Respiratory System
-
Respiratory System IntroductionThe respiratory system begins at the nose and ends at the distal alveoli. It is comprised of the upper and lower airways. The upper airway includes the nose, sinuses, and pharynx. The nose provides olfaction and temperature regulation in hyperthermic patients. The nasal turbinates initially humidify and warm air, and filter particulate matter. The lower airways include the trachea, bronchi, bronchioles, and alveoli. The primary function of the respiratory system is to deliver oxygen to the lungs to be exchanged with carbon dioxide.
-
Aspiration Pneumonia in Large AnimalsFor discussion of aspiration pneumonia in small animals, see Respiratory Diseases of Small Animals.
-
Diaphragmatic HerniaDiaphragmatic hernia is protrusion of abdominal organs or tissue through a congenital opening or traumatic rupture in the diaphragm. This may cause respiratory signs or may be subclinical. Thoracic radiography is highly diagnostic, and treatment centers on stabilization and surgical repair.
-
Fungal PneumoniaFungal infections occur more commonly in dogs than cats and even less frequently in large animals. Clinical signs include chronic cough, acute respiratory distress, and lethargy. Diagnosis can be made by serologic testing or detection of fungal antigens in urine (for Histoplasma and Blastomyces). Treatment includes systemic antifungal medication, oxygen, and sometimes anti-inflammatory medications.
-
Laryngeal DisordersLaryngeal disorders are characterized by stertorous breathing and can often lead to death if untreated. The mainstay of treatment is steroids or NSAIDs. Presumptive diagnosis is largely based on clinical signs.
-
Lungworm InfectionLungworm infection, also known as verminous bronchitis or verminous pneumonia, is an inflammatory disease of the lower respiratory tract caused by a variety of nematodes. Coughing and dyspnea are the most common clinical signs, which can be exacerbated by concomitant bacterial or viral infections. The Baermann technique is used to detect first-stage larvae in fecal samples. In some countries, an ELISA test is available to detect antibodies against Dictyocaulus viviparus; however, interpretation is hampered by persistent titers. Treatment and control of bovine lungworm is achieved primarily via strategic use of anthelmintics, although an orally administered vaccine is available in some countries.
-
PharyngitisPharyngitis is an inflammatory condition of the oro- or nasopharynx. It develops secondary to viral or bacterial infections of the upper respiratory tract. Clinical signs of pharyngitis include upper respiratory tract noise, nasal discharge, coughing, and occasionally dysphagia. The diagnosis of pharyngitis is confirmed with upper airway endoscopy. Treatment of pharyngitis includes administration of antimicrobials and anti-inflammatories and restriction of exercise.
-
Pulmonary EmphysemaPulmonary emphysema is one of the two conditions under the umbrella term chronic obstructive pulmonary disease (COPD), with the other being chronic bronchitis. Pulmonary emphysema is identified by marked overdistention of alveoli along with destruction of supporting alveolar and interstitial structures. Computed tomography is currently the best way to diagnose the disease, and treatment includes a combination of bronchodilators and anti-inflammatory medications. Because it causes permanent damage, prevention is key.
-
Respiratory Diseases of CattleRespiratory disease is among the most economically important diseases of cattle in production on a worldwide basis.
