Respiratory Diseases in Dogs, Cats and Rabbits- week 10 Flashcards
What is the usual clinical presentation of Upper Respiratory Tract Disease?
- Sneezing/ nasal discharge
- Stridor
- Increased respiratory effort
- Facial deformity
- Altered vocalisation/ Loss of voice
What is the usual clinical presentation of Lower Respiratory Tract Disease?
- Coughing
- Dyspnoea
- Exercise Intolerance
- Respiratory Distress
- Other systemic signs
What are the three most common causes of URT in cats?
- Feline Upper Respiratory tract Infection
- Feline Herpes Virus
- Feline Calcivirus
What is feline herpes virus associated with?
Sneezing.
* Ocular discharge, conjunctivitis, keratitis and corneal ulcers.
* Infection at a young age can result in chronic rhinitis.
What is feline calcivirus often associated with?
Oral ulceration.
* Sneezing and nasal discharge.
* Chronic stomatitis and gingivitis.
* Can develop pneumonia in severe cases.
What are the clinical signs of URT Infection in cats?
Depression.
* Difficulty/pain on swallowing and anorexia.
* Pyrexia.
* Ocular and nasal discharge and sneezing.
* Salivation.
* Coughing.
* Voice changes.
How might you diagnose a feline upper respiratory tract infection?
Clinical presentation is often suggestive.
* Polymerase chain reaction (PCR) from oropharyngeal or conjunctival swabs.
* Viral isolation (VI) from oropharyngeal or conjunctival swabs (not as widely available)
How might you treat a feline upper respiratory tract infection?
Supportive care (hydration, nutrition).
* Antiviral therapy for FHV-1 (e.g., famciclovir).
* Broad-spectrum antibiotics for secondary bacterial infections. (Amoxicillinclavulanate is often appropriate.
* Nebulisation (saline)and steam therapy can help ease respiratory congestion.
* Mucolytics.
How might we prevent upper respiratory tract infections?
Regular vaccination (reduce shedding and clinical signs).
* Stress can cause recrudescence so try to avoid.
* Environmental control (good hygiene, solid walls in cattery)
What is chronic rhinosinusitis?
A chronic inflammatory condition, usually post-viral (secondary to FHV-1 or FCV infections). Damage to nasal turbinates reduces mucosal immunity and leads to chronic secondary infection.
What are the clinical signs of chronic rhinosinusitis?
Persistent or recurrent nasal discharge (mucopurulent).
* Sneezing.
* Nasal obstruction
How might you diagnose chronic rhinosinusitis?
History, clinical signs and examination.
* Rule out other causes.
* Radiography.
* Rhinoscopy with biopsy for histopathology (neutrophilic and mixed
inflammatory infiltrate).
* Advanced imaging (CT or MRI) to assess sinus involvement
How might you treat chronic rhinosinusitis?
Aimed at controlling severe clinical signs.
* Broad spectrum antibiotics (often osteomyelitis of turbinates so long courses of
antibiotics (2-6 weeks) may be necessary. Ideally based on culture and sensitivity.
* Nebulised saline and steam treatment.
* NSAIDs (Care with long-term use and only if eating and well hydrated).
* Antivirals e.g., Famciclovir anecdotal reports that can be beneficial.
* Topical nasal decongestant (e.g., phenylephrine, xylometazoline) short term use only.
* Owners need to be aware that long-term management and recurrent courses of
treatment will be required.
What causes allergic rhinitis?
Caused by exposure to allergens including Pollens (from trees, grasses, or weeds), dust
mites, moulds, cigarette smoke or other airborne irritants, household chemicals or
cleaning agents. Less common than post viral chronic rhinosinusitis but can be more
responsive to treatment
What are the main clinical signs of allergic rhinitis?
Sneezing: Often intermittent but may become frequent in response to allergen
exposure.
* Nasal Discharge: Usually serous (clear, watery), though mucopurulent discharge can
occur if secondary bacterial infection develops.
* Cats may paw at their noses or face.
* Conjunctivitis: Often accompanies nasal signs in cases of allergic rhinitis.
* Coughing and Wheezing: In severe cases, allergic rhinitis may be associated with
allergic bronchitis or feline asthma.
How might you diagnose URT disease in cats?
Seasonal pattern of clinical signs.
* An improvement in clinical signs following anti-inflammatory or antihistamine therapy can
support a diagnosis of allergic rhinitis.
* Exclusion of Other Causes (especially infectious causes).
* Eosinophilic or lymphoplasmacytic infiltrate present on biopsy.
How might you treat URT disease in cats?
Reduce exposure to inhaled allergens (eg, cat litter house dust, cigarette smoke, aerosol
sprays).
* Antihistamines (eg, cetirizine), response can be unpredictable.
* Systemic administration of anti-inflammatory doses (e.g., prednisolone 1 mg/kg/day, then
titrated down to the minimum effective dose).
* Inhaled corticosteroid delivered via a feline aerosol chamber once initial signs controlled.
What are the clinical signs of URT disease in cats?
- Sneezing- Sudden and Severe
- Nasal Discharge- usually unilateral, can be serous mucopurulent or haemorrhagic
- Gagging, Coughing or Reverse Sneezing
- Pawing at the nose or face
- Halitosis- secondary infection develops due to retained foreign material
- Open-Mouth Breathing or Stridor- In severe cases where there is significant obstruction or inflammation causing respiratory distress
How might you diagnose Nasopharyngeal Foreign Bodies?
Examination of nasopharynx under general anaesthesia. May be immediately visible
or require nasopharyngoscopy.
* Nasal flushing may be necessary if located very rostrally.
How might you treat nasopharyngeal foreign bodies?
Removal of foreign material
* May require NSAIDs and or antibiotics if more long standing.
What is a nasopharyngeal polyp?
Cause is not fully understood (possibly chronic inflammation of middle ear). These are benign pedunculated growths commonly found in young cats, arising from the middle ear or nasopharynx.
What are the clinical signs of nasopharyngeal polyps?
Chronic nasal discharge (usually unilateral).
* Stertor, difficulty breathing, possible dysphagia (obstruction of nasopharynx).
* Otitis externa or media, possible vestibular signs or Horner’s syndrome if extending into middle ear
How might you diagnose Nasopharyngeal polyps?
Visual examination (otoscopy or rhinoscopy) and imaging (radiography).
* Histopathological examination after excision.
How might you treat nasopharyngeal polyps in cats?
Surgical removal of the polyp.
* Recurrence is possible, especially if the stalk is not fully excised.
* Temporary Horner’s syndrome is common but usually resolves.
* NSAID or corticosteroid can be used post-operatively to reduce secondary
inflammation.
* Antibiotics indicated if more chronic and evidence of secondary infection on
removal
What is fungal rhinitis?
Emerging disease of cats worldwide. Can be caused by Cryptococcus species (rare in UK), Aspergillus
species and Penicillium species
What are the clinical signs of fungal rhinitis?
Chronic nasal discharge +/- epistaxis.
* Stertor.
* Facial swelling
* Sometimes neurological signs if extension into the CNS
How might you diagnose fungal rhinitis?
Serology (Cryptococcus spp)
* Imaging (Radiography, endoscopy, turbinate lysis frequently seen on CT
* Cytology and Culture of fungal plaques
How might you treat fungal rhinitis?
Long-term antifungal therapy (intranasal clotrimazole or oral itraconazole or posaconazole).
* Surgical debridement may be required in severe cases.
* Guarded prognosis, recurrence likely
What is feline asthma?
Asthma is a common lower-airway inflammatory disease in cats thought to be allergic in origin
What are the clinical signs of feline asthma?
- Cough
- Increased expiratory effort
- Open Mouth breathing
- Tachypnoea
- Vomiting
How might you diagnose feline asthma?
Rule out other diseases that can mimic clinicopathologic features of
asthma
* Radiographs: bronchial or bronchointerstitial lung pattern common.
* Bronchoscopy mucus, mucosal hyperemia, airway collapse, and
stenosis.
* Eosinophilic inflammation on BAL cytology (>20% eosinophils).
* Thoracic CT can identify subtle lesions that may not be appreciated
on radiograph
How would you manage feline asthma orally?
Glucocorticoids (Prednisolone 0.25-1 mg/kg PO BID. Taper to
minimal effective dose for maintenance therapy).
* Bronchodilators (Terbutaline 0.625 mg PO BID, Theophylline
25 mg/kg PO SID)
How would you manage feline asthma (inhaling agents) ?
Glucocorticoids (Fluticasone (110 ug q 12h, may increase up
to 220 ug twice a day).
* Bronchodilators (Salbutamol or albuterol 1 puff/ 10 kg up to
a maximum of 3 puffs
What is the definition of common bronchitis?
Likely secondary to a previous airway insult, such as respiratory infections or inhaled irritants leading to permanent damage to the airways. Shares many historical, clinical and radiographic features of feline asthma
what are the clinical signs of chronic bronchitis
Chronic coughing (paroxysmal, productive, retching, gagging).
* Recurrent bouts of bronchopneumonia.
* Tachypnoea and dyspnoea.
* Exercise intolerance.
* Cachexia, debility
how might you diagnose chronic bronchitis
Radiographs showing thickened bronchial walls,
* Bronchoscopy showing excessive mucus
roughened hyperaemic mucosa.
* Nondegenerate neutrophilic inflammation on BAL
cytology
how might you manage chronic bronchitis
Glucocorticoids and bronchodilators (oral and/or
inhaled).
* Airway humidification (steam therapy)
what is bacterial pneumonia?
Less commonly identified than inflammatory disease.
* Pasteurella spp, Escherichia coli, Staphylococcus spp,
Streptococcus spp, Pseudomonas spp, B bronchiseptica, and
Mycoplasma spp have all been reported as lower respiratory
pathogens.
* Underlying infections e.g., FIV and FeLV can enhance severity.
What are the clinical signs of bacterial pneumonia?
- Cough
- Nasal discharge
- Lethargy/ pyrexia
- Tachypnoea
- Dyspnoea
- weight loss if more chronic
how might you diagnose bacterial pneumonia
Clinical signs
* Radiographs diffuse and often mixed pattern.
* Leukocytosis on haematology (mainly neutrophilia
with a left shift),
* Bronchoscopy (hyperemia of the epithelium,
prominent mucosal vessels, rounded, thickened
airway bifurcations, thick and often discoloured
mucous).
* BAL (septic and suppurative inflammation)
how might you manage bacterial pneumonia
Antibiotics ideally based on based on culture and
sensitivity from BAL samples.
* Supportive care (oxygen, nebulization, humidification,
fluids, nutritional support
What is the most commom form of lungworm?
Aelurostrongylus abstrusus is the most prevalent.
Most common in outdoor or hunting cats
What are the clinical signs of lungworm in cats?
Many infections not clinically significant.
* Lethargy and weight loss if more chronic.
* Severe burdens can cause coughing and dyspnoea/hypernoea.
* Can occasionally cause sudden death.
How might you diagnose lungworm in cats?
Detection of larvae in faecal Baermann test or BAL fluid.
* Radiographic changes variable, can be similar to those seen in feline asthma
How might you treat lungworm in cats?
Fenbendazole paste.
* Milbemycin oxime/praziquantel
* Various spot-on formulations (imidacloprid/moxidectin; emodepside /praziquantel; fipronil /(S)-
methoprene /eprinomectin/praziquantel ; or selamectin
What is infectious tracheobronchitis/ kennel cough?
A highly contagious condition caused by a number of viral and/or bacterial agents (Canine
Parainfluenza virus, Canine Adenovirus, Bordetella bronchiseptica)
What are the clinical signs of infectious tracheobronchitis?
