Infectious Cough in Dogs

Laurie Anne Walden, DVM

Infectious respiratory disease spreads easily between dogs. Public domain image from pixy.org.

An outbreak of a highly infectious cough has recently been affecting dogs in the Charlotte area. The disease spreads quickly wherever dogs gather: boarding kennels, dog day cares, dog parks, and so forth. Dogs with no symptoms can spread the infection to other dogs.
 
Most dogs have mild illness and recover at home, but some dogs develop pneumonia and need to be hospitalized. Dogs with pneumonia are at risk of dying.
 
These are some of the signs of mild illness:

• Cough (any type: soft, moist, dry, or hacking like a goose honk or a hairball being hacked up)
• Sneezing
• Runny nose
• Runny eyes

 
Call your veterinarian if your dog has any of the following signs:

• Mild signs that last longer than a few days

• Cough becoming more frequent, more pronounced, or more productive (moist)
• Cough affecting ability to sleep
• Decreased energy
• Decreased appetite

 
Take your dog to an emergency clinic right away if your dog has signs of trouble breathing:

• Continuous rapid breathing or panting
• Exaggerated chest movements while breathing
• Using muscles of the abdomen while breathing
• Holding head with neck extended forward or chin lifted up
• Puffing out the cheeks while breathing
• Purple or blue gums or tongue (in a dog whose gums and tongue are normally pink)
• Collapse

 
Causes
Many viruses and bacteria cause canine infectious respiratory disease complex (CIRDC), sometimes called kennel cough. Dogs are often infected with more than 1 agent at the same time.
 
These are some of the agents that cause CIRDC:

• Viruses: canine distemper virus, canine parainfluenza virus, canine adenovirus type 2, canine herpesvirus type 1, canine respiratory coronavirus, canine influenza virus (H3N2 and H3N8 subtypes)
• Bacteria: Bordetella bronchiseptica, Mycoplasma species, Streptococcus equi subsp zooepidemicus

 
Core vaccines (standard for all dogs) give protection against some but not all of the viral agents. Noncore vaccines (optional lifestyle vaccines) are available for canine influenza virus and Bordetella. Vaccines don’t completely prevent CIRDC, but fully vaccinated dogs tend to have shorter and less severe illness. Vaccines also help limit spread of the disease.
 
Transmission and Risk Factors
The infectious agents spread through respiratory droplets and secretions. Some of the agents stay in the environment and continue to infect dogs for weeks. Dogs are infected by direct contact with an infected dog, by inhaling respiratory droplets, or by licking contaminated objects like bowls, bedding, toys, floors, walls, or people’s hands or clothes.
 
Because CIRDC can spread silently (by dogs with no symptoms) and some of the agents persist in the environment for a long time, outbreaks can be hard to control.
 
Any dog that has contact with other dogs or spends time in areas where dogs gather can be infected. Most dogs develop only mild illness and recover within a couple of weeks. Puppies, senior dogs, and dogs with impaired immune function are at higher risk of pneumonia.
 
Some of the agents that cause CIRDC can also infect cats. The only CIRDC agent known to infect humans is Bordetella, but transmission to people is very rare. Canine influenza is not contagious to people.
 
Diagnosis and Treatment
The decision to pursue diagnostic tests depends on the individual dog. Dogs with mild illness need physical examination but often don’t undergo other tests if they have symptoms that suggest CIRDC, have been around other dogs (especially in an area with an outbreak of respiratory disease), and are feeling well otherwise. Additional diagnostic tests can include chest radiographs, bloodwork, tests for specific infectious agents, and tests to rule out other causes of coughing.
 
Treatment can range from just resting at home to being hospitalized for intensive care, depending on the severity of illness. Antibiotics don’t kill viruses, but because CIRDC often involves a combination of organisms, dogs suspected to have a viral respiratory disease (like influenza) might receive an antibiotic as a precaution against bacterial infection.
 
Prevention
These are some tips to help keep your dog safe from infectious respiratory disease:

• Keep your dog’s vaccinations current and talk to your veterinarian about noncore vaccines (canine influenza and Bordetella).
• Keep your dog away from water bowls, toys, and other objects that have been used by dogs that don’t live in your household.
• If your dog has any signs of respiratory disease, keep your dog at home: no day care, dog parks, trips to the pet store, group training, etc.
• During an outbreak, keep your dog home and away from non-household dogs, even if none of the dogs seem sick.
• Plan ahead for holiday travel during an outbreak. Instead of taking your dog to a boarding kennel, you might need to take your dog with you or find someone (friend, family member, pet sitter) to take care of your dog at home.
• Don’t put a mask on your dog.

 
For more information

• Canine infectious respiratory disease complex (AVMA): https://www.avma.org/resources-tools/pet-owners/petcare/canine-infectious-respiratory-disease-complex-kennel-cough
• Canine influenza: pet owners’ guide (AVMA): https://www.avma.org/resources/pet-owners/petcare/canine-influenza-pet-owners-guide

 
Image source: https://pixy.org/4653483/

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