Epistaxis, Nosebleed

Nosebleed, also called epistaxis, is a common disorder in dogs and frequently regarded as an emergency. It can be primary or secondary to a blood clotting disorder.

Forms of Epistaxis

Primary Epistaxis

Primary epistaxis can be caused by abnormal growths, foreign bodies, tumors (adenocarcinomas, squamous cell carcinomas, fibrosarcomas, osteosarcomas, chondrosarcoms, lymphosarcomas, transmissible venereal tumors), fungal infections, polyps, nasal parasites, lymphocytic plasmatic rhinitis, and allergic rhinitis.

Seconday Epistaxis

Seconday epistaxis can result from multiple myeloma (platelet function defect), other bleeding disorders, and hypertension (high blood pressure).

Running through tall grass increases the risk of the dogs getting a foreign body in its nose. If the epistaxis affects both sides of the nose, this may indicate a bleeding disorder. An elevated body temperature may indicate an infection. Small ulcerations in the lining of the nasal passage can cause significant nosebleed. Sudden passage of blood from the nose may result from bleeding from the lungs and may be fatal.

Factors Contributing to Increased Risk of Epistaxis

Dogs infected with Bartonella, Leishmania, E. canis, B. vinsonii or R. rickettsii may experience episodic epistaxis which can be accompanied by varying signs, depending on other body organs being affected. After treatment of the primary infections, epistaxis resolves. Dogs and people develop very similar pathological lesions when infected with Bartonella.

Epistaxis is commonly seen in dogs with systemic diseases such as canine leishmaniasis, canine monocytic ehrlichiosis, immune-mediated thrombocytopenia, estrogen toxicity, and nasal aspergillosis.

Hereditary Epistaxis

Hereditary epistaxis is a rare bleeding disorder with the characteristic features of Scott syndrome, a rare defect of platelet procoagulant activity. Affected dogs bleeding within the front portion of the eye (hyphema), bleeding into muscle tissues (intramuscular hematoma), and prolonged bleeding with skin bruising after surgery. Pedigree studies indicate a likely homozygous recessive inheritance pattern of the defect.

Glannzmann's thrombasthenia (GT) is a genetic autosomal recessive bleeding disorder caused by platelet defect. The disorder has been reported in Great Pyrenees dogs. Affected dogs may experience excessive gingival bleeding followed by uncontrolled epistaxis.

References

1. William R. Fenner, Terence A Olive. Quick Reference to Veterinary Medicine
2. Mylonakis ME, Saridomichelakis MN, Lazaridis V, Leontides LS, Kostoulas P, Koutinas AF. A retrospective study of 61 cases of spontaneous canine epistaxis (1998 to 2001)
3. Brooks MB, Catalfamo JL, Brown HA, Ivanova P, Lovaglio J. A hereditary bleeding disorder of dogs caused by a lack of platelet procoagulant activity
4. Lipscomb DL, Bourne C, Boudreaux MK. Two genetic defects in alphaIIb are associated with type I Glanzmann's thrombasthenia in a Great Pyrenees dog: a 14-base insertion in exon 13 and a splicing defect of intron 13.