- Overview of Respiratory Diseases of Cattle
- Allergic Rhinitis and Enzootic Nasal Granuloma in Cattle
- Sinusitis in Cattle
- Necrotic Laryngitis in Cattle
- Tracheal Edema Syndrome of Feeder Cattle
- Bovine Respiratory Disease Complex
- Enzootic Pneumonia of Calves and Shipping Fever Pneumonia
- Viral Respiratory Tract Infections in Cattle
- Bacterial Pneumonia in Cattle
- Contagious Bovine Pleuropneumonia
- Interstitial Pneumonia in Cattle
- Acute Bovine Pulmonary Emphysema and Edema
- Anaphylaxis in Cattle
- Hypersensitivity Pneumonitis in Cattle
- Diffuse Fibrosing Alveolitis in Cattle
- Acute Respiratory Distress Syndrome of Feedlot Cattle
- 4-Ipomeanol Toxicity (Moldy Sweet Potato) and Perilla Ketone Toxicity (Purple Mint Toxicity) in Cattle
- Toxic Gases in Respiratory Disease of Cattle
- Vena Caval Thrombosis and Metastatic Pneumonia in Cattle
-
Respiratory Diseases of HorsesViral respiratory infections are common in horses; the most notable are equine herpesvirus infection, equine influenza, and equine viral arteritis. The clinical manifestations are similar and include pyrexia, serous nasal discharge, submandibular lymphadenopathy, anorexia, and cough. In addition to respiratory disease, equine herpesvirus type 1 (EHV-1) can cause abortion and neurologic disease, and equine herpesvirus type 5 (EHV-5) is a newly recognized cause of multinodular pulmonary fibrosis. Equine viral arteritis produces respiratory disease, vasculitis, and abortion. Equine herpesvirus type 2 (EHV-2), equine rhinitis virus, and reovirus are ubiquitous viral respiratory pathogens, and infection results in minimal clinical disease. Adenovirus pneumonia is most often seen in association with severe combined immunodeficiency in Arabian foals. Hendra virus ( All.see page Hendra Virus Infection) is a zoonotic disease of horses identified in Australia; it is rapidly fatal in horses, and close contact is necessary for disease transmission.
- Overview of Respiratory Diseases of Horses
- Equine Herpesvirus Infection
- Equine Influenza
- Equine Viral Arteritis
- Hendra Virus Infection in Horses
- Pleuropneumonia in Horses
- Rhodococcus equi Pneumonia in Foals
- Acute Bronchointerstitial Pneumonia in Foals
- Strangles in Horses
- Recurrent Airway Obstruction in Horses
- Inflammatory Airway Disease in Horses
- Exercise-Induced Pulmonary Hemorrhage in Horses
- Laryngeal Hemiplegia in Horses
- Pharyngeal Lymphoid Hyperplasia in Horses
- Dorsal Displacement of the Soft Palate in Horses
- Epiglottic Entrapment in Horses
- Subepiglottic Cyst in Horses
- Fourth Branchial Arch Defect in Horses
- Diseases of the Nasal Passages in Horses
- Diseases of the Paranasal Sinuses in Horses
- Guttural Pouch Disease in Horses
-
Respiratory Diseases of PigsRespiratory diseases of pigs can be classified into two broad categories based on the extent and duration of overt disease: those that affect large numbers of pigs and may be serious but of limited duration, and those that persist in a large number of pigs for indefinite periods. Diseases in the first category can be costly, but the losses are limited rather than ongoing. They include swine influenza, classical swine fever, the pneumonic forms of pseudorabies, porcine circovirus-associated disease, and porcine reproductive and respiratory syndrome (PRRS). The causal viruses may persist in a herd, but outbreaks of overt disease tend to be self-limiting.
-
Respiratory Diseases of Sheep and GoatsLarvae of the sheep nasal botfly (Oestrus ovis) develop in the nasal sinuses of sheep. Signs of infestation include nasal discharge and sneezing. Rarely, more serious disease develops. Antiparasitic treatment with ivermectin is effective.
-
Respiratory Diseases of Small AnimalsA varying flora of indigenous commensal organisms (including Pasteurella multocida, Bordetella bronchiseptica, streptococci, staphylococci, pseudomonads, and coliform bacteria) normally reside in the nasal passages, nasopharynx, and upper trachea, and at least intermittently in the lungs of dogs and cats, without causing clinical signs. Opportunistic infections by these bacteria may occur when respiratory defense mechanisms are compromised by infection with a primary pathogen (eg, distemper, parainfluenza virus, or canine type 2 adenovirus in dogs, and rhinotracheitis virus or calicivirus in cats), other insults (eg, inhalation of smoke or noxious gases), or diseases such as congestive heart failure and pulmonary neoplasia.
- Overview of Respiratory Diseases of Dogs and Cats
- Allergic Pneumonitis in Dogs and Cats
- Canine Influenza (Flu)
- Canine Nasal Mites
- Feline Bronchial Asthma
- Feline Respiratory Disease Complex
- Kennel Cough
- Lung Flukes in Dogs and Cats
- Lung Nematodes in Small Animals
- Neoplasia of the Respiratory System in Dogs and Cats
- Pneumonia in Dogs and Cats
- Pulmonary Thromboembolism in Dogs and Cats
- Rhinitis and Sinusitis in Dogs and Cats
- Tonsillitis in Dogs and Cats
