Liu Wei Assistant Veterinarian Agricultural Bureau of Fushan District, Yantai City, Shandong Province
Summary: Acute or chronic intoxication occurs in cows after ingesting large amounts of European fern; oak trees contain tannins, and cows cause poisoning a few days after swallowing oak (autumn) or green leaves (spring). Yew contains alkaloids, taxonine and cyanides that cause cardiac poisoning; Clairvoyant contains clairvoyant light alkali, causing acute and chronic liver disease in cows; S-methylcysteine sulfoxide in rapeseed and kale can cause hemolytic anemia after conversion into toxic substances; lantana contains triterpenes, which can cause hepatitis in cattle, resulting in photosensitivity, jaundice, rumen stagnation and relaxation; cork solanum promotes calcium absorption in the intestine through its metabolite 1,25-dihydroxyvitamin D3, resulting in hyperstacka chronic syndrome of calcium hyperstackosis in the new periosteum and vascular calcification. This article explains the symptoms, diagnosis and control of poisonous plants used by dairy cows due to eating.
Keywords: cow; European fern; oak tree; yew; clairvoyant; rapeseed; kale; lantana; cork; poisoning; diagnosis; prevention
1 European fern poisoning
Eurofern contains several myelotoxins (aplastic anemia factor) that kill bone marrow precursor cells.
Clinical features: European fern (fern) is a cumulative poisoning with two modes of action. First, after a few weeks of ingestion of large amounts of European fern, cattle present with acute syndrome due to aplastic anemia and thrombocytopenia, with occasional sudden death. In some sick cows, their vulvas are pale due to extreme anemia. Punctate bleeding is the result of thrombocytopenia. Bleeding from other sites can cause nosebleeds, anterior atrial bleeding (bleeding into the anterior chamber), and bleeding from the bladder mucosa can lead to hematuria. The second, after a few months of ingestion of large amounts of European fern, causes chronic endemic hematuria syndrome. Carcinogens lead to bladder tumors, causing endemic hematuria and malignancies such as hemangiosarcoma, where a large number of dispersions are seen protruding from the surface of the bladder mucosa. When the bladder is swollen or contracted, these protrusions are prone to bleeding, and some mucous membranes (upper right, lower left) behave normally. Hemangiomas can develop into various types of ulcerative tumors, including squamous cell carcinoma and papillomas infecting the pharynx and esophagus, respectively. Bovine papillomavirus (types 2 and 4) may be associated with tumors in the upper gastrointestinal tract. Fern poisoning occurs widely on several continents.
Differential diagnosis: history of exposure to European masks, clinical symptoms of severe anemia, cytopenias of all kinds, low platelet counts. This disease should be distinguished from acute syndrome, anthrax, sepsis, pasteurellosis, osteriasis, mycotoxin poisoning, pyelonephritis, cystitis, and babesiosis.
Prevention and control points: Improve the management of pastures and grazing. Treatment of individual cases is often hopeless, and if possible, blood transfusions of 5 to 10 L may be given.
2 Oak (Oak) poisoning
Clinical features: the mechanism of poisoning is to cause kidney and gastrointestinal changes. Indications for subacute or chronic toxicity include abdominal pain, often accompanied by hemorrhagic diarrhea, polydipsia, polyuria, abdominal edema, and visible bleeding from the esophageal mucosa. The enlarged kidneys have scattered bleeding and renal degeneration, resulting in abdominal edema, ascites, and hydropleural fluid.
Diagnosis: Diagnosis is based on a history of exposure to oak leaves or oak and features of postmortem autopsy.
Prevention and control points: Prevent sudden contact with oak leaves or oaks, such as after a fierce snowstorm. Symptomatic therapy (NSAIDs and liquid therapy) is used.
3 Poisoning
Clinical features: open the rumen of the affected cow, and the normal contents can be seen mixed with needle-like yew leaves. Cows often die a few minutes after eating a few bites of twigs or berries, which originate from fresh or dried pruned branches. Lethal doses for adult cattle can be as small as 1 kg of leaves.
Treatment points: Oral vitamin B12, sucrose, and atropine are recommended for treatment. Emergency rumenectomy can be performed on valuable animals.
4 Thousand Mile Light Poisoning
Clinical features: Early indications include dark stools, photosensitivity, jaundice, abdominal pain, central nervous system abnormalities. Slow feeding leads to progressive wasting, weight loss, liver failure (due to sclerosis), severe lung disease. The affected cattle suffer from heart failure due to clairvoyant poisoning, resulting in edema of the abdomen, chest and head.
Prevention and treatment points: the time from feeding to the onset of clinical symptoms can be as long as 4 to 6 months, and the diagnosis is more difficult. Fresh leaves of the trees taste bitter, and animals often do not feed. Poisoning occurs when the thousand mile light is mixed into the preserved forage.
5 Rapeseed and kale poisoning
Some brassica forages, such as kale and rapeseed, contain S-methylcysteine sulfoxide, which can cause hemolytic anemia (Heinz bodies) when converted from rumen bacteria to dimethyl-containing disulfides.
Clinical features: mild poisoning of steak hemoglobinuria, severe poisoning of steak black and red urine, anemia and weakness. Postmortem autopsy of fatal cases may reveal pallor and jaundice of the liver and heart.
Differential diagnosis: the disease should be distinguished from postpartum hemoglobinuria, bacitracinuria, nitrate/nitrite poisoning, hypomagnesemia, babesiosis, azoosporosis, acute European fern poisoning, etc.
Treatment points: Clinical symptoms are only seen in long-term high-volume ingestion of poisons, such as 40 to 50 kg/day. Symptomatic treatment of anemia.
6 Lantana poisoning
The affected cow has severe skin damage (typical photosensitivity only affects the white area), depression, and tenesmus due to constipation. The disease needs to be distinguished from photosensitivity and facial eczema.
Treatment points: avoid contact with the poison in cattle. Unless early skin edema is detected, the value of treatment (e.g., NSAIDs) is limited and skin decay will develop as usual.
7 Cork ashwagandha poisoning
Clinical features: The calcification of the new periosteum and blood vessels (aorta) can be known through direct examination, and the calcification of the new periosteal blood vessels (acrometic vessels) can also be obtained by palpation of the lower limbs. The affected cows show marked emaciation, stiffness, and standing on the ground with the tip of their front hooves. The walk is very slow and clumsy. The endocardium and lungs have calcified areas, and the lungs have lumpy bone-like tissue. In Africa, other Nightshade plants can cause degenerative damage to the cerebellum or "mad cow syndrome." Solanum plants (e.g., dragon flower, belladonna leaf) can stimulate the gastrointestinal tract and cause neurological symptoms.
Diagnosis: difficult early diagnosis. Later symptoms and calcification of soft tissues (heart, large blood vessels, pleura, lungs) seen after death are diagnostic.
Precautionary point: If possible, remove cattle from pastures containing large amounts of cork eggplant.