‘Pink eye’ or ‘zere oogjes’ or Keratoconjunctivitis Infectiosa Ovis (KIO)

In a comparative study the clinical efficacy of five different treatments of keratoconjunctivitis infectiosa ovis (KIO) were tested, namely an intramuscular injection of chloramphenicol base (dosage 15 mg/kg), spiramycin base (Suanovil^® dosages 10 to 25 mg/kg), oxytetracycline (Engemycine^® Forte, Terramycin^® LA, dosages respectively 5 and 10 mg/kg), tiamulin (Dynamutulin^®, dosage 10 mg/kg) and subcutaneous injection of procaine penicillin G, benzathine penicillin G, and dihydrostreptomycin in the lower eyelid.

It appeared from these field trials that spiramycin base, oxytetracycline and tiamulin had a clearly positive effect on the clinical course of ‘pink eye’, although with tiamulin there was only a temporary effect (high percentage of relapses).

In view of the field data the following dosage schemes are, for the time being, advised: spiramycin. base (Suanovil^®), and oxytetracycline (formulation with a good biological availability) both 20 to 30 mg/kg and, if necessary, to be repeated on days 5 and 10 after the first intramuscular injection. The dosage scheme advised for tiamulin is 20–30 mg/kg to be repeated on day 3 and if necessary on days 6 and 9 after the intramuscular injection. In mild cases it is sufficient to rub the eyes with for example oxytetracycline eye‐ointment, a few times a day.     

Comparison in Effect of Heatsynch with Heat Detection Aids and CIDR‐Heatsynch in Dairy Heifers

The objective of the present study was to determine whether oestrous detection with the help of oestrous detection aids during the Heatsynch without timed AI protocol is equally effective with the progesterone‐combined protocol in dairy heifers. A total of 148 heifers were randomly assigned to one of the two groups. A group of heifers treated with Heatsynch with heat detection aids (n = 72) received GnRH on day 0, prostaglandin F_2α (PGF_2α) on day 7 and oestradiol benzoate (EB) on day 8, while in controlled internal drug release (CIDR)‐Heatsynch group (n = 76), CIDR was included during a period from GnRH to PGF_2α. Heifers were checked for oestrus twice daily, i.e. from 09:00 to 10:00 hours and from 15:00 to 16:00 hours starting on day 2 for Heatsynch group and on day 8 in CIDR‐Heatsynch group, and continued up to day 12. KAMAR^®heat mount detector (KAMAR^® Inc., Steamboat Springs, CO, USA) and ALL‐WEATHER^® PAINTSTIK^® (LA‐CO Industries Inc., Elk Grove Village, IL, USA) were used as heat detection aids. AI was conducted within 1 h after confirming oestrus in 72 heifers, while 19 animals were transferred with embryo 7 days after oestrus according to the request of the owners. Premature oestrus before PGF_2α injection occurred in 18% of Heatsynch group. Of 13 heifers which showed premature oestrus, six were inseminated and two of them conceived. Oestrus detection rate within 12 days after initiation of the protocols did not differ between the two groups (94% vs 95%). There was no difference in the conception rate after first AI (including heifers that were inseminated before PGF_2α injection) and embryo transfer between Heatsynch with heat detection aids and CIDR‐Heatsynch groups (36% vs 44% and 70% vs 56%). It is concluded that the use of heat detection aids to monitor the occurrence of premature oestrus prior to PGF_2α injection in Heatsynch protocol in dairy heifers was equally effective to the inclusion of CIDR.     

The effect of oxytetracycline treatment on immunity induced by Anaplasma centrale.

