An outbreak of systemic granulomatous disease in cows with high milk yields.

Seven of 92 lactating Holstein cows on a dairy farm developed urticaria with alopecia and decreased milk production, and three of the seven died over the course of 7 to 18 days. Pathologic examination of the three cows, including the two dead and one euthanized cow, revealed that the skin, liver, spleen, kidneys, heart, salivary glands, pancreas, adrenal glands, mammary glands, lymph nodes, and trigeminal ganglia had lymphocytic to lymphogranulomatous inflammation. Inflammation predominated by lymphocytic infiltration was prominent in the heart, pancreas, mammary glands, adrenal gland, and trigeminal ganglia. Severe granulomatous inflammation with multinucleated giant cells was present in the spleen and kidneys. These lesions and their distributions were most similar to those seen in suspected cases of citrus pulp toxicosis and hairy vetch toxicosis. The outbreak of this disease resolved with the elimination of Citrus pulp from the feed. Immunohistochemical detection of lymphocytes and macrophage markers confirmed dramatic hyperplasia of CD3-positive T lymphocytes in these lesions. This strongly suggested that a type 4 hypersensitivity reaction played a role in the development of the lesions.

Suspected citrus pulp toxicosis in dairy cattle.

Thirteen lactating dairy cows from a herd of 650 died over a 6-week period. Most animals were down in milk production at 1 milking and were found dead at the next milking. Two cows had elevated heart rate and enlarged mandibular lymph nodes. Two others had azotemia, elevated heart rate, hyperglycemia, and weight loss. Necropsy of 10 cows revealed hemorrhages on the intestinal serosa and epicardium, lymphadenopathy, interstitial nephritis, small intestinal hemorrhage, and interstitial pneumonia. Histopathology showed lymphocytic to lymphogranulomatous inflammation in the heart, spleen, kidney, lymph nodes, liver, lung, pancreas, and adrenal gland. Phlebitis was present in 2 livers. The lesions resembled those of hairy vetch toxicosis, but no vetch was being fed. Similar lesions have been reported with the feeding of citrus pulp. Citrus pulp was being fed to the lactating cows and had been added to the diet 6 weeks before the first death. The syndrome resolved with elimination of citrus pulp from the diet.

Toxicology of selected pesticides, drugs, and chemicals. D-limonene, linalool, and crude citrus oil extracts.

Cats are susceptible to poisoning by insecticidal products containing D-limonene, linalool, and crude citrus oil extracts. Signs of toxicosis include hypersalivation, muscle tremors, ataxia, depression, and hypothermia.

An outbreak of phototoxic dermatitis due to limes.

During the week beginning July 29, 1984, 12 children in a day camp in a suburb of Baltimore, Maryland, were noted to have skin eruptions consistent with phototoxic dermatitis. These eruptions were confined to the hands, wrists, and forearms, and appeared as discrete and confluent polymorphous patches and linear streaks. These eruptions were also macular, hyperpigmented, and nonpruritic. Clinical examination revealed that 97 (16%) of 622 children, seven (7%) of 104 counselors, and no adult staff members had a similar rash. Onsets of the rash ranged from July 19-August 11, with peak occurrence on July 25-27. All camp members were white. Sex did not vary significantly between those affected and not affected. The mean age (5.3 years) of affected children was significantly different from the mean age (6.9 years) of unaffected children (p less than 0.001). Attack rates for the eight camp units were highest in two units (57% and 74%, respectively) and ranged between 0-6% for the other six units. Activities involving work with hands by various camp units were investigated. Only exposure to making pomander balls (sachets) in arts and crafts class (when other activities were controlled for) was significantly associated with illness (p less than 0.03). In making pomander balls, children punctured the skin of limes (the principal component) with scissors, releasing oils known to contain photoreactive furocoumarin (psoralen) compounds. These compounds evidently coated the children's skin and, upon exposure to the sun, caused a phototoxic dermatitis. An environmental and botanical survey of the camp did not reveal other phototoxic agents with which campers may have had contact. This is one of the largest reported outbreaks of phototoxic dermatitis and the first in which a citrus fruit was implicated on a large scale.