Dogs and Viagra – Safe? [Answered]

Viagra is a popular and frequently used human medication. However, there are certain situations in which veterinarians prescribe human meds, and Viagra is just one example. However, as a dog owner, it is logical to wonder whether Viagra is safe for dogs. 

Will Viagra hurt my dog? No, when used correctly and following the vet’s directions, Viagra is perfectly safe for dogs. In fact, veterinarians often prescribe Viagra but not for the same reason humans use it. Namely, while men use Viagra for erectile dysfunction, in dogs, it can be used to improve the blood flow in patients with pulmonary hypertension. 

In this article, we will explain the use of Viagra in dogs – the indications and the medication’s effects and side effects. We will also answer some popular questions regarding this topic.

WHAT IS VIAGRA?

Viagra is the brand name for a drug called sildenafil. Sildenafil is a vasodilator (in more correct pharmacology terms, it is classified as phosphodiesterase type V inhibitor) and is officially used to treat erectile problems. 

However, because of its ability to dilate the blood vessels, veterinarians often use it off-label to treat conditions like pulmonary hypertension, megaesophagus, and endometritis. 

In veterinary medicine, the top reason for prescribing Viagra is managing increased blood pressure in the lungs or pulmonary hypertension. 

WHAT WILL VIAGRA DO TO A DOG?

Viagra is prescribed to dogs with pulmonary hypertension (PH) to lower the increased blood pressure within the lungs. Pulmonary hypertension should not be confused with systemic hypertension. 

PH results in impaired blood flow and compromised oxygen delivery in the lungs, as well as the increased workload of the right side of the heart. The condition is more common in small dog breeds, which can occur due to either lung or heart diseases. Old age is a significant risk factor for pulmonary hypertension.

The clinical manifestation of HP includes fainting, fast and labored breathing, coughing, lethargy, exercise intolerance, and abdominal distension. However, dogs rarely exhibit these signs and symptoms in the early phases of the condition.   

IS IT SAFE TO GIVE A DOG VIAGRA?

Although primarily formulated and labeled for humans, Viagra is safe for dogs as long as it is used correctly under a vet’s supervision. 

Are there any side effects of Viagra in dogs?

Although classified as safe, like any other drug, Viagra can cause specific side effects in extra sensitive dogs. The potential side effects of Viagra in dogs can be classified into three main groups: 

  • Skin flushing limited to the groin area 
  • Lowered blood pressure, lethargy, and behavior changes 
  • Gastrointestinal upset manifesting with diarrhea, vomiting, and appetite loss

In humans, the group of side effects includes blindness, nosebleeds, dizziness, headaches, deafness, muscle aches, nose congestion, and indigestion. However, these side effects have not been reported in dogs.

If your dog develops some side effects after starting it on Viagra, it is essential to talk to your vet. Based on the severity of the situation, the vet might recommend a dosage modification or discontinue the use of Viagra. 

Are there any risk factors for using Viagra in dogs?

Before prescribing your dog Viagra, the vet will assess both the pros and the cons. Generally speaking, the vet will not recommend the use of Viagra in dogs allergic to the active ingredient – sildenafil. 

In dogs with kidney and liver diseases and insufficiencies, the vet will prescribe Viagra in modified and much lower doses. 

The vet will recommend extra care or search for Viagra alternatives in dogs with heart diseases like ventricular arrhythmias and left-sided heart disease. 

Finally, close monitoring and frequent follow-ups are critical for dogs receiving Viagra while suffering from low blood pressure, dehydration, and bleeding disorders. 

HOW MUCH VIAGRA SHOULD I GIVE MY DOG?

How much Viagra your dog needs depends on its body weight, the severity of the underlying issue, and the method of administration. The vet will provide the exact Viagra dose for your dog, but the general recommendation is between 0.5 and 3 milligrams per kilogram of body weight. 

How is Viagra administered to dogs?

Viagra can be administered orally or via injections. There are two oral forms – tablets and liquids. Ideally, both the pills and liquids need to be administered on an empty stomach, either one hour before or two hours after a meal. 

If your dog has a sensitive tummy and receiving meds on an empty stomach causes upsets, it is possible to give Viagra with food, but first, you should talk to your vet. Additionally, if using the liquid form, make sure you shake the bottle well before use. 

Viagra injections are not something you can administer on your own at home. If your dog needs injections, you will have to make frequent vet visits until your dog’s condition is under control and it is safe to transfer to oral Viagra options. 

How long does it take for Viagra to work in dogs?

Viagra is a relatively quick-acting medication. Usually, it takes between one to two hours for its effects to kick in. After this timeframe, there will be a visible improvement in the clinical signs and symptoms. 

The Viagra effects usually last for around 24 hours. However, they may last much longer in dogs with compromised liver and kidney functions. 

Does Viagra interact with other medications in dogs?

You should always inform your vet about the medications your dog is receiving. This also includes vitamins, herbal therapies, and supplements. 

Extra caution is warranted when prescribing Viagra to dogs on ACE inhibitors, amlodipine, alpha-adrenergic antagonists, angiotensin receptor blocker, certain antifungals, cimetidine, ciprofloxacin, clarithromycin, erythromycin furosemide, heparin, nitroprusside sodium, nitrates, phenobarbital, paclitaxel, propranolol, and rifampin. 

SUMMING UP: VIAGRA FOR DOGS

If someone says his/her dog is on Viagra, do not conclude before you know all the facts. Dogs are prescribed with Viagra for many different reasons than humans. Namely, Viagra is the treatment of choice for dogs with pulmonary hypertension. 

If your dog is diagnosed with pulmonary hypertension and prescribed Viagra, make sure you use the drug following the vet’s recommendations and instructions. If at any point you have doubts, do not hesitate to consult with your trusted veterinarian.