The emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus causing COVID-19, has raised questions about whether this illness can affect canine companions. While dogs can be infected, understanding the specific risks is important for providing proper care and maintaining a safe home.
Canine Susceptibility to SARS-CoV-2
Dogs can become infected with SARS-CoV-2, but these infections are uncommon. Studies confirm that a small number of dogs have tested positive, usually after close contact with an infected person. The low number of natural infections, despite widespread human cases, suggests canines are not a primary host for the virus and are less susceptible than animals like cats or ferrets.
It is important to distinguish SARS-CoV-2 from other coronaviruses. Canine Coronavirus (CCoV) is a separate virus that causes mild gastrointestinal issues in dogs and is unrelated to the respiratory illness of COVID-19. CCoV is an alphacoronavirus, while SARS-CoV-2 is a betacoronavirus. The vaccine for Canine Coronavirus offers no cross-protection against SARS-CoV-2.
The biological reason for lower susceptibility lies in their cellular receptors. SARS-CoV-2 enters human cells by binding to the ACE2 receptor. Although dogs have ACE2 receptors, their structure differs from that of humans, making it harder for the virus to attach and replicate. This molecular difference explains why infections in dogs are infrequent and mild.
Signs and Symptoms in Infected Dogs
Many dogs infected with SARS-CoV-2 show no signs of illness. When symptoms do appear, they are mild and self-limiting. An infection may only be discovered through targeted testing in a household with a confirmed human case.
Symptomatic dogs may show signs involving the respiratory or digestive systems. Owners might observe a mild cough, sneezing, or discharge from the nose or eyes. Other reported signs include lethargy, a slight fever, and gastrointestinal upset like vomiting or diarrhea.
These clinical signs are non-specific and shared with more common canine health issues, such as kennel cough or seasonal allergies. A cough or sneeze alone is not a reason to suspect SARS-CoV-2. A veterinarian will consider the dog’s symptoms along with any known exposure to a person with COVID-19.
Transmission and Diagnosis
The primary way dogs contract SARS-CoV-2 is through close contact with an infected human. The virus spreads from person to pet through respiratory droplets from coughing, sneezing, or talking, similar to how it spreads between people.
While human-to-dog transmission occurs, the risk of dogs spreading the virus to people is very low. Dog-to-dog transmission is also considered rare. Most documented cases involve a single pet in a household becoming ill after its owner.
If a veterinarian suspects a dog has SARS-CoV-2, a diagnosis is made using a reverse transcription-polymerase chain reaction (RT-PCR) test. This is the same type of test used for humans and involves collecting a sample with a swab from the dog’s nose, mouth, or rectum. Testing is not routinely recommended for all pets but may be considered for a pet that is showing signs and has a known exposure to a person with COVID-19. Owners who are concerned should call their veterinarian first for guidance.
Management and Prevention for Dog Owners
There is no specific antiviral treatment for dogs with SARS-CoV-2. Management focuses on supportive care to help the dog’s immune system fight the infection, which includes rest, fresh water, and food. Most infected dogs have a mild illness and recover completely at home without medical intervention.
Owners with COVID-19 should take steps to prevent transmitting it to their pets. If possible, an infected person should isolate from their dog, and another household member should provide care. If the sick owner must care for their pet, they should wear a face mask and wash their hands before and after interaction.
It is important to avoid measures that could harm the pet. Face masks should never be put on a dog, as they can cause breathing difficulties. Owners should not use chemical disinfectants, alcohol, or other sanitizers on their pet’s fur or paws. Simple grooming with pet-safe shampoos is sufficient if cleaning is needed.