Yes, dogs can get the flu. Canine influenza, a relatively recent newcomer to the world of dog diseases, emerged in 2004, baffling veterinarians and pet owners alike. The initial discovery of this contagious respiratory illness occurred during investigations into respiratory problems in racing greyhounds, with the virus eventually traced back to an equine influenza strain. While the overall mortality rate due to canine influenza is generally low, estimated between 1-5%, it’s crucial for pet parents to understand that this number doesn’t tell the whole story.
Like human flu, canine influenza can significantly weaken a dog’s respiratory system, making them vulnerable to secondary bacterial infections, most notably pneumonia, which is the primary cause of death in severe cases. Certain dogs, such as puppies, senior dogs, and those with pre-existing health conditions, face a higher risk of complications and a potentially poorer outcome. So, can dogs get the flu? Absolutely. Understanding the history of this virus, recognizing the symptoms, and knowing how to protect your furry friend is essential for every responsible pet owner. This information will help you navigate the complexities of canine influenza and make informed decisions about your dog’s health.
Canine influenza, often called dog flu, is a contagious respiratory disease in dogs caused by specific Type A influenza viruses. Just like the human flu, it attacks the respiratory system, which includes the nose, throat, trachea (windpipe), and lungs. There are two main strains of canine influenza virus currently circulating: H3N8 and H3N2. It’s important to understand that these are not the same viruses that cause the human flu.
On a biological level, these viruses work by attaching to cells in the dog’s respiratory tract. Once inside the cells, the virus hijacks the cellular machinery, forcing the cell to produce more virus particles. This process damages and destroys the infected cells, leading to inflammation and the various symptoms we associate with the flu. The damage to the respiratory lining can also make the dog more susceptible to secondary bacterial infections, which can lead to more serious complications like pneumonia. Because canine influenza is a virus, antibiotics, which target bacteria, are not effective against the virus itself. Treatment focuses on supporting the dog’s immune system and managing the symptoms while the virus runs its course.
Canine influenza, or dog flu, manifests in a variety of ways, and while some dogs may show no symptoms at all, others can become quite ill. It’s crucial to be aware of the range of signs associated with this contagious respiratory illness. Keep a close eye on your dog for any of the following:
It’s important to understand that the severity of these symptoms can vary widely. While most dogs recover within 2 to 3 weeks, some may develop more serious complications, such as pneumonia, which can be life-threatening. This is especially true for puppies, older dogs, and dogs with pre-existing health issues.
Because these symptoms can also indicate other respiratory illnesses, it’s essential to contact your veterinarian if your dog exhibits any signs of illness. They can determine if your dog has canine influenza or another condition and provide appropriate treatment. Early diagnosis and intervention can significantly improve your dog’s chances of a full and speedy recovery. Remember, even if your dog seems to have a mild case, it’s still contagious and can spread the virus to other vulnerable dogs.
While both dog flu and a cold can cause similar symptoms in dogs, they are distinct illnesses with different causes and potential consequences. Here’s a straightforward breakdown:
Here’s a table summarizing the key differences:
| Feature | Dog Flu | Cold |
| Cause | Canine-specific influenza viruses (primarily H3N8 and H3N2) | Various respiratory viruses (not influenza) |
| Severity | Can range from mild to severe; fever (may not always be high), cough (can be harsh), lethargy, loss of appetite | Typically mild; runny nose, sneezing, mild cough, generally remains active |
| Complications | Pneumonia, secondary bacterial infections | Rarely causes serious complications |
| Contagiousness | Highly contagious (spreads easily through respiratory droplets and contaminated surfaces) | Mildly contagious (usually less contagious than dog flu) |
If your dog is exhibiting symptoms of a respiratory illness, it’s essential to consult with your veterinarian for proper diagnosis and treatment. Early intervention can help prevent complications and ensure your dog’s speedy recovery.
Canine influenza spreads primarily through respiratory droplets when an infected dog coughs, sneezes, or barks. The virus is airborne and can travel short distances, infecting nearby dogs. It can also spread through direct contact (nose-to-nose interaction, licking) and contaminated surfaces, such as food bowls, bedding, toys, and human hands or clothing. According to the American Veterinary Medical Association (AVMA), the virus can survive on surfaces for up to 48 hours, on hands for 12 hours, and on clothing for 24 hours, making indirect transmission a significant risk.
Biologically, canine influenza is caused by influenza A viruses (H3N8 and H3N2), which invade the respiratory tract, replicating in the epithelial cells and causing inflammation, mucus buildup, and coughing. Unlike human flu, dog flu has no seasonal pattern and can spread year-round, especially in places with high dog populations like kennels, shelters, and dog parks. Preventing the spread requires isolation of infected dogs, frequent disinfection, and vaccination to reduce the risk of transmission.
Understanding the contagious period of canine influenza is crucial for managing its spread. Dogs infected with the virus can be contagious even before they start showing any symptoms. This means they can unknowingly spread the virus to other dogs during the incubation period, which typically lasts 2-4 days.
Once a dog starts exhibiting symptoms of canine influenza, they are most contagious in the initial days of their illness. However, they can continue to shed the virus and potentially infect other dogs for up to 21 days, even if they appear to be recovering. This prolonged period of contagiousness highlights the importance of isolating infected dogs and taking precautions to prevent the spread of the virus, even if a dog seems to be feeling better.
