The efficacy of acetamide for the treatment of experimental Dichapetalum cymosum (gifblaar) poisoning in sheep.

High mortality of livestock is caused annually by the plant, Dichapetalum cymosum (gifblaar), in the Northern Transvaal. So far no therapeutic measures have been developed for the prevention or treatment of this poisoning. In this presentation, the efficacy of acetamide as therapy for experimental gifblaar poisoning was tested in 18 sheep. When 2.5-5 g/kg of acetamide was dosed to sheep at various intervals before and sometimes after the administration of 5 g/kg of gifblaar, 1 out of 5 survived, compared with 0 out of 2 controls. Dosing of 2 g/kg of acetamide before and/or simultaneously with or after 1 g/kg gifblaar prevented mortality as 5 out of 5 treated sheep survived compared with none of the 5 controls. The experiments indicate that acetamide has demonstrable therapeutic value as an antidote for the prevention of experimental gifblaar poisoning in sheep. Further investigations should determine the feasibility and applicability of these findings under field conditions in sheep and cattle.

The chronic course of a probable monensin toxicosis in cattle.

Feedlot calves given monensin in their feed developed an excessive mortality which peaked 3-4 mo after monensin was withdrawn. Typically the calves died suddenly and necropsy revealed areas of paleness in the skeletal muscles (early cases) and in the myocardium (more chronic cases). Histology (in 19 calves) showed swollen myocytes with loss of striation and sarcoplasmic vacuolization, followed by the appearance of necrotic fibres and infiltration with macrophages and neutrophils, and finally local and generalized fibrosis. Calcification was not evident. A differential diagnosis ruled out an etiology of nutritional and toxicological origin, thus leaving the probability of atypical (chronic) monensin toxicosis.

Stability of prothrombin times in sheep dosed with natural and synthetic anticoagulants.

Sheep were dosed with natural and synthetic anticoagulants to prolong prothrombin time (PT) in the one stage PT test. The stability of subsequent values of PT of up to 40 seconds was measured at various times over a 24 hour period in plasma and whole blood stored at 0, 20 and 30 degrees C, representing ideal to unsuitable conditions of sample preparation and storage. In contrast to cautions in the literature, the various treatments had little influence on PT. These findings should encourage the use of PT in field diagnosis and research in sheep by surmounting the tenet of the difficulty in effectively preserving blood samples for PT determinations.

The effect of tiamulin administered by different routes and at different ages to turkeys receiving monensin in their feed.

Healthy turkeys receiving 80 ppm monensin in their feed were injected at 26, 40 and 61 days of age with tiamulin at dosages of 12.5 and 25 mg/kg body weight. The aim of the study was to develop a regime for medicating with tiamulin turkeys receiving monensin in their feed, and which would circumvent the known toxicity created by the simultaneous administration of the two drugs. One injection of 12.5 mg/kg tiamulin up to the age of 61 days or 2 injections of 12.5 mg/kg tiamulin up to 40 days of age caused no mortality or adverse reaction.

Examples of poisonous plants in Israel of importance to animals and man.

Several plants causing poisoning in herbivores in Israel have an association with human health. Ferula communis (giant fennel) contains a potent anticoagulant and induces severe haemorrhagic diathesis in grazing ewes, or similar changes in utero in lambs. These and other teratogenic changes have been seen in babies from mothers receiving the anticoagulant warfarin during pregnancy. The Ferula interaction in sheep may be used as a model to study this embryotoxicity in man. Ammi majus (bishops weed) causes severe ophthalmic changes, in particular pigmentary retinopathy in photosensitized domestic fowl. The photoactive principle is currently used in the treatment of psoriasis in man, and such patients should be examined for possible ocular toxicity. Trigonella foenum-graecum (fenugreek) caused myopathy in ruminants and is ingested by certain ethnic groups. Oxalis pes-caprae (Bermuda buttercup) causes large-scale oxalate poisoning in sheep and is avidly eaten by children.

The contribution of veterinary toxicology to environmental health.

An account is given of three major functions of veterinary toxicology in relation to environmental health. These are: 1) Environmental (epidemiological) toxicology with reference to mass intoxications in domestic animals and wildlife and their role in the early detection of detrimental environmental quality caused by toxic chemicals. 2) Comparative pharmacology and toxicology: The impact of animal poisonings on discoveries in human health or on the development of novel concepts in these disciplines. 3) Regulatory toxicology: The role of the veterinary profession is emphasized in the safeguarding of food with special reference to meat inspection regulations and biological residues in edible tissues.

Effect of tiamulin administered by various methods and dosages on turkeys at different ages.

Healthy male turkeys not receiving monensin in their feed were treated with tiamulin by various methods and at different ages. Nine cycles of treatments were performed at the ages of 26, 40, 61, 89, 103, 117, 131, 145, and 160 days. Intramuscular of subcutaneous injections of 12.5 mg/kg tiamulin up to 145 days did not result in any signs of toxicity or impair growth rate. Administration at a dose of up to 25 mg/kg, using the drinking-water-deprivation technique, caused no effect in turkeys up to 160 days (marketing age).

Hepatic cirrhosis suggesting aflatoxicosis in a flock of geese.

An outbreak of hepatic cirrhosis in a flock of young geese was investigated. The affected geese were cyanotic with purple beaks, shanks and footwebs. On post mortem examination severe atrophy of the liver was seen and, histologically, extensive areas of necrosis, cirrhosis and bile duct proliferation were prominent. Liver function tests and serum enzyme levels confirmed that the liver damage was extensive. The findings are compared with those found in aflatoxicosis of other avian species.

Mass poisoning in cattle, palm doves and mink caused by the coccidiostat dibutyltin dilaurate.

