Pneumocystis carinii in large domestic animals in Denmark. A preliminary report

By microscopic examination of toluidine blue O stained autopsy lung imprints Pneumocystis carinii was shown in 6 calves out of 160 (3.8%), in 1 sheep out of 28 (3.6%) and in 8 pigs out of 119 (6.7%). This is the first report of Pneumocystis carinii in calves, sheep and pigs in Denmark.

Neonatal calf diarrhea induced by rotavirus

This presentation summarizes the results of a comprehensive study on rotaviruses isolated in Italy from calves and rabbits affected by neonatal diarrhea. The results clearly indicated that rotavirus infection is widespread and supported the evidence for an etiologic role of these viruses in neonatal diarrhea. The evidence of differences in virulence among bovine rotaviruses appeared also to be confirmed. Conventionally reared calves were fully susceptible to the experimental infection induced by three rotaviruses originating from heterologous hosts, i.e. monkeys, pigs and rabbits, respectively. When rotavirus strains of bovine, simian, porcine and rabbit origin were compared by cross neutralization tests, it was found the simian and porcine strains were indistinguishable and both appeared to relate antigenically to the bovine strain. On the other hand, a reciprocal antigenic correlation was found between bovine and rabbit isolates. Finally, it was proven that feeding newborn calves with colostrum of their dams, previously vaccinated with an inactivated rotavirus vaccine, could prevent the neonatal diarrhea from occurring.

A retrospective study of 51 cases of abdominal problems in the calf: etiology, diagnosis and prognosis

A retrospective study of 51 calves less than two months of age showing signs of abdominal pain or presented because of abdominal distension was carried out to evaluate the relationship between etiological, diagnostic, and prognostic characteristics. We found that the age of the calf differed with the type of lesion present. Calves under eight days of age had a 73% incidence of lesions which required surgical therapy. Atresia of part of the intestinal tract was the most frequently diagnosed problem, In eight-day to two-month-old calves, medical causes of colic were more common; only 26% of cases had lesions that required surgical correction. Gaseous distension of the abomasum and intestine was the most frequent cause of colic in older calves. Other abdominal problems observed in this study included abomasal ulceration and abomasal torsion.Mortality was more common in calves with surgical problems. Of the 21 calves with surgical problems, 76% died compared with a 20% mortality rate in the 30 calves with medical problems. Because of the high incidence of surgical problems in young calves, mortality was 69% in calves under eight days of age and only 33% in older calves. The chance of recovery decreased with the severity of hypothermia and dehydration. Most calves (75%) which were recumbent at presentation died, whereas only 29% of calves which were alert and able to stand at presentation died. Hematological findings indicative of severe inflammation were poor prognostic signs. Heart rate and the apparent severity of abdominal pain were not useful prognostic indicators.

Severity and nature of acidosis in diarrheic calves over and under one week of age

A prospective study of the severity of dehydration and acidosis was carried out in 42 calves under 35 days of age presented for treatment of neonatal diarrhea. Clinically the mean level of dehydration was 8 to 10%. The plasma volume was 65% of that in the hydrated calf but the calves only gained 6.5% in weight during therapy.Calves under eight days of age often had a lactic acidosis. Blood pH was 7.118+/-0.026 (mean +/- 1 standard error), bicarbonate concentration 18.8+/-1.3 mmol/L, base deficit 11.4+/-1.7 mmol/L and lactate of 3.6+/- 0.06 mmol/L. Calves over eight days usually had a nonlactic acidosis. Blood pH was 7.042+/-0.021, bicarbonate 10.8+/-1.0 mmol/L, base deficit 19.5+/-1.2 mmol/L and lactate 1.2+/-0.3 mmol/L. These values were all significantly different from those in younger calves.Over all calves there was a poor correlation between the severity of acidosis and dehydration(r=0.05). The severity of lactic acidosis was related to the severity of dehydration. Mean bicarbonate requirements to correct acidosis were calculated to be 200 mmol(17 g of sodium bicarbonate)and 450 mmol(37 g of sodium bicarbonate)in calves under and over eight days of age respectively. Both groups of calves required a mean volume of 4L of fluid to correct dehydration.

