People and events influence life.
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History, 20th Century↗
Biomedical subjects
R E Pierson
Publications and source records attributed to R E Pierson.
Middle ear infection in feedlot lambs.
Of 133 feedlot lambs that died and were necropsied, 67 had normal lungs and 66 had pneumonic lungs. The middle ears of all lambs were opened by a specified technique. Of the 67, 8 (12%) had otitis media, and of the 66, 26 (39%) had otitis media. The difference in prevalence in the 2 groups was highly significant (P less than 0.005). In acute stages, the mucosae of tympanic cavities and tympanic membranes were inflamed and the cavities contained fluid, whereas in later stages lumens were partially filled with exudate. In chronic stages, however, exudate remained in lumens and mucosae were thick and rough. None of the tympanic membranes was ruptured, and none of the external acoustic meatuses contained exudate. The infected ears of 24 lambs were cultured and Pasteurella haemolytica was isolated from 18, and P multocida from 3. The infections probably ascended from the pharynx through the auditive tubes into the tympanic cavities.
Animals↗
Contagious equine metritis: effect of intrauterine inoculation of contagious equine metritis agent in pony mares.
Actively growing culture of contagious equine metritis (CEM) bacteria or infective exudate (or both) were inoculated intrauterine in pony mares. A direct relationship was observed between (i) appearance and duration of cervicitis and vaginitis and (ii) vaginal exudate. Clinical signs appeared 1 to 3 days after mares were inoculated and lasted 7 to 23 days. In the acute phase of infection, all uterine and cervical samples yielded CEM bacteria. In the asymptomatic stage of infection, CEM bacteria were not isolated from uterine and cervical samples; however, in 33%, 28%, and 20% of the pony mares, CEM bacteria were present in clitoral fossa, clitoral sinus, and urethral vestibule, respectively, Sampling during early estrus increased the bacterial isolation rate to 57% in mares that were previously negative; however, 3 days later, CEM bacteria could not be isolated from 62% of the positive mares. The results of repeated exposure experiments indicated the presence of local antibodies, as no CEM bacteria could be recovered at 2, 7, and 15 days after reexposure with a small number of bacterial cells (8.4 x 10(5) cells). The CEM bacteria were isolated from all mares reexposed with a large number of bacterial cells (7.2 x 10(8)) at 2 days after second inoculation and from 50% at 7 days. However, all of the mares were negative by day 15 after reexposure, indicating increased resistance to CEM bacteria.
Animals↗
Survival of contagious equine metritis bacteria in transport media.
Survival of bacteria that cause contagious equine metritis (CEM) was evaluated in Amies modified transport (AMT) medium, in AMT medium with charcoal, and in Stuart transport medium at 37, 22, 4, and -70 C. The CEM bacteria suspended in transport media survived at 22, 4, and -70 C for longer periods in AMT medium with charcoal than they did in AMT and Stuart transport media. In 1 day, the number of bacteria in exudate stored in the absence of any transport medium decreased 15-fold at 22 C and twofold at 4 C. The CEM bacteria were isolated from exudate on cotton-tipped swabs from all three transport media at 4 and -70 C on day 10, the termination of the experiment. However at 4 C, the survival of CEM bacteria was greater in AMT medium with charcoal than it was in AMT and Stuart transport media.
Animals↗
Comparison of African and American forms of malignant catarrhal fever: transmission and clinical signs.
African and American forms of malignant catarrhal fever (MCF) infections were produced by inoculating blood from affected cattle into susceptible cattle. Ease of disease transmission, incubation period, volume of blood required for infection, and clinical signs were compared in 30 cattle with African MCF and in 19 with American MCF. American MCF was more difficult to transmit than was African MCF and required eight to ten times more blood as inoculum. American MCF incubation period was more than twice as long as that of the African MCF, but the disease course was three times shorter. Clinical signs were similar for the two forms; however, in the American form, the disease was more acute and a larger percentage of animals had severe diarrhea.
