In vitro effects of N-acetylcysteine in combination with antifungal agents against Malassezia pachydermatis isolated from canine otitis externa.

BACKGROUND: Many clinicians prescribe antifungal agents to treat canine otitis externa (OE). However, studies evaluating the antifungal effects of N-acetylcysteine (NAC) and its combinations are limited. HYPOTHESIS/OBJECTIVES: The aim of this study was to evaluate the antifungal effects of NAC alone and in combination with other antifungal agents against Malassezia pachydermatis isolated from canine OE. MATERIALS AND METHODS: M. pachydermatis samples were collected from 13 dogs with OE. The final concentration of the inoculum suspensions of M. pachydermatis was 1-5 × 106 colony forming units/mL. The concentrations of the test compounds ketoconazole (KTZ), terbinafine (TER), nystatin (NYS) and NAC were 0.02-300 µg/mL, 0.04-80 µg/mL, 0.16-40 µg/mL and 1.25-20 mg/mL, respectively. The minimum inhibitory concentration (MIC) was measured to evaluate the susceptibility of the M. pachydermatis to KTZ, TER, NYS and NAC. The checkerboard testing method and fractional inhibitory concentration index were used to evaluate the effect of NAC in combination with KTZ, TER and NYS against M. pachydermatis. RESULTS: The MIC90 values of M. pachydermatis were 4.6875-9.375 µg/mL, 1.25 µg/mL, 5-10 µg/mL and 10 mg/mL for KTZ, TER, NYS and NAC, respectively. The synergistic effects of KTZ, TER and NYS with NAC were identified in 0/13, 2/13 and 0/13 isolates, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: NAC had an antifungal effect against M. pachydermatis but did not exert synergistic effects when used with KTZ, TER and NYS. Thus, the use of NAC alone as a topical solution could be considered an effective treatment option for canine OE involving M. pachydermatis.

Corticosteroid monotherapy versus combined cytarabine continuous rate infusion and corticosteroid therapy in dogs with meningoencephalitis of unknown origin: A blinded, randomized, controlled trial.

BACKGROUND: Treatment options available for meningoencephalitis of unknown origin (MUO) in dogs are suboptimal, and currently, no single treatment protocol appears to be superior. OBJECTIVES: Compare neurological deterioration rates at 7 days between dogs with MUO treated with corticosteroids alone or combined with cytosine arabinoside (CA) continuous rate infusion (CRI) and compare clinical deterioration and survival at 30 and 100 days. ANIMALS: Sixty-nine dogs with magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) features or both compatible with MUO. METHODS: Parallel, blinded, randomized controlled trial. Simple randomization into 2 treatment groups: 4 mg/kg/day prednisolone (or dexamethasone equivalent) for 2 days or 200 mg/m2 CA CRI over 8 hours plus 2 mg/kg/day prednisolone. Blinding of the treatment protocol was carried out using reversible redaction of clinical records, and treatment failure was defined as deterioration of neurological assessment or death. Using intention-to-treat analysis, proportions failing treatment at 7, 30, and 100 days were compared using Fisher's exact test. All-cause mortality at 100 days was compared using Kaplan-Meier survival curves. RESULTS: Thirty-five dogs were allocated to corticosteroid only, and 34 dogs were allocated to combined CA CRI and corticosteroid. Proportions failing treatment at 7, 30, and 100 days were 7/35 (20%), 9/35 (26%), and 15/35 (43%) in the corticosteroid-only group and 8/34 (24%), 11/34 (32%), and 23/34 (68%) in the corticosteroid and CA CRI group. All-cause mortality at 100 days was not significantly different between groups (P = .62). Clinically relevant treatment-related adverse effects were not observed. CONCLUSIONS AND CLINICAL IMPORTANCE: We found no difference in outcome between corticosteroid monotherapy and combined cytarabine CRI and corticosteroid therapy at 7, 30, and 100 days after diagnosis in dogs with MUO.

Effect of the sodium-glucose cotransporter-2 inhibitor, DWP16001, as an add-on therapy to insulin for diabetic dogs: A pilot study.