Necrosis of the brain in calves following dehorning

This is a report of an acute hemorhagic necrotizing encephalitis following dehorning in calves on pasture. Calves were found either dead or down in extremis. Multiple necrotic inflammatory lesions were found in the cerebral cortices of affected calves at postmortem. Necrosis and hemorhage were observed microscopically to be more prominent than inflammation, indicating the peracute overwhelming nature of the process. The etiology was not determined but clostridial infection was suspected.

Metabolic acidosis without clinical signs of dehydration in young calves

Metabolic acidosis without clinical signs of dehydration was diagnosed in four calves between nine and 21 days of age. In each calf either coma or depression with weakness and ataxia was observed. Two calves had slow deep respirations. Treatment with intravenous administration of solutions of sodium bicarbonate was accompanied by a rise in blood pH and a return to normal demeanor, ambulation and appetites, allowing these calves to return to their respective herds.

A yeast related ethanol intoxication syndrome in experimental calves: prevention with nystatin

In a calf nutrition-metabolism study in which a high glucose (60% glucose and 3% lard) versus a high fat (23% glucose and 30% lard) milk replacer were compared, a syndrome characterized by anorexia, an unstable gait, depression, a distended abdomen and an odor of alcohol on the breath was observed in some calves. These signs were associated with intoxicating levels of plasma ethanol and the predominance of the yeast species Torulopsis glabrata in gastrointestinal contents of afflicted calves. Nystatin, a yeast inhibitor, was extremely useful in preventing the problem.

Indigestion in young calves. VI. Studies of diarrheic calves fed milk replacers made of normal and heat-treated skim milk and whey powder

Diarrhea occurred in 12 pre-ruminant calves after the introduction of milk replacers. Six of the calves were fed a replacer made of normally treated skim milk and whey powder, while the other 6 got a replacer made of heat-treated powders, although otherwise similar to that of the first group. Abomasal curd formation was deficient in calves fed for 9 or 17 days on the heat-treated replacer (4 of 6 calves). Otherwise, no clear differences between the calves given normally treated and heat-treated replacer occurred, as regards diarrhea, bacteriological, virological, and pathomorphological findings in the intestinal tract. Rotavirus and chlamydial infections were indicated and considered as the major cause of the diarrheic condition, although bacteria, including coliforms and Pseudomonas aeruginosa, may have contributed. The milk replacers may have been involved was provoking factors.

Cholinesterase levels in blood plasma and erythrocytes from calves, normal delivering cows and cows suffering from parturient paresis

Plasma cholinesterase (pChE) levels and erythrocyte acetylcholinesterase (eAChE) levels were studied in 6 cows before, during and after parturition (Group I), their calves (Group II), 38 cows suffering from parturient paresis (Group III) and 14 newly delivered non-paretic cows (Group IV).

The mean of the pChE level in Group I was 1.5 μkat/1 ± 0.20 before parturition and decreased significantly (P ≦ 0.05) to 1.2 ukat/1 ± 0.16 after parturition. The eAChE level was before parturition ≅ 140 ukat/1 and decreased to ≅ 130 μkat/1 4–5 weeks after parturition.

At birth the pChE level was 12.8 ukat/1 ± 5.9 in Group II. After 4 weeks the level had decreased to 2.3 ukat/1 ±0.3. In the bull calves the pChE level started to increase when they were 6 weeks old and reached a level of 5.7 μkat/1 ± 0.6 before slaughter at 6 months of age. The heifers did not show this increase. They had a level of around 2 μkat/1 throughout the investigation. The eAChE level at birth was 119 μkat/1 and increased slowly to a level of 145 μkat/1 at 6 months. No differences between the sexes were found.

The cows suffering from parturient paresis had a pChE level of 1.80 μkat/1 ± 0.30 before treatment with calcium (Ca). The level decreased significantly (P ≦ 0.001) after Ca-infusion to a level of 1.67 ukat/1 ±0.29. Group IV had a pChE level of 1.65 μkat/1 ± 0.42 at parturition. Two to 4 months later the cows that had recovered from milk fever had a level of 1.61 μkat/1 ± 0.31 and the control cows 1.66 ukat/1 ± 0.48. No differences between the groups were found for the eAChE level.

