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Infectious diseases I & II > Ruminants integument & mixed > Flashcards

Ruminants integument & mixed Flashcards

1
Q

Schmallenberg virus infection is an infectious disease of ruminants, transmitted by insects, and characterized by

A

arthrogryposis hydraencephaly syndrome.

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2
Q

SBV / Schmallenberg virus infection was first reported in

A

in 2011 in Holland and Germany.

Adult cattle had very non-specific clinical signs: fever, drop in milk production, watery diarrhea.

Later: abortions, stillbirths, malformations in cattle and sheep herds

New viral RNA was discovered in samples,
named after the geographic region of the first outbreak.

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3
Q

Causative agent of SBV infection.
family
genus
DNA type

A

Schmallenberg virus (SBV)
Genus Orthobunyavirus,
family Bunyaviridae
RNA virus

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4
Q

Schmallenberg virus serogroup and reassortment

A

Simbu serogroup

reassortment of the genomes of Sathuper and Shamonda viruses

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5
Q

Survival of SBV in environment etc.

A

Survival outside the host or vector is short

Inactivated in 50-60°C 30min
Common disinfectants can inactivate

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6
Q

Host range of SBV.

A

ruminants

Cattle, sheep, goats, buffalos, roe deer, red deer

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7
Q

Seroprevalence of SBV in cattle in Holland:

A

70%

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8
Q

Seasonality for SBV

A

Most common during high season of vectors so summertime.

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9
Q

Transmission of SBV.

A

Via blood sucking insects (mostly Culicoides spp)

In utero transmission
- In small ruminants on 28th-56th day of pregnancy
- Cattle 80th-150th day of pregnancy

Result: malformation of fetuses and newborns

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10
Q

Clinical signs of SBV in adult cattle:

A

Inappetence, weight loss
Fever (>40°C)
Drop in milk production (<50%)
Watery diarrhea
Recovery in 2-3 weeks

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11
Q

Clinical signs of SBV in calves:

A

Mild illness
Diarrhea

In utero transmission: malformation of fetuses and newborns

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12
Q

Clinical signs of SBV in newborns/neonates:

A

Cattle and small ruminants affected.

Fetuses are full term or near.

Congenital neurological disorders – lack of activity, abnormal vocalization, blindness, abnormal movements etc.

Malformations in spine and limbs, mandibula

Arthrogryposis hydranencephaly syndrome (AHS): stillbirth, premature birth, mummified fetuses, arthrogryposis (joint contractures), hydranencephaly, ataxia, paralysis, muscle atrophy, joint malformations, torticollis, kyphosis, scoliosis.

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13
Q

Suspect SBV when…

A

characteristic clinical signs in ruminants at the high season of vectors and at the following calving/lambing/kidding season.

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14
Q

Material for diagnosis of SBV: (2)

A

Aborted fetuses
Blood

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15
Q

Lab analyses for diagnosis of SBV: (3)

A

RT-qPCR – for viral RNA

Serology (ELISA, virus neutralization test) for antibodies

Histopathology

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16
Q

Vaccine for SBV?

A

Vaccine is expensive, but exists.

(Zulvac SBV protects cattle two weeks and sheep three weeks after vaccination.

In pregnant ewes vaccination reduced viraemia and infection of the embryo.)

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17
Q

Prevention & control of SBV.

A

Controlling or getting rid of the vectors – insecticides and mosquito nets.

Vaccine exists but is expensive and protection is short lived (2-3 weeks).

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18
Q

IBK

A

Infectious bovine keratoconjuntivitis

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19
Q

Infectious bovine keratoconjuntivitis is an infectious disease of cattle, sheep and goats, caused by Moraxella bovis, and is characterized by

A

blepharospasm, conjunctivitis, lacrimation, and varying degrees of corneal opacity and ulceration.

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20
Q

Causative agent of IBK.

A

Infectious bovine keratoconjuntivitis caused by gram neg. Moraxella bovis.

Family Moraxellaceae

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21
Q

serogroups of IBK

A

7 serogroups

Moraxella bovoculi has also been isolated from cattle with IBK but it is not recognized as a primary agent.

22
Q

Host range of IBK.

A

cattle, sheep, goats

Animals of all ages are susceptible
Most frequently affected: young animals

23
Q

Most common ocular disease of cattle?

A

IBK

Reported worldwide
More common during summer and fall

24
Q

Morbidity of IBK.

A

<80%

Risk factors: plant awns, face flies, ultraviolet radiation from bright sunlight, dry and dusty environmental conditions, shipping stress, trace mineral deficiencies (e.g. selenium and copper deficiency).

25
Q

Mortality of IBK.

A

0%, doesn’t kill, just blinds.

26
Q

Transmission of IBK.

