Canine nasal disease

Question 1

What are the main ddx for nasal disease?

Answer 1

Neoplasia
Lymphocytic plasmacytic rhinitis
Tooth disease
FB
Parasites
Aspergillus
Bacterial Rhinitis
Cleft palate
Oro-nasal fistula
Coagulopathy

Question 2

What are the differentials when there is loss of bone on imaging?

Answer 2

Loss of turbinate detail - Aspergillosis
Loss of turbinate detail with soft tissue opacity -Neoplasia
Bone lysis - Neoplasia, aspergillosis

Question 3

Is culture of nasal biopsies a good idea?

Answer 3

Often not, not even clear if bacterial rhinitis is a thing, and will just get a mix of commensals

Question 4

What causes sinonasal aspergillosis?

Answer 4

most often caused by Aspergillus fumigatus, a filamentous saprophyte and ubiquitous fungus, although infections with other Aspergillus species, Penicillium species and Cryptococcus neoformans have been reported.

Question 5

What are the clinical signs of nasal aspergillosis?

Answer 5

The disease is typically unilateral on first presentation, but progresses to become bilateral. Typical clinical signs are profuse mucopurulent to purulent nasal discharge, nasal pain and ulceration/depigmentation of the nasal planum. Sneezing, reverse sneezing, epistaxis, depression and decreased appetite can also be seen. The presence of facial or nasal pain and ulceration/depigmentation of the nasal planum help to differentiate it clinically from some of the other causes of nasal discharge

Question 6

How do you diagnose nasal aspergillosis?

Answer 6

Radiographic findings can include radiolucency in the rostral nasal cavity in conjunction with increased radiopacity in the caudal aspect
Increased radiopacity is also often found in the frontal sinus, due to fungal disease or fluid from reduced
drainage through the nasofrontal ostium.
‘gold standard’ for diagnosis of the disease remains
direct visualisation of fungal plaques during rhinoscopy or identification of fungal elements on cytology or histopathological examination.
Rhinoscopically, destruction of the turbinates is often
seen with aspergillosis, creating a ‘cavernous’ appearance
Fungal colonies will be recognised
as grey, white or yellow plaques if present

Question 7

How do you treat aspergillosis?

Answer 7

Topical instillation of antifungal
drugs, especially clotrimazole or enilconazole, has
been associated with greater success than oral therapy.
There are a number of options for instillation of topical
therapy, including nasal cavity catheters, intrasinus
Jamshidi needles and indwelling frontal sinus tubes.
Oral therapy is reserved for refractory cases as it is associated with hepatotoxicity, and takes a very long time
Surgical extirpation of the frontal sinuses is performed in dogs with large fungal plaques, followed by
application of topical clotrimazole
Aspergillomas in the frontal sinus are debrided
surgically if identified on CT. Rhinotomy offers a last
resort for animals with refractory disease or where
the diagnosis has not been made, but surgery by no
means guarantees success.q

Question 8

What is the prognosis for aspergillosis?

Answer 8

dogs may suffer from nasal discharge after recovery from sinonasal aspergillosis.
In most cases it is a secondary bacterial rhinitis that will respond to antibiotics, although sometimes it
may be the end result of severe turbinate destruction

Question 9

What are the signs of cryptococcus? how do you diagnose it?

Answer 9

sneezing, nasal discharge, epistaxis and nasal deformity.
Rhinoscopy may reveal roughened, erythematous nasal turbinates, and fungal granuloma may be seen as a mass lesion. The latter may also be visible on diagnostic imaging. Diagnosis is by demonstration of the fungus on histopathology as well as by tissue culture and serum antigen titres.

Question 10

What types of dogs are more at risk of nasal neoplasias?

Answer 10

older, medium to large breed dogs and it has been suggested that being dolichocephalic, living in an urban environment and being exposed to tobacco smoke all lead to increased risk.

Question 11

What are the most common nasal neoplasias?

