Infectious Dz Flashcards
Dr. Christie’s Lectures
Salmonella enterica causes….
Give me some general info please!
Salmonellosis!
G (-)
Easily transmitted between animals, humans, environment (zoonotic!)
found in 80% of raw chicken fed to animals 20-35% poultry carcasses for human consumption 5-9% raw pet food
CS of Salmonellosis
None to mild severe gastroenteritis
Dx of Salmonellosis
CS fecal culture
Tx of Salmonellosis
Minimal signs/asymptomatic - none Severe cases - isolation, AB’s chloramphenicol, SMZ/TMP, amoxi, ampicillin
Campylobacter general info please!
C. jejuni
G-
Many dogs & cats are asymptomatic carriers
CS of Campylobacter
Large bowel diarrhea
mucous, tenesmus, hematochezia
incr signs w/ STRESS
Dx of Campylobacter
Microscopic exam
Culture
PCR
Tx of Campylobacter
Abs? Unk efficacy
erythromycin, chloramphenicol, cephalosporins, enrofloxacin
Helicobacter
G (-)
Live in stomach
produce high levels of urease to survive low pH
CS of Helicobacter
May or may not cause chronic gastritis
Tx of Helicobacter
Triple therapy
2 antibiotics & antacid
amoxicillin, metronidazole & omeprazole
or
amoxicillin, metroinidazole & famotidine
Brucellosis
B. canis = G (-) aerobic, coccobacillus
cats resistant to infection, only affects dogs
transmmitted through aborted fetal material, semen, urine, milk, orally/conjucntivally?
persists intracellularly
CS of Brucellosis
Dogs can have asymptomatic infections
generalised lymphadenopathy, transient fevers even seizure
Intact males - enlarged scrotum, epididymitis, infertility, testicular atrophy
Females - infertility, abortion, stillborn pups
Other CS: Discospondylitis chorioretinitis, optic neuritis anterior uveitis
Dx of Brucellosis
Serology
titres stapy positive for up to 3 years
Rapid Slide Agglutination Test (RSAT) - good screening (95% sensitive) but not specific due to cross react w/ other bact.
Tube agglutination test (TAT) - titer >200 = active infection, 50-100 = suspect infection
still confirm w/ AGID, ELISA or PCR or bact cult
Culture aborted tissues or blood
Tx of Brucellosis
Very difficult to eradicate
Sterilise all infected animals due to public health concerns
Doxycycline & IM streptomycin - aminolycosides, doxy, quinolones
4 wks tx
retest 6-9 mos post tx
Actinomyces & Nocardia spp
G (+)
Associated w/ anerobic infections, FB migrations, pyothorax, peritonits, bite wounds.
Often has draining tracts/wounds with yellow (sulfer) granules
Associated w/ wounds & pyothorax
Canine Distemper Virus (CDV)
RNA - very susceptible in environment
CDV pathogenesis
water droplets → upper respiratory tract epithelium → multiplies in tissue MØ (<24) → lymphatics
2-4d PI ^^^ viral load in tonsils & retropharyngeal/bronchial LN
4-6d PI virus in lymphoid follicles of spleen, GALT (lamina propria of stomach, SI), mesenteric LN & liver Kupffer cells
^^^ viral replication causes pyrexia & lymphopenia 3-6d PI → 8-9d PI spreads to epithelial tissues & CNS
by 14D PI animals w/ adeq CDV abs & cell-mediated response clear virus from most tissues
Poor immune response leads to spread in skin, exocrine/endocrine glands, & epithelium of GIT, resp tract & GU tract
CS of CDV
Bilateral serous oculonasla discharge
Biphasic pyrexia
KCS
Diarrhea
Vesicles & pustules
Nasal & digital hyperkeratosis & CNS signs “hard pad dz”
tachypnea, coughing
meningeal inflammation
seizures
myoclonus
Dx CDV
3-6 mo unvaccinated (inadequately vxd) puppy
intracytoplasmic distemper inclusion bodies in erythrocytes
MRI
CSF: anti-CDV antibody, ^ protein - if blood contamination of CSF occurs & serology shows CDV +, test for Parvo. If parvo + then confirms + CDV is from vx not dz (CPV isnt neurotrophic)
Serology
PCR: buffy coat, WB, serum or CSF sample
Serum antibody testing - neutralising antibodies “gold standard” (IgG levels)
Indirect FA testing titers
Tx of CDV
Px
supportive care, anti-seizure
POOR
Prev of CDV
Vx
Killed (not in US)
Vector vaccine - canarypox based
MLV (most common)
Can cause vx reactions
Vx schedule - after initial series (6, 9, 12, 16 wks) & 1 yr booster then q 3y
public health risk - Pagets dz?
