Veterinary Medicine Quiz on Rhinitis and Shelter Care

Upper Respiratory Disease: Nasal Passage

• Presentation is by Amber Harris, DVM, DACVIM(SAIM), Clinical Assistant Professor, VETM5291, CRH II, on January 17, 2025.

Objectives

• Differentiate unilateral vs. bilateral nasal discharge.
• List differentials for various types of nasal discharge (serous/serosanguinous, mucopurulent, and hemorrhagic).
• Discuss diagnostic tests for nasal disease, including their pros and cons.
• Explain lymphoplasmacytic rhinitis (LPR) management in dogs and cats, including owner expectations.
• List common infectious nasal diseases in dogs and cats (e.g., fungal, viral, bacterial).
• Discuss treatment recommendations for these nasal diseases.
• Discuss nasopharyngeal polyps diagnosis, treatment, and outcome in cats.

Outline

• Review of brief physical exam and clinical findings.
• Nasal discharge analysis.
• Categorization of disease processes: inflammatory/immune-mediated, infectious, and non-neoplastic masses.

Clinical Findings

• Sneezing: paroxysmal?, intermittent?, reverse?
• Nasal discharge: symmetry?, character?, onset/duration?, progression?
• Other clinical findings: inciting causes/triggers?, stertor, reduced appetite (especially in cats), dysphagia, pawing/rubbing face, masses/facial distortion, nasal planum ulceration, seizures.
• Review Nasal Discharge Review slides on eLC.

Physical Examination

• Ocular retropulsion.
• Checking nasal patency.

Reverse Sneeze

• Irritation to the nasopharyngeal mucosa.

Nasal Discharge

• Unilateral: Neoplasia, tooth root abscess, foreign body, fungal, trauma.
• Bilateral: Inflammatory rhinitis, systemic disease (hypertension, coagulopathy), infectious (secondary bacterial, viral), highly erosive disease, fungal (Aspergillus, Cryptococcus), severe trauma.

Serous/Serosanguinous Discharge

• Most nasal discharge initially starts serous.
• Often associated with viral, allergic, or inflammatory rhinitis.
• Early sign of fluid overload.
• "Sanguineous" discharge indicates disease progression, chronic mucosal irritation, and mucosal erosion/destruction.

Mucopurulent/Mucoid Discharge

• Often indicates a secondary bacterial infection.
• Primary nasal bacterial infections are very rare.
• Chronic inflammation often increases mucus production.
• Puppies may have distemper on the differential list.
• May be an early indicator of developing pneumonia.

Nasal Discharge Progression

• Commonly progresses from serous to serosanguinous.
• Chronic mucosal irritation and inflammation, mucosal erosion.
• May transition to mucoid or mucopurulent due to chronic inflammation plus secondary bacterial infections (impaired host defenses).

Hemorrhagic (Epistaxis) Discharge

• Indicates erosive diseases, neoplasia, fungal (Aspergillosis), or trauma.
• Also a sign of systemic disease like coagulopathy (inherited or acquired), platelet disorders (thrombocytopenia, rickettsial diseases, immune-mediated thrombocytopathia), hypertension, vasculitis, or hyperviscosity syndrome.

Inflammatory/Immune-Mediated Disease Processes

• Lymphoplasmacytic rhinitis (LPR): Immune-mediated disease of unknown, possibly multifactorial, cause.
• Aberrant immune response and dysfunctional PRRs (pattern recognition receptors) are possible causes.
• Chronic exposure to allergens, irritants, and infections.
• Seasonal allergies, previous Feline Herpes virus, hypersensitivity manifestation, and environmental/commensal fungi are also considered.
• Expansion of atopy, IBD are possibilities.
• In dogs and cats, typically affects middle-aged individuals, with dolichocephalic breeds (like Dachshunds) potentially over-represented.
• Clinical signs include chronic bilateral nasal discharge (often serous to mucoid), nasal congestion (stertor), and possible open-mouth breathing or sneezing; cats may have reduced appetite.

LPR Diagnosis

• Diagnosis of exclusion: Ruling out other diseases or triggers.
• Definitive diagnosis: CT scan (thickened turbinates and fluid), Rhinoscopy (mucus and hyperemia), and nasal biopsy with histopathology.
• Possible concern for secondary bacterial infection.
• Significance of muco-purulent discharge.
• Histopathological examination for neutrophilic inflammation in nasal samples.
• Culture of nasal tissue is used for determining the specific bacterial type.

LPR Management

• Difficult to manage; not curable.
• Set client expectations, goal: improved clinical signs.
• Commonly used protocols include antihistamines (often not helpful), anti-inflammatories, immunosuppression, and immune modulation.
• Consider antibiotics if secondary infections are present.
• Glucocorticoids (e.g., oral prednisone/prednisolone; anti-inflammatory dose).
• Immunosuppression (dogs- maybe helpful; cats, often well).
• If steroids improve signs, consider inhaled or topical treatments.

Other Management Considerations

• Treating secondary infections based on tissue culture and sensitivity testing, environment modification (especially avoiding triggers such as cigarette smoke, perfumes/air fresheners, dusty litter), and humidification.

Infectious Disease Processes

• Fungal rhinitis (Cryptococcus neoformans): Worldwide distribution, found in bird droppings.
• Possible nasal granuloma, cutaneous lesions, and systemic involvement in cats.
• Possible CNS involvement in dogs.
• Cryptococcus Diagnosis: Cytology of nasal discharge (yeast with thick non-staining capsule detected via serum latex agglutination testing (SLA) for detecting capsular antigens.
• Treatment: Surgical debulking plus oral antifungal medication (itraconazole or fluconazole).
• Severe/CNS disease potentially requires amphotericin B.
• Aspergillus fumigatus: Sino-nasal disease of dogs, characterized by often unilateral mucoid nasal discharge.
• This can be hemorrhagic (epistaxis).
• This pathogen can involve the nasal planum (depigmentation).
• Affected breeds: German shepherds and Rottweilers; cats may have sino-orbital involvement.

Aspergillosis Diagnosis

• Nasal CT scan: loss of nasal turbinates, fluid and debris in sinuses, possible bone destruction. Specifics such as the orbital bones, palate, and frontal sinus can be examined. The possibility of the fungus invading the cribriform plate and central nervous system (CNS) needs evaluation.
• Rhinoscopy: Visualizing plaque (white, gray, necrotic) which might appear metallic. Samples are examined via cytology and fungal culture.

Aspergillosis Treatment

• Isolated to nasal passages: debulking plus topical clotrimazole (80-85% and >90% success after 1 and 2 treatments respectively).
• Infiltrative/CNS involvement: Topical clotrimazole (with caution regarding liquid formulations), plus oral antifungals (itraconazole or terbinafine). Success is less likely.

Feline Upper Respiratory Disease Complex

• Viral: Feline herpesvirus-1, Feline calicivirus, Influenza, Covid-19.
• Bacterial: Mycoplasma species, Bordetella bronchiseptica, Chlamydia felis.

Primary Infections

• Most often viral (Feline herpesvirus-1 and Feline calicivirus represent >80% of cases).
• Co-infections with Mycoplasma species, Bordetella bronchiseptica, Chlamydia felis, Streptococcus canis, and Streptococcus equi subsp zooepidemicus are common.

Secondary Infections

• Most commonly bacterial (Streptococcus sp., Staphylococcus sp., Pasteurella multocida, Escherichia coli).
• May present with mucopurulent discharge, systemic signs, and patient illness (e.g., fever, tachypnea).
• Uncommon in every case.

Pathogen Generalities

• Pathogen transmission: shedding from oculo-nasal/oral secretions, direct contact, mutual grooming, overcrowding, fomites (bowls, cages, toys).
• Aerosolization is a danger over ~4 feet.
• Morbidity is high, and mortality rates are low.

General Clinical Signs

• Possible oculo-nasal discharge (serous-to-mucopurulent), squinting (conjunctivitis), sneezing (keratitis- rhinitis), stertor (nasal congestion), possible systemic illness or lower airway signs, and/or death (primarily seen in kittens).

Feline Herpesvirus (FHV-1)

• Large, enveloped, dsdNA alphaherpesvirus.
• Minimal strain variation. Similar to canine type.
• Fragile outside host. Easily disinfected.
• Most cats exposed during their lifetime.
• May develop URTIs, dendritic ulcerations, and ulcerative/eosinophilic dermatitis.

Feline Calicivirus (FCV)

• Small, unenveloped ssRNA.
• Survives outside the host for ~30 days, resisting usual disinfection.
• Shed continuously following infection, with 45% shedding for <30 days, 45% shedding for >75 days, and ~10% becoming chronic carriers.
• Known to cause URTI, oral/nasal planum ulcerations, and reported lameness.

