Effect of recombinant human thyroid stimulating hormone on radioactive iodine uptake by thyroid carcinoma in dogs.

BACKGROUND: The high doses of radioiodine-131 (131I) and, subsequently, the high radioactive burden for dog and environment warrants optimization of 131I therapy in dogs with thyroid carcinoma (TC). HYPOTHESIS/OBJECTIVES: To evaluate the effect of a revised protocol with recombinant human thyroid stimulating hormone (rhTSH) on tumor radioactive iodine uptake (RAIU) in dogs with TC. ANIMALS: Nine client-owned dogs diagnosed with TC. METHODS: A prospective cross-over study in which tumor RAIU was calculated and compared at 8 hours (8h-RAIU) and 24 hours (24h-RAIU) after injection of radioactive iodine-123 (123I), once with and once without rhTSH (ie, 250 µg, IM, 24 and 12 hours before 123I) in each dog. Simultaneously, serum total thyroxine (TT4) and TSH were measured at baseline (T0), and 6 (T6), 12 (T12), 24 (T24), and 48 hours (T48) after the first rhTSH administration. RESULTS: Tumor RAIU was significantly higher at 24 hours with rhTSH compared to no rhTSH (mean difference = 8.85%, 95% CI of [1.56; 16.14]; P = .03), while this was non-significant at 8 hours (mean difference = 4.54%, 95% CI of [0.35; 8.73]; P = .05). A significant change of serum TT4 (median difference T24 - T0 = 35.86 nmol/L, interquartile range [IQR] = 15.74 nmol/L) and TSH (median difference T24 - T0 = 1.20 ng/mL, IQR = 1.55 ng/mL) concentrations occurred after administration of rhTSH (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Recombinant human TSH could optimize 131I treatment in dogs with TC by increasing tumor RAIU and thus 131I treatment efficacy.

A prospective, randomised, controlled, double blinded, cross-over study on the effect of a single session of pulsed electromagnetic field therapy on signs of hip osteoarthritis in dogs.

BACKGROUND: Canine coxofemoral joint osteoarthritis is a common, painful and debilitating condition. The objective of this study was to evaluate if any measurable changes in pain or lameness occurred in this patient group immediately after a single treatment with pulsed electromagnetic field therapy. Eight dogs with coxofemoral joint osteoarthritis presenting with signs of pain and lameness were prospectively recruited to this randomised, controlled, double blinded, cross-over study. Subjects attended the research facility on two occasions for one active and one placebo treatment with pulsed electromagnetic field therapy. The immediate effect of one pulsed electromagnetic field therapy treatment on pain and lameness was measured subjectively with the Helsinki Chronic Pain Index and Visual Analogue Scale and objectively using a pressure sensitive walkway. RESULTS: A statistically significant difference (P = 0.03) for change in stride length in the affected limb was recorded for subjects between the active and placebo treatments with pulsed electromagnetic field therapy. Within the active treatment results, there was a statistically significant change in the measurement for reach (P = 0.04) and stride length (P = 0.047) which got shorter in the affected limb post treatment. For the subjective outcome measures, there was no statistically significant difference between the active and placebo treatments for the evening of the treatment day or the next morning from pre-treatment values. Within the placebo treatment results a statistically significant change (improvement) was detected in Visual Analogue Score (P = 0.03) between pre-treatment and the next morning values. CONCLUSIONS: The findings of this study do not show demonstrable improvement in owner assessed pain levels or temporospatial performance in dogs with coxofemoral joint osteoarthritis immediately after a single application of pulsed electromagnetic field therapy.

Comparison between melatonin versus melatonin and photobiomodulation versus photobiomodulation in the treatment of Alopecia X in German Spitz dogs: Clinical, randomized, double-blind, parallel, non-inferiority protocol.

