Loss of smell may occur with advancing age but there is no evidence that this is
a significant problem in old cats and dogs. In part this may be because recognition
of loss of smell is a problem for owners and veterinary clinicians because there is no
change in behaviour pattern apart from reduced appetite which specifically indicates
that such a loss is present.
There are a number of age-related diseases that may affect the nose, the most important
of which are intranasal neoplasia and chronic rhinitis.
The average age of dogs and cats with intranasal neoplasia is reported to be 9 years.
The condition is less common in cats. In the dog most neoplasms are adenocarcinomas. In
cats benign polyps which extend to the nasopharynx are also seen.
Nasal tumours are locally invasive and cause destruction of bone which can be identified
on radiography and loss of the fine trabecular pattern of the nasal turbinates is
a sign of early nasal neoplasia. This is best demonstrated on intra-oral dorsoventral
projections. Spread to local tisincluding the eye and brain is common. Clinical signs
include sneezing, nasal discharges including epistaxis, obstructed air flow when
breathing and later deformity of the face or clinical signs associated with spread
to adjacent structures such as the brain.
Diagnosis is based on clinical signs, radiography and excisional biopsy. Flushing
the nasal cavity to extract exfoliated cells for cytological examination might also be a
useful technique in some cases.
Treatments that have been reported to be successful in some cases include surgery,
surgery with radiotherapy and radiotherapy alone but the prognosis is always poor-guarded.
Chronic rhinitis may be a consequence of bacterial, viral or fungal infection, trauma or
foreign bodies. Only about 50% of cases will respond to treatment and the prognosis
is poor-guarded. Treatment is dependent upon an accurate diagnosis of the underlying
cause. Even if micro-biological culture and sensitivity indicates a specific therapeutic
approach complete success may not be achieved because the infection is in a cavity,
and for this reason some clinicians prefer to flush through trephined holes or a
nasal bone flap - particularly for the treatment of aspergillus or infections extending
into sinuses. Partial or complete turbinectomy can be performed in some cases, and
some authors advocate complete bilateral extirpation of all turbinate tissues (Gourley
and Vasseur 1985).