Calves vaccinated with Anaplasma centrale were treated with 20 mg/kg of long-acting oxytetracycline (OTC/LA) before or simultaneously with vaccination or up to seven months later. Of 40 animals given one or two of OTC/LA from 3 to 13 days before vaccination, 23 become patent after vaccination, with an average prepatent period almost twice as long as that in non-treated vaccinated controls. Upon challenge with 2 x 10(8) A. centrale per dose all 17 previously non-patent calves showed average maximum parasitemias of 2 to 3.8%. Out of 30 calves treated with two to four doses of OTC/LA from one to four weeks after vaccination, 29 remained negative for A. centrale and reacted to challenge infection with average maximum parasitemias of 6.9-7.8%. Five out of 10 calves receiving OTC/LA simultaneously with the vaccination, and all of a separate group of 10 calves treated with a single dose seven days after vaccination, become patent an average of 51.6 and 63.5 d, respectively, after vaccination. Upon challenge, the five previously non-patent calves showed an average of 5.2% maximum parasitemia. In all groups, only rare parasites were seen in previously patent calves after challenge. Thirty calves treated with 2-4 doses of OTC/LA about six months after vaccination showed no or only a few parasites upon challenge. The above results show that treatment with single or multiple doses of OTC/LA a few weeks before or after administration of live A. centrale vaccine can interfere with elaboration of immunity.     

Oral absorption and bioavailability of flumequine in veal calves

Summary

The oral absorption and bioavailability of flumequine was studied in 1‐, 5‐ and 18‐week‐old calves following intravenous and oral administration of different formulations of flumequine (Flumix^®, Flumix C^® and pure flumequine). Increasing age had a negative influence on the C_max after the administration of Flumix^®, based on a larger V_D in the older calves. The C_max decreased from 5.02 ± 1.46 μg/ml in the first week to 3.28 ± 0.42 μg/ml in the 18th week. Adding colistin sulfate to the flumequine formulation and administring pure flumequine mixed with milk replacer had a negative effect on the C_max of flumequine after oral administration of 5 and 10 mg/kg body weight. The bioavailability of the orally administered flumequine formulations was 100% in all cases except after the administration of Flumix C^®, for which it was 75.9 ± 18.2%. The urinary recovery of flumequine after intravenous injection of a 10% solution varied from 35.2 ± 2.3% for Group B. to 41.2 ± 6.3% for Group C.

The dosage of 5 mg/kg body weight Flumix^® twice daily in 1‐week‐old veal calves is sufficient to reach therapeutic plasma concentrations, based on a MIC value of 0.8 μg/ml of the target bacteria.

In older calves it is advisable to increase the dosage 7.5 or 10 mg/kg body weight every 12 hours. In combination with colistin sulfate it is also advisable to increase the dosage slightly because of the negative effect of the colistin sulfate on the C_max of flumequine.     

Eradication of feline dermatophytosis in a shelter: a field study

Enzootic dermatophytosis in a shelter with approximately 140 cats was treated according to a protocol combining identification, isolation and treatment of subclinical carrier and affected animals in accordance with a three‐area system: healthy animals (no lesions and negative cultures), subclinical carrier animals (no lesions but with positive cultures) and clinically affected animals (lesions and positive cultures). The cats were examined and inspected under a Wood’s lamp and had samples taken for fungal culture every 2 weeks. Thirty‐three per cent of the cats had a positive fungal culture at the start of the study. Clinically affected animals and carriers were treated with a 0.2% enilconazole lotion (Imaverol^®) twice a week and given itraconazole (Itrafungol^®) 5 mg/kg SID orally every other week. The environment was treated once a day with a 1% bleach solution and once a week with a 0.6% enilconazole (Clinafarm^®) solution. Treated animals were considered cured after two consecutive negative fungal cultures. All cats were cured within 56 days. Prophylactic measures against dermatophytosis were implemented for new arrivals consisting of individual quarantine and the systematic taking of fungal cultures. No relapses were observed based on the fungal cultures taken from the animals and the environment over the first 10 months.     

Feeding Saccharomyces cerevisiae fermentation products lessens the severity of a viral–bacterial coinfection in preweaned calves

