Transcript pathology_of_viral_diseases._course_no._401._by_dr

Department of Pathology
Faculty of veterinary medicine
Introduction
* Viruses can be classified into
two classes DNA and RNA viruses.
* Most viruses stimulate lymphocytes,
however, equine encephalomyelitis
stimulate neutrophils firstly and
then
lymphocytes.
* Most viruses result in coagulative
necrosis, however, equine
encephalomyelitis result in
liquifactive necrosis.
Virus
and
tissue reaction
* Some viruses resulting in lysis and necrosis of cells--------------------------------Herpes v.
*Some viruses resulting in Proliferation of cells--------------------------------------Pox,Leukosis.
*Some viruses resulting in Fusion of cells and syncytial
formation-------------Paramyxovirus.
*Some viruses resulting in Apoptosis of cells-----------------------------------------Rift valley fever.
*Some viruses resulting in Transformation of cells----------------------------------Lung adenomatosis.
*Some viruses resulting in Inclusion bodies which either –
----------------intranuclear ( I/N )-----------Herpes.
------------------intracytoplasmic ( I/C )------Pox.
------------------I/N and I/C---------------Paramyxovirus.
Virus
and
infection
* Acute infection:
Virus is eliminated by host
immune response.
* Chronic or persist infection:
Virus is not eliminated and
can be isolated for long time.
* Latent infection:
Virus is apparently eliminated
and reappears under stress
factors as herpes.
Immunotolerant animal:
*Animal get infected by
virus and considered it as
self antigen(no antibodies)
*Animal appeared normal
but sheds virus to other
animals
As in BVD infection.
Viral diseases
characterized by
vesicle formation
Foot and mouth disease
F.M.D
Aphthus fever
Aphthus ruminitis
DEF.
* Viral disease of cloven footed animals; cattle, sheep, camel, and may pig.
* Not affect horse.
* Ch’ch’ : Vesicle formation on the buccal cavity, interdigital space, rumen,
reticulum, omasum, and udder.
Cause
Picornaviridae(epitheliotropic)R.N.A
R.O.I
Ingestion – Inhalation
Pathogenesis
Virus ( via R.O.I )………………………………….. Buccal cavity ( str. Spinosum )
…………………………………………Ballooning degeneration(hydropic)…………………………Vesicle( aphthus )or bullae
……………………………………………….Erosion ……………………….. Ulcer…………………………………………..Virus to circulation
………………………………………………………………..Viremia …………………………….G.I.T, Interdigital space & udder.
Lesions (i) MACRO
* Buccal lesions :
-Vesicle or bullae on anterior 2/3 of the dorsum of tongue.
-Dental pad and buccal cavity are also affected.
* Foot lesions :
-Affect interdigital space ………………………………..Lamness.
-In complicated cases the claws may slaughed.
* G.I.T lesions :
-Vesicles, Necrosis & Erosions in oesophagus, rumen APHTHUS RUMINITIS.,
reticulum, omasum,and intestine.
-Peticheal H. on abomasums, intestine, and subendocardium.
* Udder lesions :
Vesicle on Teat extend to Mamary ts …………………………………….Mastitis.
(ii) MICRO
*Epidermis
-Ballooning (hydropic Degenerations)
-Vesicle(serous fluid,epithelial cells,inflame.cells(mostly lymphocytes & few
neutrophil………………………………………..Erosion …………………………………………………Ulcer
* Dermis
Dermatitis
i) Congestion
ii) Inflammatory cells ( lymphocytes + neutrophils)
iii) Perivascular cuffing
Lesions in bucal cavity
Malignant F.M.D
DEF. : *Per acute F.M.D of young calves end with rapid death due to
(ACUTE GENERAL VENOUS CONGESTION ).*Ch’ch’ non suppurative myocarditis.
Cause : R.N.A virus.
R.O.I : Ingestion & Inhalation.
Pathogenesis : Virus via R.O.I……Viremia ….Heart muscles & Skeletal muscles.
Lesions :
(i) MACRO :
Greyish necrotic foci on the wall of left ventricle take TIGER appearance
SO known as TIGER HEART.(The same lesions are seen in skeletal Ms.)
ii)MICRO :
Zenker’s necrosis + Inflammatory cells ( Lymphocytes + Macrophages ).
(The same lesions are seen in skeletal Ms.)
***F.M.D In SHEEP :
Vesicle on teat, vulva, & dental pad////// Milder than in cattle////////
F.M.D In Lambs & Pigllets
Usually DIE.
Non-suppurative myocarditis
Vesicular stomatitis
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DEF.:*
Viral disease affect mainly horses.
* May affect cattle and pig.
* Ch’ch’ vesicle on the buccal cavity,
Interdigital space and udder
* Seasonal disease as it occurs in
summer coz of mosquito.
* Enzootic disease as it occurs in
U.S.A
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
Cause:
Rhabdoviridae genus (aphthous) e’ 7
Ag types(A,O,C,sat1,sat2,sat3,AsIA1)
 e’out cross protection between them
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
R.O.I
Mosquito bite
wound contamination
Vesicular exanthema
 Def.:
 * Viral disease affect

mainly pigs.
 * Ch’ch’ vesicle on the
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buccal cavity,

