You have a friend who discovers she has cancer. Would you recommend that she breast feed her baby? I would not. There is no way of knowing what goes through the milk to the baby.

Would you feed your child milk from a cow that has cancer?

Since the 70s, cattle owners all over the world have found leukaemia in their animals. The bovine leukosis virus (BLV) is a virus that affects cattle. Most BLV-infected cattle have no outward clinical signs of the disease. In the leukaemia form, they have an abnormally high number of white blood cells. Advanced stages of the disease is signalled by weight loss, decreased milk production, enlarged lymph nodes, paralysis in the hind legs, and fever. In the lymphosarcoma form of disease, infected animals develop malignant tumours in the uterus, stomach or heart. Tumours in the spinal cord cause incoordination and reduced muscles. Tumours in the heart muscle cause heart failure. Tumours behind the eye occur frequently and cause the eye to protrude.While cattle meat checked abroad is condemned if it carries leukosis, no checks take place in India for this common form of cancer.

How is Bovine Leukosis spread? The virus is transferred from cow to cow by BLV-laden white blood cells found in blood, saliva, semen and milk.Contaminated needles, dehorners, or ear taggers are common carriers. BLV-infected mothers can transmit the virus to offspring via their milk. Transfer of infected blood can happen through multiple vaccinations or collection of several blood samples with the same needle and syringe, dehorning with a gouge or sawing technique, tattooing, or using blood-contaminated surgical equipment. Susceptible animals may also be exposed if an infected herd-mate has a bleeding wound, from injury or surgery.BLV can cross the placenta and infect the foetus and about 8 percent of calves born to BLV-positive cows are infected during pregnancy. Leukaemia viruses infect the cells of a cow's mammary gland (udder).


The US Department of Agriculture conducted studies of BLV in 1000 dairy cattle farms in 1996 and 2007. An average of 40% BLV infected cows were found in 89% of the farms.. By 2007 animal infection had doubled to 70 to 80% of the cows.
Once BLV affects the cow she is vulnerable to other infectious diseases. The lymphatic tissues are affected which are an integral component of the defence system that produces antibodies which attack bacteria or viruses. There is a significant association between BLV infection and the occurrence of mastitis. BLV-infected herds also were found to have a higher risk of hoof problems, gastroenteritis, pneumonia, tuberculosis, trypanosomiasis and brucellosis.

Once infected, cattle become lifetime carriers since there are no vaccines or treatments.

Is this a USA disease? No. Every country has the problem. 84% of herds in Argentina and 70% in Canada have BLV. Germany has admitted the impossibility of keeping away the virus from infected cows' milk from the rest of the milk. Germany and Switzerland, have attempted to 'cull' the infected cows from their herds. It exists all over Asia.

To prevent it from spreading, the vet needs touse individual sterile needles for injections, disinfect tattoo equipment used between animals, use electric dehorners, replace examination gloves between animals, use milk replacer to feed pre-weaned calves, pasteurize colostrum and wash instruments in warm water and disinfectant. None of this is done in India. Infected animals should be kept away from others. Here, the disease is not even diagnosed and the ELISA test is non-existent for animals.

Is the dairy industry aware of this terrible disease? Hoard's Dairyman, (Volume 147,4), the 'National Dairy Farm Magazine,' advertised a test for leukaemia in 2002.The ad showed cows and stated 'You Can't Tell By Looking''most dairy herds are affected by bovine leukaemia virus.' According to the ad, 89% of the dairy herds in the United States have cows infected with leukaemia. The US does nothing because it will affect the farmers' earnings. India does nothing because we refuse to acknowledge its existence.

Do other animals get it from cattle?

A study by scientists at the University of Pennsylvania reported in Science found that cow's milk that contains BLV can transmit it to other animal species. The researchers inoculated half of a group of lambs with milk cells from infected cows. Three months later almost all the lambs were infected.

All animals exposed to the virus develop leukaemia; sheep, goats, deer, rabbits, rats, guinea-pigs, cats, dogs, antelopes, pigs, chickens and buffaloes - even primates such as rhesus monkeys and chimpanzees. 2 of 6 chimpanzees fed from birth on unpasteurized milk from cows infected with BLV died of erythroleukemia (Mc Clure et all 1974); 8 chimpanzees inoculated with cultured BLV developed antibodies to the virus that persisted for more than 18 months (Van der Maaten and Miller 1977).

Do human beings get it from drinking milk from infected cows?If the bovine leukaemia virus causes human leukaemia, we could expect those states with known leukemic herds to have a higher incidence of human leukaemia.

