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Biomedical subjects

D M Rings

Publications and source records attributed to D M Rings.

At least 19 recordsLinked to original sources

Intussusception in cattle: 336 cases (1964-1993).

OBJECTIVE: To evaluate risk factors and to describe clinical and laboratory findings, surgical management, and postoperative outcome for cattle with intussusception. DESIGN: Hospital-based, case-control epidemiologic study and retrospective case series. SAMPLE POPULATION: Medical records of cattle admitted to 17 veterinary medical teaching hospitals in North America. PROCEDURE: Epidemiologic analysis of demographic data and detailed analysis of medical records for selected cattle. RESULTS: 336 cattle with intussusception were identified, 281 had small intestinal, 7 had ileocolic, 12 had cecocolic, and 36 had colocolic intussusceptions. Sex and season were not significantly associated with cattle developing intussusception, whereas calves < 2 months old were at greater risk of developing small intestinal intussusception than older cattle. Analysis of medical records of 57 cattle with intussusception revealed that these cattle were mildly hyponatremic, hypochloremic, hypocalcemic, azotemic, and hyperglycemic. Right flank laparotomy with a cow in a standing position, followed by intestinal resection and end-to-end anastomosis was the most common means of surgical correction. Overall survival rate (20/57; 35%) and postoperative survival rate (20/46; 43%) for cattle with intussusception were much lower than previously reported. CLINICAL IMPLICATIONS: Although rare in cattle, intussusception was most common in calves < 2 months old. Survival rate for cattle treated for intussusception was low (< 50%).

Age Factors

Prevalence of lesions associated with subclinical laminitis in first-lactation cows from herds with high milk production.

OBJECTIVE: To determine prevalence of lesions associated with subclinical laminitis in first-lactation Holstein cows during early lactation and pregnant Holstein heifers during late gestation in herds with high milk production. DESIGN: Cross-sectional study. ANIMALS: 203 cattle in 13 herbs. PROCEDURE: Cattle were placed in lateral recumbency to allow visual examination and photography of their hooves. Claws on a forelimb and hind limb were examined on all cattle. Observable categories of lesions considered to be associated with subclinical laminitis in our study included yellow waxy discoloration of the sole, hemorrhage of the sole, separation of the white line, and erosion of the heel. RESULTS: Lesions in at least 1 of the categories were found in all herds. Lesions in all categories were found in 11 of 13 herds. Among claws, hemorrhage of the sole was observed most frequently in the lateral claw of the hoof of the hind limb. When days in milk was treated as a covariate, significant (P < 0.01) differences were detected in the prevalence of lesions between herds. CLINICAL IMPLICATIONS: Because the prevalence of lesions differed significantly among herds, it is logical to believe that causative factors and corrective measures also may have differed among herds.

Animal Feed

Survival of Mycobacterium paratuberculosis and preservation of immunoglobulin G in bovine colostrum under experimental conditions simulating pasteurization.

OBJECTIVE: To determine whether Mycobacterium paratuberculosis could survive in colostrum after pasteurization. Additionally, this study investigated the effect pasteurization had on IgG concentration in colostrum. ANIMALS: Colostrum samples were collected from cattle (beef and dairy) owned by the state of Ohio. PROCEDURE: Colostrum was divided into aliquots and inoculated with variable concentrations of M paratuberculosis (ATCC No. 19698: 10(4), 10(3), and 10(2) colony-forming units/ml). Half the samples at each concentration were subjected to pasteurization temperatures (63 C) for 30 minutes and the remainder were kept at approximately 20 to 23 C. All samples were incubated (Herrold's egg yolk medium with and without mycobactin J) and observed for growth during the next 16 weeks. Additionally, the IgG concentration of colostrum was determined by radioimmunoassay before and after pasteurization. Samples that coagulated at pasteurization temperatures were mechanically resuspended before measurement of IgG concentration. RESULTS: Growth of M paratuberculosis was retarded but not eliminated by pasteurization. Growth was observed in all unpasteurized samples incubated on Herrold's egg yolk medium with mycobactin J but in only 2 of 18 pasteurized samples similarly cultured. Growth from pasteurized samples appeared 5 to 9 weeks after growth was observed from nonpasteurized samples. Mean colostral IgG concentration was 44.4 g/L in nonpasteurized samples and 37.2 g/L in pasteurized samples, a decrease of 12.3%. High-quality colostrum (> 48 g of IgG/L) had a significantly greater loss of IgG concentration than did colostrum of lesser quality (P = 0.002). CONCLUSIONS: Pasteurization lessened, but did not eliminate, growth of M paratuberculosis from experimentally inoculated colostrum samples. Pasteurization resulted in a significant decrease in colostral IgG concentration but not to an unmanageable level that would preclude the colostrum's use for passive transfer of immunity. CLINICAL RELEVANCE: Colostrum is macrophage rich and may serve as a source of M paratuberculosis infection to calves. Pasteurization of colostrum may lessen the risk of infection, but will not totally eliminate M paratuberculosis.