Interdigital space

And udder
 Cause:
 Calciviridae
 R.O.I:
 Ingestion
Vesicular stomatitis
Vesicular exanthema
 Pathogenesis
 Virus ( via R.O.I ) ………Buccal cavity ( str. Spinosum)………..
spongiosis ………………. Vesicle ( aphthus ) or bullae…
Erosion…………Ulcer.
 Virus to circulation ……… Viremia ……
……………………………G.I.T, Interdigital space & udder.
 Lesions:
 As F.M.D ( Buccal, Foot, and Udder Lesions ONLY)
 N.B
 (HYDROPIC DEGENERATION REPLACED BY SPONGIOSIS IN
HORSE VESICULAR STOMATITIS)
F.M.D
Vesicular
stomatitis
Vesicular
exanthema
ANIMALS
Cloven footed
Horse, Cattle, and
Pigs.
Pigs
FATALITY
Fatal in young
Not fatal
Not fatal
MYOCARDIUM
Affected
IN YOUNG
Not affected
Not affected
IN EGYPT
Present
Not present
Not present
DIAGNOSIS OF FMD,Vesicular stomatitis&Vesicular
exanthema:
(1) Clinical Signs (Fever(aphthus fever), Off food,
Salivation,Smaking of mouth,vesicles on its sites.
(2) Post mortem lesions(Macro and Micro).
(3) Isolation And Idenification Of Virus.
(4) Diffrential diagnosis from other vesicular diseases.
Control measures :
(1)Complete eradication of infected animal.
(2) Attenuated vaccine for only 1 virus to avoid cross immunity.
PoxViridae
virus
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GENERAL Characters :
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(i) Type
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(ii) Tropism : Epitheliotropic.
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(iii) R.O.I
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: D.N.A virus with 6 genera; Orthopox, Capripox, Lapripox, Suipox, Avipox, and Parapox.
: Insect bite, Wound contamination (contact ), Inhalation, Ingestion, and
Coitus.
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(iv) Animal susceptiple :
* Affect most animals except dogs.
* Horse pox----------- 3 forms; Leg, Buccal, and Genital . Ch’Ch’ Pock lesions .
* Cow & Buffalo …….mild affection. …. Affect teat & udder causing pock lesions.
Microscopic lesions as those of sheep.
* Camel …………Fatal in Young ………… Local in adult. Ch’Ch’ Pock lesions .
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* Human …
(i) Pseudo cow pox ( MILKER’S NODULES )
Transmitted to milkers from teat cow pox through milking.
(ii) Small pox ( VARIOLA )
Fatal as it has systemic reaction + skin affections.
Human vaccinized against small pox.
 (v) Lesions : Cutanous & Systemic lesions.
 (vi) Inclusions : I/C inclusion bodies ( GUARNIERI BODIES )
 (viii) Pathogenesis of sheep pox lesions In order :
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(i) ROSEOLA St. …….. Red line of dilated vessel.
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(ii) MACULA St. …….Edema & Inflammatoty exudates.
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(iii) PAPULE St. ………Proliferations of cells.
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(iv) VESICULAR St. ……Vesicle formation.
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(v) Pastule St.
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(vi) UMBLICATED St. ( POCK LESION )……………..
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vesicles ruptured giving ulcer with elevated borders.
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(vii) ENCRUSTATION St……..Crust with scab formation.
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(viii) HEALING St. …………..Healing of deep pitted ulcer.
SHEEP POX
ORF
SCABY MOUTH
CONTAGIOUS ECTHYMA
CONTAGIOUS LABIAL
DERMATITIS
CONTAGIOUS PASTULAR
DERMATITIS
ULCERATIVE VULVITIS
ULCERATIVE DERMATOSIS
INFECTIOUS
BALANOPOSTHITIS
LIP & LEG ULCERATION
* Viral disease of SHEEP and
goat
* Ch’ch’ cutaneous eruption
(pock lesions) in areas
devoid of wool
(lips,nostril,cheek,inner
thigh&scrotum).
*Also affect pharynx, trachea,
lung,Rumen &
kidney which increase
mortality.
* Viral disease of SHEEP, GOAT
& human .
•Viral diseaseof SHEEP &
GOAT.
* Ch’ch’ Papules, Vesicle
formation &Pastules on
(oralcavity,oral commisure &
lips)
covered with thick scab.
*Ch’ch’ ulcer formation on
( vulva, glanspenis, lip& leg)
Cause
Pox virus
Para pox
Pox virus
R.O.I
DIRECT CONTACT
INGESTION
DIRECT CONTACT
CONTACT
COITUS
Pathogenesis
Roseola, Macula, Papule,
Vesicle, Pock lesion, Crust&
Healing.
___________
_____________
DEF.
SHEEP POX
Lesions
(i)
MACRO
(ii)
MICRO
* (Pock lesions) in areas devoid of wool
(lips,nostril,cheek,inner,Thigh &scrotum)
*Also affect pharynx, trachea,
lung, rumen&kidney which increase mortality.
Epidermis :
* Hydropic deg.&spongiosis in
prickle cell layer.
* Neutrophils exocytosis in
prickle cell blayer.
* I/C EOSINOPHILIC inclusion
body ( GUARNIERI BODIES )
Dermis :
* Dermatitis
i)
ii)
iii)
Congestion.
Lymphocytes.
Perivascular cuffing.
* Pathognomonic lesions
SHEEP POX CELL
* It’s virus infected
Macrophages appeared e’
-margination of chromatin,
-prominent nucleoli
- I/C inclusion
* Formed in deep dermis.
ORF
SCABY MOUTH
CONTAGIOUS ECTHYMA
CONTAGIOUS LABIAL
DERMATITIS
CONTAGIOUS PASTULAR
DERMATITIS
•Ch’ch’ Papules, Vesicl
formation &Pastules
on (oral cavity,oral commisure
& lips)
covered with thick scab.
•Formation of papillomatosis
growth on lips
covered with brown crust.
Epidermis :
* I/C BASOPHILIC inclusion
body
( GUARNIERI BODIES )
Dermis :
* Dermatitis
i)
Congestion.
ii) Lymphocytes.
iii) Perivascular cuffing.
*Pathognomonic lesions
PSEUDO CARCINOMATOUS
HYPERPLASIA
Downward proliferation of
epidermal cells into dermis
ULCERATIVE VULVITIS
ULCERATIVE DERMATOSIS
INFECTIOUS
BALANOPOSTHITIS
LIP & LEG ULCERATION
Ulcer formation on vulva,
glanspenis, lip& leg covered
with brown scab.
Epidermis :
* Destruction of epidermal
layer into dermis(
ULCERATION ).
* I/C inclusion body
( GUARNIERI BODIES )
Dermis :

