Wayne S. Schwark's research while affiliated with Cornell University and other places

Publications (18)

Article
Full-text available
Hemp based cannabinoids have gained popularity in veterinary medicine due to the potential to treat pain, seizure disorders and dermatological maladies in dogs. Cat owners are also using hemp-based products for arthritis, anxiety and neoplastic disorders with no studies assessing hemp cannabinoids, namely cannabidiol efficacy, for such disorders. I...
Article
The use of cannabinoids in veterinary medicine has been increasing exponentially recently and there is little information regarding the pharmacokinetics of cannabinoids except for cannabidiol (CBD) and tetrahydrocannabinol (THC), with even more sparse information related to their native acid forms found in cannabis. Cannabigerol (CBG) is the precur...
Article
Full-text available
The aim of this study was to compare the pharmacokinetics of a cannabidiol (CBD) and cannabidiolic acid-rich (CBDA) hemp extract in a sesame oil base and a soft gel capsule formulation. During acute twenty-four hour pharmacokinetic evaluation, maximum serum concentration (Cmax) was higher for all measurable components in the serum (CBD, CBDA, Δ-9-t...
Article
Due to their reduced frequency of dosing and ease of availability, NSAIDs are generally preferred over opioids for rodent analgesia. We evaluated the efficacy of the highly COX2-selective NSAID firocoxib as compared with meloxicam and buprenorphine for reducing allodynia and hyperalgesia in rats in a plantar incision model of surgical pain. After a...
Article
Full-text available
Cannabidiol (CBD)-rich hemp extract use is increasing in veterinary medicine with little examination of serum cannabinoids. Many products contain small amounts of Δ9-tetrahydrocannabinol (THC), and precursor carboxylic acid forms of CBD and THC known as cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA). Examination of the pharmacokin...
Article
Full-text available
The use of CBD-rich hemp products is becoming popular among pet owners with no long-term safety data related to consumption in adult dogs and cats. The purpose of this study was to determine the single-dose oral pharmacokinetics of CBD, and to provide a preliminary assessment of safety and adverse effects during 12-week administration using a hemp-...
Article
Chronic energy insufficiency resulting from inadequate feed intake or increased nutrient demand reduces plasma leptin in ruminants. Treatment of energy deficient ruminants with exogenous leptin has identified some physiological consequences of reduced plasma leptin, but their full complement remains unknown. Additional leptin-dependent responses co...
Article
Full-text available
Objectives: The objectives of this study were to determine basic oral pharmacokinetics, and assess safety and analgesic efficacy of a cannabidiol (CBD) based oil in dogs with osteoarthritis (OA). Methods: Single-dose pharmacokinetics was performed using two different doses of CBD enriched (2 and 8 mg/kg) oil. Thereafter, a randomized placebo-contro...
Article
Full-text available
Objective: To describe the pharmacokinetic parameters of oral pregabalin in normal cats after single oral dosing. Animals: Six healthy adult research cats. Procedures: Following sedation and indwelling catheter placement, one oral (4 mg/kg) dose of pregabalin was administered. Blood samples were collected at 0, 15 and 30 min and 1, 1.5, 2, 3, 4, 6,...
Article
To determine the effect of regional limb perfusion (RLP) with amikacin sulfate alone and in combination with ticarcillin/clavulanate on synovial fluid concentration and antimicrobial activity of amikacin. Experimental study. RLP with amikacin alone (A; 2.5 g) or amikacin and ticarcillin/clavulanate (AT; 2.5 g amikacin, 7 g ticarcillin/clavulanate)...
Article
Objective: To determine the pharmacokinetics and hemodynamic effects of trazodone after IV and oral administration in dogs and bioavailability after oral administration. Animals: 6 adult Beagles. Procedures: Dogs received trazodone HCl (8 mg/kg) orally and IV in a randomized controlled crossover design. Blood samples were collected at various...
Article
Objective: To assess pharmacokinetics of pregabalin in horses after a single intragastric or IV dose. Animals: 5 healthy adult mares. Procedures: Horses received 1 dose of pregabalin (approx 4 mg/kg) via nasogastric tube in a crossover-design study; after a 3-week washout period, the same dose was administered IV. Food was not withheld. Plasma...
Article
To determine the frequency of spontaneous canine herpesvirus-1 (CHV-1) reactivation and ocular viral shedding in latently infected dogs and the effect of topical ocular administration of cyclosporine. 8 mature Beagles with experimentally induced latent CHV-1 infection. Following induction of primary ocular CHV-1 infection, the presence of reactivat...
Article
Reasons for performing study: To date, no information is available on the true biological elimination half-life (T1/2) of cardiac troponin I (cTnI) in the equine species. Such data are required to better evaluate the optimal time to acquire the cTnI sample following acute myocardial injury. Objective: To determine the T1/2 of equine cTnI. Methods:...
Article
To describe the pharmacokinetics of pregabalin in normal dogs after a single oral dose. Prospective experiment. Six adult Labrador/Greyhound dogs (four females and two males) aged 2.6 (2.6-5.6) years old (median and range) weighing 33.4 (26.8-42.1) kg. After jugular vein catheterization, the dogs received a single oral dose of pregabalin ( approxim...
Article
Single-dose pharmacokinetics and genotoxicity of metronidazole in cats were evaluated. Cats received either 5mg/kg metronidazole intravenously, or 20mg/kg metronidazole benzoate (12.4mg/kg metronidazole base) orally in a single dose. Serial plasma samples were collected and assayed for metronidazole using high pressure liquid chromatography (HPLC)....
Article
Information on antibiotic concentrations in the equine eye following systemic therapy is limited. Reports that Leptospira spp. are frequently present in the eyes of horses with recurrent uveitis, emphasises a need for studies on ocular concentrations of specific antibiotics. 1) Enrofloxacin, administered i.v. at 7.5 mg/kg bwt q. 24 h, results in aq...

