The effect of intermittent treatment with sulphadimidine on coccidiosis in preruminant calves

Preruminant calves excreted coccidia oocysts in their faeces after 3 weeks of group housing. Two weeks of oral sulphadimidine (SDM) administration, 50 mg/kg on the first day of treatment followed by daily administration of 37.5 mg/kg, under the same housing conditions kept the faeces free of oocysts. Three weeks later, these calves excreted oocysts again. Repetition of the same treatment for 2 weeks controlled the infection again, but a second treatment for 5 days did not suffice. The repeated long treatment affected immunoglobulin levels adversely. SDM given repeatedly at a lower dose rate (30 mg/kg) for 1-week periods with medication-free intervals of 1 week controlled the infection and no adverse effects were noted. In comparison with controls, weight gains were greater in treated calves.     

Resistance to benzimidazole and macrocyclic lactone anthelmintics in cattle nematodes in Argentina

In April 2003, persistent scouring and ill-thrift that was reported in calves form an intensive beef rearing operation in central Argentina despite treatments with benzimidazole and ivermectin. In order to conduct a controlled faecal egg count reduction test on this herd, 40 calves 5-8-months-old were selected on the basis that they had a nematode eggs per gram (epg) of faeces count greater than 150. Animals were divided into four groups (1-4) of 10 calves. Calves of groups 1-3 were treated, respectively, with subcutaneous injection of ivermectin (200 mcg/kg), ricobendazole (4 mg/kg) and levamisole (7.5 mg/kg), while calves of group 4 remained as untreated controls. The egg count reductions carried out 10 days later were lower than 15% in calves treated with ivermectin and ricobendazole, but 100% in animals receiving levamisole. Pooled post-treatment faecal cultures showed larval percentages of 92 and 95 for Haemonchus and 8 and 5 for Cooperia in the faeces of calves treated with ivermectin and ricobendazole, respectively. This is the first reported case of Haemonchus parasiting cattle showing simultaneous resistance to avermectins and benzimidazole type anthelmintics.     

Rotavirus and enterotoxigenic Escherichia coli infections of calves on a closed Finnish dairy farm

Rotavirus and enterotoxigenic Escherichia coli infections of calves were surveyed during 2 successive years on a closed Finnish dairy farm consisting of 90–105 milking cows. From a clinical standpoint, diarrhoea was of moderate to high severity during the first year, compared to the milder disease in the second year of the study. Diarrhoea or abnormal faeces were found only in calves less than 8 weeks old, with the peak occurring during the first 2 weeks of life.In the first year, rotavirus was detected throughout the calving season in diarrhoeic or abnormal faeces of calves aged 1 day to 7 weeks. In the second calving season, rotavirus was detected only during the 4 autumn months and in calves aged 11 days to 8 weeks. Rotavirus was detected in only 1 sample of normal faeces in both years. Electron microscopy revealed no enteropathogenic viruses other than rotaviruses. Enterotoxigenic K99 E. coli was found in about half of diarrhoeic or abnormal faeces in both years and throughout the calving seasons. K99 E. coli was also found in 5–10 % of normal faeces.In the second year of the study, 45 of 101 pregnant dams were vaccinated with 2 doses of E. coli antigen. The vaccination trial did not prevent or reduce altered faeces in calves whose dams had been vaccinated compared with calves whose dams had not been vaccinated in the same year. Comparing the 2 years, the earlier uptake of colostrum together with better cleaning and disinfection of the calf house, contributed to the later and rarer occurrence of rotavirus infection in the second year of the study. The earlier uptake of colostrum together with better cleaning and disinfection of the salf house, in the second year, could not prevent enterotoxigenic E. coli infections in calves but partly prevented and modified the disease.     

