Injection In Dogs Research Articles

Ultrasound-guided retromammillary injections in dogs: a feasibility, descriptive and anatomical study

ObjectiveTo evaluate the feasibility of an ultrasound-guided technique targeting the medial branches of the dorsal ramus of the spinal nerves (DRSN) by injecting a dye solution at the caudal aspect of the base of lumbar mammillary processes [i.e. the retromammillary (RM) space]. Study designFeasibility, descriptive, anatomical study. AnimalsEleven canine cadavers. MethodsUsing anatomical dissections, the relationship between the mammillary processes and the branches of the DRSN of the thoracolumbar and lumbar spine was studied in two cadavers. Subsequently, ultrasound-guided RM injections were administered in nine cadavers, randomly assigned to low volume (LV; 0.01 mL kg–1) of a dye solution at multiple points from L3 to L6 on one side, and high volume (HV; 0.4 mL kg–1) at a single L4 point on the contralateral side. Gross anatomical dissections were immediately performed after the injections. The RM injections were feasible if ultrasonographic landmarks were identifiable in at least 80% of cases, and 80% of LV injections showed medial branch staining. A one-sample binomial test was used for testing feasibility. ResultsThe medial branches emerged shortly after the DRSN exited the intervertebral foramen and traveled towards the caudal aspect of the base of the mammillary process, which served as the target injection point. With LV, 36 out of 36 (100%) injected medial branches were stained, meeting the criteria of feasibility (p < 0.001). The median (range) number of stained medial branches per cadaver were 4 (4–4) and 2 (1–3), with LV and HV, respectively. Although no lateral branches were stained with LV, 1 (0–2) was stained with HV. Neither ventral branch staining nor epidural spread was noted in any cadaver. Conclusions and clinical relevanceUltrasound-guided RM injections are feasible and allow for selective staining of the medial branch of the DRSN in canine cadavers at the lumbar spine.

The effect of intravitreal cidofovir injection on end-stage glaucoma in dogs: a retrospective study of 153 eyes.

To evaluate the long-term efficacy, prognostic factors, and complications of intravitreal cidofovir injection in dogs with end-stage glaucoma. 130 client-owned dogs. Medical records of dogs that underwent intravitreal cidofovir injections were reviewed. A minimum follow-up period of 6 months was required as the inclusion criterion. Signalment, type of glaucoma, preinjection intraocular pressure (IOP), types of applied glaucoma eye drop, coexisting ocular diseases, outcomes, and complications were recorded. Success was defined as IOP of ≤ 25 mm Hg at the 2-week recheck that remained to the 6-month recheck. The overall success rate of intravitreal cidofovir injection was 91.5% (140/153). The success rate of a single injection was 69.3% (106/153), of a second injection was 59.5% (25/42), of a third injection was 42.9% (6/14), of a fourth injection was 33.3% (2/6), and of a fifth injection was 50.0% (1/2). Intraocular pressures at 6 months after injection were relatively higher when the injection was repeated, fewer types of glaucoma eye drop were applied prior to the injection, and cataract stages were advanced at the time of injection (P < .05). The most common complications were phthisis bulbi (42.5%), cataract progression (30.1%), and intraocular hemorrhage (16.3%). Six eyes were enucleated, and 3 were enucleated due to corneal perforation. Intravitreal cidofovir injection had a high long-term success rate in lowering IOP in dogs with end-stage glaucoma.

Preparation of Novel Donepezil Long‐Acting Injectable, IVL3003, and its Pharmacokinetic Study via Subcutaneous Injection in Dogs and Monkeys

AbstractBackgroundDonepezil is a selective oral acetylcholinesterase inhibitor to treat Alzheimer’s disease (AD). Most patients with AD need help with taking oral donepezil for forgetfulness etc. Therefore, long acting injectables (LAIs) can improve patient’s compliance and quality of life. Because of narrow therapeutic window of donepezil, precisely size controlled microsphere technology is needed for drug release control. We have developed IVL3003 as a novel sustained release monodisperse subcutaneous (SC) LAI of donepezil for one month using IVL‐DrugFluidics® technology. The purpose of this study is to evaluate the physicochemical characteristics of IVL3003 and investigate the inter‐species pharmacokinetic profile differences in beagle and monkey models.MethodVarious one month formulations of donepezil microspheres were prepared by IVL‐DrugFluidics®. Characterization of IVL3003 was performed by scanning electron microscopy (SEM), and the size distribution was measured by laser particle size analyzer (PSA). The amount of donepezil and encapsulation efficiency (EE, %) was determined by HPLC. Size distributions were expressed as span value and CV(%). Non‐clinical models were used to optimize formulations and to evaluate their pharmacokinetic properties. IVL3003 was administered to male beagle dogs (n = 3/group, 11 months old, body weight 9∼11 kg) and male cynomolgus monkeys (n = 3/group, 30∼50 months old, body weight 2.6∼3.3 kg). Plasma concentrations were monitored for one month.ResultsThe SEM images of the microspheres appeared spherical and smooth. Donepezil was well encapsulated and homogeneously. The EE(%) of microspheres was 97.5% and the residual solvent was 232.2 ppm. The span value was 0.25 and CV(%) was 10.01%. The plasma concentrations of donepezil were maintained for 28 days without any initial burst and had small individual variation. There was no big difference between species in plasma concentration and showed a similar PK profile in both.ConclusionsAs we postulated, narrow distribution of the particles was led to improvement of controlled‐release characteristics. These results proved the excellence of IVL‐DrugFluidics® as an ideal microsphere fabrication method in manufacturing uniform and monodispersed microspheres. Long‐acting injectable, IVL3003 is expected to increase the compliance and the safety in the treatment of Alzheimer’s patients. We have filed Ph I for IVL3003 recently as the 1st donepezil containing LAI.

A comparison of the motor effects and analgesic efficacy following lumbar plexus block combined with sciatic nerve block or epidural in dogs undergoing tibial plateau leveling osteotomy

ObjectiveTo compare motor effects and analgesic efficacy following an ultrasound-guided lateral approach to lumbar plexus blockade at L7 and sciatic nerve blockade (LPSNB) against epidural injection in dogs undergoing tibial plateau leveling osteotomy (TPLO). Study designProspective, randomized, blinded clinical trial. AnimalsA total of 27 healthy adult dogs undergoing unilateral TPLO surgery. MethodsDogs were allocated to either LPSNB (bupivacaine 2 mg kg–1, 0.75%) or epidural (morphine PF 0.1 mg kg–1 and bupivacaine 0.5 mg kg–1, 0.75%). Other aspects of clinical management were identical, including anesthetic drug protocol, area of presurgical clipping and bladder care. Time to perform the block, response to surgical stimuli, pain scores, rescue analgesia, time to stand and walk, motor score and time to first urination were recorded. One evaluator, unaware of treatment status, performed all evaluations. Student’s t-test or Mann–Whitney U test was used to compare continuous variables between groups, and Fisher’s exact test for categorical variables. ResultsMedian (range) times to stand and walk were shorter for LPSNB [60 (40–120) minutes and 90 (60–150) minutes, respectively, p = 0.003] than for epidural [150 (120–240) minutes and 180 (120–360) minutes, respectively, p = 0.006]. Four dogs required rescue intraoperatively (three in epidural group, one in LPSNB group, p = 0.438). Pain scores over the 24 hour evaluation period were similar, and not significantly different, for each group. Time to spontaneous urination [LPSNB, 330 (240–360) minutes; epidural, 300 (120–1440) minutes, p = 1.0] did not differ between groups. Conclusions and clinical relevanceAn ultrasound-guided lateral paravertebral approach to the lumbar plexus within the psoas compartment at L7, combined with sciatic nerve blockade, allows faster return to normal motor function, with similar pain control and impact on urination when compared with epidural in dogs after TPLO surgery.

Incidence of postoperative administration of opioids in dogs undergoing a tibial plateau leveling osteotomy after intra-operative liposomal bupivacaine administration with or without morphine epidural

ObjectiveTo determine the influence of two intraoperative pain management protocols on the need for additional opioids in patients receiving an epidural and periarticular liposomal bupivacaine (PLB) vs. PLB alone in the 12–24 h period after undergoing a TPLO.Study designRetrospective study.AnimalsOne hundred seventy-four dogs with cranial cruciate ligament tears presenting for TPLO.MethodsMedical records of dogs presenting for a unilateral or bilateral cranial cruciate ligament tear who had a TPLO performed were reviewed for signalment, weight, body condition score, and peri-operative pain management protocol. Dogs were divided into two groups: those who received an epidural and PLB, and those who received only PLB. Post-operative opioid administration was recorded for each group.ResultsPatients who received an epidural and PLB received fewer postoperative opioids. There were 36% fewer opioid injections administered to dogs who received epidurals compared to dogs who did not receive epidurals (IRR) (95% CI) = 0.64 (0.45–0.92), P = 0.02). BCS was not a significant predictor of the post-operative opioid requirement (IRR (95% CI) = 1.3 (0.75–2.4), P = 0.38). When adjusting for BCS as a possible confounder, there were 39% fewer opioid injections in dogs who received epidurals than dogs without (IRR (95% CI) = 0.61 (0.42–0.88), P = 0.009).ConclusionsThe incidence of postoperative opioid administration was significantly diminished in patients receiving both an epidural and PLB.Clinical significanceAdministration of an epidural in addition to infiltration of PLB significantly decreased the incidence of postoperative opioid administration in dogs undergoing a TPLO.

Multifactorial assessment of leukocyte reduced platelet rich plasma injection in dogs undergoing tibial plateau leveling osteotomy: A retrospective study.

This study assessed the effects of concurrent intra-articular injection and Tibial Plateau Leveling Osteotomy (TPLO) plate surface treatment with leukoreduced platelet rich plasma (lPRP) on outcomes of dogs undergoing TPLO. A retrospective study of medical records for cases presenting from January 2018 to December 2020 was performed. Client-owned dogs with naturally occurring cranial cruciate ligament rupture that underwent TPLO surgery were divided into two groups. The lPRP group included cases that underwent intra-articular injection and plate surface treatment at the time of their TPLO. The control group (C) underwent TPLO without PRP treatment. Data analyzed included: presence of surgical site infection, implant removal rate, degree of change in OA progression score, lameness score progression and radiographic bone healing. The short- and long-term complication rate, hospitalization and antibiotic therapy were also compared between the groups. Descriptive statistics, comparison analyses (Chi square test, t-test, Fisher's exact test) and multi-level logistic regression models were used for statistical analysis. A total of 110 cases met the study inclusion criteria: 54 = lPRP, 56 = C. There were no significant differences between groups with regard to gender, age, presence of meniscal tear, weight, or body condition score. Significant findings included: improved radiographic healing of the osteotomy in the lPRP group, improved global OA scores in the lPRP group, and improved lameness score at recheck examination in the lPRP group. There was no significant difference between the lPRP and C group with regard to surgical site infection and implant removal rate. Concurrent intra-articular injection and plate surface treatment with leukocyte reduced PRP at the time of TPLO, is beneficial in slowing the progression of OA, hastening the radiographic evidence of osteotomy healing, and improved lameness score on recheck examination. Leukocyte reduced PRP was not a significant factor in reducing SSI or implant removal rate.

Retrospective analysis describes safety of therapeutic joint injections in dogs.

To retrospectively investigate the safety of canine therapeutic IA injections, describing and correlating adverse events with the number of injections per visit, joint injected, signalment, body condition score, type, and volume of injectate. There were 505 joint injections across 283 visits for 178 client-owned dogs, including the shoulder, elbow, carpus, hip, stifle, tarsus, and metacarpophalangeal. A search was performed of the Cornell University Hospital for Animals medical records for relevant data, identifying dogs treated with therapeutic joint injections and rechecked between 2010 and 2022. Minor complications were noted in 70 of 283 visits and included transient soreness (18.4%, lasting a median of 2 days; range, 1 to 20 days) and gastroenteritis (6.8%). One case of septic arthritis (1/505 joints), which possessed risks of a hematogenous source, was the only potential major complication. Soreness was not correlated with the number of joints injected per visit. Larger volumes of injectate normalized to body size were more likely to be associated with transient soreness in the stifle and tarsus. Across injectates, only stem cells had significantly increased odds of soreness. Gastroenteritis was not associated with the type of injectate. Therapeutic joint injections in dogs are safe, with an extremely low risk of major adverse effects. Transient soreness is a commonly expected minor adverse event. The use of stem cells or larger injectate volumes (confined to the stifle and smaller distal joints) may be more likely to invoke discomfort.

CO97 Assessment of Enhanced Efficacy of Multiple CYTOPOINT Injections

The objective of this study was to assess the effect of additional CYTOPOINT injections in dogs that had an incomplete response to one injection.

Anaphylactic reaction after subcutaneous vitamin K1 injection in dogs: an experimental study and case report

Vitamin K1 (VK1) has been widely used as a coumarin antagonist and for the treatment of hemorrhagic disease in veterinary practice. However, the potential mechanism of adverse reaction after VK1 injection has been not fully elucidated. In this study, two cases of anaphylactic reactions after subcutaneous VK1 injection were presented, and then an experimental study was performed to further characterize the anaphylactic reactions. Two dogs developed anaphylactic reactions after subcutaneous VK1 injections and were promptly treated with antihistamines and glucocorticoids, after which abnormal signs related to anaphylaxis disappeared. Subsequently, a study was undertaken to ascertain the nature of the adverse reactions to subcutaneous VK1 injection. Six healthy laboratory beagle dogs received subcutaneous VK1 administrations once daily for eight days. They were monitored for clinical signs after each injection, and blood samples were collected for the measurement of plasma histamine and immunoglobulin E concentrations using enzyme-linked immunosorbent assay. All six dogs showed mild angioedema after the VK1 injections. The dogs also displayed clinical signs including sneezing, coughing, skin reddening, excess salivation, pawing the ground, and somnolence on days 4, 6, and 8. Plasma histamine and immunoglobulin E concentrations were significantly increased by the repeated injections. In summary, this study describes anaphylactic reactions resulting from subcutaneous VK1 administration in dogs. Clinicians should be aware that the repeated subcutaneous injection of VK1 can trigger an anaphylactic reaction in dogs.

A 3‐month toxicity study of GB‐5001, a donepezil one‐month depot injection formulation, by intramuscular injection in dogs

AbstractBackgroundDonepezil, an acetylcholinesterase inhibitor for treatment of Alzheimer’s disease (AD), is administered as daily tablets. The treatment compliance, however, is particularly challenging in AD patients for various reasons such as difficulty in swallowing medication, tolerating side effects, and/or complying with the appropriate dosage. GB‐5001 is a novel once monthly intramuscular (IM) depot injection of donepezil to improve treatment compliance developed using G2GBIO’s InnoLAMP® technology. The objective of this study was to evaluate the toxicity of GB‐5001 in beagle dogs for further development.MethodGB‐5001 was administered once every 4 weeks via bolus IM injection to 16 male and 16 female beagle dogs (7.4∼13.3 kg) for 3 months, and 4 male dogs and 4 female dogs in the vehicle group and the highest dose level group were evaluated for the reversibility or long‐term effects following a 2‐month non‐dosing recovery period. The dose levels were 0 (vehicle), 280, 560, and 1120 mg/dose. The following parameters and endpoints were evaluated in this study: standard toxicology parameters, ophthalmoscopic, electrocardiographic examination, gross, histopathologic examinations, and toxicokinetic parameters.ResultNo fatality occurred during this study and there were no toxicologically significant clinical changes or pathological findings related to GB‐5001 in all groups. Systemic exposure to Donepezil was independent of sex. Following IM injection once every 4‐weeks of GB‐5001, mean Cmax and AUC0‐last values of Donepezil increased dose dependently on Days 1 and 57. And systemic exposure (AUC0‐last) to Donepezil increased slightly (&lt;2 fold) on Day 57 compared to Day 1.ConclusionGB‐5001 was tolerated at all dose levels when administered once every 4 weeks via IM injection to male and female beagle dogs for 3 months at doses of 0, 280, 560 and 1120 mg/dose. The clinical observations of swelling and nodules at the dose sites are considered to be vehicle‐related as evidenced by the similar incidence in control. Consequently, the no‐observed‐adverse‐effect‐level (NOAEL) is considered to be 1120 mg/dose.

Onset of Action of Bupivacaine Administered via Dural Puncture Epidural versus Spinal, Lumbosacral, and Sacrococcygeal Epidural Injections in Dogs: Randomised Clinical Trial.

