition may cause visible bleeding that seems disproportionate to any obvious external cause.
Pemphigus
Pemphigus causes breakdown of connections between skin cells, leading to fragile blistering lesions that rupture easily and may bleed when the surface is disrupted. The erosions and crusts that develop can appear as areas of unexplained bleeding, particularly when grooming or minor contact occurs.
Transitional Cell Carcinoma
Transitional cell carcinoma can cause bleeding from the urinary tract when tumour tissue erodes through the bladder or urethral lining, often appearing as blood in urine without other obvious explanation. The fragile, abnormal tissue may bleed intermittently, sometimes producing visible blood outside the context of urination.
When to explore further
When the symptom is persistent or worsening
When other signs are present alongside
When daily activities or quality of life are affected
When there is uncertainty about the cause
Noting when this symptom occurs, any triggers, and how it changes over time can provide useful information for veterinary discussions.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS