Assessment and management of pain in small ruminants and camelids

Pharmacokinetics of robenacoxib following single intravenous, subcutaneous and oral administrations in Baladi goats (Capra hircus)

The purpose of this study was to assess the pharmacokinetics of robenacoxib (RX), a COX-2 selective non-steroidal anti-inflammatory drug, in goats after single intravenous (IV), subcutaneous (SC) and oral (PO) administrations. 5-month-old healthy female goats (n = 8) were used. The animals were subjected to a three-phase, two-dose (2 mg/kg IV, 4 mg/kg SC, PO) unblinded, parallel study design, with a four-month washout period between the IV and SC treatment, and a one-week period between the SC and PO treatment. Blood was drawn from the jugular vein in heparinized vacutainer tubes at 0, 0.085 (for IV only), 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10 and 24 h. Plasma RX concentrations were measured using HPLC coupled to a UV multiple wavelength detector, and the data were pharmacokinetically analysed using ThothPro™ 4.3 software in a non-compartmental approach. Following IV administration, terminal elimination half-life, volume of distribution and total clearance were 0.32 h, 0.24 L/kg and 0.52 L/h/kg, respectively. For SC and PO, the mean peak plasma concentrations were 2.34 and 3.34 μg/mL at 1.50 and 0.50 h, respectively. The t1/2λz was significantly different between the IV and the extravascular (EV) administrations (0.32 h IV vs 1.37 h SC and 1.63 h PO), suggesting the occurrence of a flip-flop phenomenon. The significant difference in Vd values between IV (0.24 L/kg) and EV (0.95 L/kg SC and 1.71 L/kg; corrected for F %) routes might have also triggered the t1/2λz difference. The absolute average SC and PO bioavailability were high (98% and 91%, respectively). In conclusion, the IV administration of RX might not be suitable for goats, due to its short t1/2λz. The EV routes, however, appear to be convenient for the drug's occasional use.

Epidural lidocaine, butorphanol, and butorphanol - lidocaine combination in dromedary camels

BACKGROUND

The use of general anesthesia in dromedary camels is constrained by risks related to decubitus. Caudal epidural analgesia is an alternative convenient technique providing loco-regional analgesia for numerous invasive and noninvasive painful conditions. Lidocaine is probably the most commonly used local anesthetic in clinical practice, but has a relatively short duration and may not provide significant long term analgesic benefits. Epidural administration of an opioid-local anesthetic mixture would improve the quality and length of analgesia and minimizes the adverse motor effects provoked by local anesthetics. Butorphanol (potent agonist-antagonist opioid) has been used to improve the duration of epidural analgesia in some animal species, but not in camels. Therefore, our purpose was to investigate the onset and duration of analgesia as well as the clinical and hemato-biochemical effects produced by the epidural administration of butorphanol (0.04 mg/kg), lidocaine (0.22 mg/ kg), and butorphanol-lidocaine (0.04 mg/kg-0.22 mg/ kg) mixture in nine adult dromedary camels in a crossover experimental study.

RESULTS

The onset of analgesia was not statistically different between lidocaine (6.5 ± 2.3 min) and butorphanol-lidocaine (7.3 ± 1.5 min) combination. Delayed onset of analgesia was reported after butorphanol administration (14.7 ± 3.5 min). Butorphanol-lidocaine combination produced marked longer duration (175 ± 8.7 min) than lidocaine (55 ± 6.8 min) and butorphanol (158 ± 5.3 min). Mild ataxia was observed in the butorphanol-lidocaine and lidocaine treated animals and slight sedation was reported after butorphanol and butorphanol-lidocaine administration. A transient significant increase in the glucose levels was recorded after all treatments.

CONCLUSIONS

Epidural administration of butorphanol augments the analgesic effects and duration of lidocaine with minimal adverse effects.

