Bovine Abortion Part 2 - Key Agents

What is the primary purpose of the Rose Bengal card test?

To screen for brucellosis.

What is epizootic bovine abortion commonly associated with?

Foothill regions of California, Oregon, and Nevada.

What kind of organism is responsible for brucellosis?

Bacteria (Brucella species).

What is the BRT test used for?

To screen for brucellosis in cattle.

What vaccination is used to prevent brucellosis in calves without causing antibody production?

RB51.

What is the zoonotic disease associated with brucellosis?

It causes undulant fever in humans.

What is the characteristic sign of abortion due to epizootic bovine abortion?

Petechiae and lymphadenopathy in the fetus.

What is the most common abortifacient serovar of Leptospira associated with abortion in the US?

Hardjobovis.

What is the key characteristic of abortions caused by listeriosis in cattle?

Usually occurs during the last trimester.

What is the most common cause of abortion in dairy cattle?

Neosporosis.

What causes sporadic abortions at any pregnancy stage in cattle?

Trueperella pyogenes.

What method is used to diagnose Bovine Viral Diarrhea (BVD)?

PCR or fluorescent antibody testing.

What vaccination is given to prevent Infectious Bovine Rhinotracheitis (IBR) in pregnant cows?

Intranasal modified-live vaccine.

What is the primary cause of infertility and embryonic death in cattle?

Campylobacteriosis.

What type of abortion does Trichomoniasis cause in cattle?

Early abortion during the first half of pregnancy.

What is the toxic principle in locoweed (Astragalus spp.) that affects cattle?

An indolizidine alkaloid.

What are the potential effects of selenium deficiency in cattle?

Abortion and weak calves.

What kind of harmful effects can moldy sweet clover have on pregnant cattle?

Can lead to abortion due to dicumarol.

What is the risk posed by ingestion of ponderosa pine needles by pregnant cows?

Abortion accompanied by profuse uterine hemorrhage.

What other plants can cause abortion if ingested by cattle?

Poison hemlock (Conium maculatum) and snakeweed (Gutierrezia microcephala).

Brucellosis CS?

Abortion in second half of gestation (around 7mos), abortion storms.

Brucellosis Dx?

Brucella ring test or brucellosis card (Rose bengal) test

Brucellosis prevention?

RB51 vaccine, does not cause AB production and is used in calves. Strain 19 causes Ab production

B. abortion in humans?

Causes undulant fever, REPORT

Epizootic bovine abortion?

1. Only seen in foothill regions of Cali, Oregon and Nevada

2. Last trimester abortion storms in heifers or cows new to the area

3. Transmitted by argasic ticks

4. Fetus has petechiae and lymphadenopathy

5. Affected are usually resistant to future infections

Leptospirosis

1. Abortion in last trimester, autolyzed (icterus with Pomona)

2. Most common serovars causing abortions in US are Hardjobovis, Pomona, Grippothyposa, Canicola, and Icterohaemorrhagiae

3. Eliminate renal carriers with long acting oxytetracycline

4. Prevent with bacterine vax every 6mos (doesnt work with hardjobovis)

5. Zoonotic

Listeriosis?

1. Sporadic abortion, usually last trimester, can occur at any stage

2. Dams often ill with fever and metritis, rarely with CS signs.

3. Usually due to poorly preserved siliage

4. Substantial autolysis or fetus and retained placenta

5. Reportable in some states, Zoonotic

Neosporosis?

1. Definitive host is the dog, vertical transmission is important

2. Most common cause of abortion in dairy cows

3. Mid to late gestation (between 4-6mos), endemic or epidemic

4. Serology of dam is highly specific

Trueperella pyogenes

1. Sporadic abortion at any stage in otherwise healthy dams

2. Most common bacterial cause of abortion

3. Autolysis of fetus

4. Dx if bacteria is isolated from fetus or fetal membranes

Ureaplasma diversum/Mycoplasma spp

Ureaplasma: is freq. present in vagina and prepuce of cattle, abortion in last trimester, fetus not autolyzed, retained placenta and necrotic amnios

Mycoplasma can cause sporadic, usually last trimester abortions.

BVD

• May have upper RT signs concurrently or up to 4mos before abortion

• Abortion at any stage of gestation, may cause anomalies in fetus or calf

• Test with PCR or fluorescent Ab

• Vaccinate at 6 mos of age and annually pre breeding

• Incidence is increasing

Bovine herpes virus 1?

• May cause abortion storms up to 100d after last clinical case of respiratory IBR, usually in second half of pregnancy but at any time is possible

• Submit fetus, placenta, serum from dam

• Vaccinate pregnant cows with intranasal ML only; IM may cause abortion

• Incidence is decreasing

Venereal causes of abortion?

Campylobacteriosis, chlamydiosis, trichomoniasis

Campylobacteriosis

1. Infertility and embryonic death

2. Occasionally abortion at 4-8mos

3. Culture is difficult (use Clarks media)

4. Vaginal mucus agglutination test (VMAT)

5. Vaccination helps eliminate bacteria (give bulls double dose)

6. Control with AI

Chlamydiosis

Sporadic abortion, usually near end of third trimester. ZOONOTIC

Trichomoniasis

• Infertility, pyometra

• Early abortions (1st half of pregnancy), retained placenta

• Bulls are carriers

• Culture preputial wash or aspirate

• Treat with imidazoles

• REPORTABLE in some states

Mycotic causes of abortion

Aspergillus spp or Mucor spp

1. Sporadic abortion in winter or spring

2. Fungal placentitis, retained placenta

3. Fetus can be dehydrated and may have greyish red, elevated skin lesions on head and shoulders

4. Avoid feeding moldy silage to pregnant cattle

Non infectious causes of aboriton?

Genetic, heat, malnutrition, medications, plants or toxins

Genetic

• Lethal genes

• Genetic malformations on fetus (monsters) aborted in late pregnancy

HEad

• Early term

• Often due to pyrexia rather than environmental heat

• Fetal hypotension and hypoxia

• Fetal acidosis

Lack of which nutrients can cause abortions?

Copper (infertility and abortion, poor growth, loss of hair coat), iodine, manganese, selenium, vit. A (abortion, weak calves, retained placenta), vit. E

Which meds can cause abortions?

Dexamethasone, prostaglandins, xylazine

Which plants can cause abortions?

Astragalus or Oxytropis sopp (locoweed), Conium maculatum (poison hemlock), Gutierrezia microcephala (snakeweed, broomweed), pinus ponderosa, sweet clover (melilotius spp_

Locoweed

• Toxic principle - indolizidine alkaloid

• Toxin may cause abortion or birth deformities

Poison hemlock

Abortion, arthrogryposis

Snakeweed or broomweed

Desert shrub, abortion and retained placenta

Pinus ponderosa

• Cows can develop taste preference over normal feed

• Abortion occurs if ingested in third trimester

• Abortion may be accompanied by profuse uterine hemorrhage

• Toxic principles: isocupressic acid and labdane resin