Serum selenium concentrations in neonatal calves: Influence of postnatal selenium injection and health status.

Background: Selenium supply plays a major role in calf rearing, as a deficiency can lead to health problems, economic loss, and even death. Therefore, postnatal selenium injections are often administered as a preventive measure. Objective: In this study, we examined the serum selenium concentrations of healthy and sick calves within the first days of life. Further, serum concentrations after injection with selenium were determined. Animals and procedure: Serum selenium concentrations from 75 calves were measured until the 10th d of life and the differences between sick and healthy calves were investigated. The variations in selenium concentration were analyzed 3 and 6 d after subcutaneous injection of 5.5 mg sodium selenite in 32 calves.To compare serum concentrations between healthy and sick calves, an independent samples t-test was used. For unequal variances, the Satterthwaite method was used; and for equal variances, the pooled sample variance was used. To analyze the statistical differences between the concentrations at different time points, the data were log-transformed and the Bonferroni correction was used. Results: The mean initial selenium concentration was 46 ± 37 µg/L. There was no statistically significant difference (P = 0.60) between sick (46 ± 34 µg/L) and healthy (46 ± 47 µg/L) calves. Serum selenium concentrations 3 and 6 d after injection of calves over 3 samples were 62 ± 19 µg/L and 50 ± 13 µg/L, respectively. Calves with an initial serum concentration of ≥ 72 µg/L showed a decrease of serum selenium concentration despite the injection. Conclusion and clinical relevance: Newborn calves showed a high variation in selenium concentration that was not influenced by health status. A single injection of 5.5 mg of sodium selenite did increase the selenium concentration in calves with selenium undersupply. After injection, none of the calves showed serum concentrations above the reference range for adult cattle. Therefore, the indication for a selenium injection can be interpreted generously if selenium undersupply is suspected.

Concentrations sériques de sélénium chez les veaux nouveau-nés : influence de l'injection postnatale de sélénium et de l'état de santé. Contexte: L'apport en sélénium joue un rôle majeur dans l'élevage des veaux, car une carence peut entraîner des problèmes de santé, des pertes économiques et même la mort. Par conséquent, des injections postnatales de sélénium sont souvent administrées à titre préventif. Objectif: Dans cette étude, nous avons examiné les concentrations sériques de sélénium de veaux sains et malades au cours des premiers jours de vie. De plus, les concentrations sériques après injection de sélénium ont été déterminées. Animaux et procédure: Les concentrations sériques de sélénium de 75 veaux ont été mesurées jusqu'au 10e jour de vie et les différences entre les veaux malades et sains ont été étudiées. Les variations de concentration en sélénium ont été analysées 3 et 6 jours après l'injection sous-cutanée de 5,5 mg de sélénite de sodium chez 32 veaux.Pour comparer les concentrations sériques entre les veaux sains et malades, un test t sur échantillons indépendants a été utilisé. Pour les variances inégales, la méthode de Satterthwaite a été utilisée; et pour des variances égales, la variance de l'échantillon groupé a été utilisée. Pour analyser les différences statistiques entre les concentrations à différents moments, les données ont été transformées par logarithme et la correction de Bonferroni a été utilisée. Résultats: La concentration initiale moyenne en sélénium était de 46 ± 37 µg/L. Il n'y avait pas de différence statistiquement significative (P = 0,60) entre les veaux malades (46 ± 34 µg/L) et sains (46 ± 47 µg/L). Les concentrations sériques de sélénium 3 et 6 jours après l'injection des veaux sur 3 échantillons étaient respectivement de 62 ± 19 µg/L et de 50 ± 13 µg/L. Les veaux avec une concentration sérique initiale ≥ 72 µg/L ont montré une diminution de la concentration sérique en sélénium malgré l'injection. Conclusion et pertinence clinique: Les veaux nouveau-nés ont montré une forte variation de la concentration en sélénium qui n'était pas influencée par l'état de santé. Une injection unique de 5,5 mg de sélénite de sodium a augmenté la concentration de sélénium chez les veaux présentant un apport insuffisant en sélénium. Après l'injection, aucun veau n'a présenté de concentrations sériques supérieures à la plage de référence pour les bovins adultes. Par conséquent, l'indication d'une injection de sélénium peut être interprétée de manière généreuse si un apport insuffisant en sélénium est suspecté.(Traduit par Dr Serge Messier).