The pharmacokinetics of transdermal flunixin in lactating dairy goats

Flunixin is a nonsteroidal anti-inflammatory drug approved for use in cattle to manage pyrexia associated with bovine respiratory disease, mastitis, and endotoxemia. In the United States, no nonsteroidal anti-inflammatory drugs are approved for use in goats, but analgesics are needed for management of painful conditions to improve animal welfare. The objective of this study was to evaluate the pharmacokinetics of transdermal flunixin in dairy goats to determine a milk withdrawal interval (WDI) to avoid violative residue contamination in the food supply. Six adult lactating dairy goats received 3.3 mg/kg of transdermal flunixin before milk, interstitial fluid (ISF), and blood samples were collected at various time points for 360 h. The samples were analyzed using tandem mass spectrometry to detect flunixin as well as the flunixin marker metabolite, 5-hydroxyflunixin followed by a pharmacokinetic WDI calculation using the US Food and Drug Administration tolerance limit method to propose safe residue levels in goat milk. The mean flunixin apparent plasma half-life was 21.63 h. The apparent milk half-life for 5-hydroxyflunixin was 17.52 h. Our findings provide a milk WDI of 60 h using the US Food and Drug Administration tolerance of 0.002 µg/mL (established for bovine milk) and a more conservative WDI of 96 h using a limit of quantification of 0.001 µg/mL following the extralabel use of transdermal flunixin in dairy goats.

Pain Management in Small Ruminants and Camelids: Analgesic Agents

Small ruminants are increasing in popularity as both production and companion animals in the United States. Among sheep, goats, and camelids, there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. This review focuses on the commonly used medications available for pain management of small ruminants and discusses the benefits and negative aspects of their use.

Pain Management in Small Ruminants and Camelids: Applications and Strategies

Small ruminants are increasing in popularity as production and companion animals in the United States, and among sheep, goats, and camelids there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. In this second portion of the review, we focus on the application of pain management in these species. These strategies include mono- and multimodal and the use of precision pain management, such as epidural drug administration, regional perfusions, and transdermal applications.

Pharmacokinetic Parameters and Estimated Milk Withdrawal Intervals for Domestic Goats (Capra Aegagrus Hircus) After Administration of Single and Multiple Intravenous and Subcutaneous Doses of Flunixin Meglumine

Introduction: The study objectives were to estimate plasma flunixin (FLU) pharmacokinetic parameters and milk depletion profiles for FLU and its metabolite (5-hydroxy flunixin; 5-OH) after subcutaneous (SC) and intravenous (IV) administration of single and multiple flunixin meglumine (FM) doses to non-lactating (nulliparous and pregnant does) and lactating dairy goats. Analytical methods (ELISA and UPLC-MS/MS) for quantifying plasma FLU concentrations were compared. The final objective was to use regulatory (FDA and EMA) methods to estimate milk withdrawal intervals following extra-label drug use in goats.

Methods: FM was administered IV and SC to commercial dairy goats at 1.1 mg/kg for single and multiple doses. Plasma and milk samples were analyzed for FLU and 5-OH via UPLC-MS/MS. Plasma samples were also analyzed for FLU concentrations via ELISA. Using statistical approaches recommended by regulatory agencies, milk withdrawal intervals were estimated following FM extra-label use.

Results: Following IV administration of a single FM dose, clearances were 127, 199, and 365 ml/kg/h for non-lactating (NL) pregnant does, NL nulliparous does, and lactating dairy does, respectively. Following multiple SC doses, clearance/F was 199 ml/kg/h for lactating does. After IV administration of a single FM dose, terminal elimination half-lives were 4.08, 2.87, and 3.77 h for NL pregnant does, NL nulliparous does, and lactating dairy does, respectively. After multiple SC doses, the terminal elimination half-life was 3.03 h for lactating dairy does. No significant differences were noted for samples analyzed by UPLC-MS/MS or ELISA. Milk withdrawal intervals ranged from 36 to 60 h depending on the regulatory statistical method and dosage regimen.

Conclusions: Subcutaneous administration of FM to goats results in similar plasma pharmacokinetic parameters as IV administration. ELISA analysis is an alternative method to UPLC-MS/MS for quantifying FLU concentrations in caprine plasma samples. Following FM extra-label administration to dairy goats, clinicians could consider 36–60 h milk withdrawal intervals.