Dermatitis
i)
Congestion.
ii) Lymphocytes.
iii) Perivascular cuffing.
Sheep pox - under tail (elevated
papule)
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Sheep pox (scab formation)
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Cow pox (udder)
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Cow pox (udder)
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Avian pox
(intracytoplasmic inclusions)
High
power
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Avian pox
(intracytoplasmic inclusions)
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Orf
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Contagious echthyma (Orf)
Index
LUMPY SKIN DISEASE
L.S.D
DEF.
* Viral disease of CATTLE & BUFFALOS.
* Ch’ch’ nodule formation on Nose,eyelid &conjunctiva.
scrotum&glanspenis in males.udder&vulva in females.
* Also Ch’Ch’ LYMPHADENOPATHY.
Cause
Capri pox
R.O.I
INSECT BITE
Pathogenesis
Lesions
(i)
MACRO
(ii)
MICRO
Bovine Papular stomatitis
* Viral disease of cattle.
* Ch’ch’ : Papules on; Buccal mucosa, Muzzle,
Gum, Dental pad, and Lips.
Para pox virus
Vasculitis ……….Thrombosis ………Ischemia ………..Necrosis
*Erythema------------ Papule-------------- expand
slowly and similar to COIN ( necrosed
center ).
* Intra dermal LUMPS ( Hard indurated nodules )
*SIT FAST:
Necrosed nodules with sequestration ……….Deep ulcer.
* Erythema begins.
•Papule-------------- On Buccal mucosa,
Muzzle, Gum, Dental pad, and Lips
Epidermis :
* Vacuolar degeneration and Necrosis.
* I/C EOSINOPHILIC inclusion ( GUARNIERI BODIES )
Dermis :
a) Epidermis :
i) Hyperplasia in epidermal cells.
ii) Vacuolar degeneration
iii) I/C inclusions.
* Dermatitis
I ) Lymphocytic infiltration.
Ii) Vascular congestion.
Iii) Perivascular cuffing
* Pathognomonic lesions
- Vasculitis
- Thrombosis
-I/C inclusion inside macrophage
b) Dermis :
Dermatitis--------I ) Lymphocytic infiltration.
Ii) Vascular congestion.
Iii) Perivascular cuffing.
Lumpy skin disease
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Lumpy skin disease
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 DIAGNOSIS OF pox viridae:
 Clinical Signs.
 Post mortem lesions(Macro and Micro).
 Isolation And Idenification Of Virus.
 Diffrential diagnosis from other
epitheliotropic diseases.
VIRAL DISEASE
OF
CATTLE
Affect
Respiratory
System
1- Bovine
Malignant OF
Cattarhal
Fever
VIRAL
DISEASE
CATTLE
B.M.C.V
Malignant Head Cattarhal Fever
M.H.C.F (I/N)
Viral disease of cattle &buffaloes ch’ch’:
(i)Erosion in upper respiratory tract
DEF. (ii) Keratoconjunctivitis.
(iii) Encephalitis.
(iv) Erosive stomatitis & gastroenteritis.
(v) Lymphadenitis.
(vi) Cutaneous exanthema.
D.N.A Herpes virus
Cause
(African(wildbeets)&sheep strain)
R.O.I
Ihalation + Ingestion
1- Bovine Malignant Cattarhal Fever B.M.C.V
Malignant Head Cattarhal Fever
M.H.C.F (I/N)
(i) Diphteretic membranes in nasal mucosa, pharynx,trachea&bronchi.
Lesio (ii) Keratoconjunctivitis, corneal opacity& edema of eyelid.
ns (iii) Encephalitis, Gliosis, myelitis& perivascular cuffing.
(iv) Erosion &ulcers along oral mucosa, omasum &intestine.
(v) Liver enlarged & mottled.
(i) (vi) Kidney shows Interstitial nephritis.
MAC
RO
(viii) In most cases, s/c blood vessels are tortuous in thorax and abdomen As
well as fibrinous poly arthritis.
(ix) Cutanous vesicular & popular exanthema.
(i) Necrosis of epithelium along respiratory and gastrointestinal tract.
(ii) (ii) Congested blood vessels.
MICR (iii) Inflammatory cells mostly lymphocytes.
O
)
2- Infectious Bovine Rhinotrachiitis I.B.R
Red Nose Disease
I.P.B & I.P.V & C.V.V
(I/N)
Viral disease of cattle & buffaloes ch’ch’:
(i) Rhinotrachiitis.
(ii) Keratoconjunctivitis.
(iii) Encephalitis.
DEF. (iv) Balano Posthitis (I.P.B)
(Infectios Pastular Balanoposthitis)
(v) Vulvo vaginitis (I.P.V)
(Infectious Pastular Vulvovaginitis)
(vi) Abortion if at late pregnancy.
D.N.A Herpes v.
Cause
(3 subtypes;resp.,genital,encephalic)
Inhalation + Sexual intercourse (C.V.V)
R.O.I (Coital Vesicular Vulvovaginitis)
2- Infectious Bovine Rhinotrachiitis
Red Nose Disease
I.P.B & I.P.V & C.V.V
(I/N)
I.B.R
3 FORMS OR 3 Subtypes
(i) Respiratory form(subtype):
(a)Erosive rhinitis(RED NOSE), Trachiitis& Bronchitis with diphtheritic membranes.
Lesions
(b)Keratoconjunctivitis & corneal Opacity DUE TO transmission of Virus via trigeminal
nerve.
(e) Encephalitis,Gliosis & perivascular cuffing.
IBR in young calves is fatal & Ch’Ch’ resp.distress, diarrhea&end by convulsion&death.
(i)
MACRO (ii) Genital form or subtype :
(a) Vulvo Vaginitis : Inflam. , vesicles&pustules of vulva & vagina.
(b) Balano Posthitis : Inflam. , vesicles&pustules of penis & prepuse.