Effect of oral or subcutaneous administration of cyanocobalamin in hypocobalaminemic cats with chronic gastrointestinal disease or exocrine pancreatic insufficiency.

BACKGROUND: No prospective study has evaluated the efficacy of oral supplementation with cobalamin in hypocobalaminemic cats. OBJECTIVES: To investigate the efficacy of oral or SC supplementation with cyanocobalamin in normalizing serum cobalamin and methylmalonic acid (MMA) concentrations in hypocobalaminemic cats with chronic gastrointestinal disease (CGID) or exocrine pancreatic insufficiency (EPI). ANIMALS: Forty-eight client-owned hypocobalaminemic (<290 ng/L) cats with normal or abnormally high serum MMA concentrations. METHODS: This study was conducted based on the prospective randomized clinical trial method. Cats with CGID or EPI were randomly assigned to 2 groups that received either oral or SC supplementation with cobalamin (250 µg/cat) for 12 and 10 weeks, respectively, in addition to other medical and dietary interventions. Each cat was evaluated 3 times (baseline, 6-week postsupplementation, and 1-week postcompletion) by measuring serum cobalamin and MMA concentrations. RESULTS: In cats with CGID or EPI, cobalamin concentrations were normalized in all cats that received either oral or SC supplementation (mean 100% [95% CI: 80.6%-100%] in both groups in cats with CGID and 100% [67.6%-100%] in both groups in cats with EPI). Among 37 cats with elevated MMA concentrations at baseline (21 cats with CGID and 16 cats with EPI), MMA concentrations were normalized in most cats with CGID (70% in oral and 82% in SC group) or EPI (88% in both groups). CONCLUSIONS AND CLINICAL IMPORTANCE: In hypocobalaminemic cats with CGID or EPI, in conjunction with other medical and dietary interventions, both oral and SC supplementation are effective at normalizing serum cobalamin and MMA concentrations.

The effects of breed and routes of administration on the plasma pharmacokinetics and faecal excretion of robenacoxib in goats.

Robenacoxib (RX) is a non-steroidal anti-inflammatory drug (NSAID) of the coxib class. This study aimed to evaluate the plasma dispositions and faecal excretion profiles of RX in Alpine and Saanen goats following oral and subcutaneous routes. Two different goat breeds were allocated into two treatment groups concerning the breed. RX was administered subcutaneously to animals at a dose of 4 mg/kg b.w. Following a one-week washout period, RX was administered by oral route to the same animals at the same dose. Heparinized blood samples were collected from all animals before drug administration (0 h) and subsequently up to 24 h. Faecal samples were collected at various times between 8 h and 36 h. The concentrations of RX in plasma and faeces were determined by HPLC. The plasma half-life (T1/2λz) of RX in Saanen goats (1.21 h) was significantly longer (P < 0.017) than in Alpine goats (0.90 h) after subcutaneous administration. In both goat breeds, statistical differences were observed between subcutaneous and oral administration of RX for T1/2λz, Tlast, Cmax, AUC0-∞, and MRT0-∞. Faecal Cmax and Tmax parameters following oral administrations were 0.92 µg/g and 0.85 µg/g at 30 h and at 24 h in Alpine and Saanen goats, respectively. The difference in plasma protein ratio between Alpine and Saanen goats may have affected the T1/2λz of the drug. NSAIDs are among the drug groups frequently detected in aquatic and terrestrial ecosystems around the world and there are data on the effects of NSAID residues on wildlife and aquatic species. Therefore, revealing the excretion of NSAIDs, which are frequently used in the veterinary field, in faeces and urine should be considered for ecological sustainability.

Use of subcutaneous maropitant at two dosages for pain management in domestic rabbits (Oryctolagus cuniculus) undergoing elective ovariohysterectomy or orchiectomy.

