Page 269 - Small Animal Internal Medicine, 6th Edition

CHAPTER 13 Clinical Manifestations of Nasal Disease 241

BOX 13.1
VetBooks.ir Differential Diagnoses for Nasal Discharge in Dogs
and Cats

Serous Discharge
Normal
Viral infection
Early sign of etiology of mucopurulent discharge
Mucopurulent Discharge with or without Hemorrhage
Viral infection
Feline herpesvirus (rhinotracheitis virus)
Feline calicivirus
Canine influenza virus
Bacterial infection (usually secondary)
Mycoplasma felis (possibly primary)
FIG 13.1
Typical grass awn. Seed heads from “foxtail” grasses have Fungal infection
stiff bristles that facilitate movement of the awns in one Aspergillus
direction and make it difficult for the awns to be expelled Cryptococcus
from the body. (Courtesy Lynelle R. Johnson.) Penicillium
Rhinosporidium
Nasal parasites
mucopurulent discharge is usually associated with neoplasia Pneumonyssoides
or mycotic infections. Capillaria (Eucoleus)
Persistent pure hemorrhage (epistaxis) can result from Foreign body
trauma, local aggressive disease processes (e.g., neoplasia, Neoplasia
mycotic infections), systemic bleeding disorders, or systemic Carcinoma
Sarcoma
hypertension. Systemic hemostatic disorders that can cause Malignant lymphoma
epistaxis include thrombocytopenia, thrombocytopathies, Nasopharyngeal polyp
von Willebrand disease, rodenticide toxicity, and vasculiti- Extension of oral disease
des. Ehrlichiosis, Rocky Mountain spotted fever and, poten- Tooth root abscess
tially, bartonellosis can cause epistaxis through several of Oronasal fistula
these mechanisms. Nasal foreign bodies may cause hemor- Deformed palate
rhage after entry into the nasal cavity, but the bleeding tends Allergic rhinitis
to subside quickly. Bleeding can also occur after aggressive Feline chronic rhinosinusitis
sneezing from any cause. Canine chronic/lymphoplasmacytic rhinitis
Diagnostic Approach Pure Hemorrhagic Discharge (Epistaxis)
Nasal disease
A complete history and physical examination can be used to Acute trauma
prioritize the differential diagnoses for each type of nasal dis- Acute foreign body
charge (see Box 13.1). Acute and chronic diseases are defined Neoplasia
by obtaining historical information regarding the onset of Fungal infection
signs and by evaluating the overall condition of the animal. Less commonly, other etiologies as listed for
Acute processes, such as foreign bodies or acute feline viral mucopurulent discharge
infections, often result in a sudden onset of signs, including Systemic disease
sneezing, although the animal’s body condition is excellent. Clotting disorders
In chronic processes, such as mycotic infections or neo- • Thrombocytopenia
plasia, signs are present over a long period, and the overall • Thrombocytopathy
body condition may be deleteriously affected. A history of • Coagulation defect
Vasculitis
gagging, retching, or reverse sneezing may indicate masses, Hyperviscosity syndrome
foreign bodies, or exudate in the caudal nasopharynx. Polycythemia
Nasal discharge is characterized as unilateral or bilateral Systemic hypertension
on the basis of both historical and physical examination
findings. When nasal discharge is apparently unilateral, a
cold microscope slide may be held close to the external nares
to determine the patency of the side of the nasal cavity
without discharge. Condensation will not be visible in front