Adenoviridae - Mastadenovirus - CAV-1

Question 1

What does canine adenovirus-1 cause?

Answer 1

Infectious canine hepatitis

aka- Rubarth’s disease

Question 2

How is CAV-1 transmitted?

Answer 2

Oronasal- all secretions and excretions.
Virus is shed in urine for at least 6-9 months.
Fomites
Ectoparasites

Question 3

Where does CAV-1 replicate?

Answer 3

Macrophages, Kupffer cells, Hepatocytes, Vascular endothelium of CNS, parenchymal cells

Question 4

What are the target organs for CAV-1 replication?

Answer 4

Liver, kidney, spleen, and lungs

Question 5

Dogs with sufficient AB titers show little clinical evidence of disease. What is the titer amount?

Answer 5

> 500

Question 6

In acute cases what clears the virus from the blood and liver and restricts hepatic damage?

Answer 6

A sufficient (>500) antibody response by day 7 post infection.

Question 7

What will a persistently low antibody (<14) titer cause?

Answer 7

Widespred centrilobular to panlobular hepatic necrosis.

Question 8

What does partial immunity result in? How much is partial immunity?

Answer 8

AB titer >16 but <500

Result in chronic active hepatitis (cirrhosis) and hepatic fibrosis

Question 9

What happens to the kidney in CAV-1 infections?

Answer 9

Glomerulonephritis

Lesions may result from immune-complex reactions after recovery from acute of subclinical disease.

Question 10

What does CAV-1 do to the eye?

Answer 10

20% of CAV-1 cases will develop cornea edema (blue eye)

Question 11

What % of dogs develop blue eye after vaccination for CAV-1?

Answer 11

<1% (but it is possible)

Question 12

When is corneal blue eye seen?

Answer 12

Dogs recovering from CAV-1 or chronic cases of CAV-1

Question 13

How does corneal blue eye occur (pathogenesis)?

Answer 13

Look carefully at slide 24-26

It is due to extensive damage to corneal epithelium and accumulation of edematous fluid in cornea storm.

Question 14

What does DIC result from?

Answer 14

Damage to endothelium

Inability for diseased liver to remove clotting factors

Question 15

What are general clinical signs of ICH?

Answer 15

Unvaccinated dogs <1 year
Concurrent with parvo or disteper
Asymptomatic on outside
Slight fever to death

Question 16

What are the peracute ICH clinical signs?

Answer 16

Death within few hours

Question 17

What are the acute ICH clinical signs?

Answer 17

Fever >104C
Vomiting
Hepatomegaly (abdominal pain)
Jaundice (uncommon in actue!)
Swollen LN
Blue eye when clinical recovery begins

Question 18

What is seen in foxes with acute ICH?

Answer 18

Encephalitis

Question 19

What clinical sign can be seen in acute ICH but is rare?

Answer 19

Jaundice/Icterus

Question 20

How is ICH diagnosed?

Answer 20

On Necropsy:
Paint brush hemorrhage in GI, LN, pancreas
Centrilobular necrosis of the liver
Grayish white foci in kidney cortex of recovered or chronic cases

Virus isolation from urine
PCR

Question 21

How is ICH treated?

Answer 21

Symptomatic and supportive.

Goal: Limit bacterial invasion, support fluid balance, and control hemorrhagic tendencies.

Question 22

What is the vaccination schedule for ICH?

Answer 22

1st vaccination between 6-12 weeks of age

2nd vaccination at 14-16 weeks

Question 23

What types of vaccinations are available?

Answer 23

Attenuated CAV-1 live vaccine – can cause shedding in urine, uni/bialteral opacity in eye, and mild nephritis – discontinued in many countries

*CAV-2 attenuated live virus strains– no shedding and very little tendency to produce corneal opacity or uveitis.