The findings show that parturition influences the pChE level in cows and that sex influences the pChE level in calves between 6 weeks to at least 6 months of age. Furthermore the elevated pChE level found in the cows suffering from parturient paresis before Ca infusion may be a further sign of a disturbance in the cholinergic system with a special preference to the neuromuscular junctions.

Peyer's patches and the follicle-associated epithelium in diarrheic calves. Pathomorphology, morphometry and acid phosphatase histochemistry

Twelve 2–5-week-old calves affected with a spontaneous intestinal disorder were examined; 8 had diarrhea and 4 were convalescents. In all the affected calves the “pseudovilli” (syn. domes or lymphoid villi) over Peyer’s patches seemed atrophic and appeared enclosed within the mucosa, owing to fusion of ordinary villi with “pseudovilli”. Morphometric examination showed a decrease of lymphoid follicle length in the affected calves as compared with controls (P < 0.01). Convalescents showed longer follicles than diarrheic calves (P<0.05). Often cytoplasmic acid phosphatase of the follicle-associated epithelium (FAE) in affected calves did not show the marked basal-apical decrease along “pseudovillus”, typical of the controls. Scanning electron microscopy revealed sparse development of concentric folds in the luminal plasma membrane of the enclosed FAE, contrasting with their abundance in the normal FAE. Transmission electron microscopy showed that the “pseudovilli” had increased numbers of ordinary villous epithelial cells. Affinity of chlamydia for FAE was shown. It is suggested that the sparse occurrence of surface folds in the FAE and the change in acid phosphatase distribution indicate diminished endocytosis of antigenic material, probably resulting from the enclosure of “pseudovilli”. The atrophy of lymphoid follicles may be another expression of the probable decreased contact with the intestinal contents.

Pathomorphology of the intestinal mucosa in diarrheic calves

The intestinal mucosa was examined in twelve 2–5-week-old calves with a spontaneous intestinal disorder, 8 with diarrhea and 4 convalescents. The calves were fed a defined milk replacer. Light microscopy including morphometry, showed villous atrophy and crypt elongation. Villous epithelial cells had decreased height, and epithelial cells of the posterior small intestine contained an increased amount of fat droplets. Accumulation of neutrophils in crypts was frequent. Scanning electron microscopy revealed blunt villi with increased numbers of necrotic cells in the extrusion zone at the tips of the villi. The convalescents had generally milder changes, particularly in the anterior small intestine. The probable etiological factors included a rotavirus and chlamydial infection, and it is concluded that these agents together with other possible noxious influences were responsible for the increased necrobiosis of apical senescent villous epithelial cells, resulting in villous atrophy and crypt hyperplasia.

An enzyme histochemical investigation of the intestinal mucosa in diarrheic calves

Selected enzymes were examined in the small intestine of twelve 2–5 week-old calves, 8 with diarrhea and 4 convalescents. The diarrheic calves showed a reduction of enzyme reactions mainly in the duodenum and middle small intestine, and the crypt reactions appeared most severely affected. In the duodenum, villous alkaline phosphatase, adenosine triphosphate-(ATP)-splitting enzyme, and β-D-galactosidase were reduced in 3 calves; the reaction in the corresponding crypts was decreased in 6 calves for the ATP-splitting enzyme and in 4 calves for the β-D-galactosidase. Six calves showed decrease of villous brush border acid phosphatase, and 3 of villous non-specific esterase. In the middle jejunum, villous ATP-splitting enzyme was reduced in 3 calves, while 5 showed decrease of the corresponding crypt reaction. Convalescents had no enzyme reduction in the duodenum, whereas 1 showed marked reduction of the ATP-splitting enzyme and aminopeptidase in the middle and posterior jejunum. The decreased enzyme reactions in the present material may be caused by immaturity of epithelial cells associated with regenerative crypt hyperplasia and/or microbial destruction of enzymes.