Animals

Umbilical hernias, umbilical abscesses, and urachal fistulas. Surgical considerations.

Swellings of the umbilical stalk, with or without herniation, are common findings in calves. Differentiation of involved structures is helpful in deciding the surgical approach and type of anesthesia required. This article deals with clinical signs, diagnostic procedures, and surgical techniques used to repair problems related to the umbilical stalk.

Abscess

Tracheal collapse.

Tracheal collapse in calves usually is associated with dystocia at birth, especially breech presentations. Inspiratory dyspnea typically is seen within the first several months of life and may worsen progressively. Lateral cervical radiographs are useful in defining the affected segments as well as identifying previously fractured ribs. Surgical stenting of the trachea will improve the calf's condition, but because this procedure is done on young calves, the tracheal diameter of the affected segment is permanently limited by the size of the prosthesis.

Animals

Surgical treatment of pleuritis and pericarditis.

Surgery of the bovine chest is rarely attempted; however, there are distinct indications and procedures available to treat both pericarditis, suppurative pleuritis and pleural effusions. Open lavage of the pericardial sac or pleural space has proven successful in carefully selected cases. The surgical procedures for pericardiotomy and thoracotomy are discussed.

Animals

Occurrence of gastric ulcers in gnotobiotic piglets colonized by Helicobacter pylori.

Archival gastric tissues from 10 of 39 gnotobiotic piglets colonized with Helicobacter pylori 26695 contained stromal leukocytic inflammation along with ulcers and erosions. In contrast, gastric tissues from 54 archival control piglets were devoid of both inflammation and ulcers. These data confirm the hypothesis that H. pylori infection alone is ulcerogenic.

Animals

Isolation of Mycobacterium paratuberculosis from colostrum and milk of subclinically infected cows.

Mycobacterial culture was performed on colostrum, milk, and feces from 126 clinically normal cows of a single herd with high prevalence of Mycobacterium paratuberculosis infection. Thirty-six (28.6%) cows were determined to be shedding the organism in the feces. Of the 36 fecal Culture positive cows, M paratuberculosis was isolated from the colostrum of 8 (22.2%) and from the milk of 3 (8.3%). Cows that were heavy fecal shedders were more likely to shed the organism in the colostrum than were light fecal shedders.

Animals

Ultrasonographic diagnosis of pyelonephritis in a cow.

A 2-year-old Holstein cow was examined because of a 2-month history of anorexia, decreased milk production, and a white vaginal discharge. Results of physical, laboratory, and ultrasound examinations were consistent with pyelonephritis. Through ultrasound examination, the right kidney and ureter were identified as structurally involved. Right nephrectomy was performed. Eight months after nephrectomy, the cow was clinically normal. In this cow, ultrasonography helped to determine disease severity, to direct the course of treatment, and to improve the accuracy of diagnosis and prognosis.

Animals

Diagnosis of Cryptosporidium on a sheep farm with neonatal diarrhea by immunofluorescence assays.

An outbreak of diarrhea in neonatal lambs occurred on a sheep farm in northern Ohio. Diarrhea commenced as early as 1 week of age and lasted for about 3-4 days. Although 100% of the newborn lambs were affected, most had recovered by 3 weeks of age. Cryptosporidium infection appeared to be the cause of diarrhea. Fecal examination of nine diarrheic newborn lambs (5-10 days old), 23 older lambs (2-3 weeks old, six with diarrhea) and 23 clinically normal ewes by immunofluorescence assays revealed infection rates of 100%, 78.3% and 17.4%, respectively. Most newborn lambs had high oocyst counts. Ewes were considered to be an important source of infection for lambs.

Animals

Concurrent infections of Giardia and Cryptosporidium on two Ohio farms with calf diarrhea.