OBJECTIVE: To describe the effect of two doses of maropitant on pain scores, food intake, and fecal output in domestic rabbits (Oryctolagus cuniculus) undergoing elective ovariohysterectomy or orchiectomy. ANIMALS: 26 (11 female, 15 male) rabbits from three institutions. PROCEDURES: Rabbits were randomly assigned to one of three treatment groups: low-dose maropitant (LDM; 2 mg/kg SC once; n=8), moderate-dose maropitant (MDM; 4 mg/kg SC once; n=10), and control (saline equivalent to 4 mg/kg maropitant SC once; n=8), administered prior to surgery. Following surgery, all rabbits were provided buprenorphine (0.06 mg/kg q 8 hours) and meloxicam (1 mg/kg q 24 hours) intramuscularly. Rabbits were monitored using video surveillance postoperatively until 24 hours after surgery or discharge from the hospital, whichever came first. Pain scores were assessed by three blinded observers, and results were grouped into early (0-4 hours), mid (5-8 hours), and late (12-24 hours) time frames. Food intake and fecal output were compared between groups. Statistical analysis was performed using Chi square, Fisher's exact tests, and a mixed model approach. RESULTS: There were no adverse effects with maropitant administration. Rabbits that received MDM had significantly lower pain scores in the mid-time frame and behavior scores in the late-time frame compared to controls. Male rabbits consumed more food than females and rabbits hospitalized longer than 12 hours consumed more food than those that were discharged prior. No significant differences were detected in facial grimace scale scores, food intake, or fecal production among treatment groups. CONCLUSIONS AND CLINICAL RELEVANCE: Moderate dose maropitant decreased pain related behaviors in the mid-time frame and behavior scores in the late-time frame after surgery. Further studies are necessary to better characterize the potential use of maropitant in postoperative analgesia.

The use of injectable subcutaneous terbutaline and topical nitroglycerin ointment in the treatment of peripheral vasopressor extravasation in 3 dogs.

OBJECTIVE: To describe the clinical course and treatment of 3 dogs with peripheral vasopressor extravasation. CASE SERIES SUMMARY: Although vasopressor extravasation (VE) is a well-documented complication in human medicine, literature describing VE and its management in veterinary patients is sparse. VE increases patient morbidity by causing local tissue injury and necrosis. The gold standard treatment for VE, phentolamine, has been periodically limited in supply in human medicine and is not consistently available for use in veterinary medicine. An alternative protocol proposed for use in people with VE combines topical nitroglycerin application with subcutaneous terbutaline infiltration. In this report, a treatment protocol utilizing these therapies was used to treat 3 dogs with VE and secondary tissue injury. NEW OR UNIQUE INFORMATION PROVIDED: This report describes 3 cases of VE-induced tissue injury in dogs. In addition, this report describes the use of perivascular terbutaline infiltration and topical nitroglycerin application as therapeutic management for VE in dogs.

Physiologic and behavioral effects of long-acting subcutaneous and transdermal buprenorphine in rats.

OBJECTIVE: To investigate thermoregulation, thermal antinociception, food/kaolin intake, fecal output, and behavior following long-acting buprenorphine preparations in rats. ANIMALS: 8 adult male rats (Rattus norvegicus) were administered long-acting SC buprenorphine (SB; 0.65 mg/kg), transdermal buprenorphine (TB; 10 mg/kg), and controls in a randomized, cross-over design. METHODS: Body temperature, self-injury, sedation, food/kaolin intake, fecal output, and thermal withdrawal latencies were measured 1, 4, 8, 12, 24, 48, and 72 hours posttreatment. Data analysis was performed with mixed linear models. RESULTS: Self-injury was present between 1 and 12 hours and 4 and 12 hours following TB and SB, respectively; sedation was associated with TB at 12 to 24 hours. Withdrawal latencies were longer in both TB and SB groups than in the control group. Food intake decreased with time in all groups but was significantly lower 24 to 48 hours after TB and 24 to 72 hours after SB versus controls. Kaolin intake decreased from baseline 48 to 72 hours in the control group. Fecal output decreased from baseline 24 to 72 hours in all groups but was significantly lower than controls 24 hours following TB and 24 to 48 hours in SB. Body temperature increased from baseline at 1 hour, 1 to 12 hours, and 1 to 24 hours in the control, TB, and SB groups, respectively, and was significantly higher than the control group 1 to 72 hours following TB and 4 to 24 hours after SB. Transdermal buprenorphine and SB in normal rats produced antinociception, self-injurious behavior, hyperthermia, and decreased food/fecal output. CLINICAL RELEVANCE: Although these buprenorphine preparations may produce antinociception, untoward effects such as hyperthermia, self-injurious behavior, and reduced food intake/fecal output may be seen.

