Distemper Outbreak in Maricopa County East Animal Shelter

Tragically, Maricopa County Animal Care and Control has reported the deaths of 49 dogs since June 3, 2019 due an outbreak of distemper virus at the East Animal Shelter. The distemper virus, morbillivirus, is highly contagious between dogs. The dogs are infected by either inhaling the virus or coming into contact with secretions that contain the virus. Once inside the body, it spreads quickly to the lymph nodes where it replicates and then infects the respiratory, gastrointestinal, urogenital and neurologic systems. The disease starts with fever and lethargy about 3-6 days after infection. A short time later, the infected dog has discharge from the eyes and nose. Most dogs are also anorexic. Many dogs will develop a secondary bacterial infection while their immune system is under siege from the distemper virus. Even with aggressive supportive therapy with antibiotics and fluids, many of these dogs will die.

Unfortunately, the dogs that survive are still not out of the woods. The virus may affect many other parts of the body. 1) Central Nervous System (CNS) – Viral infection of the CNS causes meningitis and seizures. Seizures caused by distemper are very difficult to control with medication and most dogs will either die while seizing or are euthanized to prevent suffering. The virus can also affect other areas of the brain causing myoclonus which means involuntary twitching. The jerking can be limited to one leg or include the entire body. Sometimes it renders the affected leg unusable. 2) Eyes – The optic nerve and retina may be damaged resulting in poor vision or blindness. 3) Paw Pads – Some strains of the distemper virus will cause hyperkeratosis of the pads. These abnormal pads are hard to the touch. 4) Teeth – When puppies are infected, the virus can interfere with the growth of their permanent teeth. The virus destroys the enamel layer. When the permanent teeth erupt from the gums, they are missing the outer white enamel. Without enamel, the teeth are weak and prone to fracture and infection.

Once a dog is infected, there isn’t much that can be done to help them. Patients are given antibiotics, fluids and other medications to treat the secondary infections but there aren’t any drugs to stop the virus. The good news is that this disease can be prevented with vaccination. All puppies over 6 weeks of age should receive vaccinations for distemper and parvovirus which is another deadly disease.  Depending upon the age at which vaccinations start, the pup will received 3 to 4 vaccinations spaced 2 to 3 weeks apart. The pup should be booster on their first birthday and then every 3 years after that depending upon the brand of vaccine used. Please remember, that it takes about 2 weeks for the immune system to react to a vaccine and provide an immune response. Also, not every dog will react to the vaccine in the same way. Dogs with a poorly functioning immune system may not generate a protective response to the virus.

The East Maricopa County Animal Shelter has been closed because of the outbreak. It hopes to re-open on July 1, 2019. According to azfamily.com, “The shelter is working to adopt out any dogs not showing symptoms of the virus and working on fosters for the dogs that are treatable and would do better in a quieter environment.” Please remember, distemper is a highly contagious disease. If you are thinking about fostering a dog from the shelter, please talk to your veterinarian first.


-Cumberledge, H. & Gorden, M. “Maricopa County animal shelter quarantine extended again, 49 dogs euthanized” azfamily.com, originally posted June 13, 2019 and updated on June 19, 2019.

-Tilley, L & Smith, F. Blackwell’s Five-Minute Veterinary Consult: Canine and Feline. 5th edition, John Wiley & Sons, 2011.