In most cases, it takes 10-14 days after infection before clinical signs develop, but can take up to 4-5 weeks. This delayed response means that many recently vaccinated dogs may already be infected when vaccinated. Not all dogs show the same clinical signs, which are dependent on immune status and past exposure. Puppies are more likely than older dogs to develop clinical signs, although any age of dog can be affected.

Signs are somewhat non-specific which makes diagnosis a challenge. In healthy, older dogs no clinical signs may be obvious. In some dogs the virus may only cause only a transient fever and some mild depression. Other dogs may have more severe systemic illnesses including several, though usually not all, of the following signs (2):



- nasal and ocular discharges

- coughing/ pneumonia

- dyspnea

Ocular (relatively uncommon):

- anterior uveitis – inflammation in the front corner of the eye and cloudiness of the cornea

- keratoconjunctivitis sicca (dry eye)

- optic neuritis with concurrent sudden blindness

- retinal degeneration/separation



- lack of appetite

- vomiting

- diarrhea


- callusing of the foodpads/nose (‘hard pad disease’)

Often in the course of the disease, affection of the neurological system becomes apparent. These signs can develop at the same time as onset of the above clinical signs, or may occur up to a month after initial infection. Therefore sometimes the dog may recover from the initial signs, only to develop further neurological problems weeks later. Signs include:

Neurological Signs:

- seizures

- behavioural changes

- walking in circles

- rhythmic motions or ‘tics’

- steady continual contractions of head muscles (looks like dog is chewing gum)                           

It is interesting to note that traditionally the mortality rate from infection has been quite high. This is likely because CDV is usually only diagnosed in the more severe cases with obvious clinical signs; those dogs that do not have severe signs and get rid of the virus through their own defences are not recorded (2).

Viral Characteristics
Clinical Signs
Transmission and Risk
Other Species
Treatment and Prognosis
Medical Dictionary