Harsh, hacking cough (often described as “goose honk”), often with a retch
* Nasal discharge, submandibular lymph node enlargement.
* Mild lethargy and pyrexia
How would you diagnose infectious tracheobronchitis?
Based on history (recent exposure to other dogs) and clinical signs.
* PCR testing (deep oropharyngeal swab)
How would you treat infectious tracheobronchitis?
Most cases are self-limiting and resolve within 3 weeks.
* Antitussives (e.g., butorphanol) for non-productive cough.
* Antibiotics if clinical signs >10 days or systemically unwell.
* Short-term corticosteroids (0.5 mg/kg PO BID for 3-5 days) as long as no
complications
How would you prevent infectious tracheobronchitis?
Vaccination against Bordetella and canine parainfluenza virus.
* Isolate affected individuals until coughing has resolved
What is BOAS?
A group of anatomical abnormalities seen in brachycephalic
breeds due to shortened skull structures. Highly prevalent in
English and French bulldogs and Pugs
What are the components of BOAS?
Stenotic nares, aberrant and hypertrophied turbinates.
* Nasopharyngeal narrowing and collapse.
* Elongated soft palate.
* Narrow larynx, laryngeal hypoplasia, everted laryngeal
saccules.
* Hypoplastic trachea.
* Skull base malformation
What are the clinical signs of BOAS in dogs?
Snoring, noisy breathing (stertor and stridor)
* Increased respiratory effort.
* Exercise and heat intolerance.
* Cyanosis and collapse.
* Often progress over time without intervention
How do you diagnose BOAS in dogs?
Based on breed predisposition and clinical examination.
* Endoscopic evaluation.
* Radiographs or CT for assessing tracheal and nasal anatomy
How would you treat BOAS in dogs?
Surgical management (e.g., widening of stenotic nares, soft palate resection, usually
results in significant improvement.
* Weight management and environmental modification (e.g., avoiding heat, stress,
excitement).
* Long-term management often required, as the condition tends to be progressive
What is laryngeal paralysis?
Paralysis of the arytenoid cartilages, preventing proper airway opening during
inspiration.
* Usually affects older (> 9 years) large-breed dogs with Labrador retrievers being
overrepresented.
* Acquired form is caused by damage to the recurrent laryngeal nerve and/or laryngeal
muscles (trauma, polyneuropathy, polymyopathy, intra-or extra-thoracic masses).
* Many cases classed as ‘Idiopathic’ but recent evidence suggests LP may be part of a progressive generalised neuropathy.
* A congenital form occurs in some breeds
What are the clinical signs of laryngeal paralysis?
Inspiratory stridor.
* Exercise intolerance.
* Coughing.
* Dysphagia and regurgitation.
* Dysphonia (change in or loss of bark).
* Cyanosis and collapse (severe cases
How might you diagnose laryngeal paralysis?
Clinical examination.
* Visual inspection of the larynx under light anaesthesia (failure of arytenoid
cartilages to abduct on inspiration).
* Thoracic radiographs (masses, aspiration pneumonia).
* Neurological assessment (rule out neuropathy).
* Biochemistry and haematology (rule out endocrinopathies)
How might you treat laryngeal paralysis?
Surgical intervention (unilateral arytenoid lateralization most often used, need to
monitor carefully post –op for aspiration pneumonia).
* Weight loss and exercise modification.
* Anti-inflammatory drugs to reduce laryngeal swelling.
* Management of concurrent conditions (e.g., concurrent hypothyroidism in around
30% of dogs with acquired LP
What is canine nasal aspergillosis?
Infection occurs when Aspergillus spores are inhaled, with
dogs. Fungal invasion results in local tissue destruction and
inflammation. Dolichocephalic breeds predisposed
What are the clinical signs of canine nasal aspergillosis?
Chronic nasal discharge: Serous, mucopurulent, or
hemorrhagic.
*Nasal pain and discomfort: Dogs may paw at their noses
or show signs of facial pain.
