BB CH 8 309-327 KD

Question 1

1. What is the genus and species of the woodchuck? How are they related to ground hogs and whistle pigs?

Answer 1

Marmota monax. They are names for the same animals.

Question 2

2. Woodchucks are a model of which human viral disease and why?

Answer 2

Hepatitis B Virus (a hepadnavirus). Woodchuck hepatitis virus is very similar to HBV, and they are good models for pathogenesis and vaccine development.

Question 3

3. Name the family and order of the woodchuck.

Answer 3

Family = Sciuridae
Order = Rodentia

Question 4

4. In nature woodchucks hibernate and have a huge variation in weight throughout a normal annual season. How does this make them a useful animal model?

Answer 4

Woodchucks are a model of food intake, obesity, and energy balance and hibernation because they will exhibit these changes in the normal laboratory environment.

Question 5

5. What regulations must be considered before obtaining woodchucks from the wild?

Answer 5

local and state laws on capture should be consulted before trapping this abundant animal.

Question 6

6. Which of the following is not a requirement for housing woodchucks?
   a. Metal cages designed for rabbits or dogs, modified to limit gaps greater than1.5 inches.
   b. Solid flooring
   c. Burrows
   d. Wood shavings
   e. A litter box

Answer 6

e. A litter box is not required; they will defecate in the corner of a cage and cover up feces with woodchips.

Question 7

7. True or False. Woodchuck pups are susceptible to “ring-tail” like other rodents if humidity falls below 30%.

Answer 7

False: Woodchucks are susceptible to ringtail if humidity falls below 50%

Question 8

8. True or False. Woodchucks are easily tamed and no special handling is required once they are “trained”.

Answer 8

False: Woodchucks can inflict serious bite wounds and should be handled using elkhound, elbow length primate handling gloves. Ket/Xyl should be used for restraint

Question 9

9. True or False. Chattering or wheezing is the first sign of severe respiratory disease in woodchucks. A complete medical exam should be done immediately.

Answer 9

False. Chattering or Wheezing occurs when the animals are disturbed and should not be confused with respiratory infection.

Question 10

10. What is the preferred site of venipuncture in the woodchuck?

Answer 10

Femoral vein or artery

Question 11

11. True of False. Photoperiod should be adjusted throughout the year to mimic natural lighting if woodchucks are being used for studying circannual rhythm or for breeding

Answer 11

True: circannual cycles will be shortened and breeding will become asynchronous if photoperiod is not adjusted to reflect natural conditions.

Question 12

12. True or False. Breeding occurs late in the fall just before hibernation when the woodchuck is at its peak body condition.

Answer 12

False. Breeding period occurs just after hibernation when the woodchuck is at its lowest weight.

Question 13

13. Gestation length of the woodchuck is ___________ days.
    a. 60 days
    b. 73 days
    c. 104 days
    d. 31 days

Answer 13

d. 31 days

Question 14

14. True or False. Animals in the wild live much longer than those in captivity.

Answer 14

False. Animals in the wild live an average lifespan of 14.5 months. Captive animals have lived 4.5 years and up to 14 years.

Question 15

15. True or False. Woodchucks are fussy eaters and require live prey species such as grubs and earthworms.

Answer 15

False. Woodchucks are successfully raised on commercial rabbit chow that is formed in larger pellets to promote gnawing which wear down the incisor teeth.

Question 16

16. Groundhogs are what type of ovulators?
    a. spontaneous
    b. reflex or induced
    c. both

Answer 16

c. Both. Reflex ovulation is more comon, however.

Question 17

17. True or False. Ground hogs have a double cervix and complete medial septation in the body of the uterus. This means that all the fetuses in one side of the uterine horn were derived from ova from the ipsilateral ovary

Answer 17

True

Question 18

18. True or False. Woodchuck testes descend into the scrotum during hibernation. At other times of the year the testes are abdominal.

Answer 18

True

Question 19

19. True or False. Any woodchuck showing signs of weight loss, anorexia and lethargy is in need of medical attention.

Answer 19

False. There are normal signs of torpor that can occur during hibernation season and will disapper within 24 hours if the animal is handled and manipulated.

Question 20

20. Which of the following is not a medical problem commonly found in woodchuck colonies?
    a. dermatitis
    b. diabetes
    c. ocular lesions
    d. hepatocellular carcinoma
    e. bite wounds

Answer 20

b. diabetes

Question 21

21. True or False. Due to their stoic nature, woodchucks are often found dead without displaying clinical signs of disease.

Answer 21

True

Question 22

22. A gross photo of a hepatic mass on the liver of a woodchuck should make you think of what virus?

Answer 22

Woodchuck Hepatitis Virus

Question 23

23. Woodchucks are known to carry what zoonotic diseases?

Answer 23

Rabies, Powassan virus, Toxoplasma gondii, Baylisascaris procyonis

Question 24

24. What is the most common iatrogenic disease of captive woodchucks

Answer 24

Follicular dermatitis

Question 25

True or False. As with most wild animal species, woodchucks exhibit a low incidence of non-experimentally induced cardiovascular disease

Answer 25

False: there is a high incidence of arteriosclerosis, aortic rupture, and cerebrovascular and cardiovascular disease in woodchucks

Question 26

What conditions induce hibernation in woodchucks?

Answer 26

food withdrawal | cold-room temperatures of 5-10 degrees C

Question 27

Describe the annual metabolic cycle in woodchucks

Answer 27

Autumn/early winter - physiologic hypothermia o 30 degrees C, low circulating free thyroid hormone (now bound to TBG), body weight declines, gonads slowly regain function Late winter/early spring - normothermia, increased food intake, minimal weight gain, increased prolactin Early spring - RMR is elevated, brief breeding season Spring/summer - Thyroid levels decline with rapid weight gain (fat) Summer - decreased food intake, fur molts

Question 28

How long will endogenous circannual cycles in woodchucks persist in 12:12 light cycles before conversion to "free-running?"

Answer 28

2-3 years

Question 29

How can the endogenous circannual cycle in woodchucks be entrained to 12 months, and what happens otherwise?

Answer 29

0-4 minute changes in photoperiod daily using a microprocessor. without photoperiod changes, cycles are shortened to 9-11 months

Question 30

what is the length of hibernation for woodchucks in the wild?

Answer 30

3-5 months

Question 31

How can deep hibernation be induced in woodchucks?

Answer 31

room temperature below 15 degrees C, removal of food.

Question 32

When do male woodchucks reach sexual maturity

Answer 32

20-22 months, though changes may be seen as early as 10-11 months

Question 33

How long does estrus last in woodchucks?

Answer 33

5-10 days

Question 34

what is the litter size for woodchucks?

Answer 34

2-7

Question 35

What type of virus is WHV, and what human disease does an infected woodchuck model?

Answer 35

Woodchuck hepatitis virus - Hepadnaviridae, model for hepatitis B infection and subsequent hepatocellular carcinoma

Question 36

What is Powassan virus?

Answer 36

flavivirus that causes encephalitis in humans and transmitted by Ixodes icks. woodchucks may be asymptomatic carriers.

Question 37

Ixodes cookie can transmit what agents to woodchucks?

Answer 37

1. Powassan virus (flavivirus) | 2. Akeritia marmotae (microfilaria

Question 38

Genus of WHV and other members of this genus

Answer 38

``` Orthohepadnavirus; hepatitis B virus (enveloped DNA virus)_ ```

Question 39

What are the two hypothesized mechanisms by which WHV cause HCC?

Answer 39

1. molecular integration of WHV DNA into the host DNA, leading to a mutagenic event 2. hepatic injury caused by viral infection enhances molecular events responsible for malignant transformation