Respiratory issues are common medical problems in dogs. Some breeds such as brachycephalic dogs like Pugs and Bulldogs are prone to breathing difficulties due to their shortened airways. However, respiratory problems can occur in any breed. Common respiratory conditions in dogs include kennel cough, pneumonia, collapsed trachea, laryngeal paralysis, and allergic airway disease. Symptoms of respiratory distress include coughing, wheezing, labored breathing, nasal discharge, and exercise intolerance.
There are several types of medications used to help open up the airways and improve breathing in dogs with respiratory conditions. Bronchodilators relax smooth muscle around the airways and help expand the airways. Corticosteroids reduce inflammation. Antihistamines block the effects of histamine released during an allergic response. Other therapies like cough suppressants, mucolytics, and bronchial lavage can also provide relief.
This article will provide an overview of common respiratory medications used in dogs, their mechanisms of action, and when they might be prescribed to help open up airways.
Anatomy and Physiology
The canine respiratory system is made up of the upper respiratory tract (nose, nasal cavity, throat) and the lower respiratory tract (trachea, bronchi, lungs). Air enters through the nose and passes through the pharynx, larynx, and trachea before reaching the lungs (Anatomy of the Canine Respiratory System).
Within the lungs, air passes through smaller and smaller bronchioles until it reaches the alveoli, where gas exchange occurs. The alveoli are surrounded by capillaries, allowing oxygen to diffuse into the bloodstream and carbon dioxide to diffuse out (The Respiratory System in Animals).
Airflow is regulated through breathing movements involving the diaphragm and intercostal muscles. The size of the bronchioles can also be adjusted to control airflow and ventilation.
Common Respiratory Conditions
Dogs can suffer from a variety of respiratory conditions that affect the upper and lower airways. Some of the most common include:
Kennel Cough
Kennel cough, also known as infectious tracheobronchitis, is a highly contagious upper respiratory infection in dogs caused by bacteria and viruses like parainfluenza and Bordetella bronchiseptica. It’s named kennel cough because it often spreads quickly in kennels, shelters, doggy daycares, and other crowded dog facilities. Symptoms include a forceful, honking cough along with sneezing, nasal discharge, lethargy, and loss of appetite. Most cases clear up on their own, but antibiotics may be prescribed in severe cases. Vaccination can help prevent infection (Merck Veterinary Manual).
Canine Influenza
Canine influenza is a highly contagious respiratory infection caused by canine influenza viruses H3N8 and H3N2. It spreads through coughing, barking, sneezing, or contact with contaminated objects. Symptoms resemble kennel cough, along with fever, lethargy, eye discharge, and reduced appetite. Most dogs recover fully in 2-3 weeks with rest and supportive care. Vaccines can help prevent infection (Trudell Animal Health).
Allergic Rhinitis
Allergic rhinitis refers to inflammation of the nasal passages caused by allergies to things like pollen, mold, dust mites, and dander. Symptoms include sneezing, nasal discharge, scratching at the nose and face, and reverse sneezing. Mild cases can be managed by avoiding triggers and using antihistamines. Severe cases may require prescription medication and immunotherapy (Cornell University Veterinary Specialists).
Laryngeal Paralysis
Laryngeal paralysis affects the larynx or “voice box” and causes noisy breathing, gagging, and difficulty panting. It’s most common in older, large breed dogs. Treatment ranges from lifestyle changes to surgery depending on severity. Prognosis is generally good with appropriate treatment (Merck Veterinary Manual).
Medications to Open Airways
There are several types of medications that veterinarians commonly prescribe to open up airways in dogs with respiratory conditions like asthma, bronchitis, collapsing trachea, and allergies. The main drug classes used are bronchodilators, corticosteroids, and antihistamines.
Bronchodilators work by relaxing the muscles around the airways to help open them up and make breathing easier. Common bronchodilators prescribed for dogs include:
- Albuterol – This beta-2 agonist helps expand constricted airways and is often used to treat acute asthma attacks. It’s available in oral tablet and inhaler formulations (source: https://www.vin.com).
- Theophylline – This drug relaxes airway smooth muscle and is used to control chronic asthma. It comes in oral tablet and liquid forms (source: https://www.merckvetmanual.com).
Corticosteroids like prednisone and dexamethasone reduce airway inflammation. They can be given orally or by injection. Corticosteroids are often prescribed alongside bronchodilators for conditions like severe asthma (source: https://www.ncbi.nlm.nih.gov).
Antihistamines such as diphenhydramine block histamine release to help control allergy symptoms. They can provide relief for dogs with allergic respiratory issues and may be paired with other medications (source: https://www.merckvetmanual.com).
Bronchodilators
Bronchodilators are medications that open up the airways and make breathing easier by relaxing the muscles around the bronchial tubes. They work by stimulating beta-2 adrenergic receptors which leads to bronchial smooth muscle relaxation. This allows more air to flow through the airways.
Some common bronchodilators prescribed for dogs include:
- Albuterol – This beta-2 agonist provides quick, short-term bronchodilation. It is often used for acute episodes of bronchospasm. Brand names include Ventolin and Proventil.
- Terbutaline – Another fast-acting bronchodilator in the beta-2 agonist class. It is commonly used to treat bronchospasms.