Effects of sodium lactate injection on meat quality and lactate content in broiler chickens: emphasis on injection method and dosage.

This study aims to develop an experimental model of high lactate levels in broilers to mimic the condition of birds under stress or diseases and evaluate its consequent effects on meat quality. The injection sites and dosage effects were compared separately in 2 experiments. Experiment 1 includes 3 injection sites: intraperitoneal injection, intramuscular injection, and subcutaneous injection. Experiment 2 was a dosage experiment based on the results of Experiment 1: sodium lactate intraperitoneal injection group with 1.5, 3, 6 mM concentration. The results showed that injecting sodium lactate intraperitoneally, intramuscularly, or subcutaneously all significantly decreased body weight and breast muscle weight while elevating lactic acid levels in both the blood and breast muscle of broilers. Moreover, all 3 injection methods caused a significant reduction in pH24h and an increase in the shear force value of breast muscle. In addition, dose-response experiments of intraperitoneal injection showed that a concentration of 3 mM and 6 mM were significantly decreased body weight and breast muscle weight in broiler chickens, accompanied by a notable increase in breast muscle lactate content. Compared to the control group, intraperitoneal injections of 1.5 mM, 3 mM, and 6 mM sodium lactate treatments significantly reduced the yellowness values of the breast muscle. As the dose of sodium lactate increased, the shear force value of the breast meat exhibited linear and quadratic increments, while the drip loss decreased linearly. Intraperitoneal injection of 3 mM sodium lactate also significantly reduced the pH24h of broiler breast muscle. In addition, an increased dose of lactate injections up-regulated the glycolytic pathway responsible for endogenous lactate production in the breast muscle by upregulating the expression of phosphofructokinase, pyruvate kinase and lactate dehydrogenase A. In conclusion, intraperitoneal injection of sodium lactate at 3 mM directly increased breast muscle lactate levels, providing a valuable method for establishing a high-level lactate model in poultry.

Subcutaneous amikacin administration in red-eared sliders (Trachemys scripta elegans) produces prolonged detectable plasma concentrations without biochemistry evidence of impaired renal function.

OBJECTIVE: To establish pilot data on the plasma concentrations of SC amikacin at 2 doses in red-eared sliders and evaluate concurrent plasma biochemistry parameters. ANIMALS: 8 adult red-eared sliders (Trachemys scripta elegans). METHODS: Amikacin was administered SC at target doses of 5 and 10 mg/kg with a 3-week washout period. Blood samples were collected at 0, 24, 48, 72, and 96 hours postadministration. Plasma amikacin concentrations were quantified using liquid chromatography tandem mass spectrometry. Plasma biochemistry analyses were performed before amikacin administration, 1 week post 5-mg/kg administration, and 1 week post 10-mg/kg administration. RESULTS: Mean maximum amikacin plasma concentrations were recorded 24 hours after 5-mg/kg and 10-mg/kg dosing and were 17.5 ± 2.32 µg/mL and 23.6 ± 2.92 µg/mL, respectively. Mean plasma concentrations after 5-mg/kg dosing steadily decreased to 9.1 ± 0.92 µg/mL by 96 hours postadministration. Amikacin remained detectable in all plasma samples 3 weeks post 5-mg/kg dosing with a mean plasma concentration of 1.04 ± 0.22 µg/mL. Mean plasma concentrations after 10-mg/kg dosing did not decrease over the 96-hour study period. There were no clinically relevant changes in biochemistry parameters. CLINICAL RELEVANCE: Amikacin persists at detectable plasma levels for at least 3 weeks after SC administration of a 5-mg/kg dose in red-eared sliders, which has not previously been reported in any species. No biochemistry changes consistent with renal toxicity occurred after either dose. Use caution with repeated amikacin dosing in this species until further studies can better characterize cumulative amikacin pharmacokinetics and toxic threshold.

Evaluation of pharmacokinetics of metoclopramide administered via subcutaneous bolus and intravenous constant rate infusion to adult horses.