*Sneezing
*Epistaxis
*Ulceration and/or depigmentation of the nares
How might you diagnose canine nasal aspergillosis?
Imaging: CT or radiographs show nasal turbinate destruction and increased soft
tissue density.
* Rhinoscopy: Visualization of fungal plaques within the nasal cavity; samples for
cytology, culture, or biopsy.
* Serology: Aspergillus-specific antibody tests, although not always reliable
How might you treat canine nasal aspergillosis?
Surgical debridement of fungal plaques and topical clotrimazole via instillation into
the nasal cavity or frontal sinuses under anaesthesia every 2 weeks until negative
culture/histopathology.
* Systemic antifungals (e.g., itraconazole or fluconazole) may be used but are less
effective than topical treatment.
How would you diagnose chronic bronchitis?
Radiography: Bronchial wall thickening and distortion. Bronchiectasis. Cor
pulmonale.
* Bronchoscopy: Tracheobronchial collapse, hyperaemia and thickening of
mucosa. Increased mucous.
* BAL: Lots of mucous, neutrophils on cytology.
* Blood gas analysis: Decreased oxygen saturation (PsO2 <80mmHg at rest)
How would you treat chronic bronchitis?
Glucocorticoids. Can be oral (Prednisolone, 1-2mg/kg/day PO BID for 7-
10 days then taper the dose ) or inhaled (Fluticasone 125mg BID).
* Bronchodilators, e.g., theophylline (10mg/kg PO BID) can help to reduce
diaphragm fatigue and increase mucociliary clearance.
* Nebulizers (saline, mucolytics).
* Antitussives (e.g., Butorphanol) with care.
* Weight loss
What is aspiration pneumonia?
Aspiration of solid or liquid into airways causing a severe inflammatory response, leading to alveolar damage and
infection.
* Can develop as a results of laryngeal dysfunction, megaoesophagus, iatrogenic (administration of medication into
airways instead of gastrointestinal tract), protracted vomiting and recumbency
What are the clinical signs of aspiration pneumonia?
Acute onset coughing and dyspnoea; Pyrexia; Anorexia
How would you diagnose aspiration pneumonia in dogs?
History and clinical signs.
* Radiography. Dependant lung lobes affected (right middle lung lobe, right cranial lung lobe, and left cranial caudal
lobe).
* Ultrasound. Consolidated lung has a hypoechoic appearance
How would you treat aspiration pneumonia in dogs?
Supportive care (IV fluids, oxygen therapy, nutritional support).
* Antibiotics (broad spectrum with good pulmonary penetration initially then based on culture and sensitivity)
What causes bacterial pneumonia?
Primary pathogens (Bordetella bronchiseptica or Streptococcus equi subspecies zooepidemicus)
* Can be secondary to underlying pulmonary disease
What are the clinical signs of bacterial pneumonia?
Productive cough. Dyspnoea and tachypnoea.
* Lethargy and pyrexia. Anorexia.
* Exercise intolerance
How would you diagnose bacterial pneumonia?
History
* Radiography. Focal, multifocal, or diffuse alveolar pattern.
* Ultrasound. Good for imaging area of consolidation and checking for abscessation
How would you treat bacterial pneumonia?
Address underlying cause (e.g., FB removal, continue to manage chronic disease).
* As for aspiration pneumonia
What is lungworm (in dogs) ?
Parasitic infection, with Angiostrongylus vasorum. Present throughout the UK. Dogs in
close contact with foxes (reservoir host) and/or those that habitually ingest snails, slugs
or frogs are at higher risk
What are the clinical signs of lungworm in dogs?
Can be subclinical or non-specific (lethargy, weight loss, vomiting)
* Pulmonary (most common presentation coughing, exercise intolerance, dyspnoea,
hypernoea).
* Coagulopathy (anaemia, haemorrhages (scleral/conjunctival/retinal etc, neurological
signs if bleeding in the CNS).
* Cardiovascular (rare, can include myocarditis, heart murmurs, heart failure)
How would you diagnose lungworm in dogs?