BACKGROUND: Sodium-glucose cotransporter-2 (SGLT2) inhibitors are a novel class of anti-hyperglycaemic agents. OBJECTIVE: This study aimed to evaluate the safety and the adjuvant glycaemic control effect of an SGLT2 inhibitor, DWP16001, in diabetic dogs receiving insulin treatment. METHODS: Nineteen diabetic dogs receiving insulin treatment (NPH, porcine lente and glargine insulin) were divided into two groups according to dosing frequency: DWP TOD group (n = 10) and DWP SID group (n = 9). In the DWP TOD group, 0.025 mg/kg of DWP16001 was administered once every 3 days, whereas, in the DWP SID group, 0.025 mg/kg of DWP16001 was administered once a day. Food intake was maintained during the trial period. Hypoglycaemia, ketoacidosis or unexpected life-threatening reactions were assessed as adverse effects before and after DWP16001 administration. We compared insulin requirement reduction and blood glucose level control between two groups. RESULTS: No specific adverse effects were observed during the clinical trial, and haematological parameter remained unchanged. Moreover, the fasting glucose levels and daily insulin dose in the DWP TOD group were lower than the pre-administration values, but not significantly different for 8 weeks. Systolic blood pressure, fructosamine and insulin dose decreased significantly in the DWP SID group compared to the DWP TOD group at 8 weeks (p < 0.05) without affecting food consumption. Among these patients, 10 patients were monitored while receiving DWP16001 for 12 months (DWP TOD group n = 5, DWP SID group n = 5). The fasting glucose and fructosamine levels and daily insulin dose were reduced in both groups at 12 months compared with those before receiving DWP16001. CONCLUSION: When DWP16001, an SGLT2 inhibitor, was supplied to dogs with type 1 diabetes, no adverse effects were observed, and it was confirmed that the administered insulin dose can be reduced in controlling blood glucose.

Clinical safety and efficacy of a single-dose gentamicin, posaconazole and mometasone furoate otic suspension for treatment of canine otitis externa.

BACKGROUND: A single-dose, in-clinic, veterinary professional-administered treatment for canine otitis externa was developed to improve compliance and canine welfare. METHODS: This multicentre, controlled, examiner-masked, randomised field trial was conducted in 316 dogs over 42 days. Dogs were treated once, on day 0, with the investigational product containing gentamicin, posaconazole and mometasone furoate (Mometamax Ultra [MU]) or twice (days 0 and 7) with a control product containing florfenicol, terbinafine and betamethasone acetate (CP). The primary endpoint was a composite otitis index score of 4 or less (of 12) on day 14 and 3 or less (of 12) on day 28. RESULTS: On day 28, treatment success was recorded in 128 of 143 MU-treated dogs (89.5%), significantly non-inferior to 116 of 133 (87.2%) CP-treated dogs (Farrington-Manning test, Z = 4.1351, p < 0.0001). For mixed cultures of Staphylococcus pseudintermedius and Malassezia pachydermatis, there was 100% treatment success in MU-treated dogs (n = 33), significantly non-inferior to 90.2% (37 of 41) in CP-treated dogs (Farrington-Manning test, Z = 3.1954, p = 0.0007). LIMITATIONS: Efficacy in chronic otitis externa cases was not investigated. Cytology was not used to aid in diagnosis or for identification of secondary pathogens. CONCLUSION: This unique combination, single-dose product is safe and effective in dogs with otitis externa. It offers enhanced compliance, canine welfare and quality of life by eliminating the owner burden of treating this painful condition.

Evaluation of different substance combinations in a multiple-session mesotherapy protocol for the management of osteoarthritis in dogs: a retrospective study.

OBJECTIVE: To describe the effect of different substance combinations administered through mesotherapy in dogs with hip osteoarthritis. ANIMALS: 104 dogs. METHODS: In this retrospective study, 4 groups (dogs treated with a combination of lidocaine, piroxicam, and thiocolchicoside [MG]; dogs treated with lidocaine, piroxicam, and Traumeel [TG]; dogs treated with lidocaine, piroxicam, and glucosamine [GG]; and dogs treated with the same combination as in MG combined with a photobiomodulation session [MPG]) were set. For all groups, the same treatment frequency was followed. Response to treatment was measured with the Canine Brief Pain Inventory (divided into pain interference score and pain severity score), Liverpool Osteoarthritis in Dogs (LOAD), and Canine Orthopedic Index (divided into function, gait, stiffness, and quality of life) before treatment and 15, 30, 60, 90, and 120 days after treatment. Cox proportional hazard regression analysis was used to investigate the influence of treatment, age, sex, body weight, breed, and Orthopedic Foundation for Animals score. RESULTS: Dogs had a mean age of 7.6 ± 3.1 years and body weight of 28.6 ± 5.5 kg. Hip osteoarthritis was classified as mild (4), moderate (70), or severe (30). Greater improvements were observed in MG and MPG. Kaplan-Meier estimators showed MG and MPG had longer periods with clinically significant results. Treatment was the covariable that contributed more frequently to the outcomes observed. CLINICAL RELEVANCE: The combination used in MG, particularly combined with photobiomodulation, produced longer-lasting clinically significant results.