We have previously reported that supplementation with Saccharomyces cerevisiae fermentation products (SCFP) ameliorates clinical signs and lung pathology following experimental bovine respiratory syncytial virus (BRSV) infection in preweaned dairy calves. The objectives of this study were to determine the effect of SCFP supplementation on the metabolic and endocrine responses, and disease outcome of a viral–bacterial coinfection in preweaned calves. Twenty-seven, 1- to 2-d-old Holstein-Angus cross calves were enrolled in the study; one SCFP calf was removed from the trial during the pre-challenge phase due to complications from nephritis. Calves were assigned to two treatment groups: control or SCFP-treated, base milk replacer with 1 g/d SCFP (Smartcare, soluble formula) and calf starter top dressed with 5 g/d SCFP (NutriTek, insoluble formula). Calves were infected with BRSV on day 21, followed 6 d later by intratracheal inoculation with Pasteurella multocida (PM). Calves were euthanized on day 10 post-viral infection. Calves receiving SCFP had reduced thoracic ultrasonography scores on day 7 post-viral infection (P = 0.03) and a tendency toward reduced scores on day 10 post-viral infection (P = 0.09). Calves receiving SCFP also had less severe lung pathology scores at necropsy (P = 0.06). No differences between treatments were observed in lung viral loads (P = 0.48) or bacterial lung recovery (P = 0.34); however, there was a distinction in the lung location for PM recovery, with PM isolated more frequently from the cranial lobes in SCFP-treated calves, but more frequently from the caudal lobes of control calves. Calves treated with SCFP tended (P = 0.07) to have higher serum IL-6 concentrations following the coinfection. Calves treated with SCFP had lower concentrations of serum nonesterified fatty acids and beta-hydroxybutyric acid compared with controls following experimental challenge (P = 0.03 and P = 0.08, respectively), suggesting metabolic changes favoring growth and development. There were no differences between groups in gene expression of insulin receptor, insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R), growth hormone receptor, or haptoglobin in the liver. Results from this study suggest that supplementing with SCFP may moderate the impact of a respiratory viral–bacterial coinfection on preweaned calves through metabolic and immune modifications.     

Effects of a topically applied anaesthetic on the behaviour,pain sensitivity and weight gain of dairy calves following thermocautery disbudding with a local anaesthetic

ABSTRACT

Aims: To compare the effect of a topically applied anaesthetic to no pain relief or meloxicam on the behavioural responses, pain sensitivity and weight gain of calves following disbudding with or without sedation.

Methods: A total of 364, 2–6 week-old calves from three commercial farms were systematically allocated to one of six treatment groups. All calves received a cornual nerve block prior to disbudding, with half restrained in a crate and half sedated with xylazine. Within these groups one third received no further treatment (control), one third were treated with meloxicam >10?minutes prior to disbudding and one third received a topical anaesthetic applied to the horn bud wounds following disbudding. The frequency of ear flicks, head shakes, head scratches and pain sensitivity of the wound were recorded on up to eight occasions over 24 hours after disbudding. Calves were weighed before, and 7 and 28 days after, disbudding to determine average daily weight gain (ADG).

Results: Compared to calves in the crate-control group, all other groups had reduced ear flicks at all times following disbudding (p?<?0.01). Treatment with meloxicam and topical anaesthesia in addition to sedation reduced head scratches compared to calves in the crate-control group (p?≤?0.013). At 22 hours after disbudding head shakes were reduced in sedated calves treated with topical anaesthetic compared to calves in the crate-control group (p?<?0.001). Pain sensitivity was lower in all sedated calves than unsedated calves (p?<?0.001). The ADG between Days 0–7 was 0.14 (95% CI?=?0.015–0.274) kg/day greater in sedated calves treated with meloxicam than calves in the crate-control group (p?=?0.03), and the ADG between Days 0–28 tended to be 0.06 (95% CI=?0.01–0.13) kg/day greater in sedated calves treated with topical anaesthetic than calves in the crate-control group (p?=?0.09).

Conclusion and clinical relevance: Sedation of calves for disbudding reduced the pain experienced in the following 24 hours. There was a benefit to providing calves with topical anaesthetic following disbudding on behavioural responses and pain sensitivity, which was similar to that of treating calves with meloxicam.     

The effect of different combinations of local anaesthesia,sedative and non-steroidal anti-inflammatory drugs on daily growth rates of dairy calves after disbudding

AIM: To assess the effect of sedation and local anaesthesia (LA) at disbudding, and the addition of meloxicam or ketoprofen treatment, on weight gain in dairy calves following disbudding.