A

Excretion: ocular and nasal discharge

Carriers can secrete for more than a year

Mechanial vectors – flies
Indirect contact – dust, grass

Route: via mucous membranes

27
Q

IP of IBK.

A

IP: 2-3 days

28
Q

Initial clinical signs of IBK. (3)

A

Photophobia
Blepharospasm
Epiphora

29
Q

Later signs of IBK. (3)

A

Ocular discharge may become mucopurulent

Conjunctivitis, with or without varying degrees of keratitis

Corneal ulcers

Appetite may be depressed.
In severe cases: corneal rupture and permanent blindness.

30
Q

Material for diagnosis of IBK.

A

Ocular swabs – get to the lab within 2 hours!

31
Q

Lab analyses for diagnosis of IBK.

A

Microbial culture
PCR

32
Q

Tx of IBK.

A

Tx: self-limiting dz

but ABs may be useful to prevent scarring.

In early cases: topical treatment
Later: parenteral treatment

Ancillary:
Place animal inside – out of sun light
Eye patches

33
Q

Prevention & control of IBK.

A

Fly control
Vaccines – efficacy?

34
Q

Enzootic bovine leukosis (EBL) is a contagious disease of cattle, caused by retrovirus, and characterized by

A

lymphocytosis and lymphosarcoma.

35
Q

Causative agent of Bovine lymphosarcoma.
genus
family
DNA type

A

Bovine leukemia virus (BLV)
Genus Deltaretrovirus,
family Retroviridae

RNA retrovirus

36
Q

Bovine leukemia virus is Closely related to

A

the human T-lymphotropic virus type 1 HTLV-I.

Oncogenic!

37
Q

Bovine leukemia virus survival in environment:

A

Does not survive long outside the organism.

In milk 1°C 3 days, in 10°C 48h

Inactivated by UV radiation

Common disinfectants can inactivate

38
Q

Host range of Bovine lymphosarcoma.
Age demo?

A

cattle

Uncommon in cattle <2 years of age.

More common in big herds

Milk cattle > beef cattle – higher age on average.

39
Q

Where in the world if Bovine lymphosarcoma found?

A

Reported in Canada, USA, some European countries and South America.

Eradicated in Estonia.

Notifiable disease

40
Q

Morbidity of BLV.

A

Morbidity <80%

41
Q

Transmission of BLV.

A

Excretion: blood, milk, tumor masses.
Virus is present mostly in lymphocytes.

Direct contact
Iatrogenic transmission
Insects? potentially mechanically.
Congenital infection

Route: through mucous membranes

42
Q

Clinical course of bovine leukemia virus infection.

A

Primary infection: flu-like syndrome (in 1-4 weeks)

Persistent infection: immune dysregulation (several months/years)

Persistent lymphocytosis: weakness, opportunistic infections (years)

Tumoral stage of disease: 5-10% animals make it to this point.

43
Q

Clinical signs of BLV.

A

Clinically presented in older animals (4-8 years) (long incubation period).

No clinical signs during initial stage of infection and persistent lymphocytosis.

Lymphosarcoma tumors in many sites developing rapidly.

Characterized by loss of body weight, inappetence, pallor, weakness, and loss of milk production.

Enlargement of all superficial lymph nodes (75-90%)

Abomasal ulceration
Congestive heart failure
Paresis and paralysis due to neural involvement.

Stertor due to enlargement of retropharyngeal lymph nodes.
Eventually weak and recumbent

44
Q

IP of BLV.

A

IP: 4-5 years

45
Q

Forms of sporadic bovine leukosis ( the congenital form of disease caused by BLV).

A

Sporadic bovine leukosis (congenital) has three forms:

Juvenile calf lymphosarcoma
Thymic lymphosarcoma
Cutaneous lymphoma

46
Q

Post mortem signs of BLV.

A

LNs and other tissues are infiltrated by neoplastic cells (Abomasum, heart, spleen, intestine, liver, kidney, omasum, lung, uterus).

Lymphosarcoma may appear as yellow-tan, discrete nodular masses or a diffuse tissue infiltrate.

Diffuse: enlarged, pale organ and can be easily misinterpreted as a degenerative change.

47
Q

Material for diagnosis of BLV. (2)

A

Blood
Milk

48
Q

Lab analyses for diagnosis of BLV. (3)

A

Identification of the agent – culture, PCR
Antibodies – serology
Histology

49
Q

Tx of Bovine lymphosarcoma

A

no treatment

50
Q

Prevention & control of BLV.

A

Eradication: test-and-slaughter!

Eliminate blood contamination
Colostrum feeding for antibodies

Thorough cleaning and disinfection of used equipment
Dehorning: cautery or other bloodless methods should be used

Change rectal sleeves between cows
Single use, disposable needles (IM)

Fly control

Infectious diseases I & II (33 decks)

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