Repurposing of non-steroidal anti-inflammatory drugs for combination therapies to combat multidrug-resistant S. aureus of bovine reproductive tract origin.

Multidrug-resistant bacteria have become the predominant etiology in bovine female reproductive tract infections and thus require effective treatment approaches. The main goal of this study was the molecular detection of mecA, blaZ, tetK, and aacA-aphD genes in Staphylococcus aureus (S. aureus) responsible for methicillin, beta-lactam, tetracycline, and aminoglycoside resistance respectively. Phylogenetic analysis was conducted to check the homology of staphylococcal genes with NCBI sequences. The in-vitro efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) in combination therapies against MDR S. aureus was evaluated using well diffusion assay and checkerboard method. Vaginal swab samples (n = 384) collected from bovines suffering from endometritis, pyometra, and retained placenta were tested for S. aureus. Results showed a 17.96% overall prevalence. Both phenotypic and genotypic resistance was observed among S. aureus isolates with 50.72% and 37.68% isolates being confirmed as methicillin-resistant (MRSA), 36.23% and 18.84% isolates exhibiting beta-lactam, 40.58%, and 27.54% isolates showing tetracycline, and 33.33% and 36.23% isolates showing aminoglycosides resistance based on disc diffusion and gene confirmation, respectively. Phylogenetic analysis indicated homology with previously reported Pakistani isolates suggesting the possibility of MDR S. aureus transmission within and between animals. Synergy testing indicated that combinations of ceftriaxone-ketoprofen (153.77%), ceftriaxone-meloxicam (149.55%), amoxiclav-flunixin meglumine (106.06%), and oxytetracycline-flunixin meglumine (104.47%) showed synergy on well diffusion assay. Based on the fractional inhibitory concentration index by checkerboard method, oxytetracycline-meloxicam and gentamicin-ketoprofen combinations exhibited synergistic interaction. In conclusion, MDR S. aureus resistance was mitigated in-vitro through the combination of antibiotics (oxytetracycline, gentamicin) with NSAIDs (meloxicam, ketoprofen) that could be used to create therapeutic strategies for bovine reproductive issues.

Mycophenolate mofetil as a treatment for presumed idiopathic chronic hepatitis in dogs: Six cases (2010-2022).

OBJECTIVES: The objectives of this study were to describe the clinical findings, treatment and outcomes of six dogs with presumed idiopathic chronic hepatitis treated with mycophenolate mofetil (MMF). MATERIALS AND METHODS: Medical records were retrospectively searched to identify dogs in which idiopathic chronic hepatitis was diagnosed on histopathology between January 2010 and June 2022 that were treated with MMF for at least two weeks with >2 follow-up examinations. Data recorded from each dog included signalment, clinical signs, diagnostic test results and treatment. RESULTS: Six dogs were treated with MMF at a median initial dosage of 9.6 mg/kg PO q 12 h. Reported adverse effects from MMF included decreased appetite, vomiting and diarrhoea. In all six dogs, MMF was used successfully long term for the treatment of idiopathic chronic hepatitis as determined by 46% or greater improvement of alanine aminotransferase (ALT) between 4 and 18 weeks of starting MMF. Three dogs were also temporarily treated for 4-6 months on a tapering dose of prednisone. In two dogs, ALT remained within the reference interval, and in one dog, it was very mildly elevated when on MMF alone. In all six dogs, owners reported that the medication was well tolerated. CLINICAL SIGNIFICANCE: To the authors' knowledge, this is the first report describing the use of MMF with and without a tapering dose of prednisone for the treatment of idiopathic chronic hepatitis in six dogs. Based on the outcomes of the dogs in this report, MMF can be effective for the long-term treatment of idiopathic chronic hepatitis as measured by reduction in ALT and improvement of clinical signs.

Pharmacokinetics and effects of codeine in combination with acetaminophen on thermal nociception in horses.

Codeine and acetaminophen in combination have proven to be an effective analgesic treatment for moderate-to-severe and postoperative pain in humans. Studies have demonstrated that codeine and acetaminophen, when administered as sole agents, are well tolerated by horses. In the current study, we hypothesized that administration of the combination of codeine and acetaminophen would result in a significant thermal antinociceptive effect compared with administration of either alone. Six horses were administered oral doses of codeine (1.2 mg/kg), acetaminophen (20 mg/kg), and codeine plus acetaminophen (1.2 mg/kg codeine and 6-6.4 mg/kg acetaminophen) in a three-way balanced crossover design. Plasma samples were collected, concentrations of drug and metabolites determined via liquid chromatography-mass spectrometry, and pharmacokinetic analyses were performed. Pharmacodynamic outcomes, including effect on thermal thresholds, were assessed. Codeine Cmax and AUC were significantly different between the codeine and combination group. There was considerable inter-individual variation in the pharmacokinetic parameters for codeine, acetaminophen, and their metabolites in horses. All treatments were well tolerated with minimal significant adverse effects. An increase in the thermal threshold was noted at 1.5 and 2 h, from 15 min through 6 h and 0.5, 1, 1.5, and 3 h in the codeine, acetaminophen, and combination groups, respectively.