METHODS: Friesian-Jersey cross calves, from four dairy farms, were enrolled when 3–6 weeks old. All calves (n=271) were disbudded by veterinary personnel and randomly assigned to six groups: 136 were disbudded without sedation or LA, of which 31 received 20 mg meloxicam S/C and 75 received 150 mg ketoprofen I/M. A further 135 were disbudded with sedation (0.25 mg/kg xylazine I/M) and LA, of which 30 also received meloxicam and 75 received ketoprofen. Calves were weighed 3 days before, and 15 and 30 days after, disbudding (Day 0). Daily weight gain was analysed using mixed models and ANOVA.

RESULTS: Complete results were obtained from 263 calves. From Day ?3 to Day 15, the growth rate of calves disbudded without pain relief (0.53 (95% CI=0.47–0.60) kg/day) was less that of calves disbudded with some form of pain relief (0.65 (95% CI=0.62–0.68) kg/d; p=0.004). There was no difference between the effect of meloxicam or ketoprofen (p=1.00). An interaction between use of sedation and LA and additional non-steroidal anti-inflammatory drugs (NSAID) meant that NSAID treatment did not increase growth rates in calves disbudded with sedation and LA but did increase growth rates for calves disbudded without pain relief (p<0.05). From Day 16 to Day 30 there was no effect of NSAID treatment on growth rate, but calves receiving LA and sedation grew faster (0.74 (95% CI=0.69–0.80) kg/day) than calves disbudded without LA and sedation (0.66 (95% CI=0.61–0.71) kg/day; p=0.018). From Day ?3 to Day 30, calves disbudded with sedation and LA grew faster (0.71 (95%CI=0.64–0.77) kg/day) than calves disbudded without sedation and LA (0.60 (95% CI=0.55–0.65) kg/day; p=0.011). However, addition of NSAID to sedation and LA made no further difference to growth rates (p=0.69).

CONCLUSIONS: Dairy calves disbudded with no pain relief had slower growth rates than calves receiving pain relief. From Day 15 to 30 calves given no pain relief, or NSAID alone, grew more slowly than those receiving sedation and LA at disbudding. The addition of NSAID treatment to sedation and LA did not further increase growth rates.

CLINICAL RELEVANCE: This study adds to the evidence that pain management when disbudding is beneficial for calf productivity as well as calf welfare.     

Creep feeding effects on male Nellore calves influencing behavior and performance of their dams

The objective of the present study was to evaluate the effect of different schemes of calves’ supplementation in a creep feeding system, on the behavior of Bos indicus calves and dams, and also the influence of the calves’ supplementation on dams’ performance. Forty-eight Nellore male calves (147 ± 7 kg body weight and 3 months of age) in the suckling phase and their dams (476 ± 9 kg and 6 years of age) were studied in a completely randomized design. The experiment was divided into two periods of 71 days. The treatments were 5- and 10-g supplement dry matter (DM)/kg BW day offered in periods 1 and 2, respectively (5S/10S); 10- and 5-g supplement DM/kg BW day offered in periods 1 and 2, respectively (10S/5S); 7.5-g supplement DM/kg BW day in both periods 1 and 2 (7.5S); and mineral mix ad libitum in both periods 1 and 2 (MM). No differences (P < 0.05) in body condition score (BCS), final body weight (FBW), and average daily gain (ADG) were found in dams’ performance. Calves from MM treatment spent more time (P < 0.05) grazing than the supplemented calves from 5S/10S and 10S/5S treatments, in the first period. No difference in suckling time was found between the treatments (P > 0.05) in the first evaluated period. Calves from 10S/5S treatment spent more time suckling and less time eating supplements (P < 0.05) than 5S/10S treatment animals, in the second evaluated period. Dams of MM treatment’s calves had more idle time and lower grazing time when compared with the mothers of calves from 5S/10S and 10S/5S treatments. It was concluded that different schedules of Nellore calves’ supplementation on pasture do not affect their mothers’ performance, and supplementation decreases the grazing time of calves in the suckling phase.     

