Canine Distemper

Question 1

Structure

Answer 1

Enveloped, negative-sense ssRNA

Question 2

Family

Answer 2

Paramyxoviridae, morbillivirus

Question 3

Primary Reservoir

Answer 3

Domestic Dogs

Question 4

Mortality

Answer 4

high in wide rang of species, up to 100%

Question 5

1st recorded case

Answer 5

1760 in Spain in domestic dogs

Question 6

When did it enter the US

Answer 6

1880s-> wildlife in 1920s

Question 7

Transmission Cycle

Answer 7

close contact through oronasal aerosol and urine
Potentially on fomites

Question 8

Wild reservoir host

Answer 8

foxes, hyenas, coyotes, other canids

Question 9

Intermediate host

Answer 9

raccoons

Question 10

Pathogenesis

Answer 10

lymphocyte direct viral damage and apoptosis -> secondary infection CD4+ more than CD8+-> dendritic cells-> immunodepression-> CNS cerenospinal fluid

Question 11

Recovery

Answer 11

After initial exposure, dogs can have a robust immune response and recover
75% of infections may actually be subclinical
Slow recovery and repopulation of lymphoid tissues
Functional recovery doesn’t occur and will remain immunosuppressed

Question 12

Clinical Signs Catarrhal phase

Answer 12

Transient fever 3-6 days post infection, anorexia, serous nasal discharge, mucopurulent ocular discharge, lethargy, diarrhea, pustular dermatitis, hyperkeratosis of footpads and nose planum, hypoplasia of enamel on unerupted teeth

Question 13

Clinical Signs Neurologic phase

Answer 13

localized involuntary muscle twitching, seizures with salivation and chewing movements of the jaw, circling, head tilt, nystagmus, paresis to paralysis

Question 14

Incubation time

Answer 14

7-10 days

Question 15

Shedding

Answer 15

she in high titers from all body secretions during acute phase of infections, survivors can shed for months

Question 16

Pathologic lesions

Answer 16

-rash
-hyperkeratosis of foot pads, muzzle, eyelids, and anus
-neuronal degeneration/necrosis
-thymic atrophy
-lymphatic tissue necrosis
-inclusion bodies in respiratory, urinary, and GI epithelium
-right sided dilations and left sided hypertrophy of heart
-splenomegaly
-hepatic lipidosis
-respiratory congestion and consolidation due to pneumonia

Question 17

Diagnostics

Answer 17

PCR, ELISA or IFA(most common form using discharge and tissue samples), cerebrospinal fluid analysis, distemper inclusion bodies- generally only done on necropsy

Question 18

Management

Answer 18

no vaccines for wildlife, remove carcasses as soon as find them, population control of susceptible species (virus is density dependent), decontamination of infected areas