Canine Alopecia X is a non-inflammatory hair loss disorder of unknown etiology that predominantly affects German Spitz dogs. Treatment modalities include hormone and/or melatonin supplementation and low trauma microneedling. Melatonin influences hair growth and pigmentation in several species and presents a low risk of adverse effects when used in dogs with Alopecia X. Photobiomodulation (PBM) is frequently used in human androgenetic alopecia and alopecia areata; despite this, PBM remains unexplored in canine Alopecia X. To address this knowledge gap, sixty dogs of both sexes will be randomly assigned to three groups: (i) melatonin only group (3 mg/Kg, n = 20); (ii) PBM only group (diode laser, wavelength 660nm, 100mw power, with 3 J/point, 2 sessions/week for 3 months, n = 20); (ii) PBM + melatonin group (n = 20). The objective is to determine the potential of PBM alone or in conjunction with melatonin supplementation in promoting hair regrowth (hair density and diameter) by means of dermatoscopy and planimetry over a period of 90 days.

Transcranial photobiomodulation therapy improves cognitive test scores in dogs with presumptive canine cognitive dysfunction: A case series of five dogs.

Background: Canine cognitive dysfunction (CCD) is considered the canine version of human Alzheimer's disease (AD). As with AD, CCD is a multifactorial and progressive neurodegenerative disorder for which effective treatment options are continuously being sought. Transcranial photobiomodulation (tPBMT) or transcranial laser therapy has shown promise as a treatment for cognitive impairment in rodent AD investigations and several human AD clinical trials. Aim: The purpose of this prospective case series was to evaluate the effect of tPBMT on cognitive scores when applied to senior dogs with CCD over a 60-day period. Methods: Five senior (>9-year-old) dogs with moderate (16-33) to severe (>33) cognitive scores were enrolled. Owners were instructed on the use of a Class IM laser device and administered a specific dose of laser energy transcranially to both sides of the patient's head, three times per week for one month and two times per week for a second month. No additional therapeutic measures aimed at enhancing cognitive ability were permitted during the 60-day evaluation time. Baseline cognitive scores were compared with scores obtained at 30- and 60-days post-treatment. Results: Cognitive scores showed improvement in 4/5 dogs at 30 days (27.6% reduction) and all dogs at 60 days (43.4% reduction). There were no adverse effects attributable to tPBMT. Conclusion: Results of our small case series suggest that tPBMT may improve cognitive scores in dogs with moderate to severe CCD by 30 days of application and the improvement is sustained at 60 days. Further studies are needed to ascertain optimal tPBMT protocols for CCD.

Outcomes of Stereotactic Radiation Therapy Versus Fractionated Radiation Therapy in 44 Dogs With Pituitary Masses: A Multi-Institutional Retrospective Study (2016-2022).

Although canine pituitary masses (PM) are increasingly treated with stereotactic radiotherapy (SRT), historical literature supports superior outcomes with conventional full-course fractionated radiation therapy (FRT). A multi-institutional retrospective study was performed, including dogs with PM treated from 2016 to 2022 with SRT (total dose 30 or 35 Gy in 5 daily fractions) or FRT (total dose 50-54 Gy in 19-20 daily fractions). The influence of potential prognostic/predictive factors was assessed, including pituitary: brain height, pituitary: brain volume, sex, age and endocrine status (functional [F] vs. nonfunctional [NF] PM). Forty-four dogs with PM were included (26 F, 14 NF, 4 unknown). All patients completed protocols as scheduled (SRT = 27, FRT = 17) and two dogs had suspected Grade 1 acute neurotoxicity. During the first 6 months after RT, 5/27 (19%) dogs treated with SRT (4 F, 1 NF) and 3/17 (18%) dogs treated with FRT (all F) died or were euthanised because of progressive neurologic signs. The overall median survival time was 608 days (95% CI, 375-840 days). Young age at the time of treatment was significant for survival (p = 0.0288); the overall median survival time was 753 days for dogs <9 years of age (95% CI, 614-892 days) and 445 days for dogs ≥9 years of age (95% CI, 183-707 days). Survival time was not associated with treatment type or any other factor assessed herein. A prospective study using standardised protocols would further validate the results of the present study and potentially elucidate the predictors of early death.

Administration of intratumoral GD2-directed interleukin-2 immunocytokine and local radiation therapy to activate immune rejection of spontaneous canine melanoma.

