Pulmonary function changes and clinical findings associated with chronic respiratory disease in calves.

Thirteen field cases of chronic respiratory disease in crossbred calves aged between 1 and 8 months were subjected to a standardized examination in which clinical criteria were scored and weighted to allow quantification. Predicted values for pulmonary function variables were generated using regression equations previously established in normal calves which related measured pulmonary function variables to thoracic perimeter. Subsequent pulmonary function testing of each calf was undertaken and values obtained compared with predicted values and correlated with clinical scores. Diagnosis was confirmed at post-mortem examination. Calves with chronic respiratory disease had significantly reduced inspiratory and expiratory times, tidal volume, dynamic compliance and PaO2, significantly increased respiratory frequency, airway resistance and PaCO2 and more negative transpulmonary pressure values when compared to predicted pulmonary function values for the same calves. PaO2 and PaCO2 were the only variables correlated with clinical scores, suggesting their value in the assessment of severe cases of calf respiratory disease.     

Intestinal changes associated with rotavirus and enterotoxigenic Escherichia coli infection in calves

Newborn calves inoculated with rotavirus, enterotoxigenic Escherichia coli (ETEC) serotype 020:K' x 106':K99:HNM, either alone or in combination, became depressed, anorectic, diarrhoeic and dehydrated. ETEC did not adhere to the intestine although there was extensive proliferation in the lumen. Only slight mucosal changes were induced by ETEC and the activity of membrane bound lactase remained normal. More severe mucosal damage and a decrease in lactase activity were found in newborn calves inoculated with either rotavirus or rotavirus and ETEC in combination. The most severe clinical illness was found in calves inoculated with both rotavirus and ETEC. Calves inoculated at 1 week of age with either rotavirus or ETEC remained clinically normal. Rotavirus infection produced slight mucosal changes and a reduction of lactase activity. In contrast, colostrum-fed or suckling calves up to 2 weeks old inoculated with both rotavirus and ETEC became clinically affected, showed severe mucosal damage and decreased lactase activity. There was no bacterial adhesion to the intestinal mucosa as observed by immunofluorescent labelling and light microscopy.     

Breath hydrogen concentration and small intestinal malabsorption in calves

Breath hydrogen concentrations were measured to assess intestinal carbohydrate malabsorption in preruminating calves. Oral administration of 1.25 g of lactulose (a nonabsorbable carbohydrate)/kg to calves produced breath hydrogen concentrations significantly (P less than 0.001) higher than values determined after calves were fed milk and before the treatment was given. This indicates that, in the calf, fermentation of nonabsorbed carbohydrates results in increased breath hydrogen values. To induce small intestinal malabsorption, chloramphenicol was administered orally at 50 mg/kg, 2 times a day, to 5 calves for 3 days. Before therapy was started, each calf was fitted with a duodenal cannula to facilitate collection of intestinal mucosal biopsy samples during treatment. Chloramphenicol therapy significantly (P less than 0.001) increased breath hydrogen concentrations from those values measured after calves were fed milk alone. Concurrently, chloramphenicol administration significantly decreased intestinal villous length (P less than 0.001) and D-xylose absorption (P less than 0.05), compared with those values before treatment was given. These results demonstrate that decreased intestinal absorptive capacity is associated with an increase in breath hydrogen concentrations and that breath hydrogen may be useful in evaluating malabsorption in calves with naturally occurring enteric disease.     

Some pathophysiological changes associated with infection of Eimeria zuernii in calves.

Twelve Holstein-Friesian calves were divided into two groups, one of which was infected with Eimeria zuernii. Fecal oocyst output, weight changes and various blood, cellular, protein and biochemical constituents were examined for both groups. Maximal fecal oocyst output occurred 21 days after infection. Both groups of calves gained weight in a linear fashion until day 21 postinfection when the infected group lost weight rapidly. The packed cell volume of the infected calves appeared markedly reduced. Although there was a reduction in plasma proteins it did not appear significant. There was a significant reduction in plasma Na+ and Cl- ions of the infected calves. There were no significant changes in the other blood constituents examined.     

Effects of anabolic and therapeutic doses of dexamethasone on thymus morphology and apoptosis in veal calves

Three groups of 10 veal calves were treated, respectively, with 5 mg of dexamethasone-21-isonicotinate administered intramuscularly on days 0 and 7 (group A); 0.4 mg/day of dexamethasone-21-phosphate administered orally for 20 days (group B); or left untreated as controls (group C). Two animals from each group were slaughtered on day 3, 7, 14, 32 and 52. The size and weight of the thymus decreased progressively in both treated groups until day 32. On day 14, in comparison with the controls, there was a mean reduction of 76 per cent in the thymus weight of group A and 35 per cent in group B. On day 32, the reductions were 13 per cent in group A and 50 per cent in group B, but the thymus weight of both groups had recovered completely by day 52. Dexamethasone-induced changes in thymus weight associated with lymphoid depletion and fat replacement, and there were clear correlations between these changes and apoptosis of thymocytes.     