(c) Mastitis.
(iii) Abortion form :
Infection in late pregnancy ……………. mamification & still birth;
Intra uterine fetal death 72 hrs before abortion & aborted fetous showed …………………
Necrotic hepatitis & I/N inclusion body Surrounded by hallo zone
(i) Necrosis of epithelium along respiratory and gastrointestinal tract.
(ii)
(ii) Congested blood vessels.
MICRO
(iii) Inflammatory cells mostly lymphocytes
(v) (
3- Bovine respiratory
syncytial virus
(I/C)
DEF. Viral disease of cattle
ch’ch’:
Interstitial pneumonia
accompany by
4- Parainfluenza III virus
(I/C)
Viral disease of cattle
ch’ch’:
Interstitial pneumonia
Cause R.N.A viruses ( Pneumo virus-paramyxoviridae )
R.O.I
Inhalation
3- Bovine respiratory
syncytial virus
(I/C)
4- Parainfluenza III
virus
(I/C)
PATHO Virus stimulate bronchi and alveolar epithelium result in Bronchointerstitial
GENESI pneumonia with
S:
Lesions Lung is atlectatic and consolidated with interstitial pneumonia.
(IN BOTH VIRAL INFECTION)
(i)
interstitial and subpleural emphysema.
MACRO
(ONLY IN BOVINE RESPIRATORY SYNCYTIAL VIRUS)
(ii)
MICRO
* Bronchiolitis with cells
proliferation esult in
•Hyperplasia of pneumocyte type
II (Lung epithelization).
* Accumulation of lymphocyte and
plasma cells
•Bronchioles&alveoli filled
with exudates accomp.by neutrophils
lymphocytes&macrophages
*Bronchial epithelium is hyperplastic ,
vacuolated&contain
* Hyperplasia of pneumocyte type II
with squamous metaplasia and rare
syncytial cells.
Affect
Digestive
System
5- Rinder Pest R.P
Cattle plague.(C.P)
(I/N+I/C)
DEF.
Cause
R.O.I
Viral disease of cattle and buffaloes ch’ch’:
(i) Necrosis & ulceration of G.I.T.
(ii) Degeneration of lymphoid tissues ( L.N + Spleen ).
Paramyxoviridae
Ingestion OR
Inhalation
Pathog Ingestion ………………….Regional L.N and tonsils where it multiplies
enesis : Viremia & secondary multiplication in G.I.T, upper respiratory, and
lymphoid tissues.
5- Rinder Pest R.P
Cattle plague.(C.P)
(I/N+I/C)
Lesions
(i) Bran like Necrosis & ulceration in Buccal cavity at ventral aspect of tongue,
tongue tip,dental pad, gum, oral comissure & inner aspect of lips.
(ii) Necrosis & ulceration in pharynx & esophagus.
(i)
MACRO
(vi) Necrosis & ulceration in payer’s patches.
(vii) Lymphoid tissues :
L.N …………………Enlarged & hemorrhagic
Spleen …………….Enlarged Then Atrophied
(viii) Hemorrhage in larynx, trachea, bladder &subendocardium.
(i) Syncytia formation( fusion of necrotic epithelium) + Multinucleated cells w’
(ii)
contain I/N + I/C inclusions(PATHOGNOMONIC)
(ii) Lymphoid tissues showing necrosis of lymphoid follicles w’ appeared as craters.
MICRO (iii) Lamina propria of small and large intestine show----congestion, edema&
lymphocytic infiltrations.
6- Bovine Viral Diarrhea
B.V.D
Mucosal Disease
DEF.
Cause
R.O.I
Viral disease of cattle and buffaloes ch’ch’:
(i) G.I.T lesions & diarrhea..
(ii) Leucopenia (immunosupression).
(iii) Still birth fetous with C.N.S lesions.
Flaviviridae
Ingestion OR
Inhalation
Pathog There are 2 strains of BVD;
enesis : Cytopathic strain ( CP-BVD ), Non cytopathic strain ( NCP-BVD )
Cattle may infected with each of cp-BVD & Ncp-BVD and give the infection
to fetous
At 1st 120d--------- Abortion, mummification, Resorption, teratogenic effect
> 120d------ Abortion OR Healthy calve.
Some cattle may infected with NCP-BVD and didn’t show signs and pass
virus to fetous during 1ST 120 ds………………Persistant infected calf ( PI calf ) ,
immune tolerant calf, or chronic shedders.
If PI calf infected with CP-BVD---------Show mucosal disease and usually end
fatally.
6- Bovine Viral Diarrhea B.V.D
Mucosal Disease
i) Erosion in muzzle, nose, larynx, and pharynx.
(ii) Linear erosion along oesophagus.
(iii) Erosion along rumen, omasum, and abomasums.
(i)
(iv) Congestion & edema along abomasums &small intestine.
MACRO (v) Necrosis in pyres patches.
(vi) Zebra marking in intestine.
(vii) Destructed lymphoid tissues.
(viii) Erosions in skin & interdigital space( lameness).
(ix) Foeti suffered from mummification, abortion with or without teratogenic
characters as :
*cerebral or cerebellar hypoplasia*porencephaly- hydranencephaly*microphthalmia- cataract*optic neuritis
*thymus hypoplasia.
•Necrosis of epithelium along G.I.T with; congested bl.vs., and lymphocytic
(ii)
infiltrations.
* Submucosal bl.vs. of G.I.T show vasculitis.
MICRO * Lymphoid tissues ( L.N, spleen, thymus, and pyer patches ) showing necrosis.
* Aborted fetous :
*Brain of foeti show demylination.
*Depletion of the lymphoid tissues (L.N &Spleen)
BVD
RP
OESOPHAGUS
Linear erosion
Necrotic foci
SKIN LESIONS
Interdigital spasce
Absent
FOETAL
LESIONS
CHRONIC
FORM
Present(Cerebral)
Absent
Present