Canine malignant melanoma provides a clinically relevant, large animal parallel patient population to study the GD2-reactive hu14.18-IL-2 immunocytokine as it is similar to human melanoma and expresses GD2. The objectives of this study were to evaluate safety, radiation fractionation, and identify informative biomarkers of an in-situ tumor vaccine involving local radiation therapy plus intratumoral-immunocytokine in melanoma tumor-bearing dogs. Twelve dogs (six dogs/arm) with locally advanced or metastatic melanoma were randomized to receive a single 8 Gy fraction (arm A) or three 8 Gy fractions over 1 week (arm B) to the primary site and regional lymph nodes (when clinically involved) with the single or last fraction 5 days before intratumoral-immunocytokine at 12 mg/m 2 on 3 consecutive days. Serial tumor biopsies were obtained. All 12 dogs completed protocol treatment, and none experienced significant or unexpected adverse events. Evidence of antitumor activity includes one dog with a complete response at day 60, one dog with a partial response at day 60, and four dogs with mixed responses. Histology of serial biopsies shows a variably timed increase in intratumoral lymphocytic inflammation in some dogs. Canine NanoString analyses of serial biopsies identified changes in gene signatures of innate and adaptive cell types versus baseline. There were no significant differences in NanoString results between arm A and arm B. We conclude that intratumoral-immunocytokine in combination with local radiation therapy in canine melanoma is well tolerated and has antitumor activity with the potential to inform clinical development in melanoma patients.

[Radiation therapy in veterinary medicine at the University of Liège]. / Radiothérapie en médecine vétérinaire à l'Université de Liège.

Radiation therapy has many indications in veterinary oncology and allows a multidisciplinary approach for the treatment of canine and feline patients. Radiation therapy can be recommended as a sole therapy in case of radiosensitive tumors or can be associated to surgery and/or chemotherapy after marginal excision for example. It can also be recommended as a palliative treatment for patients with an inoperable or painful tumor or disseminated disease. Radiation therapy significantly improves the quality of life and survival time of treated animals and should be part of the therapeutic modalities in veterinary medicine. The University of Liège developed the first veterinary center of radiation therapy in Belgium and can therefore participate in improving therapeutic management of cancerous animal patients.

La radiothérapie présente de nombreuses indications en oncologie vétérinaire et permet une approche multidisciplinaire pour le traitement de nos patients cancéreux canins et félins.La radiothérapie peut être recommandée seule pour le traitement de tumeurs radiosensibles, ou associée à la chirurgie et/ou la chimiothérapie notamment lors d'exérèse marginale. Elle a également sa place dans une prise en charge palliative de certains patients présentant une tumeur inopérable ou douloureuse, ou encore une maladie disséminée. La radiothérapie permet d'améliorer significativement la qualité et l'espérance de vie des animaux traités et à ce titre, doit faire partie de l'arsenal thérapeutique vétérinaire. L'Université de Liège possède, depuis peu, l'unique centre de radiothérapie vétérinaire en Belgique et peut ainsi participer à l'amélioration de la prise en charge des animaux cancéreux.

Prospective pilot study utilizing changes in quantitative values obtained on serial fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) in dogs with appendicular osteosarcoma before and after stereotactic body radiation therapy (SBRT) and carboplatin chemotherapy to assess for prediction of survival and therapeutic effectiveness.

