Pulmonary Hypertension In Dogs

Canine pulmonary hypertension (PH) is a rare, progressive disorder that affects arteries and capillaries of the lungs, i.e. the pulmonary arteries. They travel from the right side of the heart to the lungs and carry de-oxygenated blood to the lungs. Dogs are affected by Pulmonary hypertension when the pulmonary arteries get blocked, thickened, or constricted, leading to an upsurge of pressure in the pulmonary arteries, restricting blood from flowing properly.

An increase in blood pressure in the capillaries of the lungs is also caused by High blood pressure within the left atrium. Moreover, all these results in an increased vascular resistance, where the resistance must be somehow overcome for the blood to circulate to the lungs and the other organs of the body. This can eventually damage the lungs and heart.

Systemic hypertension affects the body completely whereas pulmonary hypertension particularly affects the pulmonary arteries. Pulmonary hypertension is prevalent in all dog breeds, however, most commonly it is seen in smaller breeds.

Pulmonary hypertension in dogs is not a separate disease, but it is caused due to a wide variety of illnesses. The most common cause of this condition is due to defects pertaining to degenerative heart valve diseases and chronic respiratory diseases.

Depending on the underlying cause of the condition, the signs of pulmonary hypertension can vary greatly.

Congenital

• Heart Murmur
• Intermittent Cough
• Fainting (Syncope)
• Exercise Intolerance

Cardiovascular

• Respiratory distress
• Increased heart rate
• Tachypnea - Rapid breathing
• Fluid accumulation in the lungs (pleural effusion)
• Fluid accumulation in the abdomen (ascites)

Inflammatory

• Cyanosis (purple/ blue shaded tongue and gums)
• Lack of appetite
• Collapsing or fainting
• Fatigue
• Weight loss

Infectious

• Difficulty in breathing
• Diarrhea (sometimes bloody)
• Fever
• Frequent thirst
• Frequent urination
• Vomiting

Metabolic

• Abdominal distension
• Loss of appetite/Weight loss
• No interest in exercise

Neoplastic

• Erratic/ Slow/fast/ heart rate
• Vomiting
• Lack of appetite
• Weight loss
• Exercise intolerance

The specific treatment depends on the underlying cause of the pulmonary hypertension

• Medications for PH: Tadalafil (Cialis, Adcirca), pimobendan (Vetmedin, Heartmedin, and Acardi), imatinib (Gleevac), and sildenafil (Viagra, Aphrodil, Revatio, Granpidam, Vizarsin).
• Thromboembolism: Tadalafil (Cialis) or Sildenafil Citrate.
• Pneumonia or bronchitis: Bronchodilators such as Theophylline (Theochron, Theo-24, Theodur, Elixophyllin).
• Congestive heart failure: ACE inhibitors (benazepril, enalapril, ramipril, and imidapril), diuretics like spironolactone, furosemide, etc. Extra medications that might be used are sildenafil, valsartan/ sacubitril/, and torsemide.
• Patent ductus arteriosus: Transarterial PDA coil embolization, Lateral Thoracotomy (intercostal thoracotomy), and Cardiac catheter-based (minimally-invasive surgery) occlusion.
• Pericardial disease: Partial or subtotal pericardiectomy, Pericardiocentesis.
• Diuretics (water pills): Spironolactone, furosemide etc. This is to reduce fluid buildup in the body by eliminating extra fluid and salt.

As a matter of fact, herbal remedies may not solve the problem, but they may help to reduce some of the symptoms.

Herbs: Ginger, Hawthorn, Dandelion, Parsley, Cayenne

Relaxing herbs: Valerian, Chamomile, and California poppy

Dietary Supplements: Vitamins A, B6, C, and E Carnitine-rich foods, L-Taurine, Coenzyme Q10, Magnesium, and Selenium

There are no reliable methods to prevent pulmonary hypertension in dogs, particularly since they are hereditary and in others, the etiology is unknown. However, necessary precautions can be taken to help your dog live a healthy life.

