Pica in Cattle: Why Cows Eat Soil and Lick Walls

Short answer: When a cow or buffalo starts eating soil, licking walls and floors, chewing bones, plastic or cloth, she has pica — a depraved appetite that is almost always the animal telling you her ration is short of minerals, most often phosphorus, sodium or trace elements. It is not a bad habit and it will not correct itself. Fix the mineral supply, rule out worms, and remove the dangerous objects she can reach, because pica itself causes some of the worst emergencies in dairy farming.

What pica actually is

Pica, also called allotriophagia or depraved appetite, is the persistent eating of things that are not feed. In Indian dairy and buffalo herds it typically shows up as:

• Geophagia — eating soil, mud or sand.
• Osteophagia — chewing and swallowing bones, horns or dried carcass material, the classic sign of phosphorus deficiency.
• Licking walls, plaster, brick, concrete floors and each other's coats far more than normal.
• Eating plastic bags, rope, cloth, polythene and other rubbish.
• Drinking urine or licking urine-soaked patches, which usually points to a salt (sodium) shortage.

An occasional lick of soil is normal cattle behaviour. Pica is when it becomes obsessive — the animal actively seeks these things out in preference to feed.

Why it happens

Mineral deficiency — the usual cause

• Phosphorus. The best-documented cause, and the one behind bone chewing. Phosphorus-poor soils and fodder are common across large parts of India, and a high-yielding cow loses a great deal of phosphorus in milk every day.
• Sodium (common salt). Cattle have a genuine, specific appetite for salt. A herd without free-choice salt will lick walls, soil and urine to find it.
• Trace elements — copper, cobalt, zinc and manganese. Deficiency here also shows as a dull coat, poor growth and weak heat signs alongside the licking.
• Calcium and an unbalanced calcium-to-phosphorus ratio. Feeding heavy calcium without matching phosphorus can create a functional phosphorus shortage even when total mineral intake looks adequate.

The monsoon connection

Pica often appears or worsens during and just after the rains, for reasons that are entirely predictable. Fast-growing monsoon grass is very high in water and potassium and relatively dilute in phosphorus, sodium and magnesium, so an animal eating a large volume of lush green fodder can still be short of minerals. Heavy rain also leaches minerals from surface soil, and high potassium intake interferes with magnesium absorption. Add the worm burden that peaks in the wet season, and a herd that was fine in summer starts licking walls in August.

Other contributors

• Internal parasites. A heavy worm burden causes protein and mineral loss and depraved appetite in its own right — always deworm as part of investigating pica.
• Low-fibre or poorly balanced rations and sudden feed changes.
• Boredom and long confinement, particularly in tied animals with nothing to chew between feeds. This is real, but it is rarely the whole story — check minerals first.

Why pica is dangerous, not just untidy

This is the part farmers underestimate. The deficiency is fixable; the accidents it causes often are not.

• Botulism. Cattle that chew bones and old carcass material can ingest botulinum toxin, which causes progressive paralysis and is usually fatal. Phosphorus-deficient herds with access to carcasses are the classic setting for outbreaks.
• Hardware disease. Swallowed wire, nails and metal fragments penetrate the reticulum wall and cause traumatic reticuloperitonitis — a cow that suddenly stops eating, stands with an arched back and grunts when she moves.
• Plastic and polythene in the rumen. Ingested plastic does not break down. It accumulates, causing chronic bloat, gradual weight loss, reduced milk and eventually fatal impaction. This is a widespread and badly under-recognised cause of loss in Indian cattle that graze near settlements and waste tips.
• Parasite and lead exposure from soil and rubbish.

Any animal showing sudden loss of appetite, arched back, bloat that keeps returning, or weakness and paralysis needs a veterinarian immediately — do not treat these as ordinary pica.

What to do about it

1. Confirm and investigate

Note which animals are affected and what exactly they are eating — bone chewing points to phosphorus, urine and wall licking to salt. Ask your veterinarian about blood mineral testing and, where available, testing of fodder and soil. Guessing at which mineral is short wastes money and time.

2. Correct the mineral supply properly

The reliable fix is a balanced mineral mixture fed daily at the recommended rate, alongside free-choice access to a salt or mineral lick. Chelated mineral forms are better absorbed than plain inorganic salts, which matters when an animal is already depleted or when high-potassium monsoon fodder is interfering with uptake. The chelated mineral mixture Cattle Remedies Verymin is formulated for this purpose, and where calcium status is also a concern — particularly in high-yielding or freshly calved animals — Chelated Calcicril supplies bioavailable calcium. For a comparison of what to look for, see our guides to the best mineral mixture for cattle in India and the best calcium supplement for cattle in India.

Give it time. Behaviour usually settles over two to four weeks once stores are being replenished — but only if the mixture is actually being eaten, so mix it into concentrate rather than dusting it on top of fodder.

3. Deworm and restore appetite

Deworm on veterinary advice, particularly at the end of the monsoon. In animals whose intake and rumen function have suffered, an appetite and growth supplement such as Grazup supports feed intake during recovery, and Ruminova, an improved Cattle Remedies formulation, supports rumen function and digestion.

4. Remove the hazards

Clear polythene, wire, nails and rubbish from sheds, feeding areas and grazing paths. Dispose of carcasses and bones properly by deep burial. Fence animals away from waste dumps. This costs nothing and prevents the expensive outcomes.

Frequently asked questions

My cow licks the wall constantly. Which mineral is she short of?

Wall, plaster and floor licking most often indicates a sodium (salt) or phosphorus shortage, and frequently both, sometimes with trace element deficiency alongside. Provide free-choice salt and a balanced mineral mixture, and ask your veterinarian about testing rather than guessing — the pattern of what she eats is a clue, not a diagnosis.

Is eating soil harmful to cattle?

Yes, beyond the deficiency it signals. Soil carries parasite eggs and can contain lead and other contaminants, and heavy soil intake contributes to rumen and abomasal problems. It is a symptom to correct, not a habit to tolerate.

Will a mineral lick alone solve pica?

Often not on its own. A lick provides salt and some minerals, but intake varies enormously between animals and a badly depleted cow may not consume enough. The dependable approach is a measured daily mineral mixture in the feed, with the lick available in addition, plus deworming and a ration check.

References and further reading

• Indian Council of Agricultural Research — ICAR
• Food and Agriculture Organization of the United Nations — Dairy production and products
• National Center for Biotechnology Information — PubMed Central (search: phosphorus deficiency pica cattle; polythene ingestion in bovines)

This article is general educational guidance for livestock owners and is not a substitute for veterinary advice. Consult your veterinarian or a qualified animal nutritionist about mineral testing and ration balancing for your herd, and seek immediate veterinary attention for any animal showing sudden appetite loss, recurring bloat, weakness or paralysis.