Distemper in Dogs: Symptoms, Vaccination, and Course of the Disease

What is distemper in dogs?

Canine distemper is a highly contagious, serious viral disease in dogs caused by the canine distemper virus (CDV), a morbillivirus of the Paramyxoviridae family—closely related to the human measles virus. CDV affects the respiratory tract, gastrointestinal tract, skin, and nervous system, and if left untreated, often leads to death or permanent neurological damage.

Distemper is one of the most serious infectious diseases in dogs and the primary reason for core vaccination. In Germany, the disease has been largely controlled through widespread vaccination, but it continues to occur in unvaccinated populations (shelter dogs, puppies). Ferrets, wolves, minks, and other wild animals are also susceptible.

Background + Scientific Context

Greene and Appel (2012, *Infectious Diseases of the Dog and Cat*, 4th ed.) describe the pathogenesis and clinical course: CDV is transmitted aerogenically via droplets. Following replication in the lymph nodes, viremia occurs, with the virus spreading to the epithelium of the respiratory tract, gastrointestinal tract, and urogenital tract. The biphasic fever course (1st rise: viremia; 2nd rise: organ involvement) is diagnostically characteristic. Neurological phase: CDV infects CNS cells; encephalomyelitis leads to myoclonus, ataxia, epileptic seizures, and paralysis.

Beineke et al. (2009, Veterinary Immunology and Immunopathology, PubMed 19041673) describe the immunopathology: CDV induces immunosuppression through lymphocyte depletion—thereby increasing susceptibility to secondary bacterial infections. "Old Dog Brain" syndrome: post-infectious chronic progressive encephalitis in older dogs. Inclusion bodies (intranuclear, intracytoplasmic) in infected cells are a histopathological hallmark. Mortality without treatment: 50–80%; dogs with neurological symptoms often have permanent deficits.

The WSAVA (2016, Vaccination Guidelines) classifies CDV as a core vaccine: primary vaccination during puppyhood (starting at 6–8 weeks of age, every 2–4 weeks until 16 weeks), a booster after 1 year, and then every 3 years. Modern MLV (modified live virus) vaccines provide long-lasting immunity (demonstrably ≥3 years, often longer). Vaccine protection also extends to CDV strains from wild animal populations.

Vitomalia-Position

Distemper is a disease that is almost entirely preventable—through vaccination. Those who do not vaccinate their dogs not only put their pets at risk but also contribute to reservoir populations from which unvaccinated dogs or wild animals can become infected. Core vaccination is not an optional choice.

When does distemper become a concern?

• Unvaccinated puppies: highest risk of infection
• Contact with shelter dogs or dogs with an unknown vaccination status
• Travel abroad to regions with a higher prevalence of CDV
• Contact with wild animals (foxes, martens) in endemic areas
• Neurological symptoms of unknown origin in young dogs

Practical application

Clinical course:

Phase	Period	Symptoms
Incubation	3–6 days	No symptoms
First wave of fever	Days 3–6	Fever, lethargy, loss of appetite
False remission	A few days	Apparent improvement
Phase Two	Starting in Week 2	Runny nose, cough, eye discharge, diarrhea
Neurological phase	Weeks or months later	Myoclonus, seizures, ataxia, paralysis

Diagnostics: - Direct detection: PCR from conjunctival or nasal swab, urine, or cerebrospinal fluid - Serology: CDV antibody titer (a single result is not very meaningful) - Histology: Inclusion bodies in the epithelium

Common Mistakes & Myths

• “My dog doesn’t come into contact with other dogs—is vaccination still necessary?” CDV spreads through the air over long distances and can be introduced by wild animals (foxes, martens). No contact with dogs does not mean no contact with CDV.
• “After contracting distemper, the dog is immune—that’s it.” Dogs that survive distemper may suffer permanent neurological damage. Myoclonus (involuntary muscle twitching) following distemper is common and often persists for life.
• “The vaccine only works for a short time—I have to get vaccinated every year.” Modern CDV vaccines provide proven protection for at least 3 years. Annual boosters are no longer standard for core vaccines—the WSAVA recommends a 3-year interval after the first booster.

Current State of Research (2026)

Thanks to widespread vaccination in Germany, CDV has been largely eradicated. Wildlife reservoirs (foxes, martens) and the international movement of unvaccinated dogs are current sources of risk. Research is focusing on CDV strains from wildlife populations that may not be fully covered by conventional vaccines, as well as on antibody titer tests as an alternative to routine booster vaccinations.

Frequently Asked Questions

What are the symptoms of a dog with distemper?

Early stage: Fever, lethargy, loss of appetite and thirst. Second stage: purulent, mucous discharge from the nose and eyes, cough, diarrhea, pustules on the abdomen. Neurological stage (weeks later): myoclonus (muscle twitching), ataxia, seizures, paralysis.

Is distemper curable?

There is no antiviral treatment for CDV. Treatment is symptomatic: antibiotics for secondary infections, intravenous therapy, and anticonvulsants for seizures. Dogs without neurological involvement have a better prognosis; dogs with neurological involvement have a poor prognosis and often suffer permanent damage.

How can I protect my dog from distemper?

Through vaccination. CDV is a core vaccine—initial vaccination during puppyhood (starting at 6–8 weeks), a booster after 1 year, and then every 3 years. Modern live vaccines provide long-term protection. No vaccination status = no protection, even for dogs that appear to be isolated.

Related terms

• Vaccinations for Dogs
• Puppy Vaccination Schedule for Dogs
• Neurology in Dogs
• Infectious Diseases in Dogs
• Dog Health

Sources & Further Reading

1. Greene, C. E., & Appel, M. J. G. (2012). Canine Distemper. In C. E. Greene (Ed.), Infectious Diseases of the Dog and Cat (4th ed.). Elsevier. ISBN 9781416061304.

2. Beineke, A., Puff, C., Seehusen, F., & Baumgärtner, W. (2009). Pathogenesis and immunopathology of systemic and nervous canine distemper. Veterinary Immunology and Immunopathology, 127(1–2), 1–18. https://pubmed.ncbi.nlm.nih.gov/19041673/

3. WSAVA Vaccination Guidelines Group. (2016). WSAVA Vaccination Guidelines. World Small Animal Veterinary Association. https://wsava.org