Virulent Systemic FCV

• Unique, uncommon strain, high pathogenicity, and high mortality.

Chlamydia felis

• Obligate intracellular bacteria, primitive with few metabolic pathways.
• Most common in ~2-12 month old cats.
• Induces only conjunctivitis plus possible chemosis and blepharospasm.

Other Pathogens

• Bordetella bronchiseptica: gram-aerobic coccobacillus, rarely causes coughs in cats.
• Mycoplasma species: fastidious organisms lacking cell walls, often part of a co-infection, potential opportunistic pathogens. Can be associated with signs like lower respiratory infections.

URTI Diagnosis

• History of known exposure.
• Clinical signs and exam.
• Unique associations: lightning bolt corneal ulcers, coughing in other dogs, conjunctivitis only, or URTI + systemic illness.
• PCR/organism identification.
• Oronasal/conjunctival swab.
• Important considerations.

Viral URTI Management

• Stress avoidance.
• Supportive care. Partial anorexia? Warm, smelly food; clean nose; systemically ill? Fluid, nutritional support; Treat secondary infections.
• Relative isolation
• Remember most cases are viral; signs are mild and self-limiting. There are no consistently effective primary therapies.

Viral URTI Management (Antibiotics?)

• Viral infections are the most common cause in ~80-90% of cases.
• Secondary bacterial infections as a possible differential.
• Antibiotic selection as a treatment for secondary bacterial infections. Examples of therapies: Lysine, Famciclovir, FVRCP vaccine (minimal protection, reduces disease severity/duration).

Disease Processes—Non-Neoplastic Masses

• Nasopharyngeal polyps (NPs): Originate in the middle ear or auditory tube, sometimes extending into the ear canal, and sometimes into nasopharynx.
• Composed of fibrovascular granulation tissues covered by epithelium. Minimal inflammation. Can have ulceration.
• Fatty/avascular stalk.
• Affecting young cats (often <1 yr).
• Clinical signs: stertor, bilateral mucoid nasal discharge, dysphagia, regurgitation, and /or meow modification. Possible vestibular signs.

NP Polyp Diagnosis

• Visualize polyp under heavy sedation during anesthesia using spay hooks to pull rostrally through the soft palate.

NP Polyp Treatment

• Traction avulsion (“Grab and Rip”).
• Possible Horner's Syndrome after removal in ~43% of cases (particularly likely if surgery was required), characterized by miosis, ptosis, enophthalmos, and third eyelid protrusion.
• Recovery typically occurs within 1-4 weeks.

Traction Avulsion Success

• ~41% recurrence rate reported, higher when bullae involvement occurs.
• Aural involvement is a more common cause for recurrence than the nasopharyngeal involvement.
• Following treatment with glucocorticoids (like prednisolone at 0.5-1 mg/kg/day) over 6-8 weeks, recurrence risk drops.
• Recurrence commonly seen between approximately 19 days and up to 9 months post-treatment.

Outbreak Prevention/Management: Shelter Medicine

• General considerations for shelter medicine.
• Quarantine of incoming animals.
• Minimal stress-inducing modifications to the shelter environment/practices.
• Dedicated cages, low-stress traffic areas, and hiding spaces.
• Cages separated by > 4-5 feet.
• Consider impermeable separation between cages?
• Immediate disinfection is important, plus clean equipment, PPE for staff, and visitor precautions.

How to Protect the Practice From an Outbreak

• Advanced screening/scheduling for minimizing risk.
• Treatment of URTIs on an outpatient basis.
• URTI suspect animal patients should be isolated upon arrival.
• Appropriate handling/transport in carriers.
• Limiting the number of staff involved in caring for URTI patients.
• Disinfecting equipment (stethoscopes, thermometers, etc) after contact with affected patients.
• Disinfection of the rooms and prompt clean up of soiled equipment/materials.

Disinfection/Prevention Practices

• Disinfection with diluted bleach (1:32). Diluted bleach is 1/2 cup of bleach per gallon of water.
• Potassium Peroxymonosulfate (Virkon Trifectant).
• Accelerated Hydrogen Peroxide (Accel).
• Good hygiene: hand washing (with sanitizers, including 60-90% alcohol) and PPE to prevent contamination of equipment.

Further Considerations

• Questions?
• Contact information: [email protected]