Analgesic efficacy of an intravenous constant rate infusion of a morphine-lidocaine-ketamine combination in Holstein calves undergoing umbilical herniorrhaphy

OBJECTIVE

To assess the analgesic efficacy of an IV constant rate infusion (CRI) of a morphine-lidocaine-ketamine (MLK) combination in calves undergoing umbilical herniorrhaphy.

ANIMALS

20 weaned Holstein calves with umbilical hernias.

PROCEDURES

Calves were randomly assigned to receive a CRI of an MLK solution (0.11 mL/kg/h; morphine, 4.8 μg/kg/h; lidocaine, 2.1 mg/kg/h; and ketamine, 0.42 mg/kg/h) for 24 hours (MLK group) or 2 doses of flunixin meglumine (1.1 mg/kg, IV, q 24 h) and a CRI of saline (0.9% NaCl) solution (0.11 mL/kg/h) for 24 hours (control group). The assigned CRI was begun after anesthesia induction. A pain-scoring system and incisional algometry were used to assess pain, and blood samples were obtained to measure serum cortisol concentration at predetermined times for 120 hours after CRI initiation.

RESULTS

Mean pain scores did not differ significantly between the MLK and control groups at any time. Mean algometry score for the MLK group was significantly greater (calves were less responsive to pressure) than that for the control group at 4 hours after CRI initiation. Mean cortisol concentration decreased over time for both groups and was significantly greater for the MLK group than the control group at 1, 4, and 18 hours after CRI initiation.

CONCLUSIONS AND CLINICAL RELEVANCE

A CRI of MLK provided adequate postoperative analgesia to calves that underwent umbilical herniorrhaphy. However, the technical support required for CRI administration limits its use to hospital settings. Kinetic analyses of MLK infusions in cattle are necessary to establish optimal dosing protocols and withdrawal intervals.

Ultrasound-guided psoas compartment and sciatic nerve blocks for pain management of hind limb procedures in the alpaca (Vicugna pacos)

Background:

Loco-regional anesthetic techniques are considered important in the multimodal approach to analgesia in both human and veterinary medicine. No such techniques are described in the alpaca, bar the use of epidural. This is in part due to the lack of anatomical description for this species. While this limitation exists, the use of ultrasound guidance makes peripheral nerve blocks a viable possibility in the alpaca.

Case description:

A 12-month-old alpaca was referred for the treatment of a septic left tarso-crural joint. Due to a poor prognosis, amputation of the limb under general anesthesia was performed. Sciatic and psoas compartment blocks were attempted with the ultrasound-guided injection of ropivacaine prior to the start of the procedure. While the femoral nerve was possible to visualize, no obturator nerve was identified. A 5-year old alpaca was also referred for a left hind lateral claw removal, due to a squamous cell carcinoma. The sciatic nerve block was performed prior to the claw amputation under general anesthesia. No changes in heart and respiratory rate, or blood pressure suggestive of nociception, were observed in either of these cases. At the end of both the procedures, the patients experienced uneventful recoveries characterized by the ability to maintain the standing position, interest in food, and normal behavior.

Conclusion:

This report identifies the ease of performance and the challenges encountered using the ultrasound-guided psoas compartment and sciatic nerve blocks in the alpaca. It is our hope that this report encourages the use of ultrasound-guided loco-regional techniques in this species.

Use and Efficacy of Analgesic Agents in Sheep (Ovis aries) Used in Biomedical Research

Sheep (Ovis aries) are widely used as large animal models in biomedical research. However, current literature on the use of analgesics in sheep generally focuses on an industry or farm level of use. This structured review evaluates use and efficacy of analgesics administered to sheep in a biomedical research setting. Electronic databases were searched with terms related to analgesia in research sheep. After application of exclusion criteria, 29 peer-reviewed publications were evaluated from 1995 to 2018. Drugs used for analgesia in sheep include opioids, α₂ agonists, NSAID, local anesthetics, NMDA receptor antagonists, and calcium channel blockers. Opioid agonists have previously been considered short acting and of questionable efficacy in sheep, but newer modalities may provide effective analgesia. NSAID may exhibit an analgesic effect only when inflammatory pain is present and may not be beneficial for use in acute pain models. α₂ agonists provide effective yet short-lived analgesia; however, side effects are of concern. Local anesthetics were previously widely used as stand-alone agents, as alternatives to the use of general anesthetics in sheep. These agents have since fallen out of favor as sole agents. Despite this, they provide a valuable analgesic effect when used as adjuncts to general anesthetic regimes. The NMDA antagonist ketamine provided good analgesia and is likely underutilized as an analgesic agent in sheep. Future controlled studies should further evaluate the analgesic properties of ketamine in sheep.

