Lecture 20 (Viral Diseases of Aquatic Mammals and Fish)

seals, sea lions, walruses

what is a pinniped?

dolphins and whales

what is a cetacean?

a) Pinniped Parapox

this virus, sometimes seen in free-ranging animals is a common, incidental disease of stranded seals and sea lions in rehabilitation centers and is a zoonotic concern:

a) Pinniped Parapox

b) Cetacean Parapox

c) Phocine Distemper Virus

d) Cetacean Morbillivirus

e) San Miguel Sea Lion Virus

a) Pinniped Parapox

infections manifest clinically as proliferative tumor-like lesions 2-3 cm in diameter on the skin or the mucosal surface of the mouth and nasal passages where they may obstruct airflow

a) Pinniped Parapox

b) Cetacean Parapox

c) Phocine Distemper Virus

d) Cetacean Morbillivirus

e) San Miguel Sea Lion Virus

wear gloves and personal protective gear when handling

the seal and sea lion parapoxviruses are considered zoonotic agents as animal handlers have acquired proliferative “sealpox” lesions on their hands after contact with captive, lesion-bearing seals

what recommendations could be made to the caretakers and handlers?

b) Cetacean Poxvirus

the cutaneous manifestations of this reported viral infections in dolphins and whales are hyperpigmented skin lesions described as "tattoo lesions" and it has been suggested that this virus may be associated with stressful conditions such as poor water quality, environmental contamination, and underlying ill health

a) Pinniped Parapox

b) Cetacean Poxvirus

c) Phocine Distemper Virus

d) Cetacean Morbillivirus

e) San Miguel Sea Lion Virus

b) Cetacean Poxvirus

causes hyperpigmented skin lesions, and thus is referred to as "Tattoo Skin Disease"

a) Pinniped Parapox
b) Cetacean Poxvirus
c) Phocine Distemper Virus
d) Cetacean Morbillivirus
e) San Miguel Sea Lion Virus

b) Cetacean Poxvirus

causes disseminated proliferative skin lesions in Beluga Whales

a) Pinniped Parapox
b) Cetacean Poxvirus
c) Phocine Distemper Virus
d) Cetacean Morbillivirus
e) San Miguel Sea Lion Virus

Cetacean Gammaherpesviruses

this virus is associated with mucosal lesions in digestive, genital, and respiratory tracts // pharyngeal plaques are associated with this viral infection in rough-toothed dolphins and Atlantic bottlenose dolphins

a & b both describe Gammaherpesvirus

A beached whale had a tumor like lesion on its phallus and is now in your lab for necropsy and investigation. This sign could be papillomavirus or gammaherpesvirus in a whale; how might you tell them apart?

a) ____________ would also show lesions in the GIT, Respiratory Tract, and Pharyngeal mucosa
b) ___________ would also show eosinophilic inclusions bodies on histopathology

Genital Herpesvirus

you do a necropsy on a Bottlenose dolphins and find plaques on the penile mucosa and vulvar mucosa // this virus was likely transmitted by sexual contact and the dolphin had a Hx of abortion and perinatal mortality

which virus is this most likely to be?

a) Papillomavirus

this is a highly prevalent virus found in a wide range of animals including dolphins, whales, and manatees; causes tumor-like lesions and is transmitted by contact and fomites

a) Papillomavirus

b) San Miguel Sea Lion Virus (Calicivirus)

c) Cetacean Herpesvirus (Gammaherpesvirus)

d) Influenza

b) Phocine Distemper is confined to seals, but Canine Distemper Virus can affect seals in addition to dogs

which of the following is true?

a) Canine Distemper and Phocine Distemper are species specific; no flowing at all

b) Phocine Distemper is confined to seals, but Canine Distemper Virus can affect seals in addition to dogs

c) Canine Distemper is confined to dogs, but Phocine Distemper Virus can affect dogs in addition to seals

d) Canine Distemper & Phocine Distemper can both affect both dogs & seals

true

t/f: characterization of viral isolates from distemper outbreaks have shown that phocine distemper virus is related but clearly distinct from Canine distemper

c) Phocine Distemper Virus

clinical signs in Young Seals:

-depression // anorexia // crusting conjunctivitis // nasal discharge // nasal discharge // dyspnea