OBJECTIVE: To determine the pharmacokinetics (PK) of metoclopramide administered via intravenous continuous rate infusion (IV CRI) and subcutaneous (SC) bolus and evaluate for gastrointestinal motility and adverse side effects. STUDY DESIGN: Experimental study; randomized, crossover design. ANIMALS: Six healthy adult horses. METHODS: Each horse received metoclopramide via IV CRI (0.04 mg/kg/h for 24 h) and SC bolus (0.08 mg/kg once), with ≥1 week washout period between. Plasma was analyzed by UPLC-MS/MS. Compartmental modeling was used to determine PK parameters for each treatment; nonparametric superposition was used to simulate multiple SC bolus regimens. Gastrointestinal motility and evidence of adverse effects were monitored. RESULTS: Tmax (h) for SC bolus was 0.583 ± 0.204 versus 17.3 ± 6.41 for IV CRI, while Cmax (ng/mL) was 27.7 ± 6.38 versus 43.6 ± 9.97, respectively. AUC (h × ng/mL) was calculated as 902 ± 189 for 24 h IV CRI versus 244 ± 37.4 simulated for 0.08 mg/kg SC bolus every 8 h. Simulations revealed similar exposure between groups with administration of 0.96 mg/kg/day SC bolus, divided into three, four, or six doses. SC bolus bioavailability was estimated as 110 ± 11.5%. No clear trends in motility alteration were identified. No adverse effects were noted. CONCLUSION: Repeated SC boluses of metoclopramide at 0.08 mg/kg would result in lower total drug exposure and Tmax than IV CRI administration but would be highly bioavailable. CLINICAL SIGNIFICANCE: Higher and/or more frequent SC bolus doses are needed to achieve a similar AUC to IV CRI. No adverse effects were noted; however, evaluation of alternative dosing strategies is warranted.

Comparative pharmacokinetics of intravenous and subcutaneous pantoprazole in sheep and goats.

Abomasal ulcers are a significant concern in intensive animal farming due to their impact on animal health and productivity. While proton pump inhibitors (PPIs) such as pantoprazole (PTZ) show promise in treating these ulcers, data on PTZ's pharmacokinetics (PK) in adult goats and sheep are limited. This study aims to fill this gap by investigating and comparing PTZ's PK in these species following single intravenous (IV) and subcutaneous (SC) administrations. Five healthy male goats and sheep were included in the study. PTZ concentrations in plasma samples were determined using a validated analytical method. Non-compartmental analysis was conducted, and statistical comparisons were made between IV and SC administrations and between species. Sheep and goats showed similar systemic exposure levels regardless of the administration route. However, sheep had a shorter t1/2 due to a higher Vd compared to goats. Cl values were comparable in both species, with low extraction ratio values. There were no significant differences in Cmax and Tmax between the two species with regards to SC administration, and complete bioavailability was observed. The MAT exceeded the t1/2 in both species, indicating a potential flip-flop phenomenon. Considering the AUC as a predictor for drug efficacy, and observing no significant differences in systemic exposure between sheep and goats for any route of administration, dosage adjustment between the two species may not be necessary. In field settings, SC administration proves more practical, providing not only complete bioavailability but also a longer half-life compared to IV. Further studies are warranted to explore the PK/PD of PTZ in small ruminants with abomasal ulcers, to fully comprehend its therapeutic efficacy in such scenarios.

Owners' experiences of administering meglumine antimoniate injections to dogs with leishmaniosis: An online questionnaire study.

BACKGROUND: This study examined the experiences of owners of dogs with leishmaniosis who treated their dogs with daily subcutaneous meglumine antimoniate injections. The owners' perceived ease of administering the injections, the occurrence of problems and the effects on the owners and on the dog‒owner bond were evaluated. METHODS: Dogs prescribed meglumine antimoniate as a treatment for leishmaniosis were identified using the database of the veterinary pharmacy of the Faculty of Veterinary Medicine, Utrecht University. An online questionnaire was sent to the owners of these dogs to evaluate the perceived ease of administering the injections, the occurrence of problems and the effects on the owner and the dog-owner bond. RESULTS: Responses were received from 64 dog owners. Most respondents (78%) reported that administering the injections was not difficult. Pain or the development of nodules at the injection site was reported in 50% and 40% of the dogs, respectively. Polyuria was reported in 44% of the dogs. Some owners reported that administering the injections had a negative impact on their psychological wellbeing (20%), and some would have liked more veterinary support (11%). LIMITATIONS: Some questions were answered by a limited number of people, and their responses may not be representative. CONCLUSION: Dog owners remain highly motivated to persevere with meglumine antimoniate treatment and are willing to administer the injections themselves. The availability of active support when needed during the therapy cycle may further improve their acceptance of and confidence in giving the injections.