The studies on the aetiology of diarrhoea in neonatal calves and determination of virulence gene markers of Escherichia coli strains by multiplex PCR

The purpose of this study was to determine aetiological agents of diarrhoea in neonatal calves and to investigate virulence gene markers of Escherichia coli strains isolated from calves by multiplex polymerase chain reaction (PCR). Eighty-two diarrhoeic calves and 18 healthy calves were used as subjects. Faeces were taken from the rectums of all the calves and were subjected to bacterial culture. Antigen enzyme-linked immunosorbent assay (ELISA) was performed to detect rotavirus, coronavirus and E. coli K99 in faeces of all the calves. A multiplex PCR was used to characterize E. coli strains in all the calves. Escherichia coli was isolated from 37 faeces samples, Enterococcus ssp. was isolated from 22 faeces samples and Salmonella was isolated from one faeces sample in diarrhoeic calves. Furthermore, only E. coli was isolated from all 18 faeces samples of healthy calves. Of the 37 E. coli isolated from diarrhoeic calves, K99 (18.9%), F41 (18.9%), heat-stable enterotoxin a (STa) (18.9%), Shiga toxin 1 (Stx1; 13.5%) and Shiga toxin 2 (Stx2; 5.4%) and intimin (8.1%) genes were identified by multiplex PCR. Of the 18 E. coli isolated from healthy calves, K99 (16.6%) and intimin (55.5%) genes were identified by PCR. A total of 15 rotavirus, 11 coronavirus and 11 E. coli K99 were detected in diarrhoeic calves by the antigen ELISA. As a result, this study shows that rotavirus, coronavirus, E. coli and Enterococcus ssp. were determined to play a role in the aetiology of diarrhoea in the neonatal calves. K99, F41, STa, Stx1 and Stx2 were found as the most common virulence gene markers of E. coli strains isolated from calves with diarrhoea. Multiplex PCR may be useful for characterization of E. coli isolated from calves.     

Quantitative observations on experimental reo-like virus (rotavirus) infection in colostrum-deprived calves.

Ten calves were challenged with one of two strains of reo-like virus (rotavirus). Changes in the daily faecal and urinary outputs were monitored and packed cell volume, plasma sodium, potassium and urea levels were measured. Faeces were examined for the presence of rotavirus by direct electron microscopy and immunofluorescence in cultures of PK(15) cells. All calves excreted rotavirus in the faeces for several days. Two calves remained clinically normal throughout the experiment, but in the remaining calves, faeces became mucoid in consistency and yellow-white in colour. In only two calves did the daily faecal output exceed 500 g with a fall in the dry matter content to less than 10 per cent. Slightly elevated blood urea levels and hyperkalaemia were the only changes observed in blood chemistry and these quickly returned to normal. Virus antigen was observed in the epithelial cells by immunofluorescence in the proximal and middle small intestine of calves. Pathological lesions occurred predominantly in the proximal small intestine of nine calves examined.     

The activity of albendazole against adult and larval gastrointestinal nematodes in naturally infected calves in the Netherlands

Summary The activity of albendazole against gastrointestinal helminths in naturally infected calves in the Netherlands was tested. The calves were in their fist grazing season and kept in two groups of ten. One of these groups was grazed alternately with sheep. Five out of each group were drenched with albendazole (7.5 mg/kg) on the day they were housed (November 1). Before and 2, 14, and 28 days after treatment individual faecal samples were taken from all calves and larval cultures were made. Ten calves, six treated and four untreated, were killed for post mortem studies 14 days after treatment The remaining calves were slaughtered 14 days later. The drug was highly effective in reducing the egg output, measured as the number of larvae cultured per gram of faeces. Compared with the untreated calves, the reduction was more than 99% two days after treatment, 100% at 14 days, and 99% after 28 days. It was shown that egg output 28 days after treatment came from worms which had developed from arrested larvae of Ostertagia ostertagi that had survived treatment. Post mortem results showed an efficacy of 100% against adult O. ostertagi, of almost 100% against Trichostrongylus axei, and 100% against adult and larval Cooperia oncophora. Twenty-eight days after treatment, the reduction of arrested early fourth stages of O. ostertagi was 85% in comparison with the untreated calves. Apparently less effect was found against Trichuris ovis at the given dose rate.     

Abdominal distension in collapsed diarrhoeic calves: biochemical findings and treatment.