Pharmacokinetics and bioavailability of oral firocoxib in adult, mixed-breed goats

Pharmacokinetic (PK) studies of oral firocoxib in large animal species have been limited to horses, preruminating calves, and adult camels. The aim of this study was to describe pharmacokinetics and bioavailability of firocoxib in adult goats. Ten healthy adult goats were administered 0.5 mg/kg firocoxib intravenously (i.v.) and per os (p.o.) in a randomized, crossover study. Plasma firocoxib concentrations were measured over a 96-hr period for each treatment using HPLC and mass spectrometry, and PK analysis was performed. The p.o. formulation reached mean peak plasma concentration of 139 ng/ml (range: 87-196 ng/ml) in 0.77 hr (0.25-2.00 hr), and half-life was 21.51 hr (10.21-48.32 hr). Mean bioavailability was 71% (51%-82%), indicative of adequate gastrointestinal absorption of firocoxib. There were no negative effects observed in any animal, and all blood work values remained within or very near reference range at the study's conclusion. Results indicate that oral firocoxib is well-absorbed and rapidly reaches peak plasma concentrations, although the concentration also decreased quickly prior to the terminal phase. The prolonged half-life may suggest tissue accumulation and higher plasma concentrations over time, depending on dosing schedule. Further studies to determine tissue residue depletion, pharmacodynamics, and therapeutic concentrations of firocoxib in goats are necessary.

Avaliação de anti-inflamatórios não esteroidais no tratamento da dor de ovinos submetidos à implantação de cânula ruminal e orquiectomia

RESUMO O presente trabalho objetivou comparar o efeito do flunixin meglumine, cetoprofeno e meloxicam no tratamento da dor pós-operatória de ovinos submetidos à implantação de cânula ruminal e orquiectomia. Foram utilizados 32 ovinos, machos, pesando em média 35,5±3,5kg, distribuídos em três grupos: GFlu (flunixin meglumine 1,1mg/kg i.v.), GCet (cetoprofeno 3,0mg/kg i.v.) e GMel (meloxicam 0,5mg/kg i.v.). Exame clínico e coletas de sangue foram realizados no M0 (pré-avaliação), M1 (10 minutos após a pré-avaliação), M2 (início da sutura para fixação da cânula ruminal), M3 (logo após o término da cirurgia) e em duas, 12, 23, 25, 48 e 72 horas após a cirurgia (M2h, M12h, M23h, M25h, M48h e M72h), quando foram avaliados cortisol, glicose, proteína total, albumina, γ-glutamiltransferase (GGT), aspartato aminotransferase (AST), creatina quinase (CK), ureia, creatinina e hemograma. Nos M2h, M12h, M23h, M25h e M48h, foi realizada avaliação comportamental. O GFlu apresentou maior concentração de cortisol no M12h e no M48h e maior escore de dor na fístula e no testículo no M12h, quando comparado ao GMel. Os animais do GCet apresentaram menor interação com outros membros da baia no M23h. A ação analgésica do meloxicam foi maior em animais submetidos à implantação de cânula ruminal e orquiectomia, quando comparado ao flunixin meglumine e ao cetoprofeno.