A single subcutaneous dose of eprinomectin (Eprecis®) is effective against common gastrointestinal nematodes and lungworms in experimentally infected lactating goats.

BACKGROUND: The health and productivity of dairy goats continue to be impacted by gastrointestinal nematodes (GIN) and lungworms (LW). Eprinomectin (EPN) is frequently selected for treatment because it is generally effective and does not require a milk withdrawal period. However, some factors, such as lactation, can have an impact on EPN pharmacokinetics and potentially its efficacy. To evaluate whether this can alter the efficacy of Eprecis® 2%, an eprinomectin injectable solution, a study was performed in lactating goats using the dose currently registered in cattle, sheep and goats (0.2 mg/kg). METHODS: This study was a blinded, randomized, controlled trial performed according to the VICH guidelines. Eighteen (18) worm-free lactating goats were included and experimentally challenged on day 28 with a mixed culture of infective gastrointestinal and lung nematode larvae (Haemonchus contortus, Trichostrongylus colubriformis, Teladorsagia circumcincta, Dictyocaulus filaria). At D-1, fecal samples were collected to confirm patent infection in all animals. On D0, the goats were randomly allocated into two groups of nine goats; group 1 was treated with Eprecis® 2% at 0.2 mg/kg BW by subcutaneous injection, while group 2 remained untreated. Fecal samples for egg counts were collected from all animals on days 3, 5, 7, 9, 11 and 14. On D14, all goats were killed, and the abomasum, small intestine and lungs were removed, processed and subsampled to record the number and species of worms. RESULTS: The treatment was well tolerated. After treatment, the arithmetic mean FEC decreased in the treated group and remained < 5 EPG until the end of the study, while the arithmetic mean FEC in the control group remained > 849.0 EPG. At D14, goats in the treated group had very limited or zero total worm counts, whereas all animals from the control group had a high worm burden. The measured efficacy was 100.0% against H. contortus and T. colubriformis, 99.9% against T. circumcincta and 98.0% against D. filaria. CONCLUSIONS: Eprinomectin (Eprecis®, 20 mg/ml), administered at the label dose (0.2 mg/kg), is highly effective against gastrointestinal nematodes and lungworms in lactating goats.

Two doses of subcutaneous methadone for postoperative analgesia in dogs undergoing tibial plateau levelling osteotomies.

OBJECTIVES: To evaluate analgesia, sedation and adverse effects of two doses of subcutaneous methadone in dogs undergoing tibial plateau levelling osteotomy. MATERIALS AND METHODS: Seventeen client-owned dogs undergoing unilateral tibial plateau levelling osteotomy were randomly allocated to receive either 0.25 mg/kg methadone (eight dogs) or 0.5 mg/kg methadone (nine dogs). All dogs were premedicated with methadone and 2 to 6 mcg/kg dexmedetomidine subcutaneously. They were induced and maintained on a standard protocol. All animals received a second dose of methadone subcutaneously 4 hours after premedication and a 4.4 mg/kg dose of carprofen subcutaneously at 8 hours after premedication. During surgery, blood pressure, heart rate and temperature were assessed every 5 minutes. Postoperatively, sedation scores, temperature, heart rate and Glasgow composite modified pain score - short form were assessed for 12 hours postoperatively. RESULTS: One of 17 (5.9%) dogs had intraoperative hypotension, nine of 17 dogs had intra-operative bradyarrhythmias and 17 of 17 dogs had intra-operative hypothermia. No dogs required intra-operative rescue. Composite modified pain score - short form scores were below the threshold for intervention in 16 of 17 (94.1%) animals. Only one of 17 (5.9%) dogs required rescue analgesia. Median sedation score was 0 by the T8 time point. Adverse events were rare in both groups with only vocalisation and hypothermia reported commonly postoperatively. CLINICAL SIGNIFICANCE: Two doses of methadone at either 0.25 or 0.5 mg/kg administered via subcutaneous injections pre-operatively and 4 hours later, along with 4.4 mg/kg carprofen subcutaneously 8 hours after the first methadone dose appear to provide sufficient pain control for up to 12 hours in dogs undergoing tibial plateau levelling osteotomy.

