A comparative study of two antimicrobial/anti-inflammatory formulations in the treatment of canine otitis externa

The efficacy and tolerability of a marbofloxacin-clotrimazole-dexamethasone otic suspension (MCD) was compared with a standard topical treatment using a phase III clinical trial protocol. In a total of 140 dogs with clinical signs of acute or subacute otitis externa, Staphylococcus, Pseudomonas, Enterobacteriaceae and Malassezia were isolated from samples taken at inclusion to identify the causative pathogen; a further sample was collected in the event of failure or relapse, and from dogs (at day 14) for which Pseudomonas species had been isolated at inclusion. One group received MCD (10 drops per affected ear) once daily and a second received Surolan (containing polymyxin B, miconazole and prednisolone) (5 drops per affected ear), twice daily. Each group received treatment for 7 or 14 days according to the clinical outcome on day 7. Efficacy and tolerability were evaluated on days 7, 14 and, if necessary, 28 for dogs treated for 14 days. The trial demonstrated equivalence of both treatments in terms of efficacy, with a cure rate of 58.3% for MCD and 41.2% for Surolan. Both medications were equally well tolerated by dogs, but MCD was superior in terms of pain relief, decrease in pus quantity and smell, response rate and investigator's assessment on day 14.     

Efficacy of non-acaricidal containing otic preparations in the treatment of otoacariasis in dogs and cats

Eighty-nine cats and 38 dogs naturally infested with the ear mite Otodectes cynotis were randomly allocated into two treatment groups. One group was treated with a product containing miconazole nitrate, polymyxin B sulphate and prednisolone acetate, the other with a combination of diethanolamine fusidate, framycetin sulphate, nystatin and prednisolone. The treatment (five drops in each ear) was applied twice daily for 14 days, and its efficacy was evaluated on days 7, 14 and 21 on the basis of an otoscopic examination of the external ear canal, a microscopical examination of scrapings for the presence of ear mites and clinical signs of pruritus, pain, erythema and/or exudate. Both treatments were highly effective, and there were no significant differences between the two products, either in efficacy or in the clinical improvements observed. Apart from an allergic reaction in one cat treated with the second product, no adverse effects were observed.     

Effect of emu oil on auricular inflammation induced with croton oil in mice

OBJECTIVE: To determine the acute anti-inflammatory effects of topically applied emu oil. ANIMALS: 96 male CD-1 mice assigned randomly to 4 groups, each comprising 24 mice. PROCEDURE: To induce auricular inflammation, 50 microl of a solution comprising 10 microl of croton oil dissolved in 1 ml of acetone was applied to the inner surface of the left auricle (pinna). One hour later, 3 or 5 microl of emu oil (low- and high-dose groups, respectively) or 5 microl of porcine oil (oil-control) was applied to the left pinna. Control mice remained untreated. Six mice per group were euthanatized 3, 6, 12, and 24 hours after induction of inflammation. Specimens of auricular tissue (ear plugs) were obtained, using a 6-mm biopsy punch. Magnitude of swelling was calculated as the weight difference between left (inflamed) and right (noninflamed) ear plugs; degree of edema was determined as the difference between wet and dry weights of the left ear plug. RESULTS: Magnitude of swelling was significantly reduced at 6 and 12 hours in mice treated with emu or porcine oil, compared with controls. The greatest reduction in swelling was detected in the high-dose emu group at 6 hours. Compared with controls, degree of edema was significantly reduced at 6 hours only in the high-dose group, whereas by 12 hours, all groups treated with oils had significantly less edema than controls. At 24 hours, magnitude of swelling and degree of edema did not differ among groups. CONCLUSION: Topically applied emu oil significantly reduced severity of acute auricular inflammation induced by croton oil in mice.     