Osteossíntese de fêmur e tíbia em veado-catingueiro (Mazama gouazoubira): relato de caso

RESUMO O presente estudo relata o caso de um veado-catingueiro jovem, provindo de vida livre e com histórico de atropelamento. Posteriormente à realização de exames, o animal foi diagnosticado com fratura exposta distal de tíbia (Salter-Harris tipo I) e fratura cominutiva de metáfise distal de fêmur, ambas em membro pélvico esquerdo. Para a osteossíntese da tíbia, foram utilizados pinos intramedulares de Steinmann inseridos pelos maléolos lateral e medial, de forma cruzada. A osteossíntese do fêmur foi realizada com associação de dois pinos de Steinmann, conforme técnica modificada de Rush, e placa de compressão dinâmica. As técnicas cirúrgicas adotadas foram satisfatórias para estabilização, consolidação de ambas as fraturas e retorno funcional do membro. Após 90 dias da cirurgia, o animal foi reintroduzido à natureza.

Frakturen von Gliedmaßenknochen bei 32 kleinen Wiederkäuern – Methoden und Ergebnisse der Behandlung

Gegenstand: Retrospektive Auswertung der Daten 32 kleiner Wiederkäuer, die zwischen 2001 und 2014 wegen Gliedmaßenfrakturen behandelt wurden. Material und Methode: Die Daten wurden bezüglich Spezies, Rasse und Alter der Tiere, Alter, Lokalisation und Typ der Fraktur sowie Art (konservativ: mittels PVC-Halbrohren oder Cast; chirurgisch: diverse Osteosynthesetechniken oder Amputation der Gliedmaße) und Erfolgsquote der Behandlung analysiert. Ergebnisse: Die 16 Ziegen und 16 Schafe (18 männlich, 14 weiblich) hatten ein mittleres Alter von 1,5 Jahren und ein mittleres Körpergewicht von 37,8 kg. Die Fraktur war bei 23 Tieren (71,8 %) 1–6 Tage alt, bei fünf Tieren (15,6 %) 12–60 Tage und in vier Fällen (12,5 %) fehlte eine Angabe. Von den 35 Frakturen (Mehrfachfrakturen bei drei Tieren) befanden sich 20 (57,1 %) an der Hinter- und 15 (42,9 %) an der Vorderextremität. Am häufigsten war das Os femoris (28,6 %) frakturiert, gefolgt von Radius und Ulna (22,8 %), Metatarsal- (20,0 %) und Metakarpalknochen (14,3 %). Bei 17 Tieren (63,0 %) erfolgte eine konservative und bei 10 Tieren sowie einem zunächst erfolglos konservativ behandelten Schaf (n = 11, 40,7 %) eine chirurgische Therapie. Fünf Patienten wurden aufgrund weiterer Erkrankungen und schlechter Prognose nicht behandelt. Eine Abheilung ließ sich bei 94,1 % der konservativ behandelten und 81,9 % der chirurgisch therapierten Frakturen erzielen. Bei sechs Tieren (22,2 %) traten bei bzw. nach der Behandlung Komplikationen auf. In vier Fällen kam es zur Abheilung, zwei Tiere wurden letztlich euthanasiert. Einflüsse von Alter bzw. Körpergewicht der Tiere und Alter der Fraktur auf den Therapieerfolg waren nicht nachweisbar. Schlussfolgerung und klinische Relevanz: Die Erfolgsquote von 92,6 % (n = 25) bei konservativer und chirurgischer Versorgung führt zur klaren Empfehlung, vor allem konservative Frakturbehandlungen bei Schafen und Ziegen auch in der Praxis vorzunehmen. Hierfür eignen sich insbesondere Frakturen von Röhrbeinen und Phalangen, die sich oft bereits durch sorgfältige und behutsame Palpation gut diagnostizieren lassen. Dagegen stellt bei Frakturen proximaler Knochen die chirurgische Behandlung die erste Wahl dar.

Thoracolumbar epidural anaesthesia with 0.5% bupivacaine with or without methadone in goats

Background

Epidural anaesthesia is one of the most commonly used locoregional techniques in ruminants. The lumbosacral epidural technique is reasonably easy to perform and requires low volumes of local anaesthetic drug to allow procedures caudal to the umbilicus. However, surgical procedures in the flank of the animal would require an increased volume of drugs. The anaesthetized area provided by thoracic epidural technique is larger than the lumbosacral technique; however the former is rather challenging to perform. Therefore, access through lumbosacral area to introduce a catheter into the thoracolumbar space is a potential alternative to thoracic access. Epidural anaesthesia is achieved with local anaesthetics; opioids can be added to improve analgesia. This study aimed to evaluate the effects of 0.5% bupivacaine with or without methadone, administered through an epidural catheter inserted through the lumbosacral access and advanced to the thoracolumbar space, on thoracolumbar epidural anaesthesia in goats.