Serial fluorine 18 fluorodeoxyglucose (18F-FDG) positron emission tomography-CT (PET/CT) is commonly used in human oncology to prognosticate and evaluate for therapeutic effectiveness. In this pilot study, dogs with naturally occurring appendicular osteosarcoma were evaluated with serial 18F-FDG PET/CT in an attempt to assess for response to therapy, prognostic factors, and appropriateness of imaging intervals. Fourteen dogs were enrolled in the trial. All dogs had the initial 18F-FDG PET/CT (PET1), with nine dogs having their end-of-therapy 18F-FDG PET/CT (EoT PET) 3 months after stereotactic body radiation therapy (SBRT) to the primary tumor. The median percent change from the PET1 to the EoT PET for the standard uptake value maximum (SUVmax%) was -58% (range: -17 to -88%), metabolic tumor volume (MTV%) was -99.8% (range: -65 to -100%), and total lesion glycolysis (TLG%) was -99.8% (range: -75 to -100%), all of which were significant (P < .05, <.05, and <.05, respectively). On evaluation, it was found that volumes of GTV and CTV were significant for survival (P < .05 and <.05), MTV1, TLG1, and SUVmax on the EoT PET (SUVmaxEoT) were predictive of metastasis (P < .05), and the SUVmax% was significantly correlated to the time to first event (P < .05). Based on this data, serial 18F-FDG PET/CT performed 3 months after SBRT can show a significant reduction in avidity, and the quantitative data collected may help predict metastatic disease in canine appendicular osteosarcoma.

A retrospective study of chemotherapeutic effect without wide-margin surgery or radiation therapy in dogs with oral malignant melanoma.

Background: Effective treatment for canine oral malignant melanoma (e.g., curative-intent surgery) may not be feasible or radiation therapy may be unavailable. However, chemotherapy is usually an option, and more information is needed regarding its use without adequate local treatments. Objective: Our objective was to investigate the efficacy of chemotherapy in canine oral malignant melanoma without adequate local control, using carboplatin with dose reduction in small-breed dogs and metronomic chemotherapy. Animals and procedure: Client-owned dogs with histopathologically diagnosed oral malignant melanoma were retrospectively enrolled from 2016 to 2022. The chemotherapy protocol in each case was determined by the attending clinician. Results: Thirteen dogs were included. The median progression-free interval of all 13 dogs was 42 d (14 to 953 d). The median overall survival time of dogs with chemotherapy as their only systemic treatment was 181 d (50 to 960 d; n = 11). The median dosage of carboplatin was 250 mg/m2. Response to treatment and clinical stage were significant prognostic factors. Conclusion and clinical relevance: As chemotherapy provided a median survival of 6 mo, it could be considered when adequate local control is infeasible. Earlier clinical stages or achievement of at least stable disease during chemotherapy may indicate better survival in dogs.

Une étude rétrospective de l'effet chimiothérapeutique sur le mélanome malin buccal canin dépourvu de chirurgie et de radiothérapie á large marge : le stade clinique et la réponse au traitement prédisent les résultats du patient. Mise en contexte: Des traitements efficaces pour le mélanome malin oral canin, tels que la chirurgie á visée curative, ne sont parfois pas réalisables ou la radiothérapie n'est pas disponible dans certaines régions. La chimiothérapie reste une option de traitement et davantage d'informations devraient être fournies pour les cas qui n'ont pas eu accés á un traitement local adéquat. Objectif: Cette étude visait á étudier l'efficacité de la chimiothérapie dans le mélanome malin oral canin sans contrôle local adéquat, en utilisant le carboplatine avec réduction de dose chez les chiens de petite race et la chimiothérapie métronomique. Animaux et procédure: Treize chiens appartenant á des clients atteints d'un mélanome malin oral diagnostiqué par histopathologie ont été rétrospectivement inscrits de 2016 á 2022. Le protocole de chimiothérapie a été déterminé par le clinicien traitant. Résultats: L'intervalle médian sans progression des treize chiens était de 42 jours (14­953 jours). La durée médiane de survie globale des chiens ayant reçu une chimiothérapie comme seul traitement systémique était de 181 jours (50­960 jours; n = 11). La dose médiane de carboplatine était de 250 mg/m2. La réponse au traitement et le stade clinique étaient des facteurs pronostiques importants. Conclusion et pertinence clinique: La chimiothérapie pouvait encore être envisagée lorsqu'un contrôle local adéquat était impossible. Des stades cliniques plus précoces ou des patients atteignant au moins une maladie stable pendant la chimiothérapie peuvent indiquer une meilleure survie.(Traduit par les auteurs).

Comparison of a new immobilization method using a reusable 3-point fixation cylinder system and bite-block type immobilization methods in veterinary radiotherapy.