Simple SummaryEpidural anaesthesia is commonly performed to provide long-lasting local anaesthesia in animals. Spinal anaesthesia has become popular in human anaesthesia due to a faster onset, but shorter duration, than epidural anaesthesia. Recently, dural puncture epidural anaesthesia (DPE) has been proposed as a compromise between spinal and epidural anaesthesia, providing longer duration than spinal anaesthesia with similar onset of action. This study aimed to compare the technical aspects of these techniques (onset of action, number of attempts, and time to perform them). The results showed no difference between the techniques in number of attempts required, while the epidural injections tended to be shorter than spinal and dural puncture epidural injections. The onset of action (measured as disappearance of the patellar reflex) was longer in the sacrococcygeal epidural injection than any other techniques (including lumbosacral epidural injections).The study aimed to compare bupivacaine onset time when administered via epidural anaesthesia injecting both at the lumbosacral and sacrococcygeal spaces, spinal anaesthesia, and DPE in clinical dogs. A total of 41 dogs requiring neuraxial anaesthesia as part of their anaesthetic protocol were recruited. They were randomly allocated to receive an epidural injection in the sacrococcygeal space aided by the nerve stimulator (SCO), an epidural injection in the lumbosacral (LS), a subarachnoid injection (SPI), or a DPE. The onset of anaesthesia was assessed every 30 s after the injection by testing the presence of patellar ligament reflex. The number of attempts and time to perform the technique were also recorded. Data were analysed using a one-way ANOVA for trimmed means with post hoc Lincoln test and a Kaplan–Meier curve. The significance level was set at p < 0.05, and the results are presented in absolute values and median (range). There was no difference in the number of attempts required to complete the techniques between groups (p = 0.97). Epidural injections (LS and SCO) tended to be shorter than SPI and DPE techniques, but there was no statistically significant difference (p = 0.071). The time to the disappearance of patellar ligament reflex (Westphal’s sign) in the SCO group was longer than in any other group. In conclusion, all techniques provided a rapid block of the patellar reflex. The SCO technique was the slowest in onset, while the other groups (SPI, DPE, and LS) were faster and almost indistinguishable.

Ultrasound-guided parasternal injection in dogs: a cadaver study

ObjectivesTo describe the technique of performing an ultrasound-guided distal parasternal intercostal block and to determine the distribution of two volumes of methylene blue dye solution injected in canine cadavers. Study designProspective cadaver study. AnimalsA group of seven canine cadavers weighing 12–34 kg. MethodsThe space between the transversus thoracic and the internal intercostal muscles is a virtual cavity. Ultrasound-guided injections in the distal (parasternal) intercostal space were performed using dye solution at 0.05 mL kg–1 in each intercostal space from the second to seventh (LV, low volume, six injections per dog) in one hemithorax, and 0.1 mL kg–1 in the third, fifth and seventh intercostal spaces (HV, high volume, three injections in each dog) on the contralateral side. Anatomical dissection was carried out to describe dye spread characteristics and staining of intercostal nerves. ResultsThe ultrasonographic landmarks for injection were identified in each cadaver. In the LV group the solution was found in every intercostal space (36/36), whereas the HV injection stained six intercostal spaces in two dogs, five in two, and in two dogs the solution was found in four and three spaces, respectively, demonstrating multisegmental distribution. Intrapleural staining was observed after two injections. Conclusions and clinical relevanceUltrasound-guided injection of 0.05 mL kg–1 at the distal intercostal space resulted in staining of the intercostal nerve in all dogs when performed in every space and may be an appropriate alternative to previously reported techniques. A single injection of 0.1 mL kg–1 may anaesthetize more than one intercostal nerve, but not consistently. Clinical investigations are warranted to better characterize and to refine this locoregional technique.

Temporomandibular joint injections in dogs with temporomandibular joint pain: 11 cases (2015-2019).

To describe and evaluate the clinical application of temporomandibular joint injections using betamethasone and ropivacaine in German Shepherd dogs suffering from non-odontogenic orofacial pain due to temporomandibular dysplasia and/or osteoarthritis. Outcomes in dogs presented with clinical signs of non-odontogenic orofacial pain associated to temporomandibular joint dysplasia and/or arthritis and treated with a temporomandibular joint injection were retrospectively-prospectively evaluated. The overall clinical signs free period ranged between 25 to 1579 days, with an average of 461 days. The clinical signs free period for temporomandibular joint osteoarthritis scores 1, 2 and 3 were on average 659 days (180-1579 days), 134 days (42-355 days) and 723 days (25-1377 days), respectively. Similarly the temporomandibular dysplasia scores 1, 2 and 3 were on average 306 days (26-1579 days), 1377 days and 669 days (25-1429 days) respectively. Those dogs in which only one side was injected the clinical signs free period average was 639 days (25-1578 days), compared with dogs in which both temporomandibular joints were injected showing a clinical signs free period average of 378 days (42-1377 days). The temporomandibular joint injection technique proved to be feasible with a decent outcome in dogs suffering from non-odontogenic orofacial pain associated with temporomandibular joint osteoarthritis and/or dysplasia. Further randomised studies are required to confirm the effectiveness of this intervention.

Abstract 593: Ocular drops of palonosetron reduce chemotherapy-induced acute nausea and vomiting in the dog

Abstract Background: Nausea and vomiting are common side effects of cancer therapies thereby seriously affecting the quality of life of patients. Therefore, the prevention or treatment of chemotherapy-induced nausea and vomiting has become an important part of the comprehensive treatment of cancer. Several 5-HT3 receptor antagonists have been developed in the treatment of nausea and vomiting using mainly the oral route of administration (which is not convenient due to vomiting) or the intravenous route. In this study we tested whether ocular administration of the 5-HT3 receptor antagonist palonosetron (eye drops) could prevent nausea and vomiting associated with intravenous cisplatin injection in dogs. Methods: Six adult male Beagle dogs (10-13 kg) were included in a randomized crossover study. This study was carried out in AAALAC facilities in strict accordance with the European and French animal welfare regulations for animal use in experimentation. Dogs were administered 18 mg/m2 cisplatin intravenously over a 20-min period, followed 45 min later by ocular administration (eye drops, 200µL/eye) of either placebo (2% povidone in saline) or palonosetron (30 or 120 µg/kg). The number of vomits and nausea associated behaviours, scored on a visual analogue scale (VAS), were recorded every 15 min for 7 h following cisplatin administration. Blood samples were collected to measure plasma levels of palonosetron. Results: The placebo treated group vomited an average number of 10.2±2.1 times (range 5-17) over the 7-h period following cisplatin infusion. Ocular administration of palonosetron at 30 μg/kg in cisplatin-treated dogs very strongly and significantly decreased vomiting episodes, with only 1 vomiting episode in 2 dogs overall (p&amp;lt;0.0001). After ocular administration of palonosetron at 120 μg/kg, no vomiting episodes were observed in any dog throughout the observation period (p&amp;lt;0.0001). With regards to the VAS, in the placebo-treated group the nausea-associated behaviour started between 2.5 and 2.75 h after the end of the cisplatin infusion and peaked between 3.75 and 4.25 h after the end of the cisplatin infusion. The area under the curve (AUC) of VAS was 7344 ± 1050 mm*min in the placebo-treated group. Ocular administration of palonosetron at 30 or 120 µg/kg in cisplatin-treated dogs decreased the VAS score strongly. The VAS AUCs were 320 ± 268 (p&amp;lt;0.0001) and 0 ± 0 mm*m (p&amp;lt;0.0001) in 30 µg/kg and 120 µg/kg palonosetron groups, respectively. Plasma palonosetron concentration reached 10.3 ± 3.9 ng/mL, 5 min after ocular administration of palonosetron at 30 µg/kg and 2.8 ± 0.5 ng/mL and 0.9 ± 0.2 ng/mL at 2 h and 6 h post dosing, respectively. Conclusions: This study demonstrates for the first time that palonosetron administered via ocular route produces a rapid clear-cut anti-emetic and anti-nausea effect in conscious dogs exposed to cisplatin. This finding points out the tremendous interest of this novel and convenient route of administration which could help improving the quality of life of patients. Citation Format: Sandra Nourry, Minja Hyttila-Hopponen, Pierre Montagne, Lasse Saloranta, Sari Pappinen, Jouko Levijoki, Christophe Drieu La Rochelle. Ocular drops of palonosetron reduce chemotherapy-induced acute nausea and vomiting in the dog [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 593.