Clinical signs.
* Radiography (Diffuse bronchial thickening with an interstitial
lung pattern, focal (often peripheral) alveolar infiltrates.
Variable and non-specific).
* Various diagnostic tests available (Angio Detect TM (Idexx),
inhouse Baermann’s, BAL cytology and PCR
How would you treat lungworm in dogs?
Moxidectin– imidacloprid (spot on, two doses one month apart)
or Milbemycin (once weekly for 4 weeks).
* Fenbendazole (25-50 mg/kg once daily for 5-21 days. Not
licensed for A.vasorum treatment).
* Supportive treatment as appropriate for clinical presentation
What is idiopathic pulmonary fibrosis also known as?
Westie lung disease’. Chronic and progressive interstitial lung disease.
* Unknown aetiology, mainly affecting older West Highland White Terriers (WHWTs)
What are the clinical signs of idiopathic pulmonary fibrosis known as?
Insidious onset and progression.
* Coughing.
* Panting.
* Respiratory distress, tachypnoea.
* Distinctive ‘Velcro crackle’ on auscultation.
* Cyanosis with minimal exertion.
* Weakness and syncope.
* Can cause pulmonary hypertension so may hear low-grade right-sided systolic heart murmur
How might you diagnose idiopathic pulmonary fibrosis?
Signalment (middle aged – older WHWT).
* 6- minute walking test and Arterial blood gas.
* Non-specific findings on radiography, bronchoscopy and BAL.
* Increased lung opacity on CT (better than radiography
How might you treat idiopathic pulmonary fibrosis?
Currently no effective treatments.
* Aimed at reducing clinical signs and reduce complications.
* Corticosteroids and theophylline recommended.
* Median survival was reported to be 32 months (range 2–51 months) from the onset of clinical signs
and 11 months (range 0–40 months) from diagnosis
Why are URT diseases in rabbits so important?
Obligate nasal breathers.
* URT compromise can therefore result in more significant, stressful and
debilitating disease in rabbits compared to other species.
* URT disease can be primary or secondary.
* Often termed ‘Snuffles’. Group of clinical signs relating to any infectious
cause of URT disease.
* Usually bacterial but viral and fungal causes possible.
* Dental disease, trauma, FBs and neoplasia can also cause URT disease
signs
What pathogen is implicated in rabbit URT disease?
Pateurella multocida
How may rabbit infections in URT disease extend
Infection may also extend from the nasal and paranasal cavities to the surrounding tissues including the nasolacrimal duct, conjunctivae, eustachian tubes, middle ear, inner ear and LRT
How does rabbit infection usually arise?
Infection usually as a result of contact with infected individuals, either directly or in directedly (hands/fomites)
What is usually a major factor in rabbit disease progression and severity?
Poor Husbandry
What are the clinical signs of snuffles?
- Nasal and ocular discharge
- Snuffling, Sneezing and increased respiratory rate
- Matted fur
- Dyspnoea
- Epiphora
- Head shaking/ Head tilting
- Non-specific signs (E.g weightloss, lethargy)
How might you diagnose an URT in rabbits?
- Full clinical exam
- Haematology and Biochemistry
- Deep nasal swab
- Radiography (dental disease)
- Endoscopy
- CT
- Ultrasound (useful to rule out cardiac disease)
How many days of treatment do rabbits require?
14 days
What medication should you avoid in rabbits as first line?
fluoroquinolones
When should surgery in rabbits be performed?
- Severe cases of chronic nasal bacterial infection
- can be performed to enable debridemnt
- flushing of affected tissues
What is the main issue with LRT diseases in rabbits?
No septa dividing lungs so lung diseases usually generalised.
* Respiration mainly diaphragmatic so increased intra-abdominal pressure can impair breathing
What are the clinical signs of LRT in rabbits?
Dyspnoea
* Wheezing
* Abnormal respiratory sounds
How would you diagnose LRT in rabbits?
- Radiography/ Ultrasound
- Tracheal wash