In veterinary radiotherapy, highly reproducible immobilization is important for accurate irradiation. Consequently, we developed a new reusable head-immobilization method for dogs using cylinders. This study aimed to compare the accuracy of our novel immobilization method using cylinders with that of bite-block type immobilization methods. Three immobilization methods were compared: bite-block only, bite-block combined with torso immobilization, and immobilization using cylinders. Five beagles with canine teeth underwent CT five times for each of the three immobilization methods. One beagle without canine teeth underwent CT 15 times using each method. Three maxillary landmarks (maxillary incisor, frontal sinus, and occipital bone) and one mandibular landmark (mandibular incisor) were established, and the errors in each immobilization method were measured. For all head landmarks, the error in the immobilization method using cylinders was the most reproducible, with the smallest errors. No significant differences were observed in the time required for immobilization. Although there were limitations (such as the use of dogs from a single breed, a single episode of anesthesia, no disassembly of the immobilization system between scans, and the same person performing the positioning on the same day), we found our new reusable immobilization method using cylinders was the most accurate among the three compared methods. This was a proof-of-principle study to evaluate head immobilization using cylinders, and further investigations are needed to confirm its clinical utility.

The role of companion animal models in radiopharmaceutical development and translation.

Advancements in molecular imaging and drug targeting have created a renaissance in the development of radiopharmaceuticals for therapy and theranostics. While some radiopharmaceuticals, such as Na[131I]I, have been used clinically for decades, new agents are being approved using small-molecules, peptides, and antibodies for targeting. As these agents are being developed, the need to understand dosimetry and biologic effects of the systemically delivered radiotherapy becomes more important, particularly as highly potent radiopharmaceuticals using targeted alpha therapy become clinically utilized. As the processes being targeted become more complex, and the radiobiology of different particulate radiation becomes more diverse, models that better recapitulate human cancer and geometry are necessary. Companion animals develop many of the same types of cancer, carrying many of the same genetic drivers as those seen in people, and the scale and geometry of tumours in dogs more closely mimics those in humans than murine tumour models. Key translational challenges in oncology, such as alterations in tumour microenvironment, hypoxia, heterogeneity, and geometry are addressed by companion animal models. This review paper will provide background on radiopharmaceutical targeting techniques, review the use of radiopharmaceuticals in companion animal oncology, and explore the translational value of treating these patients in terms of dosimetry, treatment outcomes, and normal tissue complication rates.

Reason for euthanasia in dogs with urothelial carcinoma treated with chemotherapy or radiation therapy or both: A retrospective observational study.

BACKGROUND: Clients want to know the ultimate cause of death in their pet after cancer treatment. The cause of euthanasia and investigation of urinary obstruction in treated dogs with urothelial carcinoma (UC) has not been specifically reported in veterinary literature. HYPOTHESIS/OBJECTIVES: Our hypothesis was that the majority of treated dogs with UC are euthanized secondary to primary tumor factors, such as urinary obstruction. ANIMALS: Fifty-nine client-owned dogs diagnosed with UC. METHODS: Retrospective observational study on clinical signs and disease at euthanasia of dogs with UC treated by radiation therapy or chemotherapy or both. RESULTS: The median overall survival time (OST) of all dogs was 339 days (range, 17-1996; 95% confidence interval [CI], 185-392; interquartile range [IQR], 112-505). Of dogs deemed to have been euthanized because of UC (50/59, 85%), the primary cause was considered to be local progression in 31/50 (62%), most often because of perceived complete or partial urinary obstruction (24/31, 77%). No variables were found to be predictive of urinary obstruction. The overall documented metastatic rate was 56%. In dogs euthanized because of UC, metastasis was deemed to be the cause in 19/50 (38%) dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Regardless of the type of treatment, UC in dogs has a poor prognosis and there is a continuing need to improve treatments that focus on local control of the primary tumor, given its high contribution to the decision for euthanasia. Proactive management to avoid the high frequency of urinary obstruction may be worthy of future investigation.

Canine primary liver tumors treated with stereotactic body radiation therapy: A case series.