Thirty-seven of 53 diarrhoeic calves hospitalised for intravenous fluid therapy were classified as very severely acidotic (total carbon dioxide less than 8 mmol/litre) by using a Harleco apparatus. All the calves were given intravenously 10 to 20 litres of electrolyte solution which contained 144 mmol/litre sodium, 4 mmol/litre potassium, 113 mmol/litre chloride and 35 mmol/litre bicarbonate, and in addition the 37 very severely acidotic calves received 400 ml of 1M sodium bicarbonate in the first 5 litres of fluid administered. Sixteen of the 37 very severely acidotic calves had a distended right flank, suggesting the presence of a dilated fluid-filled viscus. Neither their history nor other clinical signs were useful predictors of the distension. The distended calves had significantly higher plasma concentrations of sodium and chloride, and significantly lower plasma creatinine concentrations than the calves which were not distended. Treatment was successful in all the 21 non-distended calves but four of the distended calves died despite treatment. The resolution of the distension in the successfully treated calves, coincided with a significant increase in plasma bicarbonate concentration and the passage of large amounts of malodorous mucoid faeces.     

Evaluation of diagnostic tests for Johne's disease in young cattle

OBJECTIVE: To investigate the development of immune responses in calves experimentally and naturally infected with Mycobacterium paratuberculosis and to evaluate the potential for diagnostic tests to detect infected calves. DESIGN: Sequential testing of four treatment groups of calves over a 2 year period. PROCEDURE: Twenty-nine calves were allocated to four groups. Group D calves were orally dosed with M paratuberculosis, group N calves naturally exposed to M paratuberculosis, group V calves vaccinated for M paratuberculosis, and group C were control calves (not infected or vaccinated). Blood and faecal specimens were collected from each calf at monthly intervals to 18 months of age and then every 2 months until they were slaughtered between the ages of 21 and 29 months. Specimens were tested using absorbed EIA, IFN-gamma EIA and faecal culture. The infection status of the calves was confirmed by extensive histopathological examination and tissue culture. RESULTS: M paratuberculosis infection was confirmed in 10 calves, comprising six of eight orally dosed calves, three of five naturally exposed calves and one of nine vaccinated calves. The six artificially infected calves and one naturally infected calf were detected shedding M paratuberculosis in their faeces. Results with positive absorbed EIA were obtained from one artificially infected calf, one naturally infected calf and three vaccinated calves. All calves including controls had positive results on at least one occasion using the IFN-gamma EIA. In addition, seven calves had positive bovine tuberculosis results using the IFN-gamma EIA, even though bovine tuberculosis has been eradicated from Australia. CONCLUSION: Detection of M paratuberculosis infection in young cattle continues to be difficult using current tests.     

Comparison of a levamisole sustained-release bolus and ivermectin treatment to prevent bovine lungworm infection

The efficacy of a levamisole sustained-release bolus to prevent parasitic bronchitis in calves in their first grazing season was compared to ivermectin treatment at three, eight and thirteen weeks after turn out. Contamination of the pasture was established by experimentally infected seeder calves. Twenty calves were split into two groups. Ten calves of one group received a bolus at the start of the experiment. In the other group the calves were treated with ivermectin at 21, 56 and 91 days. Two principal calves from each group were killed during the experiment to study histopathological changes. Pairs of tracer calves were introduced on both pastures at intervals of four weeks throughout the grazing period. The permanent calves were challenged with lungworm larvae at housing and slaughtered four weeks later. Both systems prevented parasitic bronchitis. Larval output was completely reduced in the ivermectin-treated calves while all bolus-treated calves excreted larvae at certain times. The highest group average was 4 larvae per gram faeces. Eosinophilia, ELISA-titres and histopathological changes confirmed the differences in larval uptake. Challenge infection was not successful in either group and no worms were found at slaughter. Weight gain was significantly different at housing in favour of the ivermectin-treated calves, but after challenge this was reduced due to a higher weight gain in the bolus-treated calves. The practical consequences of the results have been discussed.     