The epithelium covering Peyer's patches in young milk-fed calves. An ultrastructural and enzyme histochemical investigation

Between the ordinary villi over Peyer’s patches there are small domes or “pseudovilli” caused by bulges in the lymphoid tissue. These “pseudovilli” were studied in 5 healthy milk-fed, about 3-week-old, pre-ruminant calves. Scanning electron microscopy revealed that the “pseudovilli” were covered by a specialized follicle associated epithelium (FAE). The FAE had poorly developed microvilli and often extensive folding of the cell surface close to the cell borders. By transmission electron microscopy the tips of the marginal folds of the FAE seemed to fuse, probably in the process of enfolding bulk material from the lumen. The FAE apical cytoplasm contained numerous thick-walled and bristle-coated invaginations, tubules and vesicles indicative of micropinocytosis. Multivesicular bodies and large vacuoles were frequent. Indications of extracellular unloading of residual bodies were found. Intraepithelial lymphocytes tended to group together, and some were rich in rough endoplasmic reticulum. Enzyme histochemistry showed weak reactions of adenosine triphosphate splitting enzyme and aminopeptidase in the FAE luminal cell border. Cytoplasmic acid phosrphatase showed a marked basal-apical decrease along the “pseudovillus” probably caused by the onset of endocytosis. The results of this study appear compatible with the concept that the FAE takes up macromolecules from the lumen by pinocytosis and sensitizes lymphocytes.

Histochemical distribution of enzymes in the small intestine of young milk-fed calves

The histochemical distribution of selected enzymes were examined in the small intestine of 5 about 3-week-old normal calves fed on whole cow’s milk. Alkaline phosphatase and β-D-galactosidase (= lactase) in the epithelial brush border, and non-specific esterase in the cytoplasm showed a strong reaction in the villi of the anterior small intestine and a marked decrease in the posterior regions. Aminopeptidase in the brush border of the villi showed a reverse distribution, with the strongest reaction in the posterior small intestine. Adenosine-triphosphate-splitting enzyme in the epithelial brush border, acid phosphatase and succinate dehydrogenase in the cytoplasm of the epithelial cells gave a relatively uniform reaction in the villi throughout the small intestine. A fluoride-resistant acid phosphatase was demonstrated in the brush border of the villi in the anterior small intestine. The distribution of enzymes demonstrated in this study was generally compatible with the known absorptive functions of the various parts of the small intestine.

Effects of transportations, a high lactose diet and ACTH injections on the white blood cell count, serum cortisol and immunoglobulin G in young calves

Twelve calves were subjected to 5 different, consecutive treatments considered to induce stress. These included a) transportations for 4–8 h at temperatures just above or well below 0°G at the start of the experiment and 6 and 11 weeks later, b) feeding a high lactose diet and c) ACTH injections.

The transportations resulted in a transient suppression in the level of serum IgG, and increase of Cortisol, blood neutrophils and lymphocytes. One and 2 weeks after the first transportation, the lymphocyte count was suppressed.

Intramuscular injections of ACTH also resulted in temporary increases in serum Cortisol, blood neutrophils and lymphocytes, but no obvious changes in IgG. Thus, the suppressed levels of IgG which were seen after the transportations did not appear to be directly related to the increased level of Cortisol.

The high lactose diet was not accompanied by a significantly higher frequency of diarrhoea and lower mean weight gain. The IgG level did not appear to be influenced by the lactose level of the diet, and calves fed a high lactose diet responded similarly to transportation as calves fed a normal type of milk replacer. Apart from some diarrhoea, no health problem occurred.

