Evaluation of intravenous regional anaesthesia and four-point nerve block efficacy in the distal hind limb of dairy cows

Blood calcium dynamics in cows receiving an aqueous calcium suspension for voluntary consumption or a calcium bolus following parturition

The form of oral calcium (Ca) supplement and the Ca source influence Ca absorption dynamics resulting in different postpartum calcemia. The objective of this study was to investigate whether an oral Ca supplement (mainly CaCO3) offered for voluntary consumption would maintain or increase postpartum blood Ca to the same degree as a Ca bolus (mainly CaCl2) providing an equivalent dose of a Ca. A total of 72 Holstein cows were blocked by expected parturition date and parity. Within each block of 3 animals, cows were randomly assigned to one of three treatments, including an oral Ca supplement offered for voluntary consumption (Ca-drink, n = 23), an oral Ca bolus (Ca-bolus, n = 24), or an untreated group (CON, n = 25). Treatments were administered once within 15 min postpartum. The Ca-drink provided 45 g of Ca (CaCO3 source) and was mixed in 20 L of lukewarm water and offered to cows for 30 min. The Ca-bolus provided 43 g of Ca (71% from CaCl2 and 29% from CaSO4) and was administered once. Both Ca-bolus and CON cows received 20-l of lukewarm water at parturition to standardize the volume of fluids (Ca-drink or 20-l lukewarm water) offered at parturition. Dairy cows offered Ca-drink had a 28% higher fluid consumption than Ca-bolus and CON cows. Milk yield and milk composition expressed in percentage protein, fat, lactose, and urea did not differ, whilst there was a small but significant increase in DMI in cows receiving the Ca-drink compared to CON, while Ca-bolus did not differ from other groups. This was consistent with reduced BW losses between week 1 and 3 in cows receiving the Ca-drink suspension. Treatment by time interactions were present for blood Ca, glucose, and urea concentrations. Blood Ca was relatively stable in Ca-drink cows, while higher fluctuations were observed in Ca-bolus cows. In Ca-bolus cows, blood Ca increased from 15 min to 6 h, decreased from 6 to 24 h, and finally increased again from 24 to 48 h. At 24 h post administration, blood Ca was greater in cows receiving the Ca-drink than cows receiving the Ca-bolus. Blood glucose was greater in Ca-bolus cows at 15 min after treatment administration compared with Ca-bolus and CON, while blood urea was higher in CON than Ca-drink and Ca-bolus throughout the sampling period. These results indicate that voluntary oral Ca resulted in a relatively stable calcemia, whereas higher fluctuations were observed in cows receiving the Ca-bolus. Due to a lack of differences between Ca-drink and Ca-bolus compared with CON, it is not possible to conclude regarding the efficacy in maintaining postpartum blood Ca.

Evaluation of the 4-point regional nerve block using 2% lidocaine in sheep

PURPOSE

To determine whether a single 4-point regional nerve block using 2% lidocaine administered distal to the fetlock of sheep with a single distal limb lameness will result in analgesia of the digits.

ANIMALS

Eighteen adult ewes with a single limb lameness originating from distal to the metacarpo/metatarsophalangeal joint were enrolled in the study.

PROCEDURES

Digital lameness was confirmed and scored based on clinical examination. Pain associated with digital lesions was assessed in triplicate using a pressure algometer to quantify mechanical nociceptive threshold. The same procedure was repeated on the contralateral limb as a control, and maximum force and time to response recorded. A 4-point regional nerve block was performed using 8 mL of 2% lidocaine. Mechanical nociception was again applied in triplicate to both limbs as described above, by a blinded investigator. Following appropriate medical treatment, the ewe was released and lameness scoring repeated.Median values for pressure and time to withdrawal were determined for affected and control limbs, and differences between pre- and post-lidocaine block measures were compared using Friedman's ANOVA test. The Wilcoxon Signed-Rank test was used to compare lameness score pre- and post-block. Statistical significance was set at α = 0.05.

MAIN FINDINGS

Application of the 4-point block resulted in a change in pressure required to elicit withdrawal (F-value 17.7; P < 0.0001) as well as time to withdrawal (F-value 20.4; P < 0.0001), for the affected limb as compared to the control limb. Lameness scores decreased following the block (Signed-rank statistic 85.5; P < 0.0001).

PRINCIPAL CONCLUSION

The 4-point nerve block resulted in anesthesia of the distal limb in sheep in this clinical model.

Review of guidelines for functional claw trimming and therapeutic approach to claw horn lesions in cattle

Lameness is one of the most pressing health and welfare problems in cattle, especially on dairy farms. The most common cause of lameness is claw pathology, often due to lack of appropriate functional claw trimming. Functional claw trimming restores the physiological shape of the claws and distributes weight properly between the claws and over the claw weight-bearing surface. It also allows closer examination of the claws for early signs of pathology. The methods of functional claw trimming described in the previous century are still applicable today, considering some recent findings on the subject. It is essential not to over-trim the claws and to maintain strict hygiene of the trimming tools. Claw horn pathology in the early stages is usually treated effectively by therapeutic claw trimming alone. The stoic nature of cattle and their natural tendency to hide pain often result in delayed treatment of claw diseases, leading to more advanced stages of disease/pathology associated with higher-grade lameness. This situation often leads to the development of neuropathic pain and hyperalgesia requiring multimodal treatment. Because claw horn diseases are multifactorial, veterinarians and others involved in animal management must be familiar with the preventive measures available to improve claw health in a cattle herd. Further research to improve claw horn quality and effectively control/prevent claw infections without polluting the environment or negatively affecting worker and animal health is still needed. This article reviews the latest knowledge on functional claw trimming and treatment of the most common claw horn diseases in cattle.

Development of novel intravenous regional anaesthetic technique for desensitization of hoof in cattle

The cattle having hoof diseases were selected in the study and divided into 2 groups having 6 animals in each group. For induction of intravenous regional anesthesia, tourniquet was placed circumferentially at the metacarpus and just below dewclaw in group 1 and 2, respectively. Mixture of lignocaine and ketamine (L+K) (4 mg/kg and 3 mg/kg b. wt.) was injected in the radial vein in group 1 animals. However, in group 2 animals the dose of L+K was halved (2 mg/kg and 1.5 mg/kg b. wt.) and injected in the dorsal common digital vein III. The anesthetic potency was monitored by observing the HR, PR, RR, systolic pressure, diastolic pressure and SPO2. In group 1 the heart rate decreased significantly at 10 min interval. Peripheral oxygen saturation significantly decreased up to 60 min and 40 minutes in group 1 and 2 animals, respectively. Systolic pressure significantly increased at 60 minute interval in group 1 animals. After removal of tourniquet, systolic pressure and diastolic pressure was significantly increased in group 2. Sensory and motor block onset time was less in group 2 as compared to group 1. Sensory and motor block recovery time was long in group 2 as compared to group 1 animals. It was concluded that novel IVRA technique was more safe as compared to standard IVRA for the hoof anesthesia in cattle because low doses of local anesthetic are required in this technique with early sensory and motor block, and prolonged effect.