SDL: Small animal nasal disease

Question 1

If an animal has nasal discharge, how should you focus the PE?

Answer 1

1. Look at facial symmetry - some conditions can cause facial deformity so important to assess and palpate the skull.
2. Lymph nodes - Need to assess for lymphadenopathy and determine whether LNs are unilaterally or bilaterally enlarged.
3. Nasal planum - check for evidence of ulceration, loss of symmetry or depigmentation.
4. Oral cavity exam - always check inside mouth for changes.
5. Nasal discharge character and air flow - Is is unilateral/bilateral? And assess nature. Test airflow by holding a wisp of cotton wool just in front of one nostril. if airflow is good, you will see it move - compare both nostrils. Can also hold a clean microscope slide in front of the nose and look for steam.

Question 2

DDx for Nasal discharge?

Answer 2

Developmental: oro-nasal fistulas

Anomalous: FB

Metabolic: Some metabolic diseases causing hypertension etc.

Neoplastic: Carcinomas, lymphoma, sarcomas

Infectious: Primary bacterial rhinitis is rare, almost always an underlying cause e.g. FB. Viral is much more common in cat than the dog. Fungal: dogs - aspergillus, cats - cryptococcus.

Trauma: split hard palates, maxillary fractures.

etc.

Question 3

Explain Aspergillosis

Answer 3

Fungal infection, caused by aspergillus fumigatus. Spores of the fungus are ubiquitous to the environment. Affected dogs tend to have longer noses, it is not seen in cats. Fungus colonises nasal cavity and the frontal sinuses and produces toxins which lyse the turbinate bones leading to secondary infections and nasal pain.

Diagnosis - visualisation of the plaques with rhinoscope and biopsy.

Treatment - topical antifungals such as clotrimazole (unlicensed).

Question 4

Explain cryptococcus

Answer 4

C. neoformans is a capsulated yeast which affects cats. Cat-to-cat transmission is not reported, therefore, thought to be airborne spores. uncommon in the UK. Young cats appear to be at increased risk. Manifests as nasal discharge and facial swelling over the bridge of the nose.

Question 5

Explain Nasal tumours

Answer 5

Typically affect older animals.

Present usually with unilateral discharge, epistaxis, sometimes a change to breathing e.g. stertor, reduced nasal airflow and unilateral lymphadenopathy.

Diagnosis: biospy.

Question 6

Explain foreign bodies

Answer 6

Cats typically seem to get blades of grass caught behind thier soft palate, leading to sudden onset retching, gagging and halitosis.

Dogs typically devleop unilateral mucopurulent discharge which responds to ABs but returns as soon as ABs are withdrawn.

Question 7

Explain Chronic lymphopasmacytic (idiopathic) rhinitis

Answer 7

Seems to be pretty dog specific, cause not identified. Dogs often present with bilateral mucopurulent discharge with a poor response to AB.

Biopsy reveals a lymphocytic and plasmacytic infiltrate.