Giardia and Cryptosporidium infections were diagnosed by immunofluorescence assay on two Ohio dairy farms with calf diarrhea problems. On the first farm, all nine diarrheic calves sampled once in June had Giardia cysts in their feces. On the second farm, all five diarrheic calves examined at the beginning of the diarrhea outbreak in March had Giardia infection. When resampled, the overall infection rate of normal and diarrheic calves was 82.4% in April, and 40.0% in August after the diarrhea subsided. Positive calves ranged from 11 to 164 days of age, and 22.2% of them were as young as 1 to 3 weeks of age. Eight of nine diarrheic calves (88.8%) on the first farm had Cryptosporidium infection. Lower infection rates (< 30%) were found on the second farm. Six of 10 positive calves were 11-22 days old, three were 164-177 days old, and one was 71 days old. Five of these 10 positive calves were also positive for Giardia infection. Five diarrheic calves on the northern Ohio farm and one diarrheic calf on the central Ohio farm were treated with metronidazole after failing to respond to antibiotic therapy. Clinical improvement was observed in all calves within 48 h after the start of treatment. The high Giardia infection rates and intensities in calves of a wide age range and the clinical response to metronidazole suggest that Giardia infection contributed to the outbreaks of diarrhea.

Animals

Isolation of Mycobacterium paratuberculosis from mononuclear cells in tissues, blood, and mammary glands of cows with advanced paratuberculosis.

Seven mature dairy cows from 6 herds were obtained with history, clinical signs of disease, and laboratory findings suggestive of advanced paratuberculosis. A surgically implanted collection chamber was used to obtain peripheral tissue fluid. Blood, mammary gland flush fluid, and collection chamber flush fluid (CCFF) samples were obtained 6 times over a 2-week period from each cow. Mononuclear cell-rich portions of these fluids obtained by gradient centrifugation were submitted for bacteriologic culture of Mycobacterium paratuberculosis and for total and differential cell counts. Bacteriologic culture of feces for M paratuberculosis and complete necropsy performed on each cow at the conclusion of the study confirmed the diagnosis of paratuberculosis. Numbers of tissue macrophages obtained from CCFF samples were lower than expected. Mean (+/- SD) differential count of tissue macrophages collected from CCFF was 65.57 (+/- 23.39). Mean calculated tissue macrophages (total cell count x differential count) collected from CCFF samples was 623.1 (+/- 784.55) cells/microliters. Mycobacterium paratuberculosis was isolated from 1 of 42 (2.4%) collections of mononuclear cell-rich portions of plasma and from 2 of 42 (4.8%) CCFF samples. Mycobacterium paratuberculosis was not isolated from any collections of mammary gland flush fluid. The collection and processing techniques used in this study did not enhance detection of M paratuberculosis infection in cows with advanced paratuberculosis, beyond that of ileocecal lymph node biopsy or fecal culture.

Animals

Serodiagnosis of paratuberculosis in sheep by use of agar gel immunodiffusion.

An agar gel immunodiffusion (AGID) test was used over a 3-year period to examine 1,871 serum samples from sheep representing 5 Mycobacterium paratuberculosis-infected flocks and 4 flocks presumed to be uninfected. Of 1,032 sheep, 31 had positive AGID test results (scoring 1 to 5), and 23 of these 31 were necropsied. Infection with M paratuberculosis was confirmed by 1 or more of the following findings: observation of typical lesions on histologic examination of sections of ileum or ileocecal lymph nodes, observation of clumps of acid-fast bacteria in mucosal smears of ileum, and isolation of the organism from feces or tissue. False-positive results on AGID testing were not found in sheep from flocks known to have exposure to Corynebacterium pseudotuberculosis. Diarrhea in infected sheep was observed infrequently; chronic, severe weight loss was the most common sign observed. On histologic examination of tissues from 20 infected sheep, 16 (80%) had diffuse lesions of the ileum and 13 (65%) had acid-fast bacteria in areas of ileal inflammation; 4 had discrete granulomas and peripheral lymphocytic infiltrates in the ileum. Sheep with diffuse lesions tended to have higher mean scores on AGID testing and examination for acid-fast bacteria, compared with those from sheep with more discrete lesions. Bacteriologic culture yielded M paratuberculosis from only 3 sheep with paratuberculosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Abomasal luminal pressure in cattle with abomasal volvulus or left displaced abomasum.

The abomasal luminal pressure was determined during surgery in 54 dairy cows with abomasal volvulus (AV) and another 50 dairy cows with left displaced abomasum. The luminal pressure was high in all cattle with AV and 49 (98%) cattle with left displaced abomasum. Luminal pressure was significantly higher in cattle with AV (median, 11.7 mm of Hg; range, 4.1 to 32.4 mm of Hg) than cattle with left displaced abomasum (median, 8.7 mm of Hg; range, 3.5 to 20.7 mm of Hg). Among cattle with AV, abomasal luminal pressure was significantly higher in cattle that died or were sold for slaughter following surgery (median, 20.6 mm of Hg; n = 8) than in cattle that were retained in the herd (median, 11.0 mm of Hg; n = 46). The luminal pressure was weakly correlated with the preoperative serum alkaline phosphatase activity but not correlated with duration of inappetence before surgery. Calculation of likelihood ratios and construction of a response operating characteristic curve for cattle with AV indicated that a cut-off value of 16 mm of Hg for luminal pressure optimized the distribution of cattle into productive and nonproductive groups. The sensitivity, specificity, positive predictive value, and negative predictive value of a luminal pressure < 16 mm of Hg in predicting a productive outcome were 0.83, 0.75, 0.95, and 0.43, respectively.