- Theophylline – This is a methylxanthine bronchodilator that provides sustained dilation of the bronchi. It takes longer to act but has a more prolonged effect. The brand name Theo-24 is commonly prescribed for dogs.
Bronchodilators are very effective for opening constricted airways and improving respiration. However, they do not address any underlying inflammation or infection. They are often used alongside other medications like corticosteroids and antibiotics to provide comprehensive treatment of respiratory diseases in dogs.
Sources:
[Drugs Used to Treat Lung and Airway Disorders] (https://www.merckvetmanual.com/special-pet-topics/drugs-and-vaccines/drugs-used-to-treat-lung-and-airway-disorders)
[Theophylline – VCA Animal Hospitals] (https://vcahospitals.com/know-your-pet/theophylline)
Corticosteroids
Corticosteroids such as prednisone, prednisolone, dexamethasone, and budesonide are commonly used to help open airways in dogs with respiratory conditions. These medications have powerful anti-inflammatory effects that reduce swelling, mucus production, and airway constriction (Bexfield et al., 2006). Corticosteroids can be administered orally, intravenously, or through inhalers directly into the lungs (Chan et al., 2023).
While corticosteroids are very effective at controlling inflammation, they do carry potential side effects. These may include increased thirst and urination, increased appetite and panting, gastrointestinal upset, and immune suppression. Dogs on corticosteroids should be monitored for signs of infection and have liver enzymes tested periodically (WSAVA, 2005). By using the lowest effective dose and shorter treatment courses when possible, vets try to balance effectiveness with minimizing side effects.
Antihistamines
Antihistamines can help reduce airway inflammation and open airways in dogs with conditions like allergies or asthma. They work by blocking the release of histamine, which is a chemical released by the body during an allergic reaction. Histamine causes inflammation and narrowing of the airways.
Some commonly used veterinary-approved antihistamines for dogs include:
- Diphenhydramine (Benadryl®) – This blocks the H1 histamine receptor and is effective at reducing many allergy symptoms including nasal congestion and sneezing. It can cause drowsiness so it is often used at night. The dosage for dogs is 1-2 mg per pound every 8-12 hours [1].
- Cetirizine (Zyrtec®) – Another H1 blocker that is less sedating than diphenhydramine. The dosage for dogs is generally 1/2 a 10 mg tablet (5 mg) per 20 pounds every 24 hours [2].
- Loratadine (Claritin®) – Also causes less drowsiness than diphenhydramine. The dosage for dogs is generally 1 mg per pound every 24 hours.
While antihistamines can provide symptom relief, they do not treat the underlying cause of respiratory inflammation. For long-term management, other medications are often needed as well.
Other Supportive Therapies
In addition to medications, other supportive therapies can help open airways and ease breathing in dogs with respiratory disease.
Humidification adds moisture to the air, which can help loosen mucus secretions in the airways. This can be achieved through the use of humidifiers or by taking a dog into a steamy bathroom. According to the ASPCA, the moisture and warmth from humidification therapy may soothe inflamed airways.1
Coupage is a technique involving rhythmic clapping or percussion along the sides of the chest wall and briskly rubbing the chest wall and airways. This can help loosen and mobilize mucus secretions stuck in the airways so the dog can cough them up. According to the NCBI, coupage may provide some relief in cases of thick mucus obstructing airways.2
Ensuring adequate rest is also important, as activity can exacerbate coughing and breathing difficulties. Restricting activity and exercise helps reduce respiratory effort in dogs with compromised airways.
When to See the Vet
If your dog is having trouble breathing or not improving with medication, it’s important to schedule a veterinary appointment right away. Labored breathing and respiratory distress are signs that your dog needs immediate medical attention. Other concerning symptoms that warrant a vet visit include:
- Fever
- Lethargy or lack of energy
- No improvement with bronchodilators or other medications
- Worsening cough
- Nasal discharge
- Rapid or shallow breathing
- Blue gums or tongue
Veterinary assessment is crucial for dogs with respiratory disease to determine the underlying cause and severity. Diagnostic tests like bloodwork, imaging, and airway cytology may be recommended. Oxygen therapy, nebulization, and hospitalization may be necessary for dogs in respiratory distress.
Never hesitate to call your vet if your dog is showing signs of labored breathing, coughing, or lethargy. Waiting too long with respiratory problems can be dangerous. Your vet will advise you on the best treatment options and whether emergency care is needed.
Summary
In summary, there are several types of medications that can help open airways in dogs with respiratory conditions. The most common are bronchodilators like albuterol and theophylline, which relax the airway muscles. Corticosteroids like prednisone reduce inflammation. Antihistamines like diphenhydramine can be used for allergic airway disease. Other therapies like coupage, oxygen, and antibiotics may also be prescribed.
It’s important to have your veterinarian accurately diagnose the underlying condition and determine the appropriate treatment plan. Self-medicating dogs with over-the-counter human medications can be dangerous and cause unintended side effects. Respiratory conditions can worsen rapidly, so close monitoring and follow-up care with your vet is essential. If you notice increased coughing, wheezing, or trouble breathing in your dog, contact your veterinarian right away for an exam and to discuss the best medication options for providing relief.
