impact of selected infectious diseases on reproductive performance in cattle

Date

Impact of selected Infectious diseases on reproductive

performance in cattle

MSD AH Animal Middle East Symposium

Beirut 2012

Brought to you by Partners in Reproduction Health Platform

Monika Ptaszynska, DVM, PhDGlobal Marketing and Technical DirectorRuminant Reproduction and Uterine Health

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Contents

• Introduction

• Infections with negative impact on the ovarian functions and higher endocrine regulatory centres. Example – BVDV infection.

• Infections causing embryonic and foetal mortality.

• Unique interaction between infectious factor and the dam’s organism in Neospora caninum infection.

• Infections associated with uterine disorders.

• Infections affecting the quality of semen.

• Diagnostic decision tree.

• Safety precautions.

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Introduction

Infectious causes of reproductive failure in cattle – why so important in

daily veterinary practice….

• They can have deep and multidirectional negative effect of herd’s reproductive performance and therefore also on its profitability.

• Some of them are zoonotic and can represent a risk to the personnel, veterinary practitioner or even the consumer of products derived from affected animals.

• Usually these infections find themselves at the very end of the routine diagnostic process employed in cases of fertility problems in the field and even if abortion took place only a small percentage of cases is given the correct diagnosis.

• Nowadays, veterinary practitioners have very good diagnostic methods and prophylactic measures at their disposal to address the majority of these infections.

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It is not only about abortions…

Folliculogenesis and ovulation

Corpus luteum function

Indirect effect through impaired GnRH/LH release

Viruses: BVD, IBR,

Bacteria: H.somni

Generalized infections accompanied by toxaemia and fever (e.g. E.Coli mastitis)

Direct effect of the infection through inflammatory changes in the ovarian tissues

Viruses: BVD, IBR

Direct negative effect on placental function and fetal development

Viruses: BVD, IBR, BTV, Akabane V, probably SBV

Bacteria: Leptospira spp., Campylobacter fetus, A.pyogenes, H.somni,

Ureaplasma spp., Listeria monocytogenes, Chlamydophila spp.,

Coxiella burnetti, Anaplasma marginale, Brucella abortus, Salmonella

spp.,

Fungi: Mucor spp.

Protozoa: Neospora caninun, Trichomonas fetus,Toxoplasma

gondii

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General timelines for selected infections affecting reproductive performance in cattle

Follicular phaseEmbryonic phase (<42d)

Fetal phase (>42d) Calving

BVD

BVD

IBR

IBR

mastitismastitis

Brucella abortusC. Fetus venerealis

Leptospira interrogans

L. interrogans hardjo

L.interroganspomona

Fungal inf.BVD

IBR

BTV

Trichomonas foetus

Neospora caninum

Toxoplasma gondii, N.caninum, Akabane, SBV

Impaired follicular growth, ovulation disorders, silent heat

Luteal deficiency, embryonic mortality, repeat breeding

Abortions during the 1st half of pregnancy

Abortions in the 2nd half of pregnancy, often with placental retention

Stillbirth or weak calves

BHV-4 (?)

Endometritis

Still very limited data for SBV

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Infections affecting ovarian functions and higher endocrine regulatory centers

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Let’s take a closer look…

Infectious factor Mechanism

BVDV, IBRV Multiplication in ovarian tissues and advanced inflammatory changes especially in the ovarian follicles and corpus luteum

Decreased estradiol secretion silent heats errors in AI timing

Delayed and/or inadequate preovulatory LH surge ovulation delay or failure

Low oocyte/embryo quality and low fertilization rate

Decreased progesterone levels in circulation Poor embryonic development, EEM

McGowan i wsp., (2002), Fray i wsp., (2002)

Mastitis in peri-insemination period

Inflammatory process and its chemical mediators impair the preovulatory LH surge (Hockett i wsp., 2000)

Cytokines produced during mastitis can directly impair maturation of the oocytes (Soto i wsp., 2003)

Clinical picture at the herd level: low heat intensity, low efficacy of AI, early returns (<25d post AI.)