Pharmacokinetics of subcutaneous ketamine administration via the Omnipod® system in dogs.

Ketamine is an injectable anesthetic agent with analgesic and antidepressant effects that can prevent maladaptive pain. Ketamine is metabolized by the liver into norketamine, an active metabolite. Prior rodent studies have suggested that norketamine is thought to contribute up to 30% of ketamine's analgesic effect. Ketamine is usually administered as an intravenous (IV) bolus injection or continuous rate infusion (CRI) but can be administered subcutaneously (SC) and intramuscularly (IM). The Omnipod® is a wireless, subcutaneous insulin delivery device that adheres to the skin and delivers insulin as an SC CRI. The Omnipod® was used in dogs for postoperative administration of ketamine as a 1 mg/kg infusion bolus (IB) over 1 hour (h). Pharmacokinetics (PK) showed plasma ketamine concentrations between 42 and 326.1 ng/mL. The median peak plasma concentration was 79.5 (41.9-326.1) ng/mL with a Tmax of 60 (30-75) min. After the same infusion bolus, the corresponding norketamine PK showed plasma drug concentrations between 22.0 and 64.8 ng/mL. The median peak plasma concentration was 43.0 (26.1-71.8) ng/mL with a median Tmax of 75 min. The median peak ketamine plasma concentration exceeded 100 ng/mL in dogs for less than 1 h post infusion. The Omnipod® system successfully delivered subcutaneous ketamine to dogs in the postoperatively.

A randomized placebo-controlled double-blinded study comparing oral and subcutaneous administration of mistletoe extract for the treatment of equine sarcoid disease.

BACKGROUND: Equine sarcoids (ES) are the most common cutaneous tumors in equids. Systemic treatment options are sparse. Subcutaneous (SC) injections of Viscum album extract (VAE) demonstrate efficacy as a systemic treatment directed against ES. OBJECTIVES/AIM: To critically assess the therapeutic efficacy of orally administered VAE. ANIMALS: Forty-five ES-affected, privately owned, 3-12 year-old horses. METHODS: A 3-armed randomized placebo-controlled, double-blinded study was conducted in a double-dummy design. Horses were subjected to oral administration and SC injections of either VAE or placebo (VAE oral/placebo SC, VAE SC/placebo oral, placebo oral/placebo SC) over a 7-month treatment period. Primary endpoint was the change of baseline of a composite index of ES number and ES area after 14 months. Second endpoint was the clinical response. RESULTS: No statistically significant difference in the composite endpoint between the 3 study arms was found. The primary endpoint showed 4 (27%) horses in the VAE oral group with complete ES regression, 3 (21%) in the VAE SC injection group, and 2 (13%) in the placebo group. The clinical response revealed complete or partial regression in 6 horses of the oral VAE group (40%), 4 of the SC injection group (29%), and 4 of the placebo group (25%). Direct comparison of oral VAE and placebo showed an odds ratio, stratified for prognosis of 2.16 (95%-CI: 0.45-10.42) and a P-value of 0.336. CONCLUSION AND CLINICAL IMPORTANCE: Oral administration of VAE is well tolerated. No statistically significant difference in the effectiveness of systemic VAE versus placebo against ES was found.

Comparison of gamithromycin residue depletion in yellow-feather and white-feather broilers after one single subcutaneous injection.

This study aimed to compare the residue depletion of gamithromycin in yellow-feather and white-feather broilers, using Sanhuang and Arbor Acres chickens as typical examples, respectively. Each breed (54 chickens) received a single subcutaneous dose of gamithromycin at 7.5 mg/kg bodyweight (BW). Tissues, including muscle, skin + fat, liver, kidney, and injection site, were collected at 6 h, 3, 5, 7, 10, 14, 21, 28, and 35 d postdrug administration. Gamithromycin concentrations in these tissues were determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The kinetics of gamithromycin were analyzed in different tissues using a noncompartmental method in the Phoenix software. Differences were observed in gamithromycin concentrations and kinetic characteristics in both breeds of chickens, with higher residue concentrations and longer residue times found in yellow-feathered broilers. In Sanhuang broilers, the elimination rates of gamithromycin followed this order: injection site > muscle > liver > kidney > skin + fat. The corresponding elimination half-lives (t1/2λzs) in these samples were 1.22, 1.30, 1.71, 2.04, and 2.52 d, respectively. In contrast, in Arbor Acres broilers, a different order was noted: muscle > injection site > kidney > liver > skin + fat, with corresponding t1/2λzs of 1, 1.23, 1.88, 1.93, and 2.21 d, respectively. These differences may be related to variations in pigments in various tissues of chickens of the 2 breeds. However, further investigations are warranted to discern the underlying reasons.