Telmisartan as an add-on treatment for dogs with refractory idiopathic epilepsy: a nonrandomized, uncontrolled, open-label clinical trial.

OBJECTIVE: To evaluate the effect on seizure frequency of add-on telmisartan treatment in dogs with refractory idiopathic epilepsy. ANIMALS: 11 client-owned dogs with idiopathic epilepsy and ≥ 2 generalized seizures/mon that were currently being treated with ≥ 2 antiepileptic drugs. PROCEDURES: Telmisartan was administered at a dosage of 0.25 to 1 mg/kg, PO, every 12 hours for 4 to 16 months. Seizure frequencies before and during telmisartan treatment were recorded. RESULTS: 10 dogs completed the 4-month treatment protocol. One dog was excluded owing to a transient increase in serum creatinine concentration; no adverse effects of telmisartan were observed in the remaining 10 dogs. A reduction in seizure frequency greater than an estimated expected placebo effect of 30% was evident in 7 of the 10 dogs. Long-term (12 to 16 months) follow-up information was available for 6 dogs, of which 4 had a further reduction in seizure frequency. Differences in seizure frequency were not statistically significant. No significant difference was found in serum phenobarbital concentration throughout the treatment period in the 7 dogs that were tested. CLINICAL RELEVANCE: Telmisartan has the potential to reduce seizure frequency when administered as an add-on antiepileptic drug in dogs with refractory idiopathic epilepsy. A randomized, double-blind, placebo-controlled trial is needed to determine the true efficacy of telmisartan. On the basis of our results, a sample size of 54 dogs with refractory idiopathic epilepsy would be needed.

A retrospective evaluation of the steroid sparing effects of oral mycophenolate mofetil (MMF) as an adjunct immunosuppressant for the treatment of canine pemphigus foliaceus.

BACKGROUND: Oral mycophenolate mofetil (MMF) currently is considered a low-risk steroid-sparing therapeutic option for the management of canine pemphigus foliaceus (PF). OBJECTIVES: This retrospective study evaluates the therapeutic outcomes of dogs with PF treated with the combination of oral MMF and glucocorticoid (GC). Clinical outcomes and adverse side effects are reported. ANIMALS: Eleven dogs diagnosed with PF. MATERIALS AND METHODS: Retrospective review of medical records from dogs presented with PF to the dermatology service of a veterinary teaching hospital between 2015 and 2020. RESULTS: Eleven dogs were identified which had received concurrent GCs and MMF. The MMF dose range was 19.8-45 mg/kg/day. Only two dogs (two of 11) treated with a mean MMF dosage of 39 mg/kg/day along with oral prednisone or dexamethasone achieved complete remission (CR). Partial remission (PR) was achieved in four of 11 dogs who received either prednisone, prednisolone or dexamethasone along with MMF (mean dosage 26 mg/kg/day). Four dogs (four of 11) showed poor response to MMF given at 28.5 mg/kg/day along with prednisone or dexamethasone. In one dog (one of 11) MMF was discontinued due to severe GI upset; transient vomiting and diarrhea was observed in four of 11 dogs. The median duration of MMF therapy in conjunction with GC for all groups was 70.5 days. Tapering of oral GCs while continuing MMF administration at the same dosage and frequency led to recurrence of lesions in all PF patients. CONCLUSION: Oral MMF combined with GC achieved CR in two of 11 PF dogs included in this study. Further research of MMF efficacy in PF may need to be performed.

Investigation of the effects of mTOR inhibitors rapamycin and everolimus in combination with carboplatin on canine malignant melanoma cells.