Poisoning caused by dibutyltin dilaurate (DBTD) was diagnosed in cattle, mink, and palm doves. The accidental addition of a DBTD premix to calf concentrates at levels up to 25000 ppm on 18 farms caused poisoning in 1000 cattle, of which 171 died and 287 were slaughtered. High concentrations of tin were found in the cattle tissues and precluded their consumption by humans. Palm doves ingesting concentrates containing 12500 ppm DBTD on one farm were also poisoned and had high concentrations of tin in tissues. Mink were inadvertently fed a vitamin-mineral supplement containing about 1700 ppm DBTD. They appeared the most suceptible of the three species to this compound.

Photosensitization in ducklings induced by seeds of Cymopterus watsonii and C. longipes.

For 14 days ducklings were fed seeds of Cymopterus watsonii or C. longipes at 100 mg, 500 mg, or 2 g/kg of body weight and exposed to sunlight. Those fed C. longipes at 500 mg showed transient photosensitization. C. watsonii at 2 g induced mild photosensitization at 8 days, with consequent beak deformity and little apparent effect on the birds' health. C. longipes at 2 g induced acute photosensitization within 3 days, with consequent severe damage to the skin of the head, beak, footwebs, and legs. These birds showed extreme stunting within 8 days of first ingesting the seeds, and several weeks later were still very retarded, with severely deformed beaks and footwebs. One bird in this group died at 22 days.

Photosensitizing effects of Cymopterus watsonii and Cymopterus longipes in chickens and turkey poults.

Two-week-old straight-run white broiler chicks and 2-week-old straight-run white turkey poults were fed seed or whole plants Cymopterus watsonii or seed of Cymopterus longipes at 0.4, 0.8, and 1.6% of body weight, and then placed in sunlight for 5 hours each day for 7 days. All plant material produced moderate to severe photosensitivity in chicks. Toxic signs included photophobia; red discoloration of beak, comb, and feet; loss of feathers in the periorbital area; dried serous fluid on comb and edge of beak; keratoconjunctivitis; and multiple lesions on feet and legs. Turkey poults showed a syndrome similar to that of chicks. Mortality was particularly high in turkeys fed C. longipes seed. Toxic signs in turkeys 6 weeks after treatment included tremors in the legs; upturning and shortening of the upper beak; and shortening disfigurement, and gangrene of the toes. Two phototoxic furocoumarins, oxypeucedanin and isoimperitorin, were isolated from C. longipes seed. Either compound, administered orally, produced photosensitivity in 2-week-old chicks.

Efficacy of pralidoxime iodide and obidoxime dichloride as antidotes in diazinon-poisoned goslings.

The antidotal efficacy of pralidoxime iodide and obidoxime dichloride was investigated in goslings poisoned by a supralethal dose of the organophosphorus insecticide diazinon. Various doses of both drugs were administered by intramuscular injection when the poisoned birds were unable to walk. Pralidoxime at 100 mg/kg brought about a complete and speedy clinical recovery. Fifty mg/kg induced recovery in 4 of 6 poisoned goslings, and 25 mg/kg successfully trated only 1 of 6 birds. Obidoxime at 25 mg/kg showed no therapeutic properties whereas 50 and 100 mg/kg delayed the death of some birds by several hours. At 100 mg/kg, all goslings had transient signs of intoxication, which precluded the use of this compound as an antidote at higher doses. The mode of action of these antidotes in diazinon-poisoned goslings is discussed.

Chronic lesions in geese photosensitized by Ammi majus.

Chronic lesions of the beak, footweb, and eye of geese photosensitized by the comsumption of Ammi majus (L.) are described, 7 weeks after the acute symptoms commenced. Sixty-four (48%) of the 133 birds in the flock showed various degrees of abnormality. All affected birds had stunting of the upper beak and cicatrization and thickening of the footweb. Eighty-nine percent of the affected birds showed ocular involvement, comprising chemosis, blepharoconjunctivitis, keratitis, symblepharon, ankyloblepharon, cicatricial ectropium, and mydriasis.

The susceptibility of young chickens, ducks, and turkeys to the photosensitizing effect of Ammi visnaga seeds.

Young chickens, ducks, and turkeys were exposed to sunlight and fed various amounts of Ammi visnaga seeds for 14 days in an attempt to induce photosensitization. In chickens, seeds at 1.25% in the diet had no effect whereas 3% induced mild signs of photosensitization within 6 to 8 days. No visible effects resulted in ducklings from 1.5, 3 and 6% in the diet, or in turkey poults from 3%. These differences appear to be due to differences between these avian species in the metabolism of the photodynamic agent.

Fluoroacetamide (1081) oisoning in wild birds.

An outbreak of poisoning in four greylag geese (Anser anser) and 35-45 teal (Anas crecca) is described. Laboratory findings led to the conclusion that a wheat bait containing the rodenticide fluoracetamide (1081) caused the poisoning. Circumstantial evidence incriminated fluoracetamide as the cause of death in white-fronted geese (Anser albifrons), mallards (Anas platyrhynchos), and chukars (Alectoris chukar).

Histology of the iris in geese and ducks photosensitized by ingestion of Ammi majus seeds.

Geese and ducks were photosensitized by the ingestion of Ammi majus seeds, and exposure to sunlight. Mydriasis was a characteristic clinical feature of this syndrome in both species. Histologically the iris of the affected birds showed vacuolisation and varying degrees of atrophy of the muscle of the sphincter pupillae. The effect of pilocarpine and physostigmine on the normal and mydriatic eyes was studied. The possible mode of action of photosensitization and the significance of these findings in the light of the use of psoralens in human medicine is discussed.