Freddie has Nasal Discharge

Question 1

As with any patient, it is important to perform a full clinical exam, but in animals with nasal discharge a focussed clinical exam is needed.

What additional tests or examinations are needed and why are they important?

Answer 1

• Facial symmetry - some conditions will cause facial deformity so its important to visually assess and palpate the skill
• Lymph nodes - need to assess for lymphadenopathy and determine whether the lymph nodes are unilateral or bilaterally enlarged. Freddie has an enlarged lymph node on the left
• Nasal planum - check the nasal planum for evidence of ulceration to see if there is any loss of symmetry or depigmentation
• Nasal discharge character and air flow: It’s really important to characterise the nasal discharge. Is it unilateral or bilateral, and what nature is it - serous (clear), mucopurulent, mucopurulent mixed with blood, or frank blood (epistaxis). Some animals don’t have the discharge at the time of examination so a good history is necessary here
• oral cavity exam

Question 2

You can test airflow from nostrils in a variety of different ways. What are the easiest ways?

Answer 2

• a) Hold a wisp of cotton wool just in front of one nostril. If the airflow through this nostril is good, the fibres should be sucked in towards the nose when Freddie inhales and blown out when he exhales. Compare the two nostrils.
• b) Hold a clean glass microscope slide in front of the nose and look for the pools of mist steaming up the slide as the animal breathes out; the angle you need to hold the slide at seems to depend on the individual dog.
• Airflow can be reduced either due to the presence of a soft tissue mass or to thick nasal discharge. Freddie has a unilateral left sided mucopurulent discharge with no blood and no reduction in airflow versus the right.

Question 3

Write a DAMNITV for differentials for nasal discharge?

Answer 3

• D
  
  • Degenerative: I can’t think of any which clearly fit here for nasal discharge - if you can, let me know!
  • Developmental: Something like an oro-nasal fistula could come in here - puppies with big splits will blow milk down their nose and have a permanent rhinitis. Remember that animals can develop spilt palates after road traffic accidents too.
• A
  
  • Anomalous: It’s hard to know where to put foreign bodies so I’m tempted to put them here. It’s amazing what animals can get stuck in their nose or nasopharynx - blades of grass, whole long sticks, heads of wheat etc.
• M
  
  • Metabolic: Some metabolic diseases causing hypertension, such as some of the endocrinopathies, renal disease, polycythemia, can lead to epistaxis which the owners would report as a form of nasal discharge - this highlights the importance of a full clinical examination.
• N
  
  • Nutritional: Not that likely, though it’s another place for the oro-nasal fistula to be placed.
  • Neoplastic: Definitely a differential. Carcinomas, lymphoma, some sarcomas can be found up the nose. More of these later
• I
  
  • Infectious: Always a good one. As usual, split this in to bacterial, viral, fungal and parasitic.
  • Primary bacterial rhinitis is rare - there is almost always an underlying cause such as an erosive viral rhinitis, a foreign body, tumour etc so these are usually secondary infections. Dogs with pneumonia can present with nasal discharge too - again, have a good listen to the thorax as part of any clinical exam. Bacterial rhinitis secondary to dental disease may be seen in older animals with chronic dental disease, or younger ones with some tooth fractures.
  • Viral nasal discharge is much more common in the cat than in the dog, and there is a separate virtual case on this coming soon.
  • Fungal disease is not uncommon. Dogs get fungal aspergillus, cats get a disease called Cryptococcus.
  • Parasitic: There is a nasal mite in the UK which can cause nasal pruritis and a discharge if severe enough.
  • Immune mediated: Systemic immune mediated diseases may cause nasal discharge, but it’s not that common.
  • There is an idiopathic chronic rhinitis in dogs which may have an immune mediated component but it’s more likely to be from an undiagnosed previous infection. Another idiopathic is rhinitis sicca where the nasal gland does not produce any secretions.
• T
  
  • Trauma: Split hard palates and maxillary fractures can definitely case a nasal discharge as can trauma to some teeth if there is an impact on their deep roots.
  • Toxins: Rare to just be a nasal disease but many toxins can have systemic consequences which may include a variety of nasal discharges of differing aetiologies.
• V
  
  • Vascular: Coagulopathies, primary or secondary can cause epistaxis which may be unilateral or bilateral.
  • Local vascular disease from tumour or foreign body vessel erosion can cause a local vascular problem too, manifesting as epistaxis.

Question 4

What is aspergillosis?

Answer 4

Aspergillosis is a fungal infection, typically caused by Aspergillus fumigatus. The spores of this fungus are ubiquitous in the environment and it is unclear as to quite what factors lead to primary fungal colonisation in some dogs not others. Affected dogs tend to have longer noses - this is a very rare disease in brachycephalic dogs and is not seen in cats. The fungus colonises both the nasal cavity and the frontal sinuses and produces toxins which lyse the turbinate bones leading to secondary infections and nasal pain. The nasal discharge also contains these toxins, and can lead to depigmentation of the nasal mucosa.