BACKGROUND: Malignant melanoma in dogs is considered to be largely resistant to conventional chemotherapy, although responses to carboplatin have been documented. Invasion and early metastasis are common features of certain melanoma subtypes that contribute to tumour progression despite aggressive local and systemic therapy. Upregulation of the PI3K/AKT/mTOR pathway has been observed in canine malignant melanoma and may represent a potential target for therapy. Rapamycin (sirolimus) and everolimus are commercially available small molecule inhibitors that target mTOR and therefore may have anticancer activity in canine melanoma. It was hypothesized that there is synergism between rapamycin or everolimus and platinum chemotherapy, and that combination drug treatment would inhibit target/downstream proteins involved in cell viability/proliferation and increase cell death in canine melanoma cells. It was further hypothesized that rapamycin or everolimus would impact metabolism by reducing glycolysis in these cells. Four canine melanoma cell lines were treated in vitro with rapamycin and everolimus as sole treatment or combined with carboplatin. Cell viability, apoptosis, target modulation, and glycolytic metabolism were evaluated by crystal violet colourimetric assay, Annexin V/PI flow cytometry, western blotting, and Seahorse bioanalyzer, respectively. RESULTS: When combined with carboplatin chemotherapy, rapamycin or everolimus treatment was overall synergistic in reducing cell viability. Carboplatin-induced apoptosis was noted at 72 h after treatment compared to the vehicle control. Levels of phosphorylated mTOR were reduced by rapamycin and everolimus in all four cell lines, but activation of the downstream protein p70S6K was not consistently reduced by treatment in two of the cell lines. Both mTOR inhibitors decreased the extracellular acidification rate of canine melanoma cells, indicating reduced cancer cell glycolytic activity. CONCLUSIONS: Inhibition of mTOR by rapalogs, such as rapamycin and everolimus combined with carboplatin chemotherapy may have activity in canine melanoma. Future mechanistic investigation is warranted, including in vivo assessment of this combination therapy.

Muscle tremors observed in white rhinoceroses immobilised with either etorphine-azaperone or etorphine-midazolam: An initial study.

Etorphine-azaperone is the most commonly used drug combination for chemical immobilisation of free-ranging white rhinoceroses, but causes several profound physiological disturbances, including muscle tremors. The addition of benzodiazepine sedatives, such as midazolam, has been proposed to reduce the muscular rigidity and tremors in immobilised rhinoceroses. Twenty-three free-ranging, sub-adult white rhinoceros bulls were darted and captured using a combination of etorphine plus either azaperone or midazolam. Skeletal muscle tremors were visually evaluated and scored by an experienced veterinarian, and tremor scores and distance run were compared between groups using the Wilcoxon rank sum test. No statistical differences were observed in tremor scores (p = 0.435) or distance run (p = 0.711) between the two groups, and no correlation between these variables was detected (r = -0.628; p = 0.807). Etorphine-midazolam was as effective as etorphine-azaperone at immobilising rhinoceroses, with animals running similar distances. Although the addition of midazolam to the etorphine did not reduce tremor scores compared to azaperone, it might have other beneficial immobilising effects in rhinoceroses, and further investigation is necessary to elucidate possible methods of reducing muscle tremoring during chemical immobilisation of rhinoceroses.

Efficacy of Panax ginseng extract combined with cephalexin as a dry cow therapy.

Our objective was to evaluate the efficacy of intramammary administration, at drying-off, of a Panax ginseng extract (PGe) combined with cephalexin (Ceph) on the post-calving bacteriological cure rate of pre-existing intramammary infections (IMI) and on the occurrence of new IMI during the dry period. In addition, milk yield and somatic cell count (SCC) in the post-treatment lactation were evaluated. One hundred and eight late-lactation cows were randomly divided into two experimental groups and were treated at drying-off with Ceph alone or PGe combined with Ceph.Cure rates for IMI present at drying-off were similar for both treatments (OR = 0.95, 95% CI = 0.33-2.74). Cure rates for Staphylococcus aureus were lower (OR = 15.4, 95% CI = 1.66-142.52) in quarters treated with PGe + Ceph than in those treated with Ceph alone. Intramammary infusion of PGe + Ceph at drying-off had no effect on preventing new dry period IMI (OR = 0.75, 95% CI = 0.38-1.51), compared with infusion of Ceph alone. Milk production and SCC in the ensuing lactation were not affected by PGe + Ceph treatment. In conclusion, addition of PGe to dry cow therapy did not show any advantage over the use of dry cow therapy alone.

Efficacy of semi-annual therapy of an extended-release injectable moxidectin suspension and oral doxycycline in Dirofilaria immitis naturally infected dogs.