Absent
VASCULITIS
Present
Absent
INCLUSIONS
Absent
Present
7- Corona
and
Rota viruses
DEF.
Viral disease of cattle& most domestic animals ch’ch’: DIARRHEA
Cause
Coronaviridae & Rotaviridae
R.O.I
Ingestion
Pathog Pathogenesis :
enesis : Ingestion …………..Intestine where viruses replicate in enterocytes
…………………resulting in damage and exofoliation of
cells……………………………………………followed by villous atrophy.
Lesions * Villous atrophy and villi appeared club shaped, blunt, and fused to
each others
( mucosa become flat or cuboidal )
MICRO *Hyperplasia & Hypertrophy Of Crypts.
* Lamina propria is heavy infiltrated by Macrophages & lymphocytes.
IN CORONA VIRUS ONLY NOT IN ROTA:
* Colon mucosa become flat or cuboidal.
* Mesentric l.N & payer patches destructed.
Affect
Lymphoid
Tissues
DEF.
Cause
R.O.I
8- Bovine ephemeral fever
9- Bovine Leukosis
Three day sickness
Viral disease of cattle and
Viral disease of cattle Ch’Ch’ : enlargement of
buffaloes Ch’Ch’ :
lymph nodes.
Fever for three days, lamness,
and enlargement of lymph
nodes.
R.N.A viruses ( Rhabdoviridae )
R.N.A viruses ( Retroviridae )
Mosquitoes
Ingestion OR Congenital
Virus by mosquitoes
Viremia …………..Localized in;
Muscles, Joints, Spleen, and
Pathog Lymph nodes
enesis
*The animal reacted with virus in four different ways;
1. It doesn’t infected due to genetic characters.
2. It is permenant infected with antibodies
( Latent infected ).
3- It is permenant infected with Benign
lymphosarcoma.
4- It is permenant infected with malignant
lymphosarcoma
*Also there are SPORADIC and ENZOOTIC leucosis.
1- THE ENZOOTIC LEUKOSIS:
* Usually affect cattle from 4-8 years.
* Ch’Ch’: Fatal lymphosarcoma.
2- THE SPORADIC LEUKOSIS :
* May be JUVENILE cal f--------------- < 5m.
* Thymic --------------------------------------- < 2y.
OR * Cutaneous ----------------------------------- 1-3y.
8- Bovine ephemeral fever
Three day sickness
Lesions
(i)
MACRO
(ii)
MICRO
9- Bovine Leukosis
ENZOOTIC LEUCOSIS :
i) Edema & hemorrhages all over
i) Enlargement of superficial and
body.
mesenteric lymph nodes.
ii) Enlargement of spleen and
ii) Abomasum contain nodules and
lymph nodes
ulcers.
iii) Interstitial lung emphysema.
iii) Heart, spleen, and kidney are
iv) Polyserositis in joints, tendon&
greatly enlarged.
peritoneum
SPORADIC LEUCOSIS :
 CALF LYMPHOMA--------------Enlargement of lymph nodes.
 THYMUS LYMPHOMA--------Enlargement of thymus.
 CUTANOUS LYMPHOMA----Cutanous plaques.
Inflammation of ; Joint, tendon,
and muscles Ch’Ch’ :
Uniform lymphocytic infiltration in
i) Congested blood vessels.
affected organs
ii) Inflammatory cells mostly
lymphocyte
Leukosis
VIRAL DISEASE
OF
SHEEP
1-JAAGSIEKTE (driving sickness)
or
LUNG OR PULMONARY ADENOMATOSIS
DEF.
Pathogen
esis
2-MAEDI (shortness of respiration)
or
OVINE PROGRESSIVE INTERSTITIAL PNEUMONIA
(I/C)
Viral disease of sheep ch’ch’ lung nodules.
Known as Driving disease because affected sheep show
clinical signs during transportation.
Viral disease of sheep ch’ch’ :
i- Progressive ( Diffuse ) lymphofollicular interstitial pneumonia ( NEVER
Virus stimulate bronchial and alveolar epithelium
Virus stimulate peribronchial lymphoid tissue and sometimes alveolar
epithelium
HEAL )
ii- Increase lung volume 2-3 times its normal volume
result in marked hyperplasia of clara cells &
pnemocyte typeII…………… Adenomatous growth of
bronchial & alveolar epithelium.
Cause
Retroviridae R.N.A Viruses
Retroviridae R.N.A Viruses (( Maedi visna(meningioencephalitis) ))
R.O.I
Inhalation
Inhalation ( with long incubation period 2-3y )
Lesions
(i)
MACRO
(ii)
MICRO
(a)
Areas of consolidation, areas of collapse &
areas of compensatory emphysema.
(a)
(a) Lung enlarged 2-3 times its volume with ribs imprints.
(B) Bronchial & Mediastinal L.N enlarged and edematous
Lung increase in size and weight with multiple nodules
all over the lung tissue.
The bronchioles and alveoli lined by columnar and
cuboidal epithelium in the form of finger like projection
known as:
Adenomatus growth in the alveolar epithelium.
(a)
(b)
(d)
Bluish I/C inclusion bodies.
Lymphofollicular sheath around; Bronchi, Bronchioles, and
Blood vessels.
Hyperplasia & Hypertrophy in the alveolar wall (pneumocyte
type II)
Hyperplasia of smooth muscle of terminal bronchioles.
(e)
(f)
Mononuclear cells infiltrations.
Meningioencephalitis and arthritis.
(c)
JAAGSIEKTE
MAEDI
LESIONS
LOCAL
DIFFUSE
Adenomat
ous
growth
COURSE
OF
DISEASE
LYMPH
NODE
PRESENT
ABSENT
SHORT
LONG
NOT AFFECTED
AFFECTED
ABSENT
PRESENT ( I/C )
INCLUSIO
N BODY
 3- P.P.R. ( Pestes de Petit Ruminant )
 The cattle plague of ( SHEEP & GOAT ).
Def. :
Viral disease of sheep and goat similar to cattle plague.