The egg production of Toxocara vitulorum in Asian buffalo (Bubalus bubalis)

The egg production of Toxocara vitulorum in Asian buffalo has been studied. Eggs were first present in the faeces of calves when they were 22.3 +/- 1.6 days old. In calves treated with pyrantel when 3 days old, the age at first patency was extended by 3.5 days indicating that there was no pre-natal transmission. Calves on only half the milk of the cow had a significantly longer prepatent period of 27.7 +/- 2.2 days. The peak egg output occurred in calves 35.7 +/- 2.6 days old and had a duration of 5.5 +/- 2.5 days with 98,000 +/- 63,700 eggs g-1 of faeces. The duration of the patent period was 35 +/- 12 days. The average lengths of populations of mature female parasites from different hosts at the time of peak egg output or older, ranged from 15.0 to 31.0 cm and was correlated with those of the males in the same populations (10.6-20.4 cm). The size of females was not affected by intraspecific competition. The proportion of males in the populations was 0.39 +/- 0.11. The egg output per female per day at the peak was 110,000 +/- 58,000 and was correlated with the size of the females at autopsy, but the egg output per female per day at the time of autopsy was lower and was not correlated, so it was concluded that the drop in egg counts was the result of reduced fecundity. The fertility of the eggs from faeces was greater than 92% throughout.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cryptosporidiosis in newborn calves in Ankara region: clinical, haematological findings and treatment with Lasalocid-NA

In the first part of the present study, a total of 109 faeces samples collected from calves suffering from diarrhoea were examined for Cryptosporidium parvum oocytes and 39 (35.8%) of them were found to be positive. On the basis of oocyte counts, 14 (36%) samples were assessed as mildly infected and 25 (64%) samples as heavily infected. The occurrence of the disease was more common in winter (56.4%) than during other seasons (autuma 0%, summer 15.4% spring 28.2%. In the present study, the ionophore polyetherantibiotic Lasalocid-Na, that is licensed as a feed additive (Bovatec, 15% Lasalocid-Na, Roche AG) in Turkey, was administered to 11 calves naturally infected with Cryptosporidium and its therapeutic effect was evaluated. Lasalocid-Na (8 mg/ kg BW) was given once daily for 3 days added to the milk. The clinical parameters of infected calves were evaluated before and 3 days after the treatment in 24 hour intervals. The oocyst counts of faeces of calves with cryptosporidiosis were between 15 x 10(6) and 96 x 10(6)/mL before treatment. No oocystes were found in faecal samples of 3 calves (27.3%) after 48 hours and 4 (40%) calves after 72 hours of treatment, respectively. The number of oocytes in the faeces of the remaining calves varied between 90 and 1.2 x 10(6)/mL during the respective period. The number of oocystes before treatment was significantly higher than the number of oocytes after treatment. One of the calves died 56 h after the first treatment despite the treatment. The pH of venous blood was decreased prior to treatment as expected. The lowest pH was 6.83, the lowest bicarbonate concentration was 3.80 mmol/l and the lowest base excess was -31.2 mmol/l. After the treatment, pH, pCO2, HCO3- and BE values of the venous blood increased significantly and reached physiological values before discharge. The differences between the values assessed before the treatment and at the 2nd, 3rd, and 4th sampling time were statistically significant. Number of leucocyte and haemoglobin concentration before the treatment were significantly higher than the values after treatment (p < 0.01). These values returned back to physiological ranges 72 hours after first treatment. Lasalocid-Na was rather well tolerated. Side effects such as the decline of the suckling reflex and intoxication symptoms in respect to present administration form and dosage were found only in one calf (9%). Treatment procedure in the present study with Lasalocid-Na was found to be suitable in combination with an adequate infusion therapy for the treatment of calves on farms with problems related to cryptosporidiosis. Although the use of Lasolacid-Na for the treatment of Cryptosporidium infection in the EU is banned, it might be used as an alternative drug outside of the EU since it has a successful effect for preventing reinfections.     

Studies on neonatal calf diarrhoea caused by rotavirus: transmission of the disease and attempted vaccination of colostrum-deprived calves

Mild to severe scouring could be produced in colostrum-deprived calves with tissue culture-adapted rotavirus and feacal material from field cases of calf diarrhoea. The feaces of experimentally infected calves contained rotavirus for at least 3 days. Pathogenic bacteria were presented in one calf only and this calf also showed the most severe gastroenteritis. Eight calves were vaccinated with a live rotaviral calf diarrhoea vaccine and subsequently challenged with infective rotavirus. Mild scouring was observed after vaccination, but the calves remained normal after challenge. Rotavirus particles were detectable in the faeces for a few days after vaccination and challenge.     