Stereotactic body radiation therapy (SBRT) is an increasingly used alternative treatment option for nonresectable hepatocellular carcinoma (HCC) in people. Comparatively, the publication of SBRT of dogs with HCC is limited. The objective of this retrospective, descriptive case series was to evaluate the clinical outcomes and toxicity data of SBRT in dogs with HCC and imaging-documented primary liver tumors using volumetric-modulated arc therapy delivery at two private institutions. Medical records of 14 dogs treated between 2018 and 2023 were reviewed. All dogs had macroscopic tumors, and 9 of 14 dogs had HCC diagnoses confirmed on cytology or histopathology. The median longest tumor diameter was 5.5 cm. The median percentage of planning target volume relative to liver volume was 27.1%. Most dogs were treated with three daily fractions of 7-7.5 Gy. All dogs completed their radiotherapy protocols. Three of nine HCC dogs experienced partial responses and clinical improvement. Five of nine HCC dogs had stable disease. Overall median survival time was 164 days for nine HCC dogs (range: 93-706 days). One late grade 5 liver and two late grade 3 kidney side effects were reported. One dog received repeated SBRT to the same HCC treatment field, and one dog had two courses of SBRT to bifocal HCC treatment fields, both with no more than grade 2 acute and chronic toxicities.

Outcomes of 35 dogs with craniomaxillofacial osteosarcoma treated with stereotactic body radiation therapy.

Canine craniomaxillofacial osteosarcoma (OSA) is most commonly treated surgically; however, in cases where surgery is not feasible or non-invasive treatment is desired, stereotactic body radiation therapy (SBRT) may be elected for local tumour control. In this study, we evaluated 35 dogs treated with SBRT. Nine dogs (26%) had calvarial, seven (20%) had mandibular and 19 (54%) had maxillary OSA. Median time to first event (TFE) was 171 days, and overall median survival time (MST) was 232 days. Site-specific MSTs were 144 days for mandible, 236 days for calvarium and 232 days for maxilla (p = .49). Pulmonary metastatic disease was observed in 12/35 (34%) patients and was detected pre-SBRT in six dogs (17%) and post-SBRT in the remaining six dogs (17%). Eighteen adverse events post-SBRT were documented. Per veterinary radiation therapy oncology group criteria, five were acute (14%) and three were late (9%) grade 3 events. Neurological signs in two dogs were suspected to be early-delayed effects. Cause of death was local progression for 22/35 (63%) patients, metastasis for 9/35 (26%) patients and unknown for four. On univariate analysis, administration of chemotherapy was associated with a longer TFE (p = .0163), whereas volume of gross tumour volume was associated with a shorter TFE (p = .023). Administration of chemotherapy and five fractions versus single fraction of SBRT was associated with increased survival time (p = .0021 and .049). Based on these findings, a treatment protocol incorporating chemotherapy and five fractions of SBRT could be considered for dogs with craniomaxillofacial OSA electing SBRT with careful consideration of normal tissues in the field.

Periodontal Pocket Therapy Using a Class IV Dental Diode Laser in Dogs: A Retrospective Analysis.

Class IV dental diode lasers have been introduced as a nonsurgical therapy for periodontal pockets in veterinary and human dentistry. This retrospective case series evaluates the use of Class IV dental diode laser therapy for abnormal periodontal pockets in a specialty veterinary dental practice. A hypothesis that the Class IV diode dental laser is a useful adjuvant modality in canine periodontal pocket therapy in the reduction of clinical pocket depth was made. This article discusses and demonstrates diode laser use in periodontal pocket therapy in a specialty veterinary dental practice and reviews the current literature. Inclusion in this study was limited to client-owned dogs with noted periodontal pocketing on any tooth type between 3 and 6 mm, which were treated with closed root planing (RP/C) and laser therapy who returned in 6 to 7 months for recheck of the pockets from the years 2017 to 2020. Twelve patients met the inclusion criteria. A total of 128 periodontal pockets were included in the study. Each periodontal pocket was a case receiving therapy. The mean periodontal pocket depth before the treatment is measured as 3.35 mm. The mean pocket depth of the periodontal pockets following treatment was 0.59 mm. The mean improvement in periodontal pocket depths after diode laser therapy when considering patient and tooth number using linear mixed-effects modeling was 2.63 mm (95% confidence interval [CI]: 1.81-3.46, P < .0001). No statistically significant results were observed for pocket type, as P values were greater than .05.

