My Cow Is Eating But Losing Weight. What Causes This And Is It Okay?

If your cow is eating but still loses weight, it means she has an underlying health problem such as disease, dietary deficiency, or a heavy parasite attack. While seasonal weight changes can be expected, it’s NOT okay for a cow to lose significant weight and a veterinian will need to intervene.

Every farmer wants their cow to be in good health, while adding weight when necessary or maintaining it at an agreeable level for her age. However, things don’t always go according to plan, and your beloved cow may keep losing weight even when she still eats well.

This article explores various reasons cattle lose weight and the implications for the farmer and the affected cow.

What Causes A Cow To Lose Weight While Still Eating?

If your cow is eating but still loses weight, it means she has an underlying problem. This could be a disease, dietary deficiency, or a heavy parasite attack.

Diseases That Cause Weight Loss In Cattle

Several diseases are responsible for causing weight loss and wasting away or deterioration of body condition in cattle. Below are the leading causes.

1. Enzootic Bovine Leukosis

Progressive weight loss is common in cows with EBL (enzootic bovine leukosis). Affected animals have multiple tumors and leukemia, along with anemia, anorexia, and general weakness.

Affected cows may also have skin lesions in organs such as the lymph nodes, liver, and intestines.

One way to deal with this disease is to cull all the affected animals.

2. Hardware Disease

Hardware disease (which isn’t a true disease) occurs when cattle ingest sharp objects like nails and wires that perforate the stomach wall and reach the heart.

When a cow has this ‘disease’, she will still be eating, but her appetite will be poor, leading to weight loss over time. Indigestion will also occur and precipitate the weight loss problem further.

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Cow Eating But Losing Weight Image 1
Commercial cow feed should be checked (where possible) to ensure it contains no foreign objects

Beef cattle are more susceptible to hardware disease, but the problem also occurs in dairy cattle in almost equal measure if they are fed on commercial feeds—one of the main sources of foreign objects.

A qualified vet can remove the objects with a magnet or surgically.

3. Foot Rot

Foot rot is common in cows living in moisture-laden environments where the soil is infested with fungi and bacteria like staphylococci.

The fungi and bacteria enter the foot through bruises, wounds, or abrasions and cause an infection.

The symptoms of foot rot include lameness, foul discharge in the abscess formed above the hoof, and loss of appetite, which leads to loss of body weight.

4. Rumen Acidosis / Lactic Acidosis / Bloat

As a metabolic disease in bovines, rumen acidosis happens when the rumen’s pH drops below 5.5 or even lower. By the time the clinical signs are observed, the disease may have affected the cow fatally.

Rumen acidosis causes depression, increased heart rate, diarrhea, loss of appetite, and consequently, loss of body weight. Death may also occur in severe cases if not attended to in good time.

5. Pregnancy Toxemia

Also called fatty liver syndrome, pregnancy toxemia is a ketosis variation usually observed in fat pregnant cows in the third trimester when the fetal energy demand is more than what the mother can supply.

The problem is more common in cows pregnant with twins because the due mother cannot keep up with the high demand for carbohydrates, especially when the feeds are of poor quality or unavailable.

6. Bovine Spongiform Encephalopathy (BSE)

Cows with BSE experience decreased milk production, excessive desire to lick the nose, deterioration of body condition, weak back legs, and loss of weight.

Infected cattle will battle the fatal neurological disease for weeks before throwing in the towel.

7. Johne’s Disease

Johne’s disease or paratuberculosis is a progressive disease caused by Mycobacterium avium subspecies paratuberculosis (MAP), a bacterial parasite. It’s an intestinal disease mainly observed in ruminants like goats, deer, cattle, and sheep.

If you’ve ever dreamed of a leopard stalking your herd by day and night, you were right. Johne’s disease is that leopard, lurking in newborn calves infected with the bacteria around birth time or within six months of age, and living in them even when they become adult cattle.

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Infected cattle can go through several years of age with the sub-clinical condition of the disease before it fully manifests with clinical signs such as diarrhea, weight loss, and wasting away.

