Lesson 74 Bacterial disease and parasites

metritis

inflammation of uterus

mastitis

inflammation mammary gland

balanoposthitis

inflammation penis or preputial cavity

endometritis

pus or mucopurulent discharge

vaginitis

discharge from vulva

orchitis

inflammation testicles

cryptorchidism

one or both testicles don’t descend from abdominal cavity into scrotum

classification RTI

venereal/ STDs

endogeneous (pathogens in normal biota)

iatrogenic(medical procedures)

brucella abortus

cattle

transmission:veneral, contact, and ingestion

females: abortion with retained placenta, infertility and mastitis

males: orchitis, epididymitis, seminal abnormalities, testicular atrophy, infertility and joint problems

diagnosis of brucella abortus

sample: semen and lymph nodes

cytology: uses Ziehl-neelsen(MZN) stain

serology: serum agglutination test (SAT)

rose bengal plate test-for screening

complement fixation test-for confirmation

PCR

How is B. abortus controlled

Test and slaughter

vaccinat female calves

RB51 strain

Vaccine can cause accidental exposure and cause disease in human

Brucella Canis

dogs (srs problem in breeding kennels)

highly contagious-veneral

males: epididymitis, prostatitis, testicular atrophy, sterility

-carries over into semen

diagnosis of Brucella canis

serology: agglutination test

necropsy: lymph node and spleen

PCR: blood, vag discharge, aborted fetus, semen

how is Brucella canis controlled

testing, euthanizing positive, clean and disinfect

Brucella suis

swine

clinical signs: abortion, sterility, still births, spondylitis (spine arthritis), abscess in organs

Which brucella strain is most significant

B. melitensis

B. melitensis

most serious infection-malta fever or undulant fever zoonotic

transmission: direct contact, milk/cheese

risk group: farm workers, slaughter house, veterinarians

what brucella species is most common in cattle in the USA

B. abortus

Leptospirosis in cows, goats, and sheep

abortion, still birth, weak offspring, infertility, red milk

Leptospirosis in pigs farm and feral

fever, abortion, stillbirth, weak/sick offspring, jaundice, acute kidney failure, loss of appetite

Q fever-Coxiella burnetti

cattle, sheep, goats

ZOONOTIC

transmission: milk, urine, feces. placenta and fluids infective

signs: abortion

risk group: veterinarian, slaughterhouse, dairy workers, farmers, researchers using sheeps

How do you treat Q fever-Coxiella burnetti

treatment: tetracyclines and vaccines available

Why is Q fever a bioterrorism agent

spore like forms that are resistant to heat, drying or common disinfectants

diagnosis of Q fever-Coxiella burnetii

smears of placentra or abortive tissue using Wright Giemsa or Ziehl Neelson

serology

pcr

How is Q fever cases controlled

testing in abortion cases, quarantine, vaccinate

NOTIFIABLE DISEASE

What are the primary clinical sign of Q fever in infected livestock

abortion and stillbirths

Listeria

cattle sheep

non contagious disease. food borne infection

transmission: ingestion, silage (most common source in dairy cows)

signs: abortion, septicemia, head tilt or facial paralysis in sheep

Pathogenesis of Listeria

ingestion→ invasion tissue→ migrate trigeminal nerve→ abscess brain stemm→ meningoencephhalitis→ circling disease

ingestion→ intestine mucosa→ blood→ placental damage→ fetal infection→ abortion, stillbirth

blood→ meninges→ meningitis

diagnosis Listeria

HX: silage feeding

signs: neurological

lesions: perivascular cuffing

culture: brain, blood, milk, placenta, fetus

Types of listeria

L. monocyotogenes: more pathogenic, ZOONOTIC

L. ivanovii: less pathogenic, abortion in sheep

How is Listeria cases handeled

isolation of sick, dispose dead and contaimenated bedding

eliminate source (silage)

ABX in feed

Listeriosis in humans

trasnmission: milk, milk products, cold meat cuts

-mostly from food processing and prep facilities

causes: abortion in women and meningitis in immune compromised adults

What is the main source of Listeria monocytogenes infection in ruminants?

contaminated silage or feed

Posthitis, balanoposthitis

also called pizzle rot or sheath rot

preputial ulcerative dermatitis

Corynebacterium spp

signs: poshthitis-foreskin inflammation

spreads from orifice to mucosa. secondary to bacterial infection

C. Pilosum C. Cystitidis

sheep and goat

-part of prepuce normal biota

predisposing factor: high protein diet→ high urea=increased ammonia

oocysts

resistant stage for environmental transmission

tachyzoites

rapidly dividing tissue stage in vertebrate host

seen in acute infection

bradyzoites

slowly dividing, encysted tissue stage found in warm blooded vertebrate hosts

seen in chronic infection

What parasite is this. Sample is from vaginal swabs of aborting cows

Tritrichomonas

definitive host

host where parasite undergoes sexual reproduction

intermediate host

host where parasite undergoes asexual development/ immature stage

paratenic host

host where parasite does not develop further

stage is not required by lifecycle

transport host

host carried parasite, no development

What is the definitive host of toxoplasma gondii

cats

Toxoplasma gondii

sheep, goat, pigs, dogs, cats, humans

zoonotic

trasnmission: spoores of oocysts in contaminated food or water. vertical transmission of tachyzoite, or consumption bradyzoite in infected tissue

risk group: immunocompromised, developing fetus, elderly

signs: abortion, stillbirth, mummification, resorption, weak offspring

-sometimes resp or neuro disorders

Diagnosis of toxoplasma gondii

PCR, ELISA, modified direct agglutination test, Sabin-feldman dye test

How do you treat toxoplasma gondii in dogs with neurological disease

clindamycin, pyrimethamine, supportive care

How do you treat toxoplasma gondii in sheeps

vaccine-toxovax marketed for breeding ewes

How to prevent toxoplasma gondii in cats and humans

avoid raw meat, stop cats from hunting outside, change litter box daily, wahs fruits and vegetables, wear gloves when gardening

How long does it take for toxoplasma gondii in litterbox to become infectious

1-5 days

Neospora caninum

dogs, coyotes, wolves (DH) and cattle sheep goats (IH)

transmission:

-dog:ingestion of infected cow

-cow: horizontal and vertical

signs: major cause abortion in cows, repro disorder, stillbirths, weak births w/ neuro dysfunction

Diagnosis of neospora caninum

cattle-histopath of fetus or placenta, PCR, ELISA

How is neospora caninum cases handeled

NO treatement in cattle

testing, dispose dead and placentas, prevent contact b/w dog and cattle

biosecurity

Tritrichomonos doetus

Bovine

transmission: veneral (folds of prepuce/penis, cervix, and uterus). WORLDWIDE

cows-inflammation reproductive tracts→ infertility, abortion

bulls- no signs but are carriers

How long does it take for cows to naturally clear tritrichomonas foetus infection

after 2-3 estrus cycles

diagnosis tritrichomonas foetus

Hx of decreased calving rate, fertility

vaginal, prepuce, or penis smear, sample, culture, or PCR

How to handle cases of Tritrichomonas foetus

no effective treatment

biosecurity, cull bulls, sexual rest for females

Trichgaurd vaccine-reduce shedding and slightly increase pregnancy and calving rate

AI insemination