Impact of palliative-intent radiotherapy with or without chemotherapy on lameness in flat coat retrievers with localised periarticular histiocytic sarcoma - a retrospective cohort, single institution study.

Histiocytic sarcoma (HS) is a common tumour in flat coat retrievers (FCRs) often affecting periarticular tissues and joints. Palliative-intent radiotherapy, seeks to achieve local tumour control, pain relief and improve limb function. However, the effect of palliative-intent radiotherapy on analgesic levels of dogs with localised HS has not been studied. We hypothesised that palliative-intent radiotherapy could improve lameness in dogs affected by localised HS. This study aimed to assess the impact of palliative-intent radiotherapy on lameness of FCRs with localised HS. A retrospective cohort single institution study was performed. Medical records of FCR dogs with HS that received external beam radiotherapy between 2003 and 2022 were reviewed and included demographic, staging, severity of baseline lameness, therapeutic management and outcome data. Descriptive statistics, McNemar's chi-squared test, Fisher's exact test and Kaplan-Meier analysis were used for statistical analysis. Thirty-nine dogs were included with a median age of 7.2 years, 25 were male and 14 were female. HS was most commonly located in the forelimb (29 dogs, 74.3%), affecting the shoulder joint (19 dogs, 48.7%). Staging was performed in all 39 dogs with 22 (56.4%) dogs having localised HS, six (15.3%) dogs had localised HS with node metastasis and 11 (28.2%) dogs had localised HS with systemic metastasis. All dogs received palliative-intent hypo-fractionated radiation therapy, 32 (82%) dogs showed improvement in lameness. In conclusion, palliative intent radiation treatment has an analgesic effect reducing lameness or clinical signs associated with affected tumour-bearing joints.

Photobiomodulation therapy in dogs undergoing TPLO after cranial cruciate ligament rupture shows promise but no statistically significant difference in a randomized trial.

OBJECTIVE: Effect of photobiomodulation therapy (PBMT) in patients with CCLR after TPLO surgery by measuring C-reactive protein (CRP), percentage weight bearing, lameness using a short form of a composite measure pain scale, evaluated by the clinician and owners, and surgical site infection. SAMPLE: 54 client-owned dogs with CCLR undergoing unilateral TPLO surgery were enrolled in this study between April 5, 2021, through April 10, 2022. METHODS: The study population was randomly assigned to either a treatment group receiving PMBT (24 dogs) or a control group (30 dogs). PMBT was performed on the treatment group immediately after induction, and 6 hours, 24 hours, 48 hours, and 8 weeks postoperatively. The control group received sham PMBT (device turned off) at the same time. Evaluation of CRP, CMPS-SF, evidence of SSI, and %WB were evaluated for all dogs 24 hours preoperatively, and then 24 hours, 48 hours, and 8 weeks postoperatively. Owners completed CMPS-SF and subjective evaluations weekly for 8 weeks postoperatively. RESULTS: No statistically significant differences were found between treatment groups when evaluating CRP, %WB, and CMPS-SF by the clinician and weekly evaluation of the CMPS-SF by owners. Although no statistically significant differences were found in patients developing surgical site infections between treatment groups, SSI was only observed in patients in the control group (5/30, 16.6%). Most were minor/superficial infections (4/30 13.3%), and a single dog (1/30, 3.3%) had a major/deep surgical site infection. CLINICAL RELEVANCE: Although with promising but not statistically significant differences between groups, surgical site infections may be reduced after PBMT application.

Stereotactic radiotherapy for advanced canine anal sac adenocarcinoma: an exploratory study.