Canine Adenovirus type 1 (CAV-1)
Highly resistant in environment
PI virus in all tissues but 10-14 d PI virus only in kidneys & excreted in urine 6-9 mos!
Pathogenesis of CAV-1
Severe viremia 4-8d PI
Hepatic parenchymal cells, vascular endothelium & CNS prime targets
ABs form by 7d PI
Acute hepatic necrosis
CS of CAV-1
moribound & die in a few hours post CS onset (fading puppy dz)
Pyrexia
tonsillar enlargement & lymphadenopathy
hemorrhagic diathesis
icterus uncommon
corneal edema & anterior uveitis
Called: Canine infectious hepatitis
Dx of CAV-1
CBC: leukopenia, lymphopenia & neutropenia
thrombocytopenia
Chem: hyperglobinemia day 7-21
^ ALT, AST & ALP
Coagulation abnormalities
UA: proteinuria
abdominal paracentesis/ abdominocentisis: yellow/hemmorhagic fluid
Serology: ^^^ titers after infection
PM pathology: swollen liver & mottled, multiple ecchymotic hemorrhages
Tx of CAV-1
Supportive care for severe hepatopathy
IVF, FFP for albumin & clotting factors, glucose, decr protein diet, laxative & lacutlose to acidify colon (to change ammonia to ammonium)
Prevention of CAV-1
Vx: use MLV for CAV-2 (good cross protection immunity)
Canine Parvovirus (CPV)
DNA virus
requires rapidly dividing cells for replication
CPV-2 (most common)
highly contagious, often fatal, vary stable & resistant in environment
younger predisposed (6wks - 6 mos)
Rottweilers
Incubation period 1-5d
CS of CPV
GIT:
- vomiting, diarrhea (yellow→hemorrhagic), anorexia
- ⇒severe dehydration
- death in 2 days
BM:
severe leukopenia (lymphopenia)
Dx CPV
CS
leukopenia (not all dogs)
fecal ELISA antigen test
fecal PCR
EM of feces
Serology only detect immunity from vaccinated animals
PM pathology: hemorrhagic enteritis, necrosis of crypt epithelium in SI, immunoflourescence
Tx of CPV
Restore fluids & electrolytes
Antiemetic agents - metoclopramide, ondansetron, maropitant (not <10wks, better >16wks)
Food, food, food
gastric protectants
WB, plasma, colloids
Prevention of CPV
Immunity post infection >20 mos
Vx: MLV
DOI: 3-7y
Virus shed for short time (4-5d)
persists in environment >5mos
Canine Coronavirus (CCV)
highly contagious
CS of CCV
enteric CV: subclinical to mild diarrhea
Dx of CCV
EM of fresh feces
Fecal PCR
serum VN & ELISA
CAN JUMP SPP - ZOONOTIC POTENTIAL!
Tx: CCV
Prevention
Supportive
Vx: MLV
Canine Rotavirus
Dx
affects <12 wks old
mild diarrhea
Fecal ELISA for rotavirus antigen
Canine Herpes virus
Pathogenesis
Cytocidal
not very stable in environment
in utero, passage through birth canal & contact w/ litter mates, oronasal secretions from dam
animal <1wk ⇒ fatal generalised infection
animal >2wks ⇒ mild or inapparent infection
repicates in nasopharynx, genital tract, tonsils, retropharyngeal LN, bronchial LN, conjunctival tissue, occas. lungs
can result in abortions/still births
multifocal hemorrhagic necrosis, DIC & thrombocytopenia
CS CHV
Neonates:
Acute death
dull, weight loss, depressed, lose interest in feeding, pass soft stools
petechial hemorrhages
older pups & adults:
mild or inapparant URI
if genital: petechiae, ecchymotic submucosal hemorrhage
vesicles
Dx of CHV
Tx
prevention
viral isolation
serology
PCR - most reliable
Unrewarding in neonates - rapidly fatal
Vx
Rabies virus (RV)
all warm blooded mammals
bite from infected animal
saliva
USA declared canine - rabies free in 2007
Vx still mandatory
prevalence of RV in wildlife increasing