The sneeze and snot of feline nasal disease (Proceedings)

The goal of this presentation is to simply the diagnostic approach and treatment of nasal disease in the feline patient.

Case studies will be utilized in this presentation.

Characterize the nasal disease

     Unilateral or bilateral

     Type of discharge - serous, mucoid, mucopurulent, hemorrhagic

     Duration of disease – acute or chronic

     Response to previous therapy

Consider disease rule-outs

     Dental disease/ tooth root abscess

          Cats – most common tooth affected is the canine tooth

     Foreign object (grass, needle, other)

     Rhinitis/sinusitis

     Nasopharyngeal polyp

     Granulomas

     Nasal/Sinus Infection

          Bacterial – primary pathogens such as Mycoplasma, Chlamydia psittaci, Bordatella bronchiseptica

          Bacterial – secondary bacterial overgrowth (not the primary problem)

          Viral – Feline herpes virus 1, Calicivirus

           Fungal – Cryptococcus neoformans, Aspergillus spp.

          Parasitic – nasal mites

     Pneumonia

     Neoplasia squamous cell carcinoma, adenocarcinoma, lymphoma, fibrosarcoma, osteosarcoma, chondrosarcoma, other

     Dysphagia, vomiting, regurgitation

     Congenital/ palate defects

     Trauma

     Coagulopathy, platelet disorder

     Systemic hypertension

     Vasculitis

Perform a complete physical exam, paying particular attention to

     Checking teeth/ thorough oral exam (hard and soft palate)

     Checking ear canals

     Ophthalmic exam/retropulsion of globes

     Checking patency of nasolacrimal ducts (fluorescein stain)

     Glass slide test to assess nasal airflow (visualize steam on glass slide)

Start diagnostic testing (progress from least invasive to more invasive procedures)

     Obtain minimum database – CBC, biochemistry profile, urinalysis, feline viral tests, blood pressure measurement, chest radiographs

     If discharge is primarily hemorrhagic – blood pressure measurement, coagulation tests (prothrombin time (PT), activated partial thromboplastin time (PTT), or activated clotting time (ACT), platelet count

     Nasal cytology - low yield but may help identify fungal infections

     Viral detection tests – PCR, direct fluorescent antibody staining, virus isolation by culture; document presence of virus; low value for proving disease as many healthy cats are positive

     Laryngeal function exam

     Imaging (Skull radiographs, CT scan) under general anesthesia = Road Map

     Nasal flush - may help remove foreign objects like grass

Nasal culture - helps identify secondary bacterial infections, may occasionally isolate fungal infection; culture of deep tissue obtained by biopsy more useful.

     Nasal biopsy – rhinoscopy allows visualization of lesion(s) and biopsies of the affected areas; biopsies may also be obtained without rhinoscopy

Initiate therapy based on findings:

      Antibiotics

           Doxycycline: 5 mg/kg every 12 hours, give with food

           Clindamycin: 11 mg/kg every 12 hours

           Azithromycin: 5-10 mg/kg every 24 hours for 3-5 days, then every 72 hours

           Azithromycin - Alternate protocol: 5-15 mg/kg every 12 -24 hours for 10 days

           Enrofloxacin or other fluoroquinolone: 2.5-5 mg/kg every 12-24 hours

           Amoxicillin-clavulanate: 11-22 mg/kg every 12 hours

      Antivirals

           L-lysine: 250 - 500 mg every 12 hours

           Interferon alpha: 25 -30 units/day orally; 10,000-20,000 U/kg/day SQ

      Anti-inflammatory agents

           Piroxicam: 1 mg/cat/day, give with food.

           Corticosteriods -Prednisolone 1 mg/kg every 12-24 hours

      Antihistamines

           Cyproheptadine (Periactin) 2 mg every 12-24 hours

           Diphenhydramine (Benadryl) 1-2 mg/kg every 12 hours

           Amitriptyline (Elavil) 5-10 mg/cat every 12-24 hours

           Chlorpheniramine (Claritin) 2-4 mg/cat every 12-24 hours

           Cetirizine (Zyrtec) 5 mg/cat every 12-24 hours

      Antifungal medication

           Ketoconazole: 10 mg/kg once daily

           Itraconazole: 5 mg/kg every 12 hours for 4 days; then 5 mg/kg every 24 hours

           Fluconazole: 50 mg/cat every 12 -24 hours for 8 weeks or 4 weeks past measurable disease

     Intranasal vaccine (Herpes/Calici)

           Initial administration, booster in 2-4 weeks, booster every 3-6 months depending on severity of the disease

     Topical treatments

           Saline flushes

           Topical decongestants

           Topical glucocorticoids

           Topical antibiotics

     Airway humidification

     Chemotherapy

     Radiation therapy

     Surgery

Selected readings

Boothe DM: Principles of drug selection for respiratory infections in cats. Comp Cont Educ Pract Vet 19:5-15, 1997.

Gaskell R, Dawson S: Feline respiratory disease. In Greene CE (ed): Infectious Diseases of the Dog and Cat, 2nd ed. Philadelphia, W.B. Saunders, 1998, pp 97-106.

Greene CE: Respiratory infections. In Greene CE (ed): Infectious Diseases of the Dog and Cat, 2nd ed. Philadelphia, W.B. Saunders, 1998, pp 582-594.

Hahn KA, Anderson TE: Tumors of the respiratory tract. In Bonagura JD (ed): Kirk's Current Veterinary Therapy XIII. Philadelphia, W.B. Saunders, 2000, pp 500-505.

Henderson SM, Bradley K, Day MJ, et al: Investigation of nasal disease in the cat – a retrospective study of 77 cases. J Feline Med Surg 6:245-247, 2004.

Hunt GB, Perkins MC, Foster SF, et al: Nasopharyngeal disorders of dogs and cats: a review and retrospective study. Comp Cont Educ Pract Vet 24:184-200, 2002.

Maggs DJ, Lappin MR, Reif JS, et al: Evaluation of serologic and viral detection methods for diagnosing feline herpesvirus-1 infection in cats with acute respiratory tract or chronic ocular disease. J Am Vet Med Assoc 214:4 502-507, 1999.

Maggs DJ, Naisse MP: Effects of oral L-lysine supplementation on the ocular shedding rate of feline herpesvirus (FHV-1) in cats. Proceedings of the 28th Annual Meeting of the American College of Veterinary Ophthalmology, Santa Fe, NM, November, 1997, p 101.

Michiels L, Day MJ, Snap F, et al: A retrospective study of non-specific rhinitis in 22 cats and the value of nasal cytology and histopathology. J Feline Med Surg 5:279-285, 2003.

Sykes JE, Anderson GA, Studdert VP, et al: Prevalence of feline Chlamydia psittaci and feline herpesvirus 1 in cats with upper respiratory tract disease. J Vet Intern Med 13:153-162, 1999.