# Canine Distemper

> Canine Distemper (CDV, Hardpad disease) is a systemic condition of dogs. Key signs are biphasic fever, mucopurulent ocular and nasal discharge and productive cough / pneumonia; diagnosis rests on PCR on conjunctival, nasal or urine swabs and CSF antibody / PCR for neurologic cases. Guarded; high mortality in unvaccinated pups.

Source: https://vetmasterji.com/diseases/canine-distemper · Last reviewed: 2026-10-01

## At a glance

- **Species:** Dogs
- **Body system:** Systemic
- **Also known as:** CDV, Hardpad disease

## Key clinical signs

- Biphasic fever
- Mucopurulent ocular and nasal discharge
- Productive cough / pneumonia
- Vomiting and diarrhoea
- Hyperkeratosis of footpads and nasal planum (hardpad)
- Neurologic signs: seizures, myoclonus, ataxia, paresis

## Other signs

- Conjunctivitis
- Anorexia, lethargy
- Enamel hypoplasia in survivors
- Optic neuritis, chorioretinitis

## Differential diagnoses

- Kennel cough (B. bronchiseptica, parainfluenza)
- Canine adenovirus-2 respiratory disease
- Toxoplasma / Neospora encephalitis
- Rabies (for neurologic forms)
- Cryptococcosis

## Diagnosis

- PCR on conjunctival, nasal or urine swabs (most sensitive in acute phase)
- CSF antibody / PCR for neurologic cases
- Serology (paired titres)
- Cytology: distemper inclusion bodies in lymphocytes / RBCs

## Treatment outline

No specific antiviral; treatment is supportive. IV fluids, broad-spectrum antibiotics for secondary bacterial pneumonia, antiemetics, anticonvulsants (phenobarbital, levetiracetam) for seizures, nutritional support. Vaccination is the cornerstone of prevention (MLV core vaccine).

- [Phenobarbital — doses and monograph](https://vetmasterji.com/drugs/phenobarbital)
- [Levetiracetam — doses and monograph](https://vetmasterji.com/drugs/levetiracetam)

> An outline, not a prescription. Check each drug’s dose for the species, the patient and the product in the drug calculator before use.

## Prognosis

Guarded; high mortality in unvaccinated pups. Neurologic signs often persist or progress in survivors.

## Related

- [Rank differentials from clinical signs](https://vetmasterji.com/diagnose)
- [Canine Parvoviral Enteritis](https://vetmasterji.com/diseases/canine-parvoviral-enteritis)
- [Canine Monocytic Ehrlichiosis](https://vetmasterji.com/diseases/canine-ehrlichiosis)

## Frequently asked questions

### What are the signs of canine distemper in dogs?

Biphasic fever, mucopurulent ocular and nasal discharge, productive cough / pneumonia, vomiting and diarrhoea, hyperkeratosis of footpads and nasal planum (hardpad) and neurologic signs: seizures, myoclonus, ataxia, paresis. Less specific signs include conjunctivitis, anorexia, lethargy and enamel hypoplasia in survivors.

### How is canine distemper diagnosed?

PCR on conjunctival, nasal or urine swabs (most sensitive in acute phase), CSF antibody / PCR for neurologic cases, Serology (paired titres) and Cytology: distemper inclusion bodies in lymphocytes / RBCs. Differentials to rule out include kennel cough (b. bronchiseptica, parainfluenza), canine adenovirus-2 respiratory disease, toxoplasma / neospora encephalitis and rabies (for neurologic forms).

### How is canine distemper treated?

No specific antiviral; treatment is supportive. IV fluids, broad-spectrum antibiotics for secondary bacterial pneumonia, antiemetics, anticonvulsants (phenobarbital, levetiracetam) for seizures, nutritional support. Vaccination is the cornerstone of prevention (MLV core vaccine).

### What is the prognosis for canine distemper?

Guarded; high mortality in unvaccinated pups. Neurologic signs often persist or progress in survivors.

## Sources

- Merck Veterinary Manual, 11th edition

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