For dogs with anal sac adenocarcinoma (ASAC), metastasis to intra-abdominal and pelvic lymph nodes occurs early in the disease course. Death is usually related to locoregional progression. Surgical excision is the treatment of choice, but may not be possible in advanced cases. Dogs treated with RT in the gross disease setting showed a 38%-75% overall response rate, but side effects to organs at risk in this area (especially the colon, bladder, and spinal cord) were reported. Stereotactic radiation therapy (SRT) utilizes highly conformal treatment planning with rapid dose fall-off and hypofractionation. SRT may help to reduce the risk of late side effects of radiation while also creating a larger biological effect on ASACs. A primary aim of this prospective, descriptive, exploratory study was to describe the safety and feasibility of an SRT protocol in a small sample of dogs with ASAC, using objective and subjective measures to monitor acute and late side effects. A secondary aim was to describe the anti-tumor response of the SRT protocol using CT at 3- and 6 months posttreatment. Five dogs completed the radiation protocol. Four had follow-up CT characteristics of complete response (1), partial response (2), and stable disease (1). Minimal acute side effects were observed. Despite some large tumor volumes, constraints for OAR were achieved in all but the spinal cord for one patient. Findings indicated that SRT is a safe and feasible treatment for dogs with ACAC. Future studies are warranted to compare patient outcomes for SRT versus other treatments.

Radiotherapy in combination with exenteration and partial orbitectomy for orbital multilobular tumor of bone in a Cocker Spaniel.

Background: Multilobular tumor of bone or multilobular osteochondrosarcoma is a tumor of flat bone in the skull. The treatment of choice for a multilobular tumor of bone is local aggressive surgical excision. Case Description: A female Cocker Spaniel dog aged 11 years presented with a history of globe displacement of the right eye for 3 months. Ophthalmic examination revealed exophthalmos, third eyelid protrusion, and slightly increased intraocular pressure OD (oculus dexter; right eye). Computed tomography (CT) revealed a mass effect in the right retrobulbar, maxilla, zygomatic, and temporal areas. Right zygomatic and temporal bone lysis were observed. Physical examination, hematology, and blood chemistry results were within normal limits. Exenteration with zygomatic arch removal was performed. During surgery, a firm 2-lobed mass (4.8 × 3.7 and 1.6 × 1.4 cm) adhered to the mandible was found in the retrobulbar area OD. Histopathological findings revealed a multilobular tumor of bone. CT imaging was performed for the remaining tumor and an extended part of the right retrobulbar mass was found. Hypofractioned radiotherapy with 6 fractions of 6 Gy was performed on days 0, 7, 14, 21, 28, and 35. At 1-month and 4-month follow-up inspections, the mass gradually reduced in size. At 8 months and 11 months after radiotherapy, the mass was unremarkable. The dog was alert during all follow-up periods to 1 year and 8 months after hypofractioned radiotherapy combined with exenteration and partial orbitectomy. Conclusion: Hypofractioned radiotherapy combined with exenteration and partial orbitectomy extended the patient's survival and decreased the size of the remaining tumor for the management of orbital multilobular tumor of bone in this dog for at least 1 year and 8 months.

Intensity-modulated radiotherapy and chemotherapy for canine right atrial tumors: A retrospective study of seven dogs.

Most primary cardiac tumors in dogs are located in the right atrium/atrial appendage, with hemangiosarcoma being the most common. The aims of this retrospective, case series were to describe outcomes for seven dogs with right atrial tumors treated with hypofractionated intensity-modulated radiotherapy and concurrent vinblastine and propranolol. One dog had a complete response, four dogs had partial responses and two dogs had stable disease after treatment. Effusions resolved in all dogs. Median progression-free survival was 290 days. Five dogs died from metastatic disease, one dog from unrelated neoplasia, and one dog is alive. Median overall survival was 326 days. Three dogs with confirmed hemangiosarcoma survived 244, 326, and 445 days. Two dogs developed clinically significant, but nonfatal, cardiac arrhythmias. One dog that received three courses of radiation had subclinical myocardial and arterial fibrosis at necropsy. Hypofractionated chemoradiotherapy was well tolerated and may provide clinical benefit in dogs with right atrial tumors.