Question 5

What is the diagnosis for aspergillosis?

Answer 5

Diagnosis requires visualisation of the plaques with a rhinoscope and biopsy for culture and histopathology. Serum aspergillus titres can be performed but the sensitivity and specificity very much depends on the laboratory.

Question 6

What is the treatment for aspergillosis?

Answer 6

Treatment typically involves use of topical anti-fungal drugs such as clotrimazole (unlicenced). There are many different techniques, the most successful involve trephination of the frontal sinuses and instillation of the clotrimazole cream. Many dogs will lead to more than one treatment, and the prognosis for return to life without nasal discharge is poor as many animals develop a chronic secondary rhinitis. This is one of the most comprehensive papers on the subject published recently.

Question 7

What is cryptococcus?

Which age of cats is most at risk?

Answer 7

• Cryptococcus neoformans is a capsulated yeast which affects cats, and rarely dogs, and appears to have a reservoir in bird guano - cat to cat transmission is not reported, so the most likely route is via airborne spores. This is a common disease in tropical areas and sites with heavy growth of Eucalyptus trees, but is rare in the UK.
• Young cats appear to be at increased risk of developing the disease, which manifests as nasal discharge and facial swelling over the bridge of the nose. In some cats, a polypoid tissue mass can be seen protruding from the nostrils. In some cases, there will be growth through the cribriform plate leading to neurological signs.

Question 8

What is the diagnosis and treatment for cryptococcus?

Answer 8

• Diagnosis is by obtaining tissue for histopathology and culture, and serological testing.
• Treatment requires both surgical debridement and anti-fungal drugs such as flucytosine and amphoteracin B, neither of which are licenced in the UK. The prognosis is typically poor for complete resolution of the disease

Question 9

What are nasal tumours and what are the presenting signs?

Answer 9

As with any tumours, these typically affect older animals, but young animals can be affected too. Presenting signs are usually a unilateral nasal discharge, often with epistaxis, sometimes with a change to the breathing such as stertor; reduced nasal airflow is very common as is unilateral lymphadenopathy. Later in the disease course, facial swelling can develop as the tumour erodes through the nasal bones and can cause proptosis.

Question 10

What is the diagnosis and treatment for nasal tumours?

Answer 10

• Diagnosis again requires a biopsy for histopathology, typically obtained by rhinoscopy. There are several tumour types which commonly affect the nose. Dogs typically seem to develop carcinomas whereas cats get lymphoma; for both a wide range of other tumour types are possible.
• Treatment for carcinomas is typically with external beam radiotherapy plus NSAIDs and antibiotics as needed. This is only palliative and the median survival time is typically 8-10 months after diagnosis. Nasal lymphoma can also be treated with radiotherapy, but some clinicians will also give chemotherapy as this is typically a systemic disease and some of these cats later develop renal lymphoma.

Question 11

What are common foreign bodies in cats and dogs?

Answer 11

• Dogs and cats can present with a wide range of foreign bodies. Cats typically seem to get blades of grass caught behind their soft palate which leads to sudden onset retching, gagging and halitosis with a mucopurulent nasal discharge sometimes following at a later time.
• Dogs can inhale anything from long sticks to seeds. They typically develop unilateral mucopurulent nasal discharge which responds to antibiotics but returns as soon as the antibiotics are withdrawn. Some animals will develop secondary fungal colonisation of the foreign material, though not usually with pathogenic species.

Question 12

What is chronic lymphoplasmacytic (idiopathic) rhinitis?

What do biopsies show?

Answer 12

• This is a difficult disease to characterise. It seems to be pretty dog specific and a clear cause has not been identified. Dogs will often present with bilateral mucopurulent nasal discharge with a poor response to antibiotics. There is no evidence of a tumour and no clear evidence of Aspergillosis. In some cases there can be mild erosion of the turbinate bones but this is not classic for this disease.
• Biopsies reveal a lymphocytic and plasmacytic infiltrate. No satisfactory treatment has been found and the condition is typically managed with a combination of topical and systemic antibiotics and immunomodulators. The prognosis for resolution is poor, but many dogs survive a long time as long as the discharge can be tolerated.
• This is one of the very few papers on the subject, despite it not being that rare.

Question 13

A long nosed, middle aged dog with unilateral left side mucopurulent nasal discharge and ventral nasal planum depigmentation. Pain present on palpation over the nasal bones. Airflow is slightly reduced on the left. The left submandibular lymph node is larger than the right

Apergillosis, nasal tumour, foreign body or idiopathic rhinitis?

