Submitted by Erika Sox, DVM, DACVIM
While we enjoy a low prevalence of Canine distemper virus in Hawaii, we do occasionally see cases here and it is important to remain vigilant to protect pets that may be vulnerable to infection.
Canine distemper is a highly contagious and often fatal viral disease of domestic dogs. Young puppies and unvaccinated adult dogs in high density housing are at highest risk. Acutely affected dogs commonly exhibit clinical signs of fever, lethargy and inappetence, respiratory signs (nasal discharge, coughing and labored breathing due to pneumonia), ocular signs (uveitis, KCS), and GI signs (anorexia, vomiting, diarrhea with or without blood). In severe cases, these may be followed by central neurologic signs such as clonic muscle tremors and seizures. Neurologic signs can take up to 3 months to develop and sometimes do so without other preceding clinical signs. 1, 2
Diagnosis is made by recognition of compatible clinical signs, along with confirmation through testing, ideally with quantitative RT-PCR which can distinguish between natural and vaccine-derived distemper. Testing is readily available through commercial veterinary labs but take several days to return, making clinical suspicion and proper handling of suspect cases imperative while awaiting results. Distemper should be considered in any febrile dog exhibiting symptoms of the GI, respiratory and neurological systems, especially if unvaccinated or incompletely vaccinated. 1, 2
Distemper is shed in all body secretions of acutely infected animals and can be spread by both direct contact and via respiratory droplets. Isolation of both clinically ill and unvaccinated exposed dogs requires designated airspace and is crucial to preventing spread. The virus is fragile in the environment and readily killed with most cleaning agents but can survive at least several hours. Staff handling affected animals should wear appropriate PPE and practice proper hygiene protocols. Detailed isolation and clearance protocols are available online. 1
There is no specific treatment or cure for Distemper virus. Treatment is generally supportive in nature and may include IV fluid therapy, anti-emetics, nutritional support, antibiotics for secondary infections, and anti-convulsant medications. 1, 2
Vaccination is highly effective in preventing disease and is considered core for all puppies and dogs worldwide. Initial vaccination should be administered at 6 to 8 weeks of age and repeated every 2 to 4 weeks until 16 weeks of age, followed by a 1-year booster and then boosters every 3 years. 3