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McGowan et al. (2002) – viraemic cows showed decreased or practically absent preovulatory

estradiol peak

As well as delayed and decreased preovulatory LH surge

No E2 surge!Dramatyczny wzrost poziomu progesteronu

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And what happened with progesterone production in infected cows…

“Healthy” post ovulatory progesterone rise

Significantly delayed and poor increase in progesterone levels

Practically no progesterone rise

McGowan et al. (2002)

Daily plasma P4 concentrations in cows after intranasal challenge with non-cytopathogenic BVDV

012345678

Time from ovulation

Pro

gest

eron

e (n

g/m

l)BVD+

BVD-

From Fray et al., 2002

Conclusions: such a low and delayed post-ovulatory progesterone production will not be adequate to support early embryonic development and pregnancy recognition

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Infections causing directly embryonic and fetal mortality

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What will happen in the herd…

Infectious factors Mechanism

BVDV Negative effect on the fertilization process and early embryonic development confirmed in vitroo (Booth i wsp., 1998 Bielański i wsp, 2000 Kafi et al., 2002).

Direct negative effect on embryonic development and evidence for embryonic infection before implantation (Tsuboi i wsp., )

IBRV/BHV-1 Infection of the embryo before implantation and disruption of placentation process (Miller i wsp., 1986)

Campylobacter fetus

Inflammatory process within the oviduct and uterus disrupt the fertilization and impair the development of the early embryo (Hum 2007)

Tritrichomonas fetus

Inflammation within the oviduct and uterus may disrupt the embryonic development and placentation (Rhyan i wsp., 1988; Anderson i wsp., 1996; Singh i wsp., 2005; Midley i wsp., 2009)

N.caninum It is postulated that the infection can cause late embryonic losses (Innes 2007).

Clinical picture in the herd: repeat breeding (especially late repeats >25d post ins.), increased inter-estrus intervals

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What will happen in the herd…

Infectious factor Mechanism/clinical picture

BVDV Fetal death can practically occur from 45 to 150 day of pregnancy. Direct infection of the fetus.

IBRV/BHV-1 Fetal death takes place within 24h of viral invasion of the placenta, usually in the second half of pregnancy. Direct infection of the fetus and placentitis. Abortion occurs several weeks (20-52 days) after the infection of the dam.

In a naïve, non-vaccinated herd, can lead to abortion storms, with 25 up to even 60% abortion rate.

BTV Transplacental infection of the fetus leading to resorption/abortion mainly before 130d of pregnancy.

Akabane virus Rarely abortion. Infection in 1st trimester – calves die soon after birth with severe neurological defects. Infection 2nd trimester – calves born with muscle-skeletal and nervous system abnormalities

Schmallenberg virus

No precise mechanism or abortion timing yet established. Abortions suspected to occur mainly during late pregnancy and considerable time after the infection of the dam. Main picture – calves born with muscle-skeletal and neurological abnormalities.


Fetal death takes place mainly between 50 and 70 days of pregnancy. Direct infection of the fetus and placentitis.

Neospora caninum Infection during the first trimester almost always leads to fetal death and abortion. Fetuses are usually aborted between 4 and 6 months of pregnancy. Direct infection of the fetus.

Clinical picture in the herd: abortions, placentitis

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Campylobacter fetus

Fetal death can take place between 4 and 7 months of pregnancy. Direct infection of the fetus and placentitis.

Leptospira hardjo Direct infection of the fetus and placentitis.

Abortions: Serovar hardjo from 4 months of pregnancy (1-3 months post infection), serovar pomona in the last trimester (1-6 weeks post infection).

Brucella abortus Direct infection of the fetus and placentitis.

Abortion takes place in 24-72h after the fetal death and usually > 5 months of pregnancy

After abortion placental retention and metritis are common.

Listeria monocytogenes

Direct infection of the fetus and placentitis. Abortion during the last trimester often followed by placental retention and metritis/endometritis.

H.somni Direct infection of the fetus and placentitis. Abortions usually in late pregnancy.

Coxiella burnetti (Q fever), Chlamydophila abortus

Sporadic abortions, mainly in late pregnancy (6-8 months) often followed by metritis and endometritis. Usually associated with close proximity to herds of small ruminants.

Salmonella Dublin Abortions usually take place in the second half of pregnancy and are followed by placental retention.

Clinical picture in the herd: abortions, placentitis

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Unique interaction between infectious factor and the dam’s organism in N.caninum infection

Important role of the specific immune situation of the pregnant cows (immunotolerance of fetal antigens) and activation of the immune response in face of the parasite re-activation (Innes i wsp., 2007).

In order to maintain pregnancy (semi-allogenic transplant) the maternal organism gives preference to regulatory cytokines: IL-10, IL-4, TGFhaving an opposite effect to inflammatory type cytokines(INT)

Infection with N. caninum usually induces cellular immune response with important participation of lymphocytes T and INT

It is thought that the natural immuno-modulation that guarantees pregnancy maintenance may impair the ability of the cows to mobilize the cellular immune response adequate for elimination of the parasite.

