Illustrated Articles

Dogs + Infectious Diseases

  • Roundworms are parasites that live freely in the intestine, feeding off of partially digested intestinal contents. Toxocara canis and Toxascaris leonina are two important species of roundworms in dogs. Infected dogs shed the microscopic roundworm eggs in their feces. Other dogs may become infected by sniffing or licking infected feces. There are many safe and effective preparations available to kill adult roundworms in the intestine.

  • Despite sounding like a toxicity, salmon poisoning is actually an infection. Salmon poisoning is caused by a type of bacteria found within parasitic flatworms that infect the tissues of wild fish found in coastal streams of the Pacific Northwest.

  • H1N1 influenza virus emerged in pigs as a genetic sharing of DNA from both human and swine influenza viruses. It caused a deadly pandemic in 2009 and continues to be an important cause of illness today. Pets including cats and dogs can be infected from their owners and become ill. It is not yet thought to transfer from pets to humans. Because influenza viruses appear to be capable of swapping genes, there is potential for new variants of influenza viruses to be generated at any time leading to another pandemic of severe disease in humans and other animals. Good hygiene and exposure restriction should be taken immediately if there is any sign of influenza-like infection to restrict spread between humans and between humans and their pets or domestic animals.

  • Tetanus is a medical condition caused by a toxin. This toxin, produced by the bacteria Clostridium tetani, affects the nerves, spinal cord and brain, leading to hyperexcitability resulting in muscle spasms. Dogs are less susceptible to the effects of tetanus toxin than humans and horses. Tetanus is typically diagnosed based on exam findings. Dogs with tetanus require intensive nursing care. Most dogs develop localized, self-limiting disease, which will respond to appropriate early treatment.

  • **This article has been specifically written for dog walkers and how they can reduce their exposure to COVID-19.** COVID-19 is a new respiratory disease in humans, initially discovered late in 2019. Although all coronaviruses are related, they are not all the same virus; SARS-CoV-2 cannot cause canine coronavirus infection, and vice versa. As a dog walker, it is important to limit direct contact with your clients. People can shed the virus without showing any symptoms of disease, so it is important to practice physical distancing even with clients who appear healthy. It is also important to limit your contact with potentially contaminated items in your clients’ homes, whether they are at home or not. The most important things you can do to minimize your risk of infection, and minimize the risk of transferring infection to your clients, is to be cautious when interacting with clients and when touching anything that could be contaminated. Communicate with your clients regularly during this pandemic. Having information about your clients’ health can help you avoid taking unnecessary risks. Finally, if you develop any signs of COVID-19, including cough, fever, and/or shortness of breath, it is important that you stay home from work.

  • **This article has been specifically written for pet sitters and how they can reduce their exposure to COVID-19.** COVID-19 is a new respiratory disease in humans, initially discovered late in 2019. Although all coronaviruses are related, they are not all the same virus. As a pet sitter, it is important to limit direct contact with your clients. People can shed the virus without showing any symptoms of disease, so it is important to practice physical distancing even with clients who appear healthy. It is also important to limit your contact with potentially contaminated items in your clients’ homes, whether they are at home or not. The most important things you can do to minimize your risk of infection, and minimize the risk of transferring infection to your clients, is to be cautious when interacting with clients and when touching anything that could be contaminated, wear a mask, and maintain at least 6 feet distance from your clients. Communicate with your clients regularly during this pandemic. Having information about your clients’ health can help you avoid taking unnecessary risks. Finally, if you develop any signs of COVID-19, including cough, fever, and/or shortness of breath, it is important that you stay home from work.

  • Tularemia is an infection of the bacteria Francisella tularensis and is most common in rabbits and rodents. Infection in dogs occurs from ingestion of an infected animal, contaminated water, or the bite of a blood sucking insect. Tularemia causes mild illness in healthy dogs. More severe clinical signs include enlarged lymph nodes and draining abscesses. Diagnosis includes physical exam, bloodwork, and urinalysis, as well as paired serum titers. PCR can also be used to identify the bacteria in a blood sample. Treatment includes antibiotics, surgical removal of any draining abscesses and any other supportive warranted by the dog’s condition. Tularemia is a reportable zoonotic disease.

  • Valley fever is a fungal infection caused by Coccidioides immitis. In the US it is most commonly found in the southwestern states with California and Arizona being most affected. The most common method of infection is through inhalation of spores that are released by disturbance of soil such as while digging. These spores infect the lungs forming spherules. Dogs with healthy immune systems avoid serious infection by walling off the spherules; however, those that have weakened immune systems can become ill. The two main forms of disease are primary and disseminated. The primary disease occurs in the lungs causing coughing, lethargy, decreased appetite, fever, and depression. Disseminated disease occurs when the fungus migrates to different areas of the body including the bones, joints, eyes, and rarely the brain. Diagnosis includes blood tests (including titer tests) and radiographs. Treatment requires prolonged anti-fungal agents and is generally successful in respiratory or primary cases; however, patients affected by the disseminated form have a more guarded prognosis.

  • Whipworms are intestinal parasites that are about 1/4 inch (6 mm) long. They live in the intestinal tract of dogs where they cause severe irritation. Whipworm infection results in watery, bloody diarrhea, weight loss, and general debilitation. Any dog with chronic large bowel diarrhea should be suspected to have whipworms, even if the stool sample was negative. Whipworms are far less common today than in previous years, because of widespread use of modern heartworm prevention products.

  • A zoonosis is a disease or infection that can be transmitted from animals to humans. Although dogs only pose a mild risk of causing disease in humans, those with immunosuppressive conditions such as HIV or those receiving chemotherapy will be at higher risk of becoming ill from these infections. The most common and significant infections that humans can get from their pet dogs include rabies, leptospirosis, ringworm, and gastrointestinal illness such as Salmonella and Campylobacter. Hygiene plays an important role in preventing the spread of these diseases, as well as preventive medicine for your dog, including regular deworming and external parasite preventives.