Methods

Six animals received two treatments each in a randomized crossover study: BUP treatment consisted of 0.5% bupivacaine (1 mL per each 10 cm of spine column; 1 ± 0.2 mg/kg BW) and BMT treatment was the same; however 1 mL of bupivacaine was replaced by 1 mL (0.22 ± 0.03 mg/kg BW) of methadone (10 mg/mL). The treatments were administered near to T11-T12 through an epidural catheter. Motor blockade and analgesia were evaluated by electrical stimulation.

Results

Heart rate, respiratory rate, ruminal motility and rectal temperature were evaluated before and after the treatment. Motor blockade was observed on both treatments, up to 6 h post-treatment. Analgesia was observed on BUP up to 4 h and on BMT up to 6 h post-treatment. Physiological values did not change at any moment.

Conclusions

Bupivacaine-methadone combination promoted longer-lasting analgesia in goats compared to bupivacaine alone when administered through an epidural catheter into the thoracolumbar space.

Electronic supplementary material

The online version of this article (doi:10.1186/s13620-017-0093-x) contains supplementary material, which is available to authorized users.

Local, Regional, and Spinal Anesthesia in Ruminants

Local, regional, and spinal anesthesias are safe, effective, often more desirable procedures for ruminants than general anesthesia. Many procedures can be performed safely and humanely in ruminants using a combination of physical restraint, mild sedation, and local, regional, or spinal anesthesia. This article focuses on the use of local anesthetics for providing anesthesia for dehorning, procedures of the nose and eye, laparotomy, reproductive procedures, teat repair, and procedures on the distal limb. Local, regional, and spinal anesthesia techniques are safe effective methods for providing anesthesia for common surgical procedures and analgesia for painful conditions in cattle and small ruminants.

The Challenges to Improve Farm Animal Welfare in the United Kingdom by Reducing Disease Incidence with Greater Veterinary Involvement on Farm

Simple Summary

Sick cattle and sheep are often treated by farmers without prior veterinary examination and, as a consequence, incorrect diagnoses and inappropriate therapies are common, but these failings largely go undetected and unreported. Many farmers maintain that market forces render veterinary care of individual sick sheep and cattle too expensive. Delays in requesting veterinary attention are not uncommon causing unnecessary animal suffering and a poorer outcome. Incidence rates of endemic diseases in the United Kingdom are too high, causing animal welfare concerns, but these could be reduced by the implementation of proven veterinary flock/herd health programmes.

Abstract

The Cattle Health and Welfare Group of Great Britain report (CHAWG; 2012) lists the most important cattle diseases and disorders but fails to fully acknowledge the importance of animal mental health and; in so doing; misses the opportunity to further promote animal welfare. There are effective prevention regimens; including vaccination; husbandry and management strategies for all ten listed animal health concerns in the CHAWG report; however control measures are infrequently implemented because of perceived costs and unwillingness of many farmers to commit adequate time and resources to basic farm management tasks such as biosecurity; and biocontainment. Reducing disease prevalence rates by active veterinary herd and flock health planning; and veterinary care of many individual animal problems presently “treated” by farmers; would greatly improve animal welfare. Published studies have highlighted that treatments for lame sheep are not implemented early enough with many farmers delaying treatment for weeks; and sometimes even months; which adversely affects prognosis. Disease and welfare concerns as a consequence of sheep ectoparasites could be greatly reduced if farmers applied proven control strategies detailed in either veterinary flock health plans or advice available from expert veterinary websites. Recent studies have concluded that there is also an urgent need for veterinarians to better manage pain in livestock. Where proven treatments are available; such as blockage of pain arising from ovine obstetrical problems by combined low extradural injection of lignocaine and xylazine; these are seldom requested by farmers because the technique is a veterinary procedure and incurs a professional fee which highlights many farmers’ focus on economics rather than individual animal welfare.