Two main parts of upper respiratory system are the nose and paranasal sinuses. The paranasal sinuses are hollow spaces in the bones of the skull, connecting with the nose and helping to add moisture to the air that a dog breathes in through its nose. Both the inside of the nose and the paranasal sinuses are covered in the same type of tissue, called the epithelium. The outer layer of this tissue is scale like, and is called the squamous epithelium. Tumors that grow from this squamous epithelium are called squamous cell carcinomas.
The cells that line skin, mouth and nose, entire gastrointestinal tract, respiratory tract and even urinary and reproductive tracts are called “epithelial cells”. They can take many shapes depending on if their job is to protect the body from the environment (skin), absorb material from the environment (GI tract), or perform some other sort of job (respiratory tract.) Epithelial cells also line body cavities, the outside of organs and blood vessels, forming a thin casing.
Squamous cell carcinomas are slow-growing, bilateral and second most common type of nasal cancers in dogs. The tumor can spread to adjoining bone and tissue and in some cases, to the brain, causing seizures.
Common symptoms associated with this type of tumor include
Runny nose that goes on for a long time
Occasional bloody nose
Excessive tears (epiphora)
Excessive sneezing
Bad breath (halitosis)
Loss of appetite (anorexia)
Seizures
Bulging eyes
Nose seems deformed