BACKGROUND: Dirofilaria immitis is a life-threatening nematode spreading globally. Arsenical treatment is currently recommended for removal of adult worms. However, arsenical treatment is not available in some countries, and there are dogs that cannot tolerate the rapid kill of adult worms; therefore, alternative adulticide slow-kill treatments are needed. Criticisms against the use of these alternative protocols include the potential for allowing disease to progress and for the development of ML-resistant worms. METHODS: The efficacy of a protocol that includes semi-annual doses (i.e. every 6 months) of commercially available extended-release injectable moxidectin suspension (ProHeart® SR-12) with 30-day oral administration of doxycycline was studied in 20 dogs with naturally occurring D. immitis infections. Each dog received treatment with ProHeart® SR-12 (0.5 mg moxidectin/kg) by subcutaneous injection and oral doxycycline (10 mg/kg/bid × 30 days) every 6 months until two consecutive negative antigen test results were obtained. Pulmonary and cardiac evaluations were performed by radiographic and echocardiographic parameters. Physical examinations, complete blood counts, clinical chemistry profiles, microfilariae and antigen tests were performed periodically. RESULTS: At enrollment, all dogs were positive for D. immitis antigen and 18 were microfilaremic. On day 30, microfilaremia counts decreased, and all dogs became amicrofilaremic by day 150. On day 180, 11 dogs were antigen-negative, and 7 more became negative by day 360. The two remaining antigen-positive dogs converted to negative by day 540 or 810. All antigen tests performed 180 days after the first negative test were negative. There was no decline in cardiac performance of the dogs throughout the study. Overall, pulmonary clinical conditions, presence of worms by echocardiography, and enlargement of caudal and main pulmonary arteries improved after treatment. Physical examinations, complete blood count results, and clinical chemistry profiles were within normal reference values. Respiratory conditions were improved, no damage to the heart was observed, and the treatment protocol was well tolerated by the animals. CONCLUSIONS: This alternative adulticide treatment was efficacious and well tolerated in naturally infected dogs. The injectable formulation provides the advantage of having veterinarians able to administer, monitor, and assess the efficacy and condition of the dog throughout the treatment and post-treatment periods.

Heartworm control in Grenada, West Indies: Results of a field study using imidacloprid 10% + moxidectin 2.5% and doxycycline for naturally-acquired Dirofilaria immitis infections.

Canine heartworm disease (CHD) results from infection with Dirofilaria immitis and while it is of global concern, it is most prevalent in tropical climates where conditions support the parasite and vector life cycles. Melarsomine dihydrochloride is the sole treatment for CHD recommended by the American Heartworm Society. However, in cases where cost or access to melarsomine precludes treatment of an infected dog, therapeutic alternatives are warranted. This randomized, controlled field study evaluated the adulticidal efficacy of a combination therapeutic protocol using 10 % imidacloprid + 2.5 % moxidectin spot-on and a single 28-day course of doxycycline and compared with that of a 2-dose melarsomine dihydrochloride protocol. Of 37 naturally-infected domestic dogs with class 1, 2 or early class 3 CHD enrolled in the study, 30 were evaluated for a minimum of 12 months. Seven dogs were withdrawn due to canine ehrlichiosis, non-compliance, or wrongful inclusion. Dogs were randomly assigned to a control (CP, n = 15) or investigational (IVP, n = 15) treatment group. CP dogs received two injections of melarsomine dihydrochloride (2.5 mg/kg) 24 -hs apart and maintained on monthly ivermectin/pyrantel. IVP dogs were treated with oral doxycycline (10 mg/kg twice daily for 28 days) and topical 10 % imidacloprid + 2.5 % moxidectin once monthly for 9 months. Dogs were evaluated up to 18 months - monthly for the first 9 months, then every 3 months. Parasiticidal efficacy was based on antigen status using the IDEXX PetChek® 34 Heartworm-PF Antigen test. By month 18, antigen was not detected in any study dog except one from the IVP group. One other IVP dog was persistently antigenemic and treated with melarsomine at month 12 according to the initial study protocol. Mean antigen concentration (based on optical density) decreased more rapidly in the CP group and by month 15 was 0.11 for the IVP and 0.07 for CP groups, with equivalent median concentrations (0.04) in both groups. Conversion following heat-treatment of antigen-negative samples occurred frequently and at similar rates in both treatment groups. Based on the bias of diagnostic tests towards detection of female worms, we conclude that monthly application of 10 % imidacloprid + 2.5 % moxidectin for 9 months combined with a course of doxycycline twice daily for 28 days resulted in effective therapy against female adults in CHD. This therapeutic option may be particularly useful in cases where financial constraint or access to melarsomine precludes treatment of an infected individual. This study was supported by Bayer Animal Health.

Clinical assessment of heartworm-infected Beagles treated with a combination of imidacloprid/moxidectin and doxycycline, or untreated.

