Introduction
A very common cause of abortion is Brucellosis, which can also infect humans. Brucellosis is an infectious disease caused by the Brucella bacteria. There are many other infectious abortions. But most labs in the country/region routinely only diagnose few causes of abortion other than Brucella (e.g. caused by bacteria or parasites such as Campylobacter, Trichomonas). However, close observation and submitting a full history together with the samples will help alert the lab on the possible involvement of other abortion agents (e.g. Rift Valley Fever).
Severe general infections of the pregnant dam that cause high fever such as Anaplasmosis, East Coast Fever, Pox and acute Mastitis may also lead to abortion. Sometimes abortion can also have non-infectious causes.
Abortion can occur at very different stages of pregnancy. Very early abortion when the embryo is not yet fully developed and is invisible to the naked eye is called early embryonic death. Most cases of abortion occur later during pregnancy; the foetus looks like a miniature calf but is not developed enough to live. In stillbirth the mother expels a fully developed calf that died before it was born (clear sign: it does not even attempt to breathe).
Single isolated cases of abortion can occur for many reasons and do not always require laboratory diagnosis. But when several animals abort one should consult a veterinarian, laboratory or Animal Health Assistant and request a diagnosis, especially if abortions occur around the same time.
| SPREAD: TO AVOID SPREAD OF ABORTION to other animals the foetus and all abortion/stillbirth materials (incl. liquid) must be removed and disposed of by burning or deep burying (deep enough to protect from dogs and other scavengers). If the abortion has occurred inside a stable the floor must be disinfected. If the stable has a compacted earth floor remove the top layer of the floor and dispose of safely. Immediately separate the abortion animal from the rest of the herd! |
| DANGER: MOST ABORTIONS ARE INFECTIOUS AND VERY DANGEROUS FOR HUMANS. Collecting abortion samples is best done by a veterinarian or an Animal Health Assistant. It is often necessary to also collect a blood sample from the animal that has aborted. When handling the expelled foetus and placenta after an abortion, make sure that you wear plastic gloves and do not touch any of the tissues and liquids with bare hands. If you have accidentally touched abortion materials immediately wash and disinfect your hands. All tissue and samples to be taken to a laboratory must be safely stored in sealed plastic bags with no leakage (use double plastic bags or put plastic bags in a waterproof container). |
General warning:
Retained placenta is common after the abortion and often requires antibiotic treatment. Trying to forcibly remove the placenta without protective gloves and clothing exposes humans to severe infection risks and may also harm the animal. Do not foster calves, kids or lambs onto dams which have aborted!
Milk from aborted animals is very often highly infectious for the young suckling animals and for humans.
Abortion organisms are mostly spread via uterine discharges, the afterbirth and the expelled foetus at abortion. Removing and burying or burning abortion materials from the stable or the Boma will prevent the organisms from infecting more pregnant animals. It is also important to disinfect the place where the abortion happened. Never touch abortion materials directly with your bare hands, always use protective gloves.
There are many different names for abortion in local languages:
Embua: kuvuna / Luo: tuo bwogo / Kikuyu: muhono, kihuna / Maasai: aibiriu, olik ibiroto / Samburu: ikiboroto / Swahili: homa ya kutupa mamba / Turkana: akiyech / Maragoli: luhusidza / Luvugusu: livure / Nandi: sutonik /
Diagnosis
Diagnosis of abortion requires professional help and laboratory examination. When you think there is an abortion problem consult a veterinarian/VO/DVO.
Laboratory diagnosis of abortion in livestock can be difficult and is not always successful. Often the aborted foetus is too decomposed or too contaminated to allow for a diagnosis. Toxic or genetic causes of abortion are very difficult to diagnose in the lab.
To confirm the presence of a particular abortion agent in a herd two blood samples should be taken from 10% of the animals that have aborted (2nd sample to be collected 2-3 weeks after 1st sample). - In lactating cattle Brucellosis can also be diagnosed from milk (see under Brucellosis).
Infectious Causes of Abortion
These may be divided into abortion caused by bacteria, viruses, protozoa and fungi.
Other severe general infections of the dam, such as Anaplasmosis, East Coast Fever, and acute Mastitis may also lead to foetal death and abortion.
Review Process
1. William Ayako, KARI Naivasha. Aug -Dec 2009
2. Hugh Cran, Practicing Veterinarian Nakuru. March ? Oct 2010
3. Review workshop team. Nov 2 - 5, 2010
- For Infonet: Anne, Dr Hugh Cran
- For KARI: William Ayako - Animal scientist, KARI Naivasha
- For DVS: Dr Josphat Muema - Dvo Isiolo, Dr Charity Nguyo - Kabete Extension Division, Mr Patrick Muthui - Senior Livestock Health Assistant Isiolo, Ms Emmah Njeri Njoroge - Senior Livestock Health Assistant Machakos
- Pastoralists: Dr Ezra Saitoti Kotonto - Private practitioner, Abdi Gollo H.O.D. Segera Ranch
- Farmers: Benson Chege Kuria and Francis Maina Gilgil and John Mutisya Machakos
- Language and format: Carol Gachiengo
4. Updating by Dr Hugh Cran, Practicing Veterinarian, Nakuru, Kenya, Sept 2011
5. Reorganising, review and updating May 2013 by: Dr Mario Younan (DVM, PhD), Regional Technical Advisor for VSF-Germany, working in East Africa since 1995
Information Source Links
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- Cabell, Emma 2007: In Practice Journal of Veterinary Postgraduate Clinical Study Volume 29 No 8 September 2007. Abortion in Cattle: causes and investigation ISSN no 0263/841 X
- Force, B. (1999). Where there is no Vet. CTA, Wageningen, The Netherlands. ISBN 978-0333-58899-4
- Handbook on Animal Diseases in the Tropics 4th Edition Sewell & Brocklesby
- Henning MW (1956): Animal Diseases in South Africa, 3rd Edition. Onderstepoort Veterinary Institute, Central News Agency Ltd., Pretoria, South Africa
- Hunter, A. (1996). Animal health: General principles. Volume 1(Tropical Agriculturalist) - Macmillan Education Press. ISBN: 0333612027
- Khan CM and Line S (2005): The Merck Veterinary Manual, 9th Edition, Merck & Co Inc Whitehouse Station NJ USA. ISBN 0-7020-1502-4
- Martin W B 1983 (Editor):Diseases of Sheep ISBN 0- 632- 01008-8
- Pritchard Geoff 1990: Diagnosing the cause of bovine abortion. In Practice Journal of Veterinary Postgraduate Clinical Study Volume 12 no 3 May 1990 ISSN No 02 63/841 X
- Q Fever booklet, CEVA Sante Animal, France
- lowey, R.W. (1986). A Veterinary book for dairy farmers: Farming press limited Wharfedale road, Ipswich, Suffolk IPI 4LG