The gastrointestinal mucosa in young milk-fed calves. A scanning electron and light microscopic investigation

Gastrointestinal segments from 4 healthy, 17-, 21-, 22- and 23-day-old calves fed on whole cow’s milk were examined. Scanning electron microscopy showed that the anterior duodenum had short villi varying in shape from leaf-shaped to nodular; the middle duodenum had broad, tongue-shaped villi and the anterior, middle, and parts of the posterior jejunum had slender, finger-shaped or leaf-shaped villi. The villi of the mucosa covering Peyer’s patches in the posterior jejunum were short and either conical or tongue-shaped; there were also small “pseudovilli” caused by bulges in the lymphoid tissue. Morphometry showed that the villi were longer in the anterior jejunum than in the duodenum and the posterior parts of the jejunum (P < 0.005). Morphologically fat absorption was most heavy in the anterior third of the small intestine. Moderate amounts of fat were also found in the epithelium of the posterior jejunum and of the abomasum. Large fat droplets were seen in apical duodenal enterocytes, in contrast to the small epithelial droplets in other areas with fat absorption. Nile blue staining indicated that the fat in the large droplets was esterified.

Indigestion in young calves III. The influence of powders from heat-treated skim milk and whey

Two experiments comprising 24 calves, lasting 44–46 days, have been carried out in order to examine the influence of powders from heat-treated skim milk and whey on indigestion in young calves. The frequency of diarrhoea increased much (P < 0.01) in the first experiment when feeding the heat-treated products, but little in the other. Possible reasons for this difference are discussed. Calves fed heat-treated products in the first experiment consumed 13.8 1 of electrolyte fluid per head per day 14–22 days after commencing the test, when both diarrhoea and fluid consumption reached peak values. It is postulated that some of the calves might have succumbed without electrolyte fluid.

Indigestion in young calves. IV. Lesions of ruminal papillae in young calves fed barley and barley plus hay

Fiftysix calves, in 2 similar experiments, were given 1 of 4 diets including a high lactose milk replacer: ground barley (GB), ground barley plus coarse hay (GB + GH), coarse hay (CH) and the liquid diet only (NS) ; the 2 last diets were held as controls. The calves were on the experimental diet from 1–2 weeks of age until slaughtered at 7-8 weeks of age. As observed by stereo-microscopy, the ruminai papillae in calves fed on GB were thickened, mostly finger- or club-shaped and sometimes nodular; nodular papillae were always arranged on prominent mucosal folds. Scattered nodular papillae had white coats. For calves fed on GB + CH the papillae were mostly finger- or tongue-shaped. Histologically papillae in calves fed on GB had hyperplasia of secondary papillae and epithelial layers. Microabscesses associated with penetrating hairs were frequent, and some calves had dyskeratosis with infiltration of polymorphonuclear leucocytes at the apex of papillae, identified as the white coats. For calves given GB+CH, abscesses and apical dyskeratosis were absent and the hyperplasia of epithelial layers milder than in the case of the GB diet. An ameliorative effect of hay on papillary changes caused by barley is indicated.

Indigestion in young calves. V. The influence of grass silage and fine hay

In an experiment with 24 young calves, lasting 45 days, all were fed a high lactose milk replacer causing some diarrhoea. Eight calves received grass silage and 8 fine hay in addition, while 8 received no solid supplement to the milk replacer (NS). Somewhat more (P < 0.05) dry matter was ingested from silage than hay. Weight gain was similar on the 2 supplements and much greater (P < 0.001) than on NS. Both silage and fine hay reduced (P < 0.01) the frequency of diarrhoea, approximately to the same extent. Further, silage or hay gave higher pH (P = 6.0.01 and 0.02, respectively) and less gram positive cocci and rods in the rumen fluid, better developed ruminai papillae and heavier (P < 0.01) empty reticulo-rumens than NS. Some calves fed silage had ulcers in the rumen, the same having occurred on fine hay in earlier experiments, but not in the present one. Althogether, the 2 roughages gave very similar results.