-pneumonia develops

-mortality is high in naive populations

a) Pinniped Parapox

b) Cetacean Parapox

c) Phocine Distemper Virus

d) Cetacean Morbillivirus

e) San Miguel Sea Lion Virus

c) Phocine Distemper Virus

associated with a high mortality in naive populations; a canine vaccine has been given to monk seals in Hawaii to protect against this virus:

a) Pinniped Parapox
b) Cetacean Parapox
c) Phocine Distemper Virus
d) Cetacean Morbillivirus
e) San Miguel Sea Lion Virus

d) Cetacean Morbillivirus

this virus is closely related to rinderpest and peste de petits ruminants // seen in Bottle Nosed Dolphins, Striped Dolphins, and Minke Whales and largely associated with strandings

a) Pinniped Parapox
b) Cetacean Parapox
c) Phocine Distemper Virus
d) Cetacean Morbillivirus
e) San Miguel Sea Lion Virus

d) Cetacean Morbillivirus

causes lesions on the skin, mouth, joints, and lungs // also targets the brain and lungs primarily leading to infections there // can see pneumonia and other secondary infections from compromised immunity

a) Pinniped Parapox
b) Cetacean Parapox
c) Phocine Distemper Virus
d) Cetacean Morbillivirus
e) San Miguel Sea Lion Virus

d) Influenza

killed 162 New England harbor seals in 2011 and has been associated with Pilot Whale Strandings as well:

a) Papilloma Virus
b) San Miguel Sea Lion Virus (Calicivirus)
c) Cetacean Herpesvirus (Gammaherpesvirus)
d) Influenza

1. H3N8
2. H13N2 & H13N9

1. ______ was the recently mutated avian flu that killed harbor seals in 2011

2. _____ & _____ were the flu viruses that jumped from gulls to pilot whales in 1984

choices: H3N8, H5N1, H7N6, H13N2, H9N13, H13N9

b) San Miguel Sea Lion Virus (Calicivirus)

this aquatic mammal virus appears to be a serotype of vesicular exanthema in swine (VESV)

a) Papilloma Virus
b) San Miguel Sea Lion Virus (Calicivirus)
c) Cetacean Herpesvirus (Gammaherpesvirus)
d) Influenza

b) Pacific Ocean

San Miguel Sea Lion Virus has only been seen in the:

a) Atlantic Ocean
b) Pacific Ocean

b) San Miguel Sea Lion Virus (Calicivirus)

by 4 months of age, most sea lions already have antibodies to ___________; interestingly humans exposed to this virus will develop antibodies to it too
-opaleye fish are a reservoir of the virus

a) Papilloma Virus
b) San Miguel Sea Lion Virus (Calicivirus)
c) Cetacean Herpesvirus (Gammaherpesvirus)
d) Influenza

San Miguel Sea Lion Virus (Calicivirus)

clinical signs:

-lesions in marine mammals is skin vesicles on the dorsal surfaces of the for flippers

-lesions erode and leave shallow, fast-healing ulcers

-can cause premature parturition

-affected pups have interstitial pneumonitis and encephalitis and fail to thrive

supportive treatment only → skin lesions resolve without treatment

what is the Tx for San Miguel Sea Lion Virus (Calicivirus)?

Infectious Pancreatic Necrosis

-this is a severe viral disease of young salmonid fish and Atlantic salmon
-adults can carry virus without showing symptoms
-virus is spread via infected water, also vertically
-high mortality but some survive

Infectious Pancreatic Necrosis

what virus is this?

clinical signs include:

-abdominal swelling

-not eating

-abnormal swimming

-darkening of skin

-feces trailing from vent

Channel Catfish Virus disease

-this virus is very virulent in young naive populations of cultured channel catfish with mortality near 100%

-clinical signs include → distended abdomen (pot-bellied) // convulsive swimming with a head-up posture // lethargy // exophthalmia // hemorrhages at the base of the fins

Infectious Pancreatic Necrosis

Upon necropsy of an Atlantic salmon fish you see necrosis to the pancreas and thick mucus inside intestines. Would you assume Infectious Pancreatic Necrosis or Channel Catfish Virus Disease?

Channel Catfish Virus Disease

Upon necropsy of a catfish you see red or yellow-tinged peritoneal fluid, enlarged spleen, petechial hemorrhages on kidney, liver and visceral fat. Would you assume Infectious Pancreatic Necrosis or Channel Catfish Virus Disease?

-few therapeutic approaches

-avoidance & prevention major tools (Biosecurity)

-understanding the biology of the virus

-water supply considerations, high water quality

-broodstock screening, no mixing of batches, moving fish

-vaccines, if available

-breeding genetically resistance fish

talk about treatment of viral diseases in fish