What to do for cats that cannot breathe (Proceedings)

Cats who cannot breathe are the most fragile patients we treat each day. Cats tend to be more compromised on presentation as they hide their breathing issues better from their owners. It is important to balance diagnostic procedures with therapeutic intervention so that these cats can be quickly stabilized and effectively treated.

This presentation will use case studies to highlight major points.

Emergency presentation

      1) Provide supplemental oxygen. (flow-by oxygen, face mask, nasal oxygen, oxygen cage).

      2) Quickly assess the cat's status (while providing supplemental oxygen). Can the cat handle initial diagnostic tests (chest radiographs, blood work) if the cause is not readily apparent or are interventional measures (oxygen, drugs, thoracocentesis) required?

      3) Perform chest radiographs (NOT whole cat radiographs) if the cat is stable (while providing supplemental oxygen). Also consider an effusion check with ultrasonography if available.

      4) If the cat is not stable, administer emergency drugs (one injectable dose each of a corticosteroid, bronchodilator, and diuretic) (while providing supplemental oxygen). Perform thoracocentesis. Drain both sides of the chest if fluid or air is present and submit fluid for analysis and cultures. If the tap is negative, put any material aspirated on a slide for cytologic analysis.

      5) Perform definitive diagnostics when the cat is more stable, providing supplemental oxygen if needed..

Physical exam findings once the cat has been stabilized

     • Be quick but thorough! Handle with care to prevent decompensation.

     • Minimize handling. Hit the "high points" first. Perform as much of the exam from observation of the cat while it is in the oxygen cage or otherwise receiving oxygen supplementation. (Flow-by oxygen works well initially).

          o Body condition

          o Hydration status

          o Mucous membrane color

          o Heart rate and rhythm, presence of murmur

          o Pulse rate and character

          o Respiratory rate and character; chest compressibility

          o Cough or no cough

          o Type of breathing pattern: obstructive (slow and deep), restrictive (rapid and shallow)

          o Open mouth breathing, panting, increased abdominal effort

          o Nasal congestion, nasal discharge

          o Oral exam

          o Ocular exam

          o Otic exam

          o Palpation of cervical trachea

          o Abdominal palpation

          o Musculoskeletal exam

          o Neurologic evaluation

Historical information can provide important clues and insights into the cat's clinical condition.

     • geography and environment

     • recent exposure to other animals, toxins, irritants, trauma

     • past illness and injuries

     • vaccination and heartworm status

     • description of clinical signs

     • duration of clinical signs

     • presence of coughing or not

     • progression of clinical signs

     • any previous treatment/response to therapy

Rule outs should be based on disease localization.

     • Airway diseases

          o Upper airway: stenotic nares, nasal passage obstruction, nasopharyngeal polyp, laryngeal dysfunction, neoplasia, foreign body, trauma, parasites, inflammation

          o Lower airway: extraluminal compression (lymphadenopathy, cardiac enlargement, heart-based tumors), allergic, inflammatory, infectious, parasitic, neoplasia, airway irritant

     • Pulmonary parenchymal diseases: pneumonia (bacterial, viral, fungal, parasitic, aspiration), edema (cardiogenic, noncardiogenic), neoplasia (primary, metastatic), inflammatory, acute respiratory distress syndrome, hemorrhage (trauma, coagulopathy), pulmonary thromboembolism

     • Pleural diseases: pneumothorax, hemothorax, pyothorax, chylothorax, cardiogenic effusions, neoplasia, peritoneopericardial hernia, FIP

     • Cardiac disease

     • Diaphragmatic diseases: hernia; impingement due to organomegaly, obesity, peritoneal effusions, masses/neoplasia

     • Anemia, Methemoglobuinemia

     • Toxin exposure

     • Neurologic compromise: tick paralysis, botulism, central nervous system disease

Emergency drugs

     • Oxygen, oxygen, and more oxygen.

     • Corticosteriods: Dexamethosone SP 1-2 mg/kg SQ, IV, IM

     • Diuretics: Furosemide 2-4mg/kg SQ, IV, IM

     • Bronchodilators: Aminophylline 4 mg/kg IM

Terbutaline 0.01 mg/kg SQ

Things to consider:

     • Coughing cats = asthma

     • For cats with heart failure, it is better to be aggressive with diuretics and end up with an azotemic patient (can fix azotemia) than a dead patient from pulmonary edema (cannot fix"dead").

Selected readings

Hopper K: Dyspnea, tachypnea, and panting. In Tilley LP, Smith Jr. FWK (ed): The 5-minute Veterinary Consult: Canine Feline, 3rd ed. Philadelphia, Lippincott Williams and Wilkins, 2004, pp 380-381.

Lappin MR: Cough and dyspnea: initial diagnostic plan. In Lappin MR (ed): Feline Internal Medicine Secrets. Philadelphia, Hanley and Belfus, Inc., 2001, pp 28-36.

Mawby D: Dyspnea and tachypnea. In Ettinger SJ, Feldman EC (eds): Textbook of Veterinary Internal Medicine, 6th ed. St. Louis, Elsevier Saunders, 2005, pp 192-195.

Mazzaferro EM: Small airway disease. In Lappin MR (ed): Feline Internal Medicine Secrets. Philadelphia, Hanley and Belfus, Inc., 2001, pp 37-42.