Indigestion in young calves. I. Different lactose levels in milk diets and milk replacers

Increasing the lactose content of different milk replacers or milk diets by approx. 30 % of the dry matter increased the frequency of diarrhoea the first 10–12 days in young calves on all occasions in 5 experiments comprising 120 calves. For all diets taken together, this effect was highly significant. Total daily intakes of lactose amounted to 200–480 g. When lactose was given on top of the milk rations, the growth rate increased significantly, whereas the growth rate was usually insignificantly reduced when lactose replaced other nutrients in milk diets or milk replacers, their levels of protein and fat becoming low. Albumin and total protein in blood plasma were significantly lower when the dietary protein level was low. Milk replacers with 20 or 40 % whey powder, replacing skim milk powder, performed equally well, but gave significantly less growth than the old-fashioned feeding of whole milk-skim milk. Intake of hay and barley and a number of clinical and histological or pathological parameters did not vary consistently with dietary level of whey powder or lactose. Feeding whole milk all the time resulted in low intake of hay and barley and poorly developed forestomachs, but high dressing-out %. Substituting soya for part of the skim milk powder in milk replacers gave abomasal content with no curds. In most cases, pH in the rumen appeared to be nearly up to neutral until the calves ate ground barley, about 1 month old.

Indigestion in young calves. II. The influence of ground barley, coarse and fine hay

Four experiments comprising 86 calves have been carried out in order to examine the influence of ground barley, coarse and fine hay, when raising young calves on a high lactose milk replacer causing diarrhoea. The frequency of diarrhoea decreased when feeding barley (P < 0.01) or fine hay (P < 0.001), but increased when feeding coarse hay (P<0.01). Barley increased (P < 0.01) live weight gain and carcass weight, reduced (P < 0.001) rumen pH, favoured gram-positive cocci and rods in the rumen, caused hyperkeratosis and gave increased (P < 0.01) empty reticulo-rumen weights, the latter being supposed to be enhanced by hyperkeratosis. The calves ate more (P < 0.001) fine than coarse hay, fine hay being superior (P < 0.01) in promoting growth of the rumen. All hay maintained a predominantly gram-negative rumen flora, but somewhat different from that on the milk replacer, and counteracted (P < 0.01) low pH in the rumen and apparently also hyperkeratosis due to barley. The results with barley indicated no relationship between diarrhoea and hyperkeratosis.

Ferrokinetic studies in normal and iron deficiency anemic calves

Ferrokinetic studies were performed on control calves and on calves with experimentally induced iron deficiency anemia, all 15 weeks old.

The plasma iron clearance half time was about 4 times shorter in the experimental than in the control group. The low plasma iron concentration in the anemic calves was partially compensated by a more rapid plasma iron disappearance. Therefore the difference in the plasma iron turnover rate was reduced.

The mean value of plasma iron daily renewal rate was about 3 times higher in the experimental than in the control group.

The maximum uptake of injected ⁵⁹Fe into blood cells was reached 14 to 16 days after injection. The uptake of ⁵⁹Fe was about 10% higher in the control than in the experimental group.

Using the values from the ferrokinetic study, the iron need for calves could be estimated. The requirement of iron to maintain a normal and constant Hb in a calf weighing 100 kg at a growth rate of 1 kg/daily was estimated as being 17.5 mg/day. Based on information in the literature and assuming a retention of dietary Fe of 25%, the total daily iron need for such a calf gaining 1 kg/day would be 160–180 mg.

A hematologic and blood chemical study of Swedish purchased calves

The hemoglobin (Hb), packed cell volume (PCV), erythrocytes (R.G.), serum iron (SI) and unsaturated iron binding capacity (UIBG) were examined in a total of 386 purchased calves for the duration of 1 year. The calves were tested within 3 days of arrival at the buyer’s herd. The average age of the calves was 28 ± 10 days (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\overline {\rm{x}} \pm {\rm{s}}$\end{document} ).

The results may be summarized as follows: Approx. 35% of the calves had Hb values ≦ 10.0 g/100 ml. Fifteen% of the calves had ≦ 6.0 × 106 R.C. per µl. Fifty-three calves or about 14% showed SI values ≦ 40 µg/100 ml and 131 calves or 34% ≦ 80 µg/100 ml. Twenty-seven % of the calves had UIBG values > 501 µg/100 ml. Almost half the calves (48%) had a saturation percentage of transferrin with iron below 20% and 138 calves (36%) below 15%.

These figures among others in the study indicate that 13–35% of the purchased calves suffered from iron deficiency anemia.