Answer 11

Carcinomas (adenocarcinoma, squamous cell
carcinoma and undifferentiated carcinoma) represent
approximately two thirds of tumours, with sarcomas
(fibrosarcoma, chondrosarcoma, osteosarcoma and
undifferentiated sarcoma) comprising the majority of
the rest. There are occasional reports of other tumours;
for example, melanoma.

Question 12

How does nasal neoplasia start out?

Answer 12

Nasal neoplasia is typically a unilateral disease process, at least initially, and the average duration of clinical signs before diagnosis is three months.

Question 13

What are typical clinical signs of nasal neoplasia?

Answer 13

nasal discharge, epistaxis, sneezing, stertor, stridor and epiphora. Air flow will typically be reduced on
the affected side.

Can progress to facial deformity and pain, exophthalmus, intractable epistaxis and seizures if there is invasion into the cranium, usually via the cribriform plate.

Question 14

How do you diagnose nasal neoplasia?

Answer 14

A definitive diagnosis of nasal neoplasia can only
be made by histology. Supportive data can be obtained with imaging (radiography, CT or MRI) and rhinoscopy
A nasal flush should always be performed in cases
of suspected nasal neoplasia, as a piece of the tumour
is occasionally dislodged and later identified when the
pharyngeal packing is removed.

Question 15

What is the MST for a dog with nasal carcinoma?

Answer 15

in untreated dogs with carcinoma was just 88 days for

dogs with epistaxis and 224 days for those without.

Question 16

How do you treat nasal neoplasia?

Answer 16

aimed at slowing progression and reducing tumour mass; this is best achieved with fractionated radiation therapy, which is very well tolerated by most dogs, although loss of sight in at least one eye will be seen in almost half of dogs treated this way. Median survival and one- and two year survival times vary between reports

Question 17

What is idiopathic lymphoplasmacytic rhinitis?

Answer 17

microscopically characterised by infiltration of the nasal mucosa with lymphocytes and plasma cells, although variable numbers of neutrophils and eosinophils may also be present.
The definitive cause of LPR is unknown, although some authors believe that the condition is a chronic inflammatory response to an inhaled irritant, pollutant or allergen. An immune-mediated pathogenesis has also been suggested, but poor glucocorticoid response in most dogs with LPR does not support this hypothesis

Question 18

What does lymphoplasmacytic rhinitis present concurrently with?

Answer 18

nasal neoplasia, fungal rhinitis, dental disease, oronasal fistula or foreign body rhinitis; therefore it is imperative that these diseases be thoroughly excluded before a definitive diagnosis is made

Question 19

How does lymphoplasmacytic rhinitis appear on imaging?

Answer 19

CT images may mimic fungal rhinitis as turbinate
destruction occurs in some cases, although typically
the changes are not as pronounced and destruction of the nasal septum, bones of the frontal sinuses and cribriform plate are not expected. Frontal sinus opacification on CT can occur due to fluid trapping. Changes on endoscopy are non-specific

Question 20

How do you treat lymphoplasmacytic rhinitis?

Answer 20

extremely frustrating and a cure is rarely achieved.
Allergen avoidance is usually unhelpful and difficult to
accomplish.
While systemic corticosteroids are seldom
effective in controlling clinical signs, inhaled steroid
therapy (eg, fluticasone propionate or beclomethasone) does seem to lead to a partial improvement in some animals.
Antihistamine medications are rarely effective but can reduce severity
Long-term administration of antibiotics that have immunomodulatory effects, combined with nonsteroidal anti-inflammatory agents, can be helpful in some animals. Doxycycline is frequently trialled for a
period of four to six weeks; however, as recent studies
have failed to identify any infectious agent associated
with this disease, any beneficial effect may well be from immunomodulation.

Question 21

What is Pneumonyssoides caninum?

Answer 21

canine nasal mite.
The life cycle and mode of transmission of the parasite
are not fully known. Cases typically present with nonspecific signs referable to the upper respiratory tract, including sneezing and reverse sneezing. P caninum has recently been identified in the UK. Treatment options include milbemycin oxime 1 mg/kg given orally three times at 10-day intervals. This dose regimen is more frequent than the monthly dose of 6 to 12 mg/kg recommended for flea infestations.