Subcutaneous administration of ceftazidime at 20 and 40 mg/kg produces theoretically therapeutic plasma concentrations for at least 120 hours in red-eared sliders (Trachemys scripta elegans).

OBJECTIVE: To evaluate and compare the pharmacokinetic parameters of SC ceftazidime administered at 20 and 40 mg/kg to red-eared sliders. ANIMALS: 8 adult red-eared sliders (Trachemys scripta elegans). METHODS: In a sequential, 2-period study with a 3-week washout period between treatments, ceftazidime was administered SC to turtles at 20 and 40 mg/kg. Blood samples were collected from the subcarapacial sinus at 0, 24, 48, 72, 96, and 120 hours after ceftazidime administration. Plasma ceftazidime concentrations were quantified using reversed-phase HPLC. RESULTS: Mean plasma half-life after 20- and 40-mg/kg dosing was 39.75 ± 8.0 hours and 33.03 ± 6.56 hours, respectively. Mean maximum plasma concentration after 20- and 40-mg/kg dosing was 71.0 ± 15.93 µg/mL and 120.0 ± 30.62 µg/mL, respectively. Mean plasma ceftazidime concentrations remained ≥ 8 µg/mL, the theoretical MIC for various reptile pathogens for all time points. CLINICAL RELEVANCE: Results indicate that ceftazidime dosed at either 20 or 40 mg/kg produces plasma concentrations exceeding the theoretical MIC of various reptile pathogens for at least 120 hours. An ideal dosing interval could not be determined, as all plasma concentrations remained above the threshold of interest for all time points. Follow-up studies should focus on establishing a dosing interval and more rigorous monitoring for potential adverse effects.

Plasma pharmacokinetics of clorsulon following administration of a single subcutaneous or intravenous injection to cattle.

The benzenedisulfonamide derivative clorsulon is a potent fasciolicide which is marketed in fixed combination injectables, typically combined with the macrocyclic lactone ivermectin. In the presented pharmacokinetic study, the plasma profile of clorsulon in 32 healthy, young Brown Swiss cattle was administered a single intravenous dose at 3 mg/kg body weight or subcutaneously at 3, 6 or 12 mg/kg body weight (4 intact male and 4 female animals per treatment) as a 30% w/v clorsulon injection formulation. Serial blood samples were collected up to 24 days after administration to establish the pharmacokinetics, bioavailability and dose proportionality of clorsulon. Following a single intravenous injection of clorsulon at 3 mg/kg body weight, the area under the concentration versus time curve from the start of dose administration to the time of the last quantifiable concentration (AUClast ) was 4830 ± 941 day*ng/mL, and half-live was 2.37 ± 0.98 days. The back extrapolated concentration at time 0 was 38,500 ± 6070 ng/mL. The volume of distribution at steady state and clearance were 685 ± 107 mL/kg and 664 ± 127 mL/day/kg, respectively. In the groups dosed at 3, 6 or 12 mg/kg body weight by subcutaneous injection, clorsulon plasma concentrations rose to maximum within 0.5 day and decreased to the last sample point. For these groups, the maximum plasma clorsulon concentrations were 3100 ± 838, 5250 ± 1220 and 10,800 ± 1730 ng/mL, respectively, and the AUClast was 5330 ± 925, 9630 ± 1300 and 21,500 ± 3320 day*ng/mL, respectively. Half-lives, 2.01 ± 0.62, 3.84 ± 1.42 and 5.36 ± 0.60 days, respectively, increased significantly with dose, likely related to increasing dose volume. Clorsulon was well absorbed and fully bioavailable (103%-114%) after subcutaneous injection. No gender-related difference in systemic exposure was observed. Assessment of Cmax and AUClast demonstrated a proportional increase in systemic exposure to the clorsulon subcutaneous doses over the range of 3-12 mg/kg body weight.