Citations

... Further investigations at 2mg/kg dosing of a 50:50 mixture of CBD and CBDA showed superior absorption of a soft chew formulation compared to an oil base, and that administration with food may increase absorption of the active molecules 1,7 . Previous published studies of a similar blend of CBD/CBDA have proven safety and have shown pharmacokinetics of this specific blend as well as other blends of cannabinoids 1,2,6,8,9,10 . ...
... Treatments were divided evenly between the two daily concentrate meals, top-dressed and thoroughly mixed immediately prior to feeding. Levels of CBD supplementation were determined based on the previous literature in horses [15] and other species, using up to 1.5 mg CBD/kg BW [5,7,16,17] to avoid negative implications on liver health. An oil-based formulation was chosen due to ease of administration and higher bioavailability when compared to solid-based formulations [5,[18][19][20]. ...
... The increase in serum ALP levels were seen in dogs at 2 mg CBD/kg BW and at 2.5 mg CBD/kg BW [5,6]. Increases in ALT serum levels were reported in mice at 615 mg CBD/kg BW and in cats at 2 mg CBD/kg BW [4,7]. These studies indicate that CBD may have the potential for dose-dependent liver injury. ...
... It has also been identified in multiple studies that CBD may induce the cytochrome p450 mediated oxidative metabolism in the liver and cause an increase in alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activity, which suggests that liver injury is present. The increase in serum ALP levels were seen in dogs at 2 mg CBD/kg BW and at 2.5 mg CBD/kg BW [5,6]. Increases in ALT serum levels were reported in mice at 615 mg CBD/kg BW and in cats at 2 mg CBD/kg BW [4,7]. ...
... Two pharmacokinetic studies of pregabalin in laboratory cats have been published [15,16] showing good absorption and bioavailability, as well as a linear pharmacokinetic profile. Lamminen et al. (2022) [16] reported the bioavailability of 94%, mean maximum plasma concentration of 10.1 µg/mL reached between 0.5 and 1 h, area under the curve of 129 h*µg/mL, and a mean half-life of 14.7 h after administration of the oral solution formulation used in this clinical study with a dose 5 of mg/kg. ...
... Measurement of cardiac biomarkers is now emerging in veterinary medicine and their use in small animal and equine clinical practice is growing [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. Although speciesspecific studies have been carried out [39][40][41], it is still frequently assumed that human and veterinary cardiac biomarker behavior is comparable. Therefore, data such as half-time and stability have been extrapolated from human medicine to veterinary sciences, and animal models have been used to study human (patho)physiology [42][43][44][45][46][47][48]. ...
... Some studies regarding IVRLP of horses have investigated the use of a time-dependent antimicrobial drug, either alone or in combination with a concentration-dependent antimicrobial drug. [23][24][25][26] The results of these studies have been contradictory, with some studies finding a high concentration of the time-dependent drug in the synovial fluid after 24 hours, 25,26 and others finding that the time-dependent drug failed to maintain a high concentration for 24 hours. 23,24 However, even with time dependent drugs, a high C max > MIC ratio is an important indicator of efficacy since increased C max leads to increased bacterial cell death, better penetration and reduction in resistance formation. ...
... Utilizing a higher order animal model is also necessary, and canines are considered a promising model, as they contain certain pathways that nematodes lack (e.g., NF-kB) and exhibit a similar neurodegenerative process as humans. Previous research in dogs has demonstrated tolerability and analyzed pharmacokinetic and pharmacodynamic parameters of CBD and TRA (Bartner et al., 2018;Jay et al., 2013). Additionally, future studies using higher order animals should include a full-life exposure set to further con rm the lack of toxicity of both compounds and also allow for the examination of the effects on more complex behaviors than those of C. elegans (Maccarrone, 2017). ...
... Pregabalin has not yet been used extensively in the horse under clinical conditions, and hence pharmacodynamic and dosing information is sparse [135]. The pharmacokinetic properties of pregabalin after intravenous and intragastric administration, respectively, of a single dose (4 mg kg -1 ) have recently been reported [136]. After intravenous administration, initial plasma concentrations ranged from 20 to 28 μg ml -1 , and the elimination half-life was between 7 and 8 h. ...
Reference: Analgesia
... Reactivation may occur as a result of immunosuppression from concomitant disease or stress, leading to shedding either with or without signs of clinical disease in its natural host. 6,37,50,51 For example, such reactivation was observed in apparently healthy M. giganteus (seropositive to MaHV-1) that resulted in shedding an alphaherpesvirus similar to MaHV-1 and MaHV-2 after being treated with dexamethasone (a glucocorticoid capable of immunosuppres- sion). 23 Increased endogenous glucocorticoids observed during stressful conditions can similarly result in reactivation of herpesviral infections. ...