Diarrhea associated with trichomonosis in cats

OBJECTIVE: To establish clinical features, course of illness, and treatment outcome of cats with diarrhea and concurrent infection with Trichomonas organisms. Prevalence of fecal trichomonads in a geographically comparable population of healthy indoor and feral cats also was assessed. DESIGN: Longitudinal study and a cohort study. ANIMALS: 32 cats with diarrhea and naturally acquired trichomonosis that were native to North Carolina, Virginia, Connecticut, and Tennessee; 20 healthy indoor cats; and 100 feral cats. PROCEDURE: Trichomonosis was diagnosed in 32 cats by identification of organisms in fresh feces or by protozoal culture of feces. RESULTS: Diarrhea associated with the large intestine and trichomonosis were diagnosed in 32 cats. Median age of the cats was 9 months; 23 cats were < or = 1 year old at the time of diagnosis. Two cats developed diarrhea accompanied by infection with Trichomonas organisms after the addition of an infected kitten into the home. Duration of diarrhea ranged from 2 days to 3 years. Six cats had a coexisting enteric infection. Treatment with antimicrobials improved fecal consistency and reduced the number of flagellates in the feces, but did not eliminate infection. Diarrhea (with microscopically detectable flagellates) was observed shortly after antibiotics were discontinued. Trichomonads were not recovered from feces of any healthy indoor or feral cats. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings suggest that trichomonosis may be a cofactor in development of diarrhea in young cats. Trichomonas organisms were not identified as part of the indiginous fauna of healthy indoor or feral cats.     

Determination of lactose and xylose malabsorption in preruminant diarrheic calves.

In preliminary studies feeding the poorly absorbed carbohydrate sorbitol at 2.3 g/kg body weight as an indication of maximal fermentative capacity failed to produce the expected large increase in breath hydrogen excretion but did produce a transient diarrhea in five out of six control calves. Twelve healthy control and eighteen diarrheic calves were fed lactose or D-xylose on consecutive days at 1.15 g/kg body weight and a concentration of 46 g/L. Breath and blood samples were collected at 1 h intervals from 0 to 7 h. After administration of lactose, there was a significant increase in breath hydrogen excretion in diarrheic versus control calves. The increase in plasma glucose concentrations was delayed in diarrheic calves but the area under the absorption curve was similar in control and diarrheic calves. After administration of D-xylose, breath hydrogen excretion did not increase significantly but plasma D-xylose concentrations were significantly reduced in diarrheic calves. The pathogens commonly isolated from the feces were Cryptosporidium species, rotavirus and coronavirus. The number of pathogens and the severity of the calves' acid-base deficit were not related to the severity of carbohydrate malabsorption. Decreased absorption of lactose and D-xylose may be the result of intestinal villous atrophy caused by viral or parasite infection. It was concluded that carbohydrate malabsorption rather than a specific lactose maldigestion is a significant problem in diarrheic calves. Diarrheic calves appear to digest and absorb lactose when fed in small amounts.     

Recrudescence of infectious bovine rhinotracheitis virus and associated neural changes in calves treated with dexamethasone

Reactivation of infection bovine rhinotracheitis (IBR) virus in calves administered dexamethasone (DM) was studied in 2 experiments. At 2, 3, 5, 15, or 30 months after inoculation of the Los Angeles strain of IBR virus, IV injections of DM were given for 5 consecutive days to induce a recurrent infection (experiment 1). Three months after the 1st treatment, a 2nd recurrent infection was induced, using DM with the same doses as used in experiment 1. The virus was excreted from nasal secretions from the 4th to the 10th day after initial treatment with DM, and from the 6th to the 9th day after the 2nd treatment. On pathologic examination, trigeminal ganglionitis, consisting of many proliferated microglia and inflammatory cells, was observed in all DM-treated calves. Moreover, degeneration of the ganglion cells and neuronophagia were prominent features in the calves after the 2nd recurrent infection. These observations indicated that the trigeminal ganglion may be one of the latent sites of IBR virus in calves after intranasal infection and that calves can develop a recrudescent infection after DM treatment several times during their lifetime.     

Diarrhea associated with intestinal Cryptosporidiosis in turkeys

Turkey poults were suffering from diarrhea on a farm in which several previous grow-outs of turkeys had experienced a clinically identical problem. Upon necropsy, significant gross lesions were restricted to the gastrointestinal tract. Segments of small intestine were pale and distended with cloudy mucoid material and a few gas bubbles. The ceca contained fluid and gas. Fresh organ portions were collected and fixed in 10% neutral buffered formalin and submitted for histological processing and examination (light microscopy and scanning and transmission electron microscopy). Small (2-4 micron) basophilic bodies identified as Cryptosporidium sp. were present in enterocytes of the middle and lower small intestine. The villi were moderately atrophic, the crypts were hypertrophic, and the lamina propria was infiltrated by large numbers of lymphocytes, heterophils, and fewer macrophages and plasma cells. Numerous intraepithelial leukocytes and exocytosing inflammatory cells also were present.     