It is also postulated that apart from the direct effect of the parasite on the fetal development, the immune response activated within the

placenta may have a fetotoxic effect and lead to abortion.

Immunosuppressive effect of progesterone????

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Infections typically accompanied by endometritis


Brucella abortus Endometritis and salpingitis leading to decreased fertility and infertility.

Listeria monocytogenes

After abortion: placental retention and metritis/endometritris.

Campylobacter fetus

Endometritis, moderate cervicitis and salpingitis.

H. somni Nonspecific endometritis of variable intensity.


Endometritis, moderate cervicitis and salpingitis.

BHV-4 In the US cases of purulent, ulcerative endometritis associated with BHV-4 infection were described in cows in the early post partum period (Wellemans i wsp.,1984; Frazier i wsp., 2001,Frazier i wsp., 2002; Gur 2010)

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Infections affecting the semen quality

Infectious factor Mechanizm Decreased semen quality

Shedding with semen

Brucella abortus Inflammation of the testicles, seminal vesicles and epidydimis

Yes, acute & chronic phase

Yes, directly

Camp. fetus Usually asymptomatic Usually Not Yes, indirectly

Leptospira hardjo Replication in the testicles and seminal vesicles


Yes, directly

H. somni Replication in the testicles and seminal vesicles


Yes, directly

Wirus IBR Replication in the testicles and seminal vesicles. Balanoposthitis

Possible in acute phase, usually Not in chronic phase.

Yes (periodical activation due to immunosuppression) throughout the lifetime

Wirus BVD Replication in the testicles and seminal vesicles

Possible in acute phase, usually Not in PI individuals

Yes in the acute phase, PI individuals in large quantities, permanently

BTV Replication in the testicles and seminal vesicles

Possible in acute phase Yes in the acute phase

Trich. fetus Usually asymptomatic Usually Not Yes, indirectly

N. caninum Not defined Usually Not Probably limited

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Orientation diagnostic decision tree

Low reproductive results

Decreased fertility Abortions in 1st trimester

♂♀Silent heats BVDV BVDVLow AI efficacy BTV BTVEarly repeats L.hardjo L.hardjo

N.caninum Camp. FetusTrich. Fetus

♂♀ N.caninumBVD IBRVIBRV BVD Abortions in 2nd half of pregnancyMastitis Trich. Fetus

Camp. FetusMastitis

IBRV IBRVB.abortus B.abortus

Late repeats L.hardjo Camp. FetusIncreased heat intervals L.pomona L.hardjo

L.monocytogenes L.pomonaN.caninum L.monocytogenesSBV N.caninum

♂♀ C.burnetti SBVBVD IBRV Ch.abortus C.burnettiIBRV BVD S.Dublin Ch.abortus

Trich. Fetus H.somni S.DublinCamp. Fetus H.somni

AI only NM & AI, NM only




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What are our possibilities for diagnosis and control in some of the infections?

Infectious factor Diagnostics Eradication/prophylactics

Brucella abortus Cow: ELISA, PCR

Fetus: isolation, PCR

Monitoring & elimination of positive individuals

In some countries vaccination (RB51)

Camp. fetus Cow, bull: isolation, IFAT, ELISA, PCR

fetus: isolation, PCR


Strict control of bullsIn some countries vaccination Shift to AI

BVD Cow: ELISA,

Fetus: isolation, IFAT, PCR

Monitoring & elimination of PI individuals Vaccinations (Important: with products that afford protection against transplacental infection)

IBR Cow: ELISA,



Vaccination & eradication programs (based on marker vaccines)

BTV Cow: ELISA,


Vaccination

Control of the vectors.

Trich. fetus Cow, bull: isolation, PCR

Fetus: isolation, PCR

Monitoring & elimination of positive individuals,

Strict control of bulls

In some countries vaccination (♀)

Shift to AI

SBV Fetus: PCR detecting viral antigens only available at present.

No measures available yet. Control of vectors available.

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On the safety…

• Due to the zoonotic potential, care should always be taken when handling the abortion material to ensure safety of the veterinary surgeon, their assistants and bystanders.

• Adequate instruction should be given to the owners and personnel in contact with aborting animals to ensure their safety.

• If an infectious cause of the abortion/stillbirth is suspected the affected animal should be isolated, the place where abortion took place cleaned and disinfected and the abortion material safely disposed after the adequate samples have been collected.

• In particular pregnant women and women of child-bearing age should avoid contact with aborted material.

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Thank you very much for your kind attention

Questions…

impact of selected infectious diseases on reproductive performance in cattle

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