Answer 13

Aspergillosis

Question 14

An outdoor cat which is gagging and pawing at its mouth. He has a unilateral purulent nasal discharge, is sneezing and has halitosis. There is no change in airflow

Apergillosis, nasal tumour, foreign body or idiopathic rhinitis?

Answer 14

Foreign body

Question 15

A middle aged dog with stertorous breathing and unilateral right mucopurulent nasal discharge with occasional frank epistaxis. No change to the nasal planum and no pain on palpation over the nose. The right submandibular lymph node is enlarged, firm and non-painful. There is no airflow on the right.

Apergillosis, nasal tumour, foreign body or idiopathic rhinitis?

Answer 15

Nasal tumour

Question 16

A middle aged dog with unilateral nasal discharge and sneezing. There is no depigmentation of the nasal planum, no change to the breathing and no reduction in airflow.

Apergillosis, nasal tumour, foreign body or idiopathic rhinitis?

Answer 16

idiopathic rhinitis

Question 17

Freddie’s clinical picture in terms of his age, history and clinical examination are suggestive of a foreign body, but he needs a good, logical work-up to be sure we don’t miss anything. There are a lot of different tests which can be done on dogs with nasal disease, and often these animals need referral for further investigation.

There are all sorts of different things which you can do with any case, some of which are more worthwhile than others. What are the tests you would like to do on Freddie in terms of gold standard, if you cannot refer it and some that are probably not worth the money?

(This is by no means set in stone and depends on what kit you have and how much money Freddie comes with.)

Answer 17

• Gold standard:
  
  • Rhinoscopy
  • CT/MRI of the nose
  • Coagulation screen
  • Nasal biopsies if no FB see
• If you cant refer it
  
  • Intra-oral radiography
  • Blind nasal flush
• Probably not worth the money
  
  • Nasal swab for culture
  • Ultrasound of the nose

Question 18

Freddie’s coagulation screen is unremarkable so he is anaesthetised for a CT of his nose to see what is up there. There are a variety of different appearances to the nose on CT depending on what the pathology shows. CT scans are made up of many slices, which we cannot replicate in this package.

What is circled on this slice?

What is significant about it?

Answer 18

Nasal turbinates

This is the main area of interest. The right side as you look at the image shows the normal structure of the nasal turbinates with a maze of fine bones. Ventrally on the left side as you look at the image there is an area of more homogenous opacity which is abnormal. It is not possible to tell whether this is fluid or soft tissue but is definitely not normal.
To try and determine the pathology type, you need to look at how the surrounding area looks. In this case, the turbinates look normal and the area is well defined. See the next set of slides for a comparison

Question 19

What is circled here?

Answer 19

Mandible

Question 20

What is circled here?

Answer 20

Endotracheal tube

Question 21

What is circled here?

Answer 21

Air opacity

Question 22

What is circled here?

Answer 22

Grey is a soft tissue opacity. In this case, the soft tissue is Freddie’s tongue which has been pulled to the side of his mouth.

Question 23

This is a slice through the nose of a 2 year old German Shepherd dog which presented with unilateral nasal discharge with some blood and sterorous breathing.

What is your diagnosis?

Answer 23

Unfortunately, she has an aggressive carcinoma of in her nose; you can see a slightly heterogenous soft tissue mass fully occluding the right side of the nose as you look at it and you can see the central nasal septum has been both pushed aside (deviated) and is no longer intact. Ventrally on the right, there is also slight disruption of the hard palate bones

Question 24

This is a nose at the same level of an 11yo Golden Retriever

What is wrong?

Answer 24

This is a nose at the same level of an 11yo Golden Retriever with severe aspergillosis. There are very few normal bony turbinates left and there is a lot more air space than normal. The nasal septum here looks very thin and there are areas of increased soft tissue opacity. These are likely to be a combination of nasal discharge and fungal plaques.

Question 25

What is wrong with this dog?

Answer 25

This is the German Shepherd with a nasal carcinoma again. Her tumour has invaded the frontal sinuses so you can see there is a soft tissue opacity filling the normally air filled sinus on the right side which is tumour - the left side is currently unaffected in comparison.

Question 26

Before rhinoscopy, how should you prepare?

Answer 26

* Preparation * It's important to keep these animals safe when looking up their noses. You need to place a throat pack and keep the nose down so they don't aspirate blood or mucus * Measuring the scope * The next important thing is to ensure that you know how far you can introduce the rhinoscope. It is possible to put the scope through the cribriform plate into the brain which isn't good, so before you start, measure to the level of the medial canthus of the eye and put a piece of tape on the scope so you don't go in too far - this is the safe limit as to how far back you can go. As Freddie has a localised lesion, we can also measure that distance on the scope and look at that level for the abnormal area. In his cases, this is 5cm in.