Effect of diet on preweaning performance of Sahiwal calves

The objective was to study the growth potential of Sahiwal calves given milk or milk replacer with or without concentrates. For this purpose, forty-eight Sahiwal calves were divided into four groups of 12 animals each with equal sex ratio. In each group, the calves were offered either milk or a milk replacer (MR) at a rate of 10% of their body weight adjusted weekly. In addition to this, calves were fed either a starter ration plus Egyptian clover hay (SR + H) or hay only (H) until the end of trial. The milk or MR was withdrawn gradually from day 56 until animals were weaned completely by day 84. Calves offered milk grew faster than those offered MR (357 ± 9 vs. 162 ± 9 g/day; p < 0.05) and displayed higher weaning weights (51.6 ± 0.8 vs. 35.2 ± 0.8 kg; p < 0.05). The calves offered SR + H grew faster (311 ± 9 vs. 208 ± 9 g/day; p < 0.05) and displayed higher weaning weights (48.7 ± 0.8 vs. 38.1 ± 0.8 kg; p < 0.05) than those fed H alone. Calves offered milk plus SR + H showed the highest growth rate and weaning weights (401 ± 13 g/day and 56.3 ± 1 kg, respectively). The lowest growth rate and weaning weights were observed in calves offered MR and H only (115 ± 13 g/day and 30.3 ± 1 kg, respectively). Calves offered the MR had higher number of scour days than those offered milk (13.5 vs. 3.3). The feeding of whole milk in combination with the starter ration and hay resulted in superior growth rates, higher weaning weights, and healthier calves than the other feeding regimens.     

Sucking behaviour of hand-reared newborn dairy calves

AIM: To determine the feeding ability of calves during the first 4 days after birth.

METHODS: The sucking behaviour of 171 dairy calves, fed from individual bottles during the first 4 days after birth, was evaluated by quantifying the volume of colostrum consumed, the duration of feeding, and speed of drinking. Calves had been separated from their mothers and brought into a rearing shed in the morning, when <24 h of age, and were offered 2 L colostrum from a bottle in the afternoon of the same day, and twice daily thereafter.

RESULTS: Newborn calves became efficient suckers from bottles within 24 h of removal from their dams (collection). On the day after birth, 95% of calves drank the 2 L of colostrum offered during the afternoon feed, and by Day 4 virtually all calves (99%) drank this amount. Calves that had inadequate colostrum from their dam were more likely to drink all 2 L offered after collection, but a small number of calves that had not had colostrum from their dams and drank <500 ml at the afternoon feed following collection were likely not to drink 2 L on the following days. However, calves that did not drink all 2 L on Day 1 were not disadvantaged in comparison to those that did, in that they were equally likely to drink 2 L on Day 4.

CONCLUSIONS: The majority of calves became efficient drinkers within 48 hours of birth, but a small number of slow feeders may need individual feeding at least up to 4 days after birth.     

Evaluation of age-dependent susceptibility in calves infected with two doses of Mycobacterium avium subspecies paratuberculosis using pathology and tissue culture

The longstanding assumption that calves of more than 6 months of age are more resistant to Mycobacterium avium subspecies paratuberculosis (MAP) infection has recently been challenged. In order to elucidate this, a challenge experiment was performed to evaluate age- and dose-dependent susceptibility to MAP infection in dairy calves. Fifty-six calves from MAP-negative dams were randomly allocated to 10 MAP challenge groups (5 animals per group) and a negative control group (6 calves). Calves were inoculated orally on 2 consecutive days at 5 ages: 2 weeks and 3, 6, 9 or 12 months. Within each age group 5 calves received either a high – or low – dose of 5 × 10⁹ CFU or 5 × 10⁷ CFU, respectively. All calves were euthanized at 17 months of age. Macroscopic and histological lesions were assessed and bacterial culture was done on numerous tissue samples. Within all 5 age groups, calves were successfully infected with either dose of MAP. Calves inoculated at < 6 months usually had more culture-positive tissue locations and higher histological lesion scores. Furthermore, those infected with a high dose had more severe scores for histologic and macroscopic lesions as well as more culture-positive tissue locations compared to calves infected with a low dose. In conclusion, calves to 1 year of age were susceptible to MAP infection and a high infection dose produced more severe lesions than a low dose.     