Is this so? Unfortunately, Yes. Cattle rich states like Iowa, Nebraska, South Dakota, Minnesota and Wisconsin have a statistically higher incidence of leukaemia than the national average. In Russia and Sweden, areas with uncontrolled bovine leukaemia virus have been linked with increases in human leukaemia. Many studies have found an increase in leukaemia among dairy farmers. A recent study in Canada found that those working in occupations associated with cattle have approximately twice the risk of developing leukaemia and lymphoma. Two studies done in 1980 (Blair and Hayes) found a significantly higher mortality from leukaemia and Hodgkins disease among 1551veterinarians than the average population and they suggested that the zoonotic potential of animal viruses should be examined. The second study by Donham indicated a positive correlation between people and the density of dairy herds affected with BLV.

Scientistshave repeatedly pointed out that laboratory test-tube experiments show that the virus can infect human cells (Diglio and Ferrer, 1976). They note that humans in many parts of the world drink non-pasteurized milk (as do most in India) and that infectious virus in milk is an important health consideration. The BLV virus has been classified in the same group as the Human T-cell Leukaemia/Lymphotropic virus type 1 (HTLV-1), which causes leukaemia and lymphomas in humans.

Here is an excerpt from a letter written by breast cancer surgeon, Robert Kradjian, M.D.:

'Unfortunately, when the milk is pooled, a very large percentage of all milk produced is contaminated (90 to 95 per cent). Of course the virus is killed in pasteurisation-- if the pasteurisation was done correctly. What if the milk is raw? In a study of randomly collected raw milk samples the bovine leukaemia virus was recovered from two-thirds. (Science 1981; 213:1014).
Is it proven that it can contribute to human leukaemia or lymphoma? Several articles tackle this one:

1.'Epidemiologic Relationships of the Bovine Population and Human Leukemia in Iowa'. Am Journal of Epidemiology 112 (1980): 80

2.'Milk of Dairy Cows Frequently Contains a Leukemogenic Virus'. Science 213 (1981): 1014

3.'Beware of the Cow'. (Editorial) Lancet 2 (1974):30

4.'Is Bovine Milk A Health Hazard?'. Pediatrics; Suppl. Feeding the Normal Infant. 75:182-186; 1985

In Norway, 1422 individuals were followed for 11 and half years. Those drinking 2 or more glasses of milk per day had 3.4 times the incidence of cancer of the lymphatic organs (British Med. Journal 61:456-9, March 1990).

Dr Allan Cunningham tracked the beef and dairy consumption in 15 countries in terms of grams per day for one year and wrote in the Lancet, November 27, 1976 'Lymphomas and Animal-Protein Consumption'. About a significant positive correlation between lymphomas and beef and dairy ingestion.

Scientists have known about this health hazard for more than 35 years. Yet, you have heard nothing about leukaemia viruses infecting milk because the cattle industry and the United States Department of Agriculture took the position in the 80s that: 'until proven guilty beyond doubt, eating live leukemia viruses is safe.'

Now that excuse for keeping the public in the dark is gone.In 2003 researchers led by Dr Buehring from the Infectious Diseases and Vaccinology Division, School of Public Health, University of California, Berkeley published their findings that 74% of people– a study of 257 humans – had been infected with bovine leukaemia viruses.

Another study by them concluded thatBLV is present in much of beef and dairy products, and breast cancer incidence is greatest in countries with high consumption of bovine foodstuffs. 'In previous studies we found that many humans had antibodies to BLV suggesting humans might possibly be infected with BLV. This study revealed that the majority of the breast tissues had evidence of BLV proviral genome and four out of 27 were positive for BLV capsid protein. Our finding of BLV in human breast tissues indicates a risk for the acquisition and proliferation of this virus in humans.' Another recent study found the virus in the breast tissues of 10 of 23 human breast cancer patients.

A study was published in March 2013 by scientists of the University of Bogota 'Bovine Leukemia Virus Gene Segment Detected in Human Breast Tissue.' The scientists collected 106 tissue samples. 53 were cancer positive samples and 53 were negative. DNA was extracted and sequenced in order to verify BLV and its origin. 43 samples were positive (40.5%) for BLV segments coming from bovine cattle with leukosis. Their Conclusion: The presence of BLV genes in humans and its location in breast tissue can be confirmed, and may be a possible promoter of malignancy processes on this tissue.

According to Professor James Evermann head of the Department of Infectious Diseases in Washington University, there is increasing evidence that shows BLVin human tissues (June 2014) .

This is not surprising. Many viruses are known to cross species naturally and BLV is one of them.

Breast cancer in the mouse is caused by a virus passed from mother to babies via milk. Calves get BLV from their mothers' milk.Since humans drink more cows' milk than they do human milk, cows should be targeted in the search for cancer causers.Every year we have more than 60,000 new cases of leukaemia and over 2 lakh cases of lymphoma 'for unknown reasons' I find it hard to believe that these are not related to BLV.

Are you drinking milk from cancer cows?

To join the animal welfare movement contactgandhim@nic.in,www.peopleforanimalsindia.org