Prednisolone succinate and prednisolone acetate in cattle: pharmacokinetics and action on the adrenal gland

The pharmacokinetics of prednisolone were studied in a group of 6 cows given prednisolone 21-sodium succinate IV and IM (600 micrograms/kg of body weight expressed as prednisolone alcohol) and prednisolone acetate IM (600 micrograms/kg of body weight expressed as prednisolone alcohol). After IV administration of prednisolone 21-sodium succinate, the half-life of elimination was 3.6 +/- 1.177 hours. After IM administration of prednisolone 21-sodium succinate, absorption was rapid and complete. After IM administration of prednisolone acetate, absorption was very slow with an absorption half-life of 48 hours, but was still complete. Basal plasma hydrocortisone was about 7.5 ng/ml. After IV and IM administration of prednisolone 21-sodium succinate, plasma hydrocortisone returned to normal values within 48 hours. In contrast, after IM administration of prednisolone acetate, a long adrenal suppression lasting from 4 to 6 weeks was observed.     

Double‐blinded cross‐over study on the efficacy of pentoxifylline for canine atopy

The pathogenesis of canine atopy has not been established completely. Recent studies have shown that tumour necrosis factor alpha and Interleukin‐6 play a role in allergic reactions in humans and mice. Pentoxifylline (PTX) suppresses synthesis of these cytokines and may be a useful therapy for modulating the symptoms of canine atopy. The objectives of this study were to investigate the effects of PTX (10mg kg^?1 twice daily for 4 weeks) on clinical signs (erythema and pruritus) and intradermal skin test reactivity in atopic dogs (n = 10). The study was a double‐blinded, placebo controlled, crossover clinical trial with a washout period of 2 weeks between treatments. Clinical signs were evaluated and scored by the investigator and owners. During PTX treatment, scores of pruritus and erythema decreased significantly. PTX did not affect intradermal skin test reactivity to house dust mite at 15 min (allergen of reference for this study).     

Suppression of cortisol responses to exogenous adrenocorticotrophic hormone, and the occurrence of side effects attributable to glucocorticoid excess, in cats during therapy with megestrol acetate and prednisolone.

The major purpose of this investigation was to determine the effect of prednisolone and megestrol acetate in cats on the adrenal cortisol response to exogenous adrenocorticotrophic hormone during drug administration at dose rates employed for management of some inflammatory feline dermatoses. Prednisolone (at least 2 mg/kg/day) and megestrol acetate (5 mg/cat/day) were each administered orally to seven cats from days 1 to 16. Three additional cats received no therapy. Basal and stimulated cortisol concentrations, food and water intake, hematology, blood biochemistry, urinalyses, and hepatic and cutaneous histology were studied in all cats before, during, and two weeks following the end of treatment. Cats given prednisolone or megestrol acetate had significant suppression of stimulated cortisol levels on day 8. This change was more marked on day 15, when the suppression in cats given megestrol acetate was also significantly more severe than in those receiving prednisolone. Recovery of adrenal reserve was considered present on day 30 in six of seven cats given prednisolone, but in only three of seven receiving megestrol acetate. Eosinopenia, glycosuria and hepatocyte swelling from glycogen deposition were occasionally recorded in treated cats of both groups, providing additional circumstantial evidence for glucocorticoid activity of megestrol acetate in cats. It is advised that abrupt withdrawal of prednisolone or megestrol acetate therapy be avoided in this species to reduce the chance of precipitating clinical signs of hypoadrenocorticism, even after treatment for as little as one week.     