Prospects of raising Sahiwal cow calves for veal production under tropical environment

The objective of present study was to evaluate the growth potential of Sahiwal calves for veal production on whole milk or whole milk and milk replacer combined in a ratio of 50:50 (MMR). For this purpose, 48 Sahiwal calves (both male and female) were assigned to four dietary treatments having 12 animals/treatment. Calves in the treatments A and B were offered whole milk at 15 or 20 % of their body weight (BW), respectively, up to day 84 adjusted on weekly basis. The calves in treatments C and D received the same amount of milk as in treatments A and B until day 21, respectively, after which 50 % of the milk offered was replaced with a blend of chickpea (Cicer arietinum) flour and vegetable (corn) oil mixed in water (MR) until day 84. The constituted MR had 3.1, 2.8, and 14.3 %, CP, EE, and DM, respectively. The growth and intake data were analyzed using repeated measures analysis, with MIXED Procedures of SAS in a 2?×?2 factorial design. The two factors were feeding level and feeding source. Calves offered whole milk grew faster (P?<?0.05) and had greater weaning weights (P?<?0.05) than those offered MMR (606.4?±?18.1 vs 331.3?±?18.1 g/day and 70.4?±?1.5 vs 47.8?±?1.5 kg, respectively). Greatest daily BW gain (656?±?26 g/day) and weaning weight (74.6?±?2.1 kg) were observed in calves given treatment B while the lowest production cost/kg of BW gain (≈US$3.6?±?0.2) was observed in calves given treatment A. The daily BW gain of calves fed milk ad libitum was 716?±?40 and 836?±?40 g/day, during 5–8 and 9–12 weeks, respectively. The number of days calves exhibited scours was higher in calves offered MMR than those offered whole milk. Replacement of 50 % milk with a blend of chickpea flour and vegetable oil, as an alternative to milk replacer, did not support growth equivalent to whole milk and was not effective in reducing feeding cost during the weaning period. Sahiwal calves may have promise for being raised for veal production under tropical environments.     

Cardiovascular effects of a continuous rate infusion of lidocaine in calves anesthetized with xylazine,midazolam, ketamine and isoflurane

ObjectiveTo assess the cardiovascular changes of a continuous rate infusion of lidocaine in calves anesthetized with xylazine, midazolam, ketamine and isoflurane during mechanical ventilation.Study designProspective, randomized, cross-over, experimental trial.AnimalsA total of eight, healthy, male Holstein calves, aged 10 ± 1 months and weighing 114 ± 11 kg were included in the study.MethodsCalves were administered xylazine followed by ketamine and midazolam, orotracheal intubation and maintenance on isoflurane (1.3%) using mechanical ventilation. Forty minutes after induction, lidocaine (2 mg kg^?1 bolus) or an equivalent volume of saline (0.9%) was administered IV followed by a continuous rate infusion (100 μg kg^?1 minute^?1) of lidocaine (treatment L) or saline (treatment C). Heart rate (HR), systolic, diastolic and mean arterial pressures (SAP, DAP and MAP), central venous pressure (CVP), mean pulmonary arterial pressure (mPAP), pulmonary arterial occlusion pressure (PAOP), cardiac output, end-tidal carbon dioxide (Pe’CO₂) and core temperature (CT) were recorded before lidocaine or saline administration (Baseline) and at 20-minute intervals (T20-T80). Plasma concentrations of lidocaine were measured in treatment L.ResultsThe HR was significantly lower in treatment L compared with treatment C. There was no difference between the treatments with regards to SAP, DAP, MAP and SVRI. CI was significantly lower at T60 in treatment L when compared with treatment C. PAOP and CVP increased significantly at all times compared with Baseline in treatment L. There was no significant difference between times within each treatment and between treatments with regards to other measured variables. Plasma concentrations of lidocaine ranged from 1.85 to 2.06 μg mL^?1 during the CRI.Conclusion and clinical relevanceAt the studied rate, lidocaine causes a decrease in heart rate which is unlikely to be of clinical significance in healthy animals, but could be a concern in compromised animals.     

Experimental and clinical trials of long acting oxytetracycline in the treatment of canine ehrlichiosis

Summary

Four splenectomized dogs were experimentally infected with Ehrlichia canis and treated at the point of illness with long acting (LA) Oxytetracycline at different dosages. Terramycin LA, when given at a dose of 20mg/kg body weight (deep intramuscularly) twice, at a four‐day interval, was found to have effectively controlled the disease and has replaced the usual 7–14 successive days’ treatment regimen when other groups of tetracycline drugs arc used.