Africa↗
Serological identification of the bacterial agent of contagious equine metritis.
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Agglutination Tests↗
Clinical and clinicopathologic observations in induced malignant catarrhal fever of cattle.
In an epizootic of malignant catarrhal fever in 1976/1977 in southern California, 166 cows (17%) died. Blood from one of those cows was used in transmission studies involving 8- to 14-month-old steers. In 17 (74%) of 23 inoculated steers, the disease was reproduced. The clinical signs in 8 of the diseased steers were characterized by an initially mild intestinal form of the disease, which suddenly fulminated and terminated in death within 1 to 3 days. No lesions or only mild oral or ocular lesions were noticed in this group, but in the other steers, such lesions predominated. It was concluded that a subtle form of the disease can terminate in acute fatal indigestion.
Animals↗
Contagious equine metritis: clinical description of experimentally induced infection.
Contagious equine metritis was reproduced experimentally in 6 pony mares. The disease was characterized by rapidly developing cervicitis and by varying amounts of exudate. The exudate, apparent as early as 48 hours after inoculation, drained from the cervix as a tenacious, mucopurulent discharge for several days, then rapidly disappeared. In all mares, the clinical disease cleared within several weeks of inoculation, without treatment.
Animals↗
Etiology of malignant catarrhal fever outbreak in Minnesota.
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Animals↗
Experimental transmission of malignant catarrhal fever in cattle: gross and histopathologic changes.
Bovine malignant catarrhal fever (MCF) was serially transmitted from a spontaneous case to 19 cattle through 12 passages during a 12-month period. Seventeen of 23 cattle (74%) injected with whole blood and 2 of 5 cattle (40%) injected with blood mononuclear cells developed clinical signs of MCF after a mean incubation period of 30.2 days. A previously unreported nonsuppurative polyarthritis is described. Large numbers of lymphoid cells were found in synovial fluid and in cerebrospinal fluid. Histopathologic changes of lymphoid infiltration and proliferation, necrosis of epithelial tissues, and nonsuppurative vasculitis were found in almost all organs of the body. The possibility that MCF may be a viral-induced, cell-mediated immunopathologic disease with pansystemic lymphoreactivity and necrosis is discussed.
Animals↗
Shipping fever pneumonia in yearling feedlot cattle.
During each week of 1974, we surveyed, for illnesses and deaths, a continually changing population of yearling feedlot cattle that, for the year, totaled 407,000 animals. About 5.1% of the cattle sickened and, of these, 18.9% died. From the 3,943 fatalities, 1,988 necropsies were made. About 75% of the clinical diagnoses and 64% of the necropsy diagnoses were respiratory tract diseases; of the fatalities from respiratory tract diseases, 75% were attributed to shipping fever pneumonia. Nearly 72% of fatal cases of shipping fever pneumonia occurred during the first 45 days on feed. In the lungs of most cattle with shipping fever pneumonia, bronchiolitis, fibrinous exudate, colonies of microorganisms, lymphatic clots, intravascular clots, thromboses, and foci of necrosis were found. Pasteurella spp, Mycoplasma spp, and infectious bovine rhinotracheitis virus were isolated from pneumonic tissues. It was hypothesized that pathogenic Pasteurella spp and other microorganisms in nasal secretions transfer from the nasopharynx into the lungs by draining along the tracheal floor into ventral bronchi, bronchioles, and alveoli, and that pasteurella endotoxin, formed in infected lobules, thromboses and occludes lymphatics, capillaries, and veins and thereby causes ischemic necrosis.
Animals↗
Diseases of yearling feedlot cattle in Colorado.
During all of 1974 we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. The morbidity was 5.1%, with a case mortality of 18.9% and a population mortality of 1.0%. Both morbidity and mortality were higher during fall and winter than during spring and summer. Of the 3,943 dead cattle, 1,988 were necropsied. The most prevalent diseases were: pneumonia, 48%; diphtheria, 6%; brisket disease, 6%; hemorrhagic colitis, 5%; riding injury, 4%; bloat, 3%; calculosis, 2%; endocarditis, 2%; abomasal ulcers, 2%; bovine viral diarrhea, 2%; embolic pulmonary aneurysm, 1%; and pulmonary edema, 1%.