While canine influenza can present with a range of symptoms, it’s crucial to distinguish between mild and severe signs. The following table outlines the difference between early warning signs and symptoms that require immediate veterinary attention:
| Mild Symptoms | Severe Symptoms (Seek Vet Care ASAP) |
| Occasional cough | Persistent, deep, wet cough |
| Mild runny nose | Thick yellow/green nasal discharge |
| Slight fever | Fever over 104°F |
| Tired but responsive | Extreme weakness, disorientation |
| Normal breathing | Difficulty breathing, wheezing, blue gums |
Diagnosing canine influenza can be tricky as its symptoms often mimic other respiratory illnesses. A veterinarian will typically start with a thorough physical examination and gather a detailed history of your dog’s recent activities, potential exposure to other dogs, and the progression of symptoms. However, because many respiratory illnesses share similar signs, further testing is usually necessary for a definitive diagnosis.
Several diagnostic tools are available:
It’s important to note that a positive test for canine influenza doesn’t necessarily mean the dog will develop a severe illness. However, it does confirm the presence of the virus and allows the veterinarian to provide appropriate care and advice on preventing further spread. Your veterinarian will determine which test is most appropriate based on the stage of your dog’s illness and other factors.
While many dogs recover from canine influenza without lasting effects, the virus can lead to several potential complications, some of which can be quite serious. Understanding these risks is crucial for proactive pet owners.
There is currently no evidence that canine influenza (dog flu) can spread from dogs to humans. The viruses that cause dog flu are specific to dogs and do not typically infect people. While it’s theoretically possible for influenza viruses to mutate and cross species barriers, this has not happened with canine influenza. There have been no reported cases of humans contracting dog flu.
However, it’s always important to practice good hygiene when interacting with animals, including washing your hands after handling dogs or cleaning up after them. This helps prevent the spread of any potential illnesses, even if the risk is low.
Yes, cats can get dog flu, although it’s less common than in dogs. While the H3N2 strain of canine influenza has been shown to infect cats, they are generally less susceptible and experience milder, shorter-lived illnesses. Infections are more likely in situations where cats are in close contact with infected dogs, such as shelters or multi-pet homes. Symptoms in cats can include runny nose, sneezing, congestion, lethargy, loss of appetite, and sometimes fever. Though less frequent, more severe respiratory issues can also occur. If you have both dogs and cats, and your dog has canine influenza, isolate the dog, practice good hygiene, and monitor your cats closely. Consult your vet if your cat shows any signs of illness.
Yes, vaccines are available to protect dogs against canine influenza, specifically targeting the H3N2 and H3N8 strains. These vaccines are designed to reduce the severity and duration of clinical signs, decrease viral shedding, and minimize lung lesions associated with the infection.
Types of Canine Influenza Vaccines:
Monovalent Vaccines:
Bivalent Vaccines: These vaccines offer protection against both H3N2 and H3N8 strains, providing broader immunity for dogs at risk of exposure to multiple strains.
Vaccination Protocol:
Efficacy and Safety:
Studies have demonstrated the effectiveness of these vaccines. For instance, research on the Nobivac® Canine Flu H3N8 vaccine showed a significant reduction in clinical disease severity and viral shedding post-vaccination. Similarly, the Nobivac® NXT Canine Flu H3N2 vaccine has been shown to significantly reduce coughing and lung lesion scores, as well as the duration of viral shedding. These vaccines have been proven safe across various breeds and ages, with minimal adverse effects reported. Always consult with a veterinarian to determine the most appropriate vaccination strategy tailored to your dog’s specific needs and lifestyle.
Protecting other dogs in your household from canine influenza (dog flu) involves a combination of isolation, vaccination, hygiene, and environmental control. Immediately separate the sick dog from all other pets in the house. This means separate living quarters, food and water bowls, and toys. Keep the infected dog in a room that can be easily cleaned and disinfected.
Wash your hands thoroughly with soap and water after handling the infected dog, their belongings, or anything they may have come into contact with. Disinfect all surfaces that the infected dog has touched, including floors, bedding, bowls, toys, and even your shoes. Use a veterinary-grade disinfectant or a diluted bleach solution (1:32 ratio of bleach to water).
Consider vaccinating your healthy dogs against canine influenza. Vaccines can significantly lessen the severity of the illness. Restrict visitors to your home, especially those with dogs, to prevent potential spread. Veterinarians can provide guidance on isolation protocols, disinfection methods, and monitoring your other dogs for signs of illness.
You should take your dog to the vet if flu symptoms worsen or persist beyond a few days. Signs that require immediate veterinary attention include high fever (above 104°F), difficulty breathing, thick nasal discharge, persistent deep cough, extreme lethargy, or refusal to eat or drink. Puppies, senior dogs, and those with underlying health issues are at higher risk of complications and should be monitored closely.
At Pet Pawty, we always recommend consulting a veterinarian for proper diagnosis and care. As we’ve mentioned throughout this article, the information provided here is for informational purposes only and should not substitute advice from a qualified veterinarian. Your vet can accurately diagnose your dog’s condition, rule out other potential causes, and recommend the most appropriate treatment plan.
©2025 Petpawty. All Rights Reserved