Cause:
RNA virus antigenic related to cattle plague, canine
distemper, and human measles.

R.O.I :
Ingestion OR inhalation.

Postmortem and microscopic findings -----------------------------Similar to cattle.
 4- Border disease ( Hairy Shakers ds.) OR Fuzzy lambs:

Def.:

Viral disease of sheep and lambs Ch’ch’ abortion, still birth, and small weak lambs with tremor,abnormal body conformation
and hairy fleeces (Hairy Shakers OR Fuzzy lambs).


Cause:

R.N.A ( Flaviviridae ) called BORDER because it occurred between Wales & England. R.O.I: Ingestion

Pathogenesis:
Ingestion--------Viremia-------(i) In NON pregnant sheep….Causes a mild disease.


(ii) In pregnant sheep…………..Cross placenta in pregnant ewes
* During 1st 85 ds of pregnancy: Foetus is aborted OR still born has teratogenic character


(demylination, hyperpigmentation) OR immunotolerant lambs with hair follicles affection (fuzzy appearance).
* During 1st 85 ds of pregnancy: The immune system capable of destroying the virus SO foetal death is rare and all

lambs are born normal with antibodies.


Post mortem lesions in aborted foetus:

(i) lambs may aborted or mummified or immune tolerant.

(ii) CNS malformation.

(iii) Abnormal skin pigmentation.

(iv) Fuzzy appearance of skin due to thickness of follicles & wool fibers.