Spread of lungworm (Dictyocaulus viviparus) infection by Pilobolus fungi among stabled calves

Pilobolus kleinii spores isolated from cattle faeces were administered daily by the oral route to two donor calves excreting Dictyocaulus viviparus larvae in their faeces.Faeces were collected at daily intervals from the donor calves, and on each day a pooled sample of 500 g was placed outside a pen containing two parasite-free experimental calves. A wire screen prevented the experimental calves from coming into contact with the artificially deposited faecal portions.Pilobolus kleinii fruit bodies were observed on the faecal surface in large numbers 5–10 days after deposition.Sporangial discharge was observed to be directed against a window which served as the only light source. Sporangia were found up to 110 cm away from the faeces, and it was estimated that at least 29% of them had been transmitted to a feeding trough placed close to the wire screen. Infective D. viviparus larvae were observed on some of the discharged sporangia.The experimental calves started excreting low numbers of D. viviparus larvae in their faeces 40–49 days after the first portions were deposited. These results indicate that P. kleinii was reponsible for the infection of the experimental calves with D. viviparus, through the discharge of sporangia carrying infective lungworm larvae.     

Parasites of domestic and wild animals in South Africa. XII. Artificial transmission of nematodes from blesbok and impala to sheep, goats and cattle.

Sheep were successfully infested artificially with the larvae of Haemonchus contortus, Trichostrongylus axei, Trichostrongylus falculatus and Impalaja nudicollis, cultured from the faeces of blesbok naturally infested with these nematodes. Haemonchus placei, Longistrongylus sabie, Trichostrongylus colubrifomis, T. falculatus, Impalaia tuberculata and Cooperia hungi likewise became established in sheep, goats and calves dosed with larvae cultured from the faeces of infested impala. Sheep and goats could also be infested with Cooperioides hamiltoni and Oesophagostomum columbianum of impala origin, but Cooperioides hepaticae could not be transmitted either to these hosts or to calves.     

Experimental Salmonella typhimurium infection in calves.

The paper describes the clinical, bacteriological and pathological findings in experimental Salmonella typhimurium infection in calves. Oral doses of 10(8) and 10(9) organisms produced clinical disease and high mortality; doses ranging from 10(4)--10(7) organisms were less consistent in their action. Jersey calves appeared more susceptible to infection than Friesian calves. The clinical signs in most calves were pyrexia and a characteristic diarrhoea that lasted for up to 11 days; more severe symptoms were seen in the calves that received the higher doses. Following infection, all calves excreted S typhimurium in their faeces, the highest counts being observed in the calves that died. In the calves that survived, counts ranging from 10(2)--10(5)/g faeces occurred continuously for up to a maximum of 20 days and subsequent intermittent excretion occurred in a number of calves. In the calves that died, necrotic enteritis in the ileum and large intestine was the most striking lesion; lesions were uncommon in other organs. The findings are discussed in relation to the pathogenesis, diagnosis and control of the disease.     

Chemotherapeutic efficacy of sulphadimidine, amprolium, halofuginone and chloroquine phosphate in experimental Eimeria bareillyi coccidiosis of buffaloes

Sulphadimidine, amprolium, halofuginone and chloroquine phosphate were administered to buffalo calves 10 days after experimental infection with Eimeria bareillyi. Animals given sulphadimidine or amprolium remained clinically normal and shed only a few oocysts in their faeces. Halofuginone was found partially effective and chloroquine phosphate completely ineffective in preventing faecal oocyst discharge and intestinal lesions. Sulphadimidine and amprolium treated calves gained weight, but chloroquine treated calves suffered progressive weight loss similar to that of infected untreated controls. No significant alterations of haematological values were observed either in the treated calves or in the untreated controls.     

Effects of a lactoperoxidase system and lactoferrin,added to a milk replacer diet,on severity of diarrhoea,intestinal morphology and microbiology of digesta and faeces in young calves