Biopsy of sentinel lymph nodes after injection of methylene blue and lymphoscintigraphic guidance in 30 dogs with mast cell tumors

AbstractObjectiveTo report the outcomes associated with sentinel lymph nodes (SLN) detection and extirpation guided by radionuclide and methylene blue injections in dogs with cutaneous and subcutaneous mast cell tumors (MCT).Study designClinical prospective cohort study.AnimalsThirty client‐owned dogs with MCT amenable to wide‐margin excision, without evidence of distant metastasis and abnormal regional lymph nodes (RLN).MethodsTechnetium‐99 m and methylene blue were injected peritumorally. Dogs underwent preoperative γ‐camera scintigraphy and an intraoperative γ‐probe‐guided SLN extirpation. Outcomes included technical and surgical complications, number of SLN, SLN location respecting the expected RLN, and histopathology results.ResultsSentinel lymph node mapping was applied to 34 MCT in 30 dogs without any complication. Sentinel lymph nodes were not identified in three of 34 tumors, all with previous scar tissue. Sentinel lymph nodes did not correspond to expected RLN in 19 of 30 (63%) tumors. Histological examination confirmed an early or overt metastasis in 32 of 57 (56%) SLN extirpated.ConclusionSentinel lymph node mapping and biopsy with radionuclide and injection of methylene blue was associated with low morbidity and allowed detection of SLN in dogs with MCT at first presentation without scar tissue.Clinical significanceIncorporation of SLN mapping and extirpation allows for a personalized staging approach in dogs with MCT. The presence of scar tissue in dogs with recurrent tumors seems to be a limitation for SLN mapping with this technique.

Computed tomographic lymphangiography via intra-metatarsal pad injection is feasible in dogs with chylothorax.

Lymphangiography can be useful for preoperative planning in chylothorax. Conventional ultrasound-guided intranodal injection can be difficult in some cases and is dependent upon operator skill. Alternative methods have been proposed to simplify the procedure, but their feasibility has not been sufficiently evaluated in clinical cases. The primary purpose of this multicenter, retrospective, descriptive study was to assess the feasibility and describe the clinical findings of CT lymphangiography by intrametatarsal pad injection in dogs with naturally occurring chylothorax. Twenty dogs were analyzed, and enhancement of thoracic ducts (TDs) was successful in 18 (90%) dogs within 5-14 min after initiating the injection, while successful enhancement of the lymphatic vessels cranial to the popliteal lymph nodes was seen in all dogs within 5 min after injection. The dose with good success to achieve TD enhancement was 1mL/kg (concentration 350mg I/kg). Only two dogs had mild discomfort after recovery from general anesthesia. Computed tomography lymphangiography by intrametatarsal pad injection is a feasible, easy, and safe procedure, which could provide adequate TD and cisterna chyli enhancement, identify TD number and cisterna chyli location and structure, and contribute to surgical planning.

Pharmacokinetics of morphine in combination with dexmedetomidine and maropitant following intramuscular injection in dogs anaesthetized with halothane.

The purpose of this study was to evaluate the pharmacokinetics of morphine in combination with dexmedetomidine and maropitant injected intramuscularly in dogs under general anaesthesia. Eight healthy dogs weighing 25.76±3.16kg and 3.87±1.64years of age were used in a crossover study. Dogs were randomly allocated to four groups: (1) morphine 0.6mg/kg; (2) morphine 0.3mg/kg+dexmedetomidine 5μg/kg; (3) morphine 0.3mg/kg+maropitant 1mg/kg; (4) morphine 0.2mg/kg+dexmedetomidine 3μg/kg+maropitant 0.7mg/kg. Blood samples were collected before, 15 and 30min, and 1, 2, 3 4, 6 and 8hr after injection of the test drugs. Plasma concentration of the drugs was determined by liquid chromatography-mass spectrometry. The elimination half-life (T1/2 ) of morphine was higher and the clearance rate (CL) was lower when combined with dexmedetomidine (T1/2 =77.72±20.27min, CL=119.41±23.34mlkg-1 min-1 ) compared to maropitant (T1/2 =52.73min±13.823mlkg-1 min-1 , CL=178.57±70.55) or morphine alone at higher doses (T1/2 =50.53±12.55min, CL=187.24±34.45mlkg-1 min-1 ). Combining morphine with dexmedetomidine may increase the dosing interval of morphine and may have a clinical advantage.

