Hi Epistaxis is because of lot of reasons - If it is a fresh blood can be due to haemoprotozoan infection or due to leeches. Any nasal growth or mass, nasal sinusitis or damage to the nasal planum or inflammation of nasal cavity. Get the blood works done like cbc, lft,kft and pcr (TICK Fever panel) and if found no improvement ct scan to be considered.

It can be an infection, tumor or protozoal infection better to get further investigation done

It can be trauma, sinus tumor, blood protozoal infection, etc Kindly get him checked. He may need tests and imaging to identify the root cause.

It may be be due to allergic reaction, internal  injury , infection. Contact for consultation.

It could be due to internal injuries in nasal passage or due to severe allergies . Please visit your near by vet for physical examination.