Chondrodystrophy in calves associated with manganese deficiency

A severe congenital chondrodystrophy in Charolais calves is described. Thirty-two calves were born on the same farm with shortened limbs and enlarged joints. Histologically, there was poor cartilage maturation with excessive amounts of rarefied cartilage matrix. There were degenerative changes in the chondrocytes and a severe reduction in the mucopolysaccharide content of all body hyaline cartilage. The cartilage matrix, when examined ultrastructurally, showed loose, disorganised fibres in a rarefied matrix, and extensive vacuolation of the chondrocytes. A low level of manganese was found in the liver of an affected calf. The pregnant cows were fed on apple pulp and corn silage, both of which are low in manganese.     

Diarrhea associated with enterotoxigenic Bacteroides fragilis in foals

Enterotoxigenic Bacteroides fragilis (ETBF) was isolated from the feces of 10 of 40 Thoroughbred foals with naturally acquired diarrhea. Of the 10 foals positive for ETBF, 6 were less than or equal to 7 days old. Fecal specimens from 4 of the 10 foals also were positive for rotavirus, and one fecal specimen was positive for Salmonella enteritidis. Clinical or hematologic differences were not evident between foals infected with ETBF only and those infected with ETBF and another recognized enteric pathogen. Only 1 of 10 foals infected with ETBF died. Of 25 adult rabbits with ligated ceca, 23 developed mucoid, often hemorrhagic, diarrhea after inoculation of 5 X 10(9) viable ETBF cells into the ileum. Nine of 13 (69%) rabbits inoculated with 1 of 3 isolates of ETBF died, but none of 12 inoculated with 1 of 6 other isolates of ETBF died. Enteric disease did not develop in 15 rabbits inoculated with nonenterotoxigenic B fragilis.     

Diarrhea associated with myenteric ganglionitis in a dog

Diarrhea in a Border Terrier was associated with inflammatory lesions of the myenteric plexus. This lesion has been documented rarely in dogs. It is speculated that the myenteric plexus lesions were responsible for an autonomic nervous system dysfunction, which resulted in extreme intestinal hypermotility and subsequent diarrhea. Suggested tests for dogs suspected to have autonomic dysfunction are given.     

Characteristics of developmental changes in the kinetics of glucose and urea in Japanese Black calves: comparison with Holstein calves

The current study was conducted to clarify the characteristics of glucose and urea kinetics in male Japanese Black calves, using a glucose and urea dilution method with stable isotopes, at preweaning (3 wk of age) and postweaning (13 and 26 wk of age) stages, in comparison with the kinetics of glucose and urea in male Holstein calves. Six Japanese Black and 6 Holstein calves were arranged in a 2 (breed) x 3 (stage) factorial block design. These 12 suckling calves were fed only whole milk, offered concentrate and or chardgrass hay after 3 wk of age, and weaned at 6 wk of age. Under steady-state conditions, glucose challenges (1.0 mg/kg of BW; [U-13C]d-glucose) and urea challenges (both 2.2 mg/kg of BW; [13C]urea and [15N2]urea) were performed at the 3 stages examined. There were no significant differences in plasma glucose concentrations between Japanese Black and Holstein calves at any stage, but the glucose concentrations at 3 wk of age were greater (P <0.05) than those at 13 wk of age in both breeds. The glucose pool size in Japanese Black calves was smaller (P <0.05) than that in Holstein calves at all stages. Within each breed, there were no significant differences between the glucose pool sizes at 3 and 13 wk of age, but the glucose pool size was larger (P <0.05) at 26 wk of age. Moreover, Japanese Black calves had greater glucose irreversible loss rates (P <0.01) than Holstein calves at 3 wk of age, and the glucose irreversible loss rates were less (P <0.05) on and after 13 wk of age in both breeds. Japanese Black calves had greater plasma urea N concentrations (P <0.05) than Holstein calves at all stages, and in both breeds, the urea N concentrations increased (P <0.05) with age. The urea pool size was smaller (P <0.01) in Japanese Black calves than in Holstein calves at all stages, and in both breeds, the urea pool size increased (P <0.05) with age. In comparison with Holstein calves, Japanese Black calves had greater urea irreversible loss rates (P <0.05) on and after 13 wk of age and greater urea recycling rates (P <0.05) at 26 wk of age. In addition, in both breeds, urea irreversible loss rates and urea recycling rates increased (P <0.05) with age. We conclude that Japanese Black calves have partially different glucose and urea kinetics from Holstein calves and that the kinetics of these metabolites in both Japanese Black and Holstein calves are strongly influenced by weaning.     

Chronic enteritis associated with the malabsorption and protein-losing enteropathy in the horse

Chronic granulomatous enteritis associated with weight loss and hypoproteinemia was identified in 2 horses. Both horses continued to have normally formed feces. Malabsorption of carbohydrate and lipid, with concomitant gastrointestinal protein loss was demonstrated in 1 case. One horse was treated symptomatically and gained 108 kg. In both cases, principal gastrointestinal lesions were partial to total villus atrophy and transmural mononuclear leukocytosis, with lymphocytes and histiocytes predominating. The cause of the condition was not identified in either case.