The objective of the present study was to determine the effects of the combination of a lactoperoxidase system (LP‐s) and lactoferrin (LF) added to a milk replacer diet on severity of diarrhoea, the morphology of the small intestinal mucosa, and the microbiology of digesta and faeces in young calves, in comparison with a control diet. The experiment was conducted with 30 young calves, 15 per treatment, during the period of 7–21 days of age. During this period, calves are sensitive to gastrointestinal disturbances that can cause diarrhoea. The results showed a significantly (p < 0.05) reduced severity of diarrhoea in the LP‐s/LF group compared to the control group as assessed by faecal consistency scores. Numbers of CFU (colony forming units) of Escherichia coli in jejunal and colonic digesta and in faeces were lower in the LP‐s/LF group compared with the control group. The differences were significant in both colonic digesta (p < 0.1) and in faeces (p < 0.05). Examination of the small intestinal mucosa, using a dissecting microscope, indicated more finger shaped villi in the distal jejunum of LP‐s/LF‐treated calves compared with the control group (p < 0.05). Histometrical measurements showed that these villi were significantly (p < 0.05) longer.     

Toxocara vitulorum in suckling calves in The Netherlands

A Dutch farmer with beef cattle and suckling calves noticed one of the calves suffering from diarrhoea and observed large white worms near the perineum. In the faeces of this calf, eggs of Toxocara vitulorum were found. The majority of the cows in the herd were of the Piemontese breed previously imported from southern France. Treatment with albendazole was successful. Two other calves had positive faecal egg counts. One month after treatment of these calves with doramectin, no eggs were found. To prevent further infections on the farm and dissemination of this uncommon infection to other farms, the farmer decided to have all his cattle slaughtered.     

Laboratory study of Mycobacterium bovis infection in badgers and calves

Two experiments with badgers infected with Mycobacterium bovis are described. In the first, badgers were infected by intravenous inoculation of a bovine isolate of M bovis. The course of the disease in these and its spread to healthy badgers and calves was monitored by clinical, immunological and bacteriological means. In the second experiment a group of naturally infected badgers were observed for a period of up to four years. They were found to excrete M bovis in their faeces for periods of between 165 and 1305 days before they died of tuberculosis or were killed. M bovis was also shed in the urine. The badgers in both experiments were examined regularly and blood samples were taken for complement fixation tests. Faeces, urine, pus and sputum were also collected for cultural and biological tests and the badgers were skin tested using Weybridge bovine and avian tuberculin. The skin tests were uniformly negative while the complement fixation test were positive in some infected badgers but gave very variable results. Only the isolation of M bovis gave a definite diagnosis of tuberculosis in the living badger but a number of badgers which were found to have tuberculosis at post mortem were not detected while alive by this method. Environmental samples from the yards, including badger faeces, soil, hay, scrapings from feeding bowls and water were regularly examined for the presence of M bovis but apart from faeces only one water sample was positive, indicating that the organism did not persist for long in the environment. In both experiments calves developed sensitivity to bovine tuberculin after six months' exposure to infected badgers. The experiments further demonstrate the potential of a badger population to become endemically infected with M bovis and to act as a source of infection for cattle.     

Spread of infective Dictyocaulus viviparus larvae in pasture and to grazing cattle: Experimental evidence of the role of Pilobolus fungi

Four calves experimentally infected with Dictyocaulus viviparus were made Pilobolus-free by hygienic measures and by feeding them irradiation sterilized feed. Two of the calves were orally administered laboratory cultured Pilobolus sporangia daily. As a result, the faeces from one air contained D. viviparus larvae and Pilobolus spores, and the faeces from the other pair contained D. viviparus larvae, but no Pilobolus spores.

Two identical plots were used for deposition of the two kinds of faeces, and one of them remained free of Pilobolus fructification. Herbage sampling and the use of tracer calves revealed that on this plot the larval contamination and the infectivity of the pasture were greatly reduced. A mean larval count of 1321 near the faecal pats (0–5 cm) in the plot where Pilobolus was observed was reduced to 69 per kg of herbage on the Pilobolus-free plot. At a distance of 100 cm from the pats, a reduction from 99 to 3 larvae per kg herbage was found.

Each plot was grazed by four parasite-free tracer calves for 3 days. During the subsequent stabling period of these calves, the lungworm larval excretion of those from the Pilobolus-free plot was reduced by 90% and the clinical symptoms were milder than those which grazed the plot which contained the fungus. The mean post mortem worm counts after 4 weeks of stabling showed a reduction from 167 to 25 worms.

A more marked effect of Pilobolus fungi on the transmission of D. viviparus infection is to be expected under field conditions where calves are grazing more selectively than in the present study.