Comparison of the sedative effects of medetomidine administered intranasally, by atomization or drops, and intramuscular injection in dogs

ObjectiveTo compare the sedative effects of intranasal atomization (INA) of medetomidine with intranasal drops (IND) and intramuscular (IM) injection in healthy dogs. Study designProspective, blinded, randomized study. AnimalsA group of 18 mixed-breed shelter-owned dogs weighing 27 ± 4.3 kg (mean ± standard deviation). MethodsThe dogs were randomly assigned to equal groups of six dogs for administration of medetomidine (40 μg kg−1) by INA, IND and IM routes. Ease of administration was evaluated using a resistance scale. Composite sedation score (CSS), heart rate (HR) and respiratory frequency (fR) were measured immediately before (T0, baseline) and after drug administration at time points 15, 45, 75 and 120 minutes. The time of onset of sedation was recorded. Ease of administration and onset of sedation were analysed by the Kruskal–Wallis and post hoc Dunn’s tests. Repeated measures analysis of anova and least significant difference tests were used to analyse CSS, HR and fR over time. Tukey’s post hoc test was used for time point comparisons among groups. Significance was set at p < 0.05. ResultsNo differences were detected among groups for ease of administration (p = 0.346). CSS increased in all groups from baseline values. Onset of sedation in IM was 6.3 ± 2.0 minutes, in INA was 7.2 ± 2.5 minutes and in IND was 20.7 ± 5.4 minutes. CSS in IND was lower than in the other groups at T15 and lower than in INA at T45. CSS was not different between IM and INA. HR and fR decreased in all groups compared with respective baseline values. HR in IND was lower than in IM at T45–T120. Conclusions and clinical relevanceINA medetomidine (40 μg kg−1) can be an alternative and noninvasive route to IM injections for sedating healthy dogs. IND resulted in a slow onset of sedation.

Evaluation of sites of velopharyngeal structure augmentation in dogs for improvement of velopharyngeal insufficiency

BackgroundVelopharyngeal structure augmentation methods are used as alternatives to velopharyngeal plasty. Anatomic sites of implantation/injection vary widely due to a lack of standardized criteria. Here, we experimentally investigated optimal sites of velopharyngeal structure augmentation via saline injection in dogs as they naturally exhibit velopharyngeal insufficiency (VPI).MethodsVelopharyngeal structure augmentation was performed on 10 beagles (age range: 20–24 months; weight range: 9–12 kg). Saline containing 1/80,000 epinephrine was injected intraorally in 1-mL increments into the nasal mucosa of the soft palate (n = 4), posterior pharyngeal wall (n = 3), or bilateral pharyngeal walls (n = 3) of each dog. Nasal air leakage was measured under rebreathing until velopharyngeal closure was achieved; the measurement was performed using flow meter sensors on both nasal apertures, and the oral cavity was filled with alginate impression material to prevent oral air leakage.ResultsPre-injection, the dogs exhibited an average of 0.455 L/s air leakage from the nasal cavity. The dogs with saline injected into the nasal mucosa of the soft palate achieved steady augmentation, and nasal air leakage disappeared under rebreathing following 6-mL saline injection. Conversely, nasal air leakage remained in the dogs with saline injected in the posterior pharyngeal wall or bilateral pharyngeal walls.ConclusionsDuring VPI treatment in dogs, augmentation was most effective at the nasal mucosa of the soft palate. Improvement in nasal air leakage was highly dependent on the saline injection volume. Although velopharyngeal structures vary between dogs and humans, velopharyngeal closure style is similar. Thus, our results may aid in the treatment of VPI patients.

Comparison of pain response after subcutaneous injection of two maropitant formulations to beagle dogs

The antiemetic maropitant, with metacresol as preservative (Cerenia, Zoetis), has been associated with pain after subcutaneous injection in dogs and cats. Recently, a generic formulation containing benzyl alcohol was authorised...