Animals↗
Atypical interstitial pneumonia in yearling feedlot cattle.
During each week of 1974, we surveyed, for illnesses and deaths, a constantly changing population of yearling feedlot cattle that, for the year, totaled 407,000 animals. From 3,943 fatalities, 1,988 necropsies were made; of this number, 106 (5.3%) had atypical interstitial pneumonia. The death rate was higher during summer and fall than during the other seasons and was evenly distributed throughout each of the 4 stages of fattening. Gross pulmonary lesions involved both lungs and were prominent throughout the caudal (diaphragmatic) lobes. Epithelialization, hemorrhage, fibrin, hyaline membranes, emphysema, bronchiolitis, and interstitial edema were common, whereas chromatin strands, bronchiolar edema, interstitial emphysema, and obliterating bronchiolitis were less common histopathologic features.
Animals↗
Brisket disease in yearling feedlot cattle.
During all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle maintained at 1,600 m altitude. Of 1,988 cattle necropsied, 116 (5.8%) had brisket disease. The malady occurred during all seasons but was most common throughout fall and winter. The gross changes were hypertrophy and dilatation of the right ventricle and generalizaed passive congestion. The postulated causative factors were high genetic susceptibility, rapid growth rate, previous mountain grazing, and hypoventilation with airway hypoxia.
Animals↗
Bulling among yearling feedlot steers.
In a survey to determine the cause of illness and deaths among yearling feedlot cattle, bulling was found to be one of the major problems. During the years 1971-1974, 54,913 (2.88%) steers became bullers and represented an annual loss of around +325,000. Some of the causes of bulling were found to be hormones, either as implants or in the feed. In 1974, from 1,988 necropsies, it was determined that 83 steers died from riding injuries.
Anabolic Agents↗
Fetal abomasal ulcers in yearling feedlot cattle.
During all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. From the 3,943 dead cattle, 1,988 necropsies were made; of this number, 31 (1.6%) had ulcers with fatal perforations or hemorrhages; a similar additional number of necropsied cattle had innocuous ulcers as incidental findings. Ulcers developed during all seasons and all stages of fattening, but were more common during the first 45 days of winter-initiated fattening than during other times. Perforations of the abomasal wall resulted in spillage of abomasal contents into the abdominal cavity and the development of peritonitis.
Abomasum↗
Sudden deaths in yearling feedlot cattle.
A survey of the causes for fatal diseases of yearling feedlot cattle was conducted on more than 407,000 cattle during a 14-month period. Of the 4,260 (1%) cattle that died during this period, 1,358 (32%) were categorized as cases of "sudden death syndrome." Of the 11 most frequent causes of the syndrome, as determined at necropsy, only 4--bloat, pulmonary aneurysms, riding injury, and hemopericardium--were considered as short-course problems and true causes of sudden death. The largest number of cases of sudden death were attributed to pneumonia (113 animals). Consequently, the sudden death syndrome is a misnomer for many long-course diseases and, in some instances, a mask for neglect because, as clinically used, the name frequently includes cattle that have been sick, often with pneumonia, for several days.
Animals↗
Bronchiectasis in yearling feedlot cattle.
Thoughout all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. From the 3,943 dead cattle, 1,988 necropsies were made; of the cattle necropsied, 32 (1.6%) had bronchiectasis. In this disease, the permanently dilated small bronchi and bronchioles, located in ventral parts of the lungs, were filled with accumulations of exudate and microorganisms, including Pasteurella hemolytica, Pasteurella multocida, Corynebacterium pyogenes, Escherichia coli, Salmonella anatum, Staphylococcus spp, and Mycoplasma arginini.
Animals↗