BACKGROUND: Administration of moxidectin topically and doxycycline PO has been utilized experimentally as an alternative treatment for heartworm disease. However, clinical effects of this protocol remain poorly characterized. OBJECTIVE: To evaluate the clinical and postmortem findings associated with administration of doxycycline and monthly 10% imidacloprid + 2.5% moxidectin (IMD + MOX, Advantage Multi/Advocate) to Dirofilaria immitis-experimentally infected as compared to nontreated control dogs. ANIMALS: Sixteen purpose-bred, female, Beagle dogs. METHODS: Prospective, blinded, experimental study. Animals with surgically transplanted adult heartworms were randomized into 2 study groups of equal size: a nontreated control group (n = 8) and an IMD + MOX and doxycycline-treated group (n = 8). Randomization was performed using a complete block design according to circulating microfilarial concentrations, measured before treatment. Serum biochemical profiles, CBCs, thoracic radiographs and echocardiograms were performed prior to and 3 weeks after transplantation, and monthly for 10 months. Postmortem gross and histopathologic evaluations were performed. RESULTS: Compared to control animals, mean ± SD serum alanine aminotransferase (181 ± 203 U/L vs 33 ± 7 U/L; P < .0001) and alkaline phosphatase (246 ± 258 U/L vs 58 ± 19 U/L; P < .0001) activities were significantly higher in the treated group on day 28. Radiographic and echocardiographic evidence of heartworm disease was observed in both groups; however, no significant differences in these variables were noted between groups. Mean ± SD pulmonary arterial thrombus score was significantly higher in the treated vs nontreated group (3.9 ± 0.4 and 1.5 ± 2.1, respectively; P = .01). CONCLUSIONS AND CLINICAL IMPORTANCE: The treatment protocol was well-tolerated with no clinically relevant adverse effects for any variable evaluated during the observational period.

Azithromycin and Diminazene Aceturate Combination Therapy in Experimental Multidrug-resistant Trypanosoma brucei brucei Infection in Albino Rats.

Azithromycin and diminazene aceturate combination therapy in experimental multidrug-resistant Trypanosoma brucei brucei infection in albino rats was evaluated. A total of forty-five female albino rats were used. These rats were randomly assigned to nine groups of five rats each. Group 1 was the uninfected-untreated group while groups 2 - 6 were infected with 1 × 106 trypanosomes suspended in 0.3 ml of normal saline intraperitoneally. Following infection and parasitaemia, group 2 was untreated while group 3 was treated once with 7 mg/kg diminazene aceturate. Groups 4 - 6 were treated with 10, 20 and 30 mg/kg azithromycin respectively for 7 days. Groups 7 - 9 were treated with combination of 7 mg/kg diminazene aceturate (DA) once and 10, 20 and 30 mg/kg azithromycin (AZT) respectively for 7 days. Level of parasitaemia, haematological indices (packed cell volume, total erythrocyte count, total leukocyte count, haemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration), survivability, body weight and rectal temperature were used to assess the effectiveness of the combination therapy. A significant reduction in parasitaemia levels was observed in the DA-treated group and AZT-treated group 6 while clearance of parasitaemia was observed in the DA-AZT treated groups 7 - 9 for periods between 1 and 5 days post treatment. The haematological indices and survivability of the DA-AZT treated groups were better than the DA-treated group despite the relapse recorded in those groups. One rat each in the DA-AZT combination groups survived till the end of the experiment. In conclusion, the DA-AZT combination treatment can be used as a possible adjunct to DA in the treatment of multidrug-resistant T. brucei brucei. The combination also enhanced survivability and decreased the effect of the disease in rats.

Evaluation of treatment with a combination of mycophenolate mofetil and prednisolone in dogs with meningoencephalomyelitis of unknown etiology: a retrospective study of 86 cases (2009-2017).

BACKGROUND: Combination therapy with glucocorticoids and adjunctive immunomodulating drugs has been generally accepted as a standard treatment regimen for meningoencephalomyelitis of unknown etiology (MUE). We hypothesized that treatment with MMF as an adjunctive agent along with glucocorticoids would be effective and well-tolerated protocol in dogs with MUE. Eighty-six dogs with MUE between May 2009 and June 2017 were included (59 females and 27 males; mean age of 5.93 years; mean body weight of 3.83 kg). The medical records of dogs with MUE treated with prednisolone and MMF were retrospectively evaluated to determine the therapeutic response, survival time, and treatment-related adverse effects. RESULTS: A partial or complete response (CR) was recorded for 75 dogs. The overall median survival time from the initiation of treatment was 558 days. Dogs that showed CR with no relapse over the treatment period (from diagnosis to death) had significantly longer median survival times. A significantly higher mortality hazard ratio of 4.546 was recorded in dogs that failed to achieve CR. The interval between the onset of clinical signs and the clinical presentation was not significantly associated with CR, relapse rate, and survival time. Adverse effects included gastrointestinal upsets in 26 dogs (30.23%), sporadic infections in 17 dogs (19.77%), and pancreatitis in seven dogs (8.14%). CONCLUSIONS: The results suggest that adjunctive MMF treatment for MUE is safe and comparable to other immunosuppressive protocols. The treatment should focus on the achievement of CR and preventing relapse for successful management.