Predej^® 2X* at the rate of 2 mg given intramuscularly concurrently eliminated the local inflammatory reaction caused by the injection of Terramycin LA.

Twenty‐four out of the 26 naturally infected dogs which were treated in a similar way were completely cured; one died before it could receive the full treatment, and another received a second medication five weeks after the first treatment, showing recurrent epistaxis; blood samples taken from this dog were negative for E. canis.     

Efficacy of florfenicol for treatment of naturally occurring infectious bovine keratoconjunctivitis

OBJECTIVE: To determine the efficacy of florfenicol for treatment of calves with naturally occurring infectious bovine keratoconjunctivitis (IBK). DESIGN: Randomized controlled field trial. ANIMALS: 63 beef calves and 80 dairy calves between 4 and 12 months of age. PROCEDURE: Calves were randomly assigned to 1 of 3 treatment groups. Calves in the SC treatment group received a single dose of florfenicol (40 mg/kg [18.2 mg/lb of body weight), SC, on day 0. Calves in the IM treatment group received florfenicol (20 mg/kg [9.1 mg/lb]), IM, on days 0 and 2. Calves in the control group received injections of saline solution (0.9% NaCl), IM, on days 0 and 2. Calves were reevaluated every other day for 20 days after treatment. RESULTS: Corneal ulcers healed by day 20 in 48 of 49 (98%) calves treated with florfenicol IM, 39 of 42 (93%) calves treated with florfenicol SC, and 33 of 52 (63%) control calves. CONCLUSIONS AND CLINICAL RELEVANCE: Florfenicol administered SC (1 dose) or IM (2 doses 48 hours apart) was effective for treatment of calves with naturally occurring IBK.     

The physiological and physical status of single calves at birth in a dairy herd in New Zealand

AIM: To determine the physiological status of calves at birth and the perinatal factors that might predispose newborn calves to debility and death, using criteria previously established for newborn lambs.

METHODS: Friesian mixed-aged cows and heifers on a dairy farm in New Zealand that were close to calving were separated from the main herd and observed 24 h a day until they calved. Cows in which labour did not progress for over 1 h or which were in distress were assisted. About 12–13 min after birth, rectal temperature was measured and a blood sample was taken from each calf. The packed cell volume (PCV) and plasma lactate, glucose and fructose concentrations were determined. The time to stand for each calf and the air temperature and weather conditions at birth were recorded.

RESULTS: The parameters measured were within normal ranges for newborns for the majority of calves. Calves sired by an Angus bull and born to heifers (AngusX) had significantly higher plasma lactate and fructose concentrations than Friesian calves born to cows, but there were no significant differences between the two breeds in any of the other parameters measured. Calves of both breeds born with assistance had significantly higher plasma lactate concentrations than those born without. Friesian calves that were assisted at birth had significantly lower PCvs and took significantly longer to stand than calves born without assistance. Assisted AngusX calves were significantly heavier than their unassisted counterparts. Calves born during windy and wet weather and when air temperatures were below 10°C had lower rectal temperatures, took longer to stand and had higher plasma glucose concentrations than those born in dry weather and when air temperatures were above 10°C.

CONCLUSIONS: Calves with physiological parameters outside the normal range had experienced difficult labour and/or intrapartum hypoxaemia. Placental insufficiency and maternal undernutrition during late pregnancy did not apparently contribute to neonatal problems in the present study.     

Epidemiological features of calf mortality due to hemophilosis in a large feedlot

Hemophilosis was the most significant cause of mortality in fall-placed calves in a large feedlot in Saskatchewan, despite routine single immunization of calves with a commercial Haemophilus somnus bacterin on arrival. Common manifestations of fatal H. somnus infection were myocarditis and pleuritis; occasionally, thrombotic meningoencephalomyelitis (TME), peracute septicemia, and pneumonia were observed. Circumstantial evidence suggested that H. somnus may be a pathogen in polyarthritis. Death from pneumonia mainly occurred during the first five weeks in the feedlot. Death from myocarditis, pleuritis, TME, and septicemia, and euthanasia because of polyarthritis, occurred mainly after the third week in the feedlot.