Abomasum

Risk factors for abomasal volvulus and left abomasal displacement in cattle.

A hospital-based case-control study was conducted to evaluate and compare risk factors for abomasal volvulus (AV) and left displaced abomasum (LDA) in cattle. Medical record abstracts were derived from 17 North American veterinary schools by the Veterinary Medical Data Program for all cattle admitted between Jan 1, 1977 and Dec 31, 1986, and for those with a diagnosis of AV or LDA. From a total of 108,956 individual cattle records, 1,036 cases of AV and 7,695 cases of LDA were identified, with a ratio of LDA to AV cases of 7.4 to 1. In-hospital mortality was 23.5% for AV and 5.6% for LDA. Age, breed, gender, and season each had significant (P less than 0.05) effects on risk for AV and LDA. Risk for AV and LDA increased with increasing age, with greater risk in cattle aged 4 to 7 years. Dairy cattle were at higher risk of developing AV (adjusted odds ratio, 36.4) and LDA (adjusted odds ratio, 95.2) than were beef cattle. The odds of AV in Brown Swiss cattle were significantly (P less than 0.0001) lower, and the odds of LDA in Guernsey cattle were significantly (P less than 0.0001) higher than those in Holstein cattle. Female cattle were also at higher risk of developing AV (adjusted odds ratio, 3.3) and LDA (adjusted odds ratio, 29.1) than were male cattle. The odds of AV and LDA varied considerably throughout the year, with the lowest number of cases observed in autumn. Seasonal development of AV differed significantly (P less than 0.0001) from that of LDA, with the odds of AV and LDA being highest in January and March, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Abomasum

Prognostic value of surgical and postoperative findings in cattle with abomasal volvulus.

A prospective study evaluating the prognostic value of surgical and postoperative findings in 80 cattle with abomasal volvulus was performed. Surgical correction of abomasal volvulus was performed in all animals. After surgery, cattle were categorized into 3 groups: productive (acceptable milk production or appetite, n = 59), salvaged (poor milk production or appetite, n = 10), and nonsurvivors (n = 11). Cattle with omasal-abomasal volvulus had a significantly (P less than 0.005) worse prognosis than cattle without omasal involvement. Large abomasal fluid volume, venous thrombosis, and blue or black abomasal color before decompression were all indicative of a poor prognosis. Most cattle had poor or fair appetites the first day after surgery; productive animals had marked improvement in appetite over the next 3 days. All cattle observed to have a good appetite within 3 days after surgery were later determined to be productive animals. The heart rate decreased in all groups after surgery; however, tachycardia (heart rate greater than 80 beats/min) was sustained in cattle that were later salvaged for slaughter. Diarrhea was observed after surgery in 54% of cattle. The duration of diarrhea was significantly shorter (P = 0.009) in productive cattle than in salvaged and nonsurviving cattle. The presence or absence of diarrhea was only of predictive value when considered in conjunction with the estimated abomasal fluid volume.

Abomasum

Preoperative prognostic indicators in cattle with abomasal volvulus.

A prospective study evaluating preoperative prognostic indicators in 80 cattle with abomasal volvulus was done. Surgical correction of the abomasal volvulus was performed in all animals. After surgery, cattle were categorized into 3 groups: productive (acceptable milk production or appetite, n = 59), salvaged (poor milk production or appetite, n = 10), and nonsurvivors (n = 11). Mean values for study variables did not differ significantly between salvaged and nonsurvivor groups. Cattle in these 2 groups were combined to form a nonproductive group, which was compared with the productive group. Productive cattle had a significantly lower preoperative heart rate than nonproductive cattle, were less dehydrated, had lower serum alkaline phosphatase (ALP) activity and serum creatinine concentration, more frequent rumen contractions, higher serum Na+ and Cl- concentrations, and had been inappetent for a shorter period. Significant differences were not detected in blood pH, base excess, anion gap, PCV, and serum K+ concentrations between the 2 groups. Feces from nonproductive cattle tended to be reduced in volume and were significantly darker. A number of preoperative prognostic indices were evaluated by calculating the sensitivity, specificity, and positive predictive value (+PV) of each variable and by using logistic regression. Positive predictive values were generally higher in identifying productive cattle than nonproductive cattle.(ABSTRACT TRUNCATED AT 250 WORDS)

Abomasum