Liz Buchanan BVSc MRCVS
Hello - One cause of red ear tips is pinnal vasculitis, whereby the blood-vessels in the ear flap (which are amongst the extremities of the body in dogs) become inflamed and often itchy, due to systemic changes within the body such as allergy, drug reactions or autoimmune disease. Another possibility may be bleeding / bruising due to blood that is failing to clot, although this doesn't look typical. Other more common causes of red ears include trauma, often self-trauma, secondary to mites and so on; foreign bodies lower down the canals. Ears flaps are cartilage covered in skin, so skin disease often appears first on the ears, allergy especially. Are there any other signs? Particularly if signs are progressing (changing / increasing) or the patient is uncomfortable, then damage may be prevented while waiting for an appointment, so although you don't perveive this to be an emergency, it could be worthwhile seeking triage from your emergency vet.