Infectious Lecture 4th Year 27-12-2016 (2) Dr.Osamah Muwafk
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CONTAGIOUS BOVINE PYELONEPHRITIS
Etiology and Epidemiology:
1. Corynebacterium renale
2. C. renale has little apparent resistance to physical or
chemical agents
3. The disease is widespread
4. Source of infection is urine of affected or carrier animals
5. Transmission by direct contact, or by the use of contaminated
brushes or by the careless use of catheters
6. Infection can be spread venereally
7. cows appear to be much more susceptible than bulls
8. In cows, clinical cases are more common in early lactation
9. An increase infection in the colder seasons of the year
10.
Bulls can be predisposed to pyelonephritis by
obstructive urinary abnormalities
11.
the disease is highly fatal
PATHOGENESIS
1. Trauma to the urethra, or urine stasis, may facilitate
ascending infection
2. Pyelonephritis usually develops as an ascending infection
involving successively the bladder, ureters, and kidneys
3. The destruction of renal tissue and obstruction of urinary
outflow ultimately result in uremia and the death of the
animal
4. Piliated and nonpilipiliated forms of C. renale have a greater
ability to attach to urinary tract epithelium, are more resistant
to phagocytosis and are probably important to carriage of the
organism and to the initial ascending infection
Infectious Lecture 4th Year 27-12-2016 (2) Dr.Osamah Muwafk
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CLINICAL SIGNS:
1. passage of blood stained urine
2. an attack of acute colic manifest by swishing of the tail,
treading of the feet and kicking at the abdomen, and straining
to urinate, the attack passing off in a few hours
3. a fluctuating temperature (about 39.5 °C,103°P)
4. capricious appetite
5. loss of condition
6. fall in milk yield over a period of weeks
7. the presence of blood, pus, mucus, and tissue debris in the
urine, particularly in the last portion voided
8. rectal examination detectable thickening and contraction of
the bladder wall and enlargement of one or both ureters.
9. Left kidney may show enlargement, absence of lobulation
and pain on palpation
10. Ultrasound examination shows a reduction in renal pelvis
diameter, a reduction in renal parenchyma and the bladder
wall is hyperechoic.
11. Ultrasound may demonstrate a dilated renal collecting system
containing echogenic material and can be an aid in the
determination of the severity of the disease.
12. The course is usually several weeks or even months
13. the terminal signs are those of uremia
CLINICAL PATHOLOGY:
1. There is proteinuria and hematuria
2. Urine pH is greater than 8.5
3. Specific gravity has been recorded between 1.008 and 1.021
4. Microscopic examination will show pyuria
Infectious Lecture 4th Year 27-12-2016 (2) Dr.Osamah Muwafk
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N ECROPSY FINDINGS:
1. The kidneys are usually enlarged and the lobulation less
evident than normal
2. The renal calyces and grossly enlarged ureters contain blood,
pus, and mucus
3. Light colored necrotic areas may be observed on the kidney
surface
4. Changes visible on the cut surface include excavation of
papillae, abscessation and wedge-shaped areas of necrosis
that extend from the distal medulla into the cortex
5. The bladder and urethra are thick-walled and their mucous
membranes are hemorrhagic, edematous and eroded
TREATMENT:
procaine penicillin G, large doses (15000 IU/kg BW) are
recommended daily for at least 3 weeks
DIFFERENTIAL DIAGNOSIS:
1. Acute intestinal obstruction : absence of a palpable
obstruction and the disappearance of abdominal pain within a
few hours
2. Traumatic reticulitis
3. Nonspecific cystitis: can only be differentiated by culture of
the urine
4. Polypoid cystitis: is a nonspecific result of bladder
inflammation and may be a cause of dysuria and obstructive
uropathy, The differential diagnosis is best made by
endoscopic examination, which reveals multiple frond-like
fungiform polyps and papillae on the bladder wall
Infectious Lecture 4th Year 27-12-2016 (2) Dr.Osamah Muwafk
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CHLAMYDOPHILA ABORTION (ENZOOTIC ABORTION OF
EWES, OVINE ENZOOTIC ABORTION (OEA) ) :
ETIOLOGY:
1. Chlamydophila abortus (previously Chlamydia psittaci
bioypel/serotypel)
2. Has a tropism for ruminant placenta
3. causes the disease commonly referred to as ovine enzootic
abortion (OEA)
4. The organism causes a similar disease in goats, and while this
organism also can produce abortion in cattle, pigs and horses
EPIDEMIOLOGY:
1. The disease is one of the commonest causes of diagnosed
abortion in sheep and goats
2. the major source of infection is the placenta and the uterine
discharge of aborting ewes
3. Transmission of Cp. abortus are through ingestion of
organisms shed in vaginal fluids and placental membranes at
the time of abortion or lambing, or through inhalation of
aerosols from the environment
4. venereal or passive venereal transmission is a possible route
of infection
5. Persistent infection can be demonstrated in the endometrial
cells of the reproductive tract and the organism is excreted in
vaginal fluids during estral periods
6. It has a major economic impact on agricultural industries
worldwide
7. Major zoonotic risk is to pregnant women because of the
ability of Cp. abortus to colonize the human placenta
Infectious Lecture 4th Year 27-12-2016 (2) Dr.Osamah Muwafk
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8. Human infection in early pregnancy results in abortion
whereas later infection can result in stillbirth or pre-term
labor
PATHOGENESIS:
1) Following infection
2) The organism resides first in the tonsil
3) Then disseminated by blood and lymph to other organs
4) During pregnancy an immune modulation leads to release
from the latent state and development of bacteremia and
infection of the placenta
5) The organisms invade the trophoblast cells of the fetal
cotyledon
6) Spreads to the intercotyledonary regions of the chorion to
produce a suppurative necrotic placentitis
7) Impairment of the maternal-fetal exchange of nutrients and
oxygen and fetal death and abortion
CLINICAL FINDINGS:
1. There are generally no premonitory indications of the
impending abortions
2. Abortion occurs in late pregnancy
3. Ewes appear to suffer no systemic effects
4. Retained placenta and metritis can be sequel in goats
5. A vaginal discharge lasting up to 3 weeks following the
abortion is common
CLINICAL PATHOLOGY:
1. Complement fixation test
2. ELISA tests
Infectious Lecture 4th Year 27-12-2016 (2) Dr.Osamah Muwafk
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NECROPSY FINDINGS:
1. Placental cotyledons are necrotic and hemorrhagic
2. The intercotyledonary areas are thickened, edematous, and
leathery
DIFFERENTIAL DIAGNOSIS:
- Other causes of abortion in ewes
CONTROL
1. Ewes that have aborted should be isolated from the rest of the
flock
2. Tetracycline has been used in early pregnant sheep within an
aborting flock to attempt to reduce subsequent abortions
3. Vaccines:
1) Killed vaccines
2) Freund's incomplete adjuvant has provided a vaccine
that provides better protection
3) A live vaccine containing a temperature-sensitive
attenuated strain of C psittaci
4) Recombinant and DNA vaccines