Micro:
(i) Thymus of lambs are necrosed.
(ii) Brain of lambs show demylination, Porencephaly, hydranencephaly.
5-RIFT VALLY FEVER R.V.F (I/N)
DEF.
Cause
R.O.I
Lesions
(i)
MACRO
(ii)
MICRO
Viral disease of sheep & cattle and may human ch’ch’:
(a) Hepatitis.
(b) High mortality esp. calves&lambs.
(c) Abortion in
(d) High mortalities in neonates.
(e) Zoonotic importance as it transmissible to man leading to death.
(Bunyaviridae) R.N.A Viruses
Arthropod (mosquito)
PATHOGENESIS :
Lesions:
Bite ………………….viremia ……………………………liver,spleen, L.N & other organ
(a) Viremia(cutanous H. & Pt. hemorrhage in serous membranes with hemorrhagic enteritis) death
within 24 hrs.
(b) Hepatomegally,yellow colour, with Subcapsular hemorrhage& small white focal necrotic areas.
(c) Hemorrhagic and edematous cholangitis.
(d) Gall bladder enlarged and edematous.
(e) Spleen & L.N ………………………….Enlarged,hemorrhagic&necrosed.
(f) Pregnant cattle aborted with retained placenta
(g) Aborted Foetus :
i- Cutaneous hemorrhages and petechial
ii- hemorrhages in serous membranes with
iii- hemorrhagic enteritis.
(a) Acidophilic I/N inclusion bodies in hepatocytes & Kupffer cells.
(b) Liver showing; Focal diffuse paracentral coagulative necrosis with living neutrophils
-In advanced cases necrotic foci were completely necrosed and appeared appeared (washed out )
(c)Wide areas of blood lagoons.
(d) Increase apoptotic cells.
(e) Cholestasis in liver, Thrombosis&fibrin in sinusoids.
(f) Micro Of Foetus As Those Of adults.
6- BLUE TONGUE or( SORE MOUTH )
DEF.
Viral disease of sheep , (rare) in goat & (inapparent) in cattle ch’ch’:
Tongue cyanosis & Ulceration.
Can cross placenta of pregnant female.
Cause
R.O.I
(Bunyaviridae) R.N.A Viruses
Arthropod (mosquito)
PATHOGENESIS :
Bite ……viremia ……….endotheliotropic ……….endothelial damage……Vasculitis ……………. vascular permeability
(i) Edema&hemorrhage
ii) Thrombosis
iii) Ischemia & necrosis
Lesions:
Lesions
(i)
MACRO
(ii)
MICRO
Per Acute Stage:
Pulmonary edema & death due to Asphyxia.
Acute stage:
(a) Tongue cyanosis due to local v.c. of lingual vein (BT)
(b) Ulcer in oral mucosa.( sore mouth ).
(c) Ulcer in omasum, abomasums& intestine.
(d) Pt.hemorrhage in abomasum.
(e) Pt.hemorrhage in intestine.
(f) Congestion of nose ( sore muzzle)
(g) Skeletal muscle show edema & hemorrhage.
(h) Inflammation of cornet & erosion of interdigital space.
(i) Pt.hemorrhage in heart esp.
(i)T.adventitia of pulmonary vessels (PATHOGNOMONIC)
(ii) T.adventitia of aorta.
(iii)subendocardial region.
(a) In advanced stage, dermatitis & loss of wool.
(b) Cross placenta in pregnant females;
(i) 50-55d …………………………Hydran encephaly & Retinal dysplasia.
(ii) 75d ……………………………..Porencephaly.
(iii) > 100d ……………………….Mild focal Meningeoencephalitis
1.
2.
Necrosis of epithelium with lymphocytic infiltration.
Vasculitis, thrombosis, venous congestion, edema, and hemorrhages in underlying C.T
VIRAL DISEASE
OF
CANINES
1- Canine distemper(C..D)
Canine measles
Hard pad disease
( I/N + I/C )
DEF.
Pantropic viral disease of dogs Ch’Ch’ multisystem Affections (Resp.,Nervous,Occular,Skin&Digestive)
Cause
R.N.A virus ( Paramyxoviridae)
R.O.I
Inhalation
PATHOGENE Inhalation ---------Regional L.N (multiplication & replication)---------------Thoracic duct---------Circulation-SIS
------------------------Target organs
5 Forms
Lesions
(i) Nervous form :
(a) Gliosis with I/N + I/C inclusion bodies.
(b) non supp. meningioencephalitis
(c) Spongiosis&demylination.
(d) Perivascular cuffing.
(ii) Occular form :
(a) I/N + I/C inclusion bodies.
(b) Keratitis
(c) Optic neuritis.
(iii) Skin form :
(a) I/N + I/C inclusion bodies.
(b) Hyperkeratosis in foot pad ( HARD PAD DISEASE ).
(iv) Respiratory form :
(a) I/N + I/C inclusion bodies.
(b) Cat. Or purulent rhinopharyngitis.
(c) Giant I.S pn. Ch’ch’ hyperplasia of pneumocyte type II with syncytia formation.
(v) Alimentry form :
(a) Eosinophilic I/N + I/C inclusion bodies.
(b) Gastro enteritis.
(e) Retinitis
2- Infectious canine hepatitis
I.C.H
( I/N )
DEF.
Viral disease of dogs ch’ch’ : Hepatitis
Cause
DNA virus ( Adenoviridae )
R.O.I
Ingestion
PATHOG
ENESIS
Ingestion …………………Blood ( viremia )…………………………….Liver
Lesions
MACRO :
(i) Liver appear yellow & enlarged.
(ii) Edematous cholangitis.
(iii) Gall bladder enlarged & hemorrhagic.
(iv) Hemorrhage in serous membranes.
(v) CORNEAL OPACITY ( In Late stage )
MICRO :
(i) I/N inclusion body in hepatocytes & kupffer cells .
(ii) Hepatitis
(iii) Cholangitis.
(iii) Centrolobular necrosis
Canine distemper
(intracytoplasmic
inclusions)
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3- Canine parvo virus
( I/N )
DEF.
Viral disease of canine Ch’Ch’ : Bloody diarrhea.
Cause
DNA virus ( Adenoviridae )
R.O.I
Ingestion
PATHOG Ingestion---Virus replicate in oropharynx------Blood
ENESIS
i) Bone marrow-----Neutropenia.
ii) Lymphopiotic tissues—Lymphopenia.