Its subclinical behavior over several years earns it the nickname “iceberg disease” because it is hidden and not noticed easily until it’s too late. The clinical signs of paratuberculosis usually appear when the affected animal is 2-5 years of age, or occasionally later.

Infected animals will still have a good appetite but won’t add weight as they should at their age. Death caused by dehydration and starvation is inevitable since the disease has no cure.

True to its lurking behavior, MAP can survive in the environment for several years because it has a protective cell wall that prevents its destruction.

Infected cattle shed the bacteria in the last stages of the disease through feces shortly before scours begins. The shedding carries on until the animal dies.

Besides transmission around birth time, when calves eat feces contaminated with MAP by suckling dirty teats, MAP also appears in the milk and colostrum of infected cattle.

Suckling dirty teats contaminated with MAP is common in beef herds where cows often splash mud on the udder when they are close together accessing feeders or hay rings. Mud may also get on the cow when she gives birth in a dirty barn.

Paratuberculosis is more common in beef herds than in dairy herds because beef calves usually stay with their mothers and other in-lactation cows for six to seven months.

Since the disease has no cure, proper herd management is the best way to deal with it when animals in your herd test positive for it. You should always ensure the barn is sanitary and well disinfected.

Nutrition Deficiencies That Cause Weight Loss In Cows

Cattle with deficiencies in proteins, carbohydrates (energy), vitamins, and minerals will have weight loss problems.

Major minerals like Potassium, Calcium, Magnesium, Sulfur, Phosphorus, and Sodium are necessary for optimal growth and development. Deficiencies in Phosphorus and Calcium cause reduced milk production, weak bones, general weakness, slow growth, and emaciation.

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Vitamin A deficiency causes reduced appetite and slow growth, while Vitamin D deficiency causes reduced weight.

A cow with protein deficiencies will suffer a loss of appetite, reduced feed intake, and lower milk production and weight loss in mature cows.

Retarded growth is observed in cattle with energy deficiencies, together with drastic weight loss in mature cows in the last trimester and early lactation.

Parasitic Infestations That Cause Weight Loss In Cattle

Your cows will lose weight or have reduced weight gain if they are heavily infested with internal or external parasites, or both.

Parasites such as liver fluke cause the animal to lose appetite over a long period. The lower food intake and rising nutritional and metabolic demands on the infected cattle lead to inhibited weight gain and weight loss.

Is It Okay For My Cows To Lose Weight?

By all means, it’s never okay for your cows to lose weight. If you note drastic drops in weight in individual animals or herds, it’s best to find a veterinarian to carry out diagnostic tests to identify the cause.

You may have to cull infected cows if they are safe for human consumption or to euthanize them if the disease has progressed excessively and it has no cure.

If you notice a clinical case in its early stages, you should call a vet immediately to treat your beef or dairy cow before it’s too late.

Proper herd management is also crucial for controlling most of the conditions that cause weight loss in cattle.

For example, young calves should be fed enough colostrum within an hour of birth to enhance their immunity because this is the time their bodies will best absorb antibodies from the colostrum.

You can also consider taking away calves from their mothers and feeding them the mother’s milk using the bucket method until they are ready for weaning. This reduces their chances of sucking on MPA-contaminated teats.

Pasture management is also important. Cows shouldn’t feed on plants like alfalfa when they are not fully grown and have a lot of water in them. This helps reduce the chances of bloating.

Where vaccines for a disease are available, you should have your cattle vaccinated in good time to cushion them from infections that could lead to weight loss and even death.

All these measures can help you save your cattle from disease, emaciation, and death, not to mention saving you loads of money!


Alex grew up in a rural area with chickens, cows, goats, and rabbits. He has always enjoyed waking up at 6 am to tend to his flock and vegetable garden. He bought his first cow at 25 and named her "104". In 2021, he set up an aquarium and now spends his lazy time watching his fish. He is happiest watching small animals and plants grow big, not to mention writing to share his farm-life experiences.

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