The following diagnostic tests are essential in diagnosing and treating your pet's cough. A complete history and physical examination
Chest radiographs (X-rays) with several views: with your pet on his back (dorsoventral) and on his side (lateral). These help to evaluate the heart, blood vessels, lungs, pleural space, or space between the lung and the body wall, diaphragm and mediastinum, which is the area between the left and right lungs.
Radiographs are taken during both inhalation and exhalation to evaluate the airways and lungs. Fluid around the lungs (pleural effusion), lung tumors (neoplasia), or heart failure may be identified.
Complete blood count (CBC), heartworm test and serum biochemistry tests
Fluoroscopy (moving X-ray) or tracheoscopy, which uses a scope inserted into the trachea or windpipe to produce an image, to document airway collapse
Removal of a fluid sample from the chest cavity in cats with pleural fluid. This is called a diagnostic thoracentesis. The fluid is evaluated for cells, bacteria, protein and other constituents and is often sent to a clinical pathologist for analysis.
Additional diagnostic tests may be recommended depending on earlier test results and/or lack of response to initial treatments. Recommendations may include:
Ultrasonography. This is an imaging technique in which deep structures of the body are visualized by recording echoes or reflections of ultrasonic waves. It is performed on the thorax (chest) when heart disease, pericardial effusion (fluid within the sac around the heart), heart-base or mediastinal tumor, hernia or large pleural effusion is suspected.
Serology. This is a blood test of antigen-antibody reactions for toxoplasmosis (a parasitic disease), systemic mycoses (fungus infections) and other infectious agents.
Cytology and culture of respiratory fluid is often done to determine cell type and bacteria present. The exact method depends on clinical condition, breed, clinician experience, availability of equipment and the nature of abnormalities on the chest X-ray. You should discuss the relative risks and benefits of each procedure with your veterinarian.
Tracheal aspiration may be done to obtain a sample of tracheobronchial secretions. The procedure may be done under a local anesthetic or a general anesthetic (asleep). When a local anesthetic is used a needle is inserted through the skin and into the trachea. During general anesthesia a sterile catheter is placed through a sterile, endotracheal tube. Fluid is then obtained.
Bronchoscopy. A scope is used to enter the bronchi to obtain a biopsy and to obtain samples for cell culture and cytology (complete cell study). It provides clear visualization of the trachea and smaller airways.
A fine-needle aspirate (FNA) of the lung is an alternative for assessing the patient with multiple, diffuse (not localized) or very dense lung disease.
Endoscopy. This provides direct visualization of the upper airways, trachea and bronchi using a scope, and is indicated in cases of unexplained airway obstruction or inflammation. Rigid or fiberoptic (coated with flexible glass) endoscopes with brushes and biopsy instruments are used. Following visual inspection, fluid may be flushed into the airway and retrieved for analysis.
Biopsy. Removal of cell or tissue sample of the lung for examination, usually microscopically
Surgery to remove portions of the lung that contain tumors, infection, or foreign material
Direct fecal smears or special sedimentation methods (Baermann) along with fecal flotation to screen for lungworms if X-rays suggest lungworm infection (Paragonimiasis).
Fluoroscopy or tracheoscopy to demonstrate dynamic collapse of a major airway when it cannot be shown by routine X-rays
When the eye, skin or lymph nodes (glands) are abnormal in a cat with chronic cough, specialized tests may be helpful. These can include blood tests, laboratory tests for infectious diseases, biopsy samples or needle aspiration of abnormal tissue.
Esophagoscopy. A scope is inserted into the esophagus and specialized blood tests for myasthenia gravis (skeletal muscle weakness) to diagnose problems of the esophagus that may lead to aspiration pneumonia
The electrocardiogram (EKG), a recording of the heart's electrical action, and echocardiogram, a test recording the movement and position of the heart, are both useful for assessing patients with suspected heart failure or pericardial disease. The pericardium is the sac enclosing the heart.
Consultation with appropriate specialists is recommended when the problem is confusing or difficult to diagnose.