Appropriate diet, Heart and lung healthy exercises, Tick and flea preventatives (Heartworm preventatives), and proper Dental care should be on the priority list for dog owners.

Boxer, Chihuahua, Cocker Spaniel, Doberman Pinscher, Irish Wolfhound, Mastiff, Miniature Schnauzer, Old English Sheepdog, Samoyed, Standard Poodle , West Highland White Terrier, Weimaraner, Small Dog Breeds, Middle Age Dogs, Senior Dogs

1. Causes:

• Cardiac causes: Arrhythmias, Age-related changes to the heart, congenital defects (such as pulmonic stenosis, aortic stenosis), muscles of heart disease (such as arrhythmogenic right ventricular dysplasia/cardiomyopathy, canine dilated cardiomyopathy, hypertrophic cardiomyopathy, etc), myocarditis (heart muscles inflammation), Pericardial disease, patent ductus arteriosus, Pulmonic Stenosis), trauma to the heart muscle (i.e. when a dog gets hit by a vehicle) and valvular diseases (Valvular stenosis, Valvular prolapse) and cardiomegaly (endocardiosis).

• Non-cardiac reasons: Diabetes mellitus, diseases of the spleen, liver, or GI tract, pancreatic inflammation, gastric dilatation volvulus (enlargement and twisting of the stomach due to rapid accumulation of large amounts of air), neurologic disease (i.e. tumors of the brain), low blood magnesium, endocrine disease (i.e., of the adrenal gland, thyroid gland); muscular dystrophy, severe anemia (low red blood cell count); toxins, medications and anesthetic agents.

2. Types:

Primary Pulmonary Hypertension

• Also known as essential or idiopathic hypertension
• No known or underlying cause
• Mostly asymptomatic
• Extremely rare

Secondary Pulmonary Hypertension

• Caused by an underlying disease or disorder
• Symptomatic
• Chronic lung diseases (vasoconstriction, pneumonia, bronchitis, tracheal collapse)
• Pulmonary thromboembolism (large blood clotting)
• Metabolic disorders
• Kidney disease
• Tumors
• Chronic left-lateral congestive heart failure
• Hyperadrenocorticism
• Cushing's disease
• Heartworm disease

3. Mortality:

The untreated pulmonary hypertension shows clinical signs usually within 6 months. Dogs with PH have more than a 50% mortality rate by one year of age if left untreated.

After congestive heart failure has developed due to various causes, Life expectancy is variable and it is typically around 6-14 months.

4. Diagnosis:

• Routine hematology, urinalysis
• Serum chemistry profile
• Electrocardiogram
• Cardiac ultrasound
• Echocardiography

5. Prognosis:

When diagnosed early and given proper treatment for the underlying causes of PH, most dogs live a normal life. Unless there are complications from already developed heart failure or other heart problems, there is rarely any need for medications in the future.

Time to visit the vet clinic for an examination, if you notice any of the following:

• Rapid breathing (known as “tachypnea”)
• Labored breathing
• Abnormal pulses
• Loud heart murmur

Things to consider

• In general, 20 to 30%of dry matter protein required
• On a dry matter (DM) basis, the sodium intake should be restricted to <0.25%, chloride should be restricted to < 0.35% (DM), and potassium <50% DM
• When the household water has more than 150ppm sodium, switch to distilled water
• Cut off Salty Foods, Snacks, crackers, chips, bread, pizza, cheese, other dairy products, etc
• Omega-3 fatty acids(fish oils) and amino acid foods/ supplements
• B vitamins, Vitamin E, co-enzyme Q10, carnitine, and Magnesium

The prognosis for PH in dogs depends on the severity of underlying conditions and earlier detection. This progressive heart condition can be successfully managed with positive treatment plan and many affected dogs can live normal lives, if other complications have not developed.