Non-Arsenical heartworm adulticidal therapy using topical moxidectin-imidacloprid and doxycycline: A prospective case series.

This prospective case series evaluated the adulticidal efficacy of topical 10 % moxidectin/2.5 % imidacloprid (M/I; Advantage Multi®, Bayer, Shawnee Mission, KS, USA) and doxycycline in dogs with naturally occurring heartworm infection (HWI). Twenty-two dogs with HWI whose owners declined melarsomine were treated with M/I at the preventive dosage twice monthly for 90 days then monthly thereafter and doxycycline (median [interquartile range; IQR] dosage 12.6 [12.0-16.1] mg/kg/day) for the first 15 days. Although strict activity restriction was not imposed, owners were asked to prevent their dogs from exercising strenuously. This protocol was referred to as the MOXY protocol. Antigen testing was performed every 30-60 days, until dogs had 'no antigen detected' (NAD). Twenty-one of the 22 dogs ultimately converted to NAD by 434 days (median [IQR]), 234 (179-303). One dog remained positive 701 days after MOXY initiation and was considered a treatment failure. All sera which converted to NAD on HW antigen testing were retested after heat-treatment. Twelve dogs had NAD on the heat-treated test on the same day as having their first NAD on the conventional test. Six of 9 dogs testing positive after heat-treatment were retested and all 6 had NAD on a heat-treated test within 2-3 months. Microfilaremia was cleared in all 8 dogs re-tested. Four dogs required treatment for cough, thought due to heartworm (HW) death, an average of 89 days after initiation of MOXY. This cough was most likely due to pneumonitis with heartworm-pulmonary thromboembolism. One dog required hospitalization for 24 -h and recovered fully with corticosteroid therapy and supportive care and 2 dogs were treated in an outpatient fashion with steroids. The MOXY protocol was tolerated and 96 % (21/22) of dogs converted to NAD, though 2 dogs required greater than 1 year to achieve this result. Nonaresenical-adulticide therapy may result in pneumonitis and heartworm-pulmonary thromboembolism at unpredictable times, potentially months after initiation of macrocyclic lactone therapy and exercise restriction should be considered when using a nonarsenical protocol. Although not currently recommended by the American Heartworm Society (AHS), non-arsenical strategies are in use and the goal of this study was to evaluate the efficacy, duration of therapy, and safety of an accelerated dosing protocol of M/I with doxycycline.

A prospective randomized, double-blinded clinical study evaluating the efficacy and safety of bupivacaine versus morphine-bupivacaine in caudal epidurals in cats with urethral obstruction.

OBJECTIVE: To investigate the efficacy and safety of the caudal epidural technique in cats with urethral obstruction (UO). DESIGN: Prospective, double-blinded, randomized, sham-controlled study. ANIMALS: Eighty-eight male cats with UO. INTERVENTIONS: Thirty cats randomized to bupivacaine epidural (BUP), 28 cats to bupivacaine-morphine epidural (BUP/MOR), and 30 cats to sham epidural (SHAM). MEASUREMENTS AND MAIN RESULTS: Time to perform the epidural and efficacy of the epidural was assessed by evaluation of tail and perineal responses. The amount of propofol for urinary catheterization and time to administration of rescue analgesia (buprenorphine) was recorded. Cats were monitored for epidural complications. The median time to perform the epidural was 2 min (range, 0.2-13 min and range, 0.5-13 min), with an epidural success rate of 70%. The median amount of propofol administered for urinary catheterization was significantly less in the BUP (2.1 mg/kg; range, 0-7.5 mg/kg) and MOR/BUP cats (1.85 mg/kg; range, 0-8.6 mg/kg) as compared to SHAM cats (4 mg/kg; range, 0-12.7 mg/kg) (P = 0.006, P = 0.0008, respectively). The median time to administration of rescue analgesia was also significantly longer in the BUP (10 h; range, 2-32 h) and MOR/BUP cats (10 h; range, 4-45 h) as compared to SHAM cats (4 h; range, 2-36 h) (P = 0.0026, P = 0.0004, respectively). There were no recognized complications related to the epidural. CONCLUSION: Caudal epidural appears to be safe, may reduce the amount of IV anesthesia needed to facilitate urinary catheterization, and can be used to provide long-term analgesia in the hospital.