The median fatal disease onset (FDO) for pneumonia was day 12; for septicemia, day 17; for polyarthritis, day 18; for myocarditis and pleuritis, day 22; and for TME, day 29. Calves that died from myocarditis frequently were found dead in their “home” pen; however, 88% of these animals had been treated previously. Fifty-seven percent of the calves that died from pleuritis were never treated, and those that died from TME or septicemia were either never treated or died shortly after initial treatment.

     

Comparative plasma ampicillin levels and bioavailability of five parenteral ampicillin formulations in ruminant calves

Summary

Plasma ampicillin concentrations were determined in an eight‐ways crossover trial involving six ruminant calves, which were treated intravenously (i.v.) with sodium ampicillin at 15.5 mg/kg and intramuscularly (i.m.) with five different ampicillin trihydrate or ampicillin anhydrate formulations at 7.7 mg/kg. The mean plasma concentration‐time curve (C_p)after intravenous ampicillin sodium administration was described biexponentially, as: C_p = 38.8 e ‐0.0268t + 0.45 e ‐0.0058t.

Intramuscular injection, into the lateral neck, of Ampikel‐20^® and Polyflex^® resulted in 100 per cent bioavailabilities within 12 h post injection (p.i.), but the biological half‐lives (t½>) were different, being 2.1 and 3.8 h, respectively. Ampikel‐20^® produced the hïghest peak plasma drug concentrations (mean C _max:4.8 μg ampicillin/ml). After intramuscular injection of Penbritin® the mean bioavailability for the first 12 h p.i. was 63 per cent, the mean t½>, was 5.9 h, and the mean C_max was 1.8 μg/ml. Treatment with Albipen^® and Duphacillin^® resulted in low plasma ampicillin levels, which were maintained for 3 to 6 days p.i., limited bioavailability during the first 12 h p.i., and a mean t½> of 22.2 and 11.9 h, respectively. Plasma concentrations of ampicillin from four hours onwards after i.m. and s.c. administration of Ampikel‐20^® at a dose level of 15.5 mg/ kg were similar.

The duration of potentially therapeutic plasma ampicillin concentrations after administration of each formulation is presented. Pre‐slaughter withdrawal times for diseased calves are suggested for the different formulations studied.     

Comparison of a rebound and an applanation tonometer for measuring intraocular pressure in normal rabbits

Objective To compare intraocular pressure (IOP) measurements made on healthy adult rabbits without the effect of tranquilizers using the new applanation tonometer, Tono‐Pen Avia^®, and the rebound tonometer Tonovet^®. Methods Intraocular pressure was measured throughout the day (6:00, 9:00, 12:00, 15:00, and 18:00 h) in 38 adult New Zealand White rabbits (76 eyes). The animals were 20 males and 18 females, with a mean weight of 3.5 kg and an average age of 6 months. A complete ocular exam (including Schirmer tear test, fluorescein staining, slit‐lamp biomicroscopy, and direct ophthalmoscopy) was performed on all animals at the beginning of the trial. Rebound tonometry was performed, and after 10 min, anesthetic drops were instilled and applanation tonometry was carried out. IOP values obtained using the two techniques were analyzed statistically. Results The mean IOP was 9.51 ± 2.62 mmHg with Tonovet^®, and 15.44 ± 2.16 mmHg with the Tono‐Pen Avia^®. Significant differences between measurements with the two tonometers were observed (P < 0.001). The linear regression equation describing the relationship between the two tonometers was y = 0.4923x + 10.754 (y = Tonovet^® and x = Tono‐Pen Avia^®). High IOPs were recorded in the early measurements (6:00), but the average IOPs from both devices were statistically similar throughout the day (P = 0.086). The correlation coefficient was r² = 0.357. No significant difference in IOP regarding gender was observed. Conclusion The Tono‐Pen Avia^® recorded higher levels of IOP compared with the Tonovet^®. Early in the day, the IOP of rabbits was higher than later in the day, regardless of the tonometer used.