iii) crypt cells of Jejunum&ileum-----------Necrosis.
MACRO :
(i) Hemorrhagic gastroenteritis
(ii) Myocarditis in puppies associated with edema
MICRO :
i) I/N inclusion in epithelial cells.
ii) Necrosis in gastric and intestinal mucosa.
Lesions
iii) Lamina propria& submucosa revealed;
a. Congested blood vessels.
b. Inflammatory cells.
c. Large amount of RBCs.
VIRAL DISEASE
OF
EQUINES
1- EQUINE ENCEPHALITIS
DEF.
Cause
Viral disease of equine ch’ch ’nervous signs
AND brain lesions : Encephalitis & Myelitis
Viral disease of equine ch’ch’ : Pulmonary edema & Cardiac
edema Associated with
i) Frothy exudates from the nostrils
ii) Swelling of supra orbital fossa.
Horse ……Highly suseptiple .
Mule……LESS suseptiple
Donky & Zebra………………………………..Resistant animals
(Togaviridae, 3 strains:Eastern,Western&Venzulian)
R.N.A Virus
(Reoviridae)
Mosquito Bite
R.O.I
PATHOG Bite-------------- Viremia --------------Nervous
ENESIS system
Macro:
Lesions
2- AFRICAN HORSE SICKNESS
A.H.S
NOT CHARACTERESTIC
Micro :
(i) Encephalitis&Myelitis restricted in
grey matter.
(ii) Perivascular cuffing.
(iii) malacia with Proliferation of
microglia cells.
Bite--------------Viremia----------------multiply in endothelium
of blood vessels………Vasculitis----------------Bl. Permeability------------------------------------Edema & Hemorrhage
4 FORMS
(i) Acute Pulmonary Form ( DUNKOP ) :
(a) Frothy exudates from the nostrils.
(b) Pulmonary edema.
(c) Hydrothorax.
(d) Pneumonia.
(ii) Sub acute cardiac form ( DIKOP ) :
(a) Swelling of supra orbital fossa.
(b) Hydropericardium & fluid may reach to 2 litres.
(c)Epicardium & Sub endocardial hemorrhage.
(d) Pericarditis.
(e) HEMORRHAGIC GASTRO ENTERITIS
(iii) Mixed form :
DUNKOP + DIKOP
(iv) Mild form : Affect resistant animals ( Donky & Zebra ).
Perivascular lymphocytic
cuff
Viral encephalitis
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1. EQUINE INFECTIOUS ANEMIA
DEF.
Cause
R.O.I
Viral disease of equine Ch’Ch’ :
Hemorrhage, Anemia, and Icterus.
(Retroviridae)
Arthropodes
PATH Bite------------Blood (viremia)--------OGEN Attack RBCs ………………Hemorrhages
ESIS in all body.
1. Equine viral arteritis
Viral disease of equine Ch’Ch’ :
i) Edema & abortion in mares
ii) Death in foals.
RNA virus
( Arterioviridae)
Inhalation
Inhalation------Virus multiply in alveolar
macrophages------------Lymph node----------Blood (viremia)--------Endothelium of small
bl.vs------Edema & hemorrhage (vasculitis).
i) Pale mucous membranes or may be i) Edema in eye lids & Conjunctivitis.
icteric
ii) Ascitis, hydrothorax, & hydropericardium.
Macr
ii) Edema in subcutaneous tissues.
iii) Edema in colon & caecum.
o
iii) Enlargement of spleen and lymph iv) Edema in hind limb.
nodes.
v) Edema in scrotum & prepuse.
i) Perivascular lymphocytic infiltration i) Vasculitis Ch’Ch’:
in
a- Thrombosis b- Fibrinoid necrosis
c- Perivascular lymphocytic infiltration
Micro most organs.
ii) Macrophages infiltration in liver
ii) Edema.
with
iii) Hemorrhages.
hemosidrin in kupffer cells.
VIRAL DISEASE
WITH
NERVOUS
MANIFESTATIONS
Rabies
Disease Of Hydrophopi
Disease Of Photophopia
(I/C)
DEF.
Cause
R.O.I
PATHOGE
NESIS
Clinical
signs
MACRO
MICRO
Viral encephalitis of all mammals including man Ch’Ch’ nervous signs.
R.N.A virus (neurotropic) (Rhabdoviridae).
(i) Bite of carnivora through infected saliva.
(ii) Wound contamination.
* Vampire bats act as reservoir for virus.
Incubation Period-----------------From few days to several months Accord. To site of bite.
1- Virus replicate at the site of infection in myocytes-------------enter neuromuscular junction.
2-virus transport via sensory nerves by centripedal force to CNS where it replicate.
3-virus Travel via cranial nerves by centrifugal force to target organs (Salivary Gl& Muscles).
2Form:
(i) Furious form :
(a) Restless.
(b) irritable.
(c) Response to auditory & visual stimulation
(d) Excitable
(e) Photophopic.
(f) Hydrophopic (g) Eat unusuall foreign object
(ii) Dump OR Paralytic form :
(a) Dropping of saliva with mouth froth due to parotid adenitis. ( As animal unable to swallow )
(b) Dropped jaw due to paralysis in masseter muscles.
(c) Change in sound tone and hydrophobia due to paralysis in laryngeal muscles.
(d) Choking sound.
(e) Generalized paralysis.
NOT CHARACTERSTIC
(i) Macerated foot pad.
(ii) Foreign bodies in stomach.
i) Non Suppurative encephalomyelitis.
ii) I/C inclusion bodies (NEGRI BODIES) + clear hallow
*Negri bodies demonstrated with (SELLER’S) OR (VAN GIESSON’S)
(Present in PURKINGE CELLS in cerebellum in herbivorus animals & in HIPPOCAMPUS in canines).
iii) Focal microgliosis in white & grey matter ( BABES NODULES )
iv) Perivascular cuffing.
v) Ganglioneuritis in trigeminal ganglia ch’ch;
a) Acute degeneration of ganglion cells.
B) Microglial nodules.
Intracytoplsmric inclusions
(Negri bodies-Rabies)
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