Effect of short-term oral and inhaled corticosteroids on airway inflammation and responsiveness in a feline acute asthma model

The objective of this study was to investigate whether high-dose inhaled fluticasone propionate (FP), alone or in combination with salmeterol (SAL), is as effective as oral prednisolone in reducing airway inflammation and obstruction in cats with experimentally-induced acute asthma. Six cats sensitised to Ascaris suum (AS) were enrolled in a prospective controlled therapeutic trial and underwent four aerosol challenges, at 1-month intervals with AS allergen. The allergen - stimulated animals received four consecutive days treatment with either oral prednisolone at 1mg/kg twice daily, 500 μg of FP inhaled twice daily, or a combination of FP/SAL at 500 μg/50 μg inhaled twice daily, respectively, according to a randomised cross-over design. Treatment-related changes in lung function, airway responsiveness (AR) and bronchoalveolar lavage fluid (BALF) cytology were assessed. Barometric whole-body plethysmography (BWBP) was used for the assessment of respiratory variables and AR. No significant differences in respiratory rate or Penh (an estimate of airflow limitation measured by BWBP) were detected among treatment groups. Allergen-induced airway hyper-responsiveness was significantly inhibited by all three steroid treatments (P<0.05). The mean BALF eosinophil percentage (±SEM) was lower after oral and inhaled corticosteroid treatment and these changes were significant for groups receiving prednisolone and the FP/SAL combination. Findings suggest high-dose FP, particularly in combination with SAL, is effective in ameliorating airway inflammation and hyper-responsiveness in this model of acute feline asthma, and highlight the potential use of these drugs in cats experiencing acute exacerbations of the naturally occurring disease.     

Dexamethasone and prednisolone in the horse: pharmacokinetics and action on the adrenal gland

Pharmacokinetics of dexamethasone and prednisolone were studied in 6 horses given dexamethasone alcohol (IV or IM) or dexamethasone 21-isonicotinate as a solution IV or IM (50 micrograms/kg of body weight), prednisolone 21-sodium succinate IV or IM (0.6 mg/kg of body weight), or prednisolone acetate IM (0.6 mg/kg of body weight). Plasma concentrations were determined using a high-performance liquid chromatographic method. After dexamethasone alcohol (IV) or dexamethasone 21-isonicotinate (IV), the half-life of elimination was similar (53 minutes) for both formulations. After dexamethasone (alcohol and isonicotinate, IM), concentrations were low or nondetected. After prednisolone 21-sodium succinate (IV), the half-life of elimination (99.5 minutes) was significantly (P less than 0.01) longer than that for dexamethasone. After prednisolone 21-sodium succinate (IM), absorption was rapid and bioavailability was high. After prednisolone acetate (IM), absorption was slow and prednisolone was present in plasma for about 7 days. Due to the nonlinearity of prednisolone kinetics, a bioavailability higher than 100% was obtained. The basal plasma hydrocortisone concentration was approximately 70 ng/ml. After dexamethasone (IV or IM), plasma hydrocortisone values decreased after a 2-hour delay and returned to base line after a 3 to 4 day delay. After prednisolone 21-sodium succinate (IV or IM), plasma hydrocortisone decreased immediately (IV) or rapidly (IM) and returned to base line after a 24-hour delay. After prednisolone acetate (IM), plasma hydrocortisone decreased for up to 21 days.     

Comparison of prednisolone and dexamethasone effects in the presence of environmental control in heaves-affected horses

This study was designed to compare the efficacy of oral prednisolone and intramuscular (IM) dexamethasone in heaves-affected horses with environmental control. A total of 16 horses, aged 8-20years, with heaves were included in the study. Complete examinations were performed on Day 0 (before treatment), Day 13 (after treatment) and Day 30. Clinical variables, arterial blood gases, mucus scoring and carina evaluation (during endoscopy), and bronchoalveolar lavage (BAL) cytological analysis were all assessed. The horses were randomly assigned to receive either oral prednisolone (1mg/kg) or IM dexamethasone (0.1mg/kg). The animals were clinically scored and mucus accumulation evaluated. Results were analysed by repeated measures ANOVA with time (days of treatment) and treatment as the main effects. When combined with environmental control, prednisolone and dexamethasone treatments had similar effects on heaves score, blood gases and endoscopic scores. However, dexamethasone had a more beneficial effect on BAL cytology.     

Putative peanut allergy-induced urticaria in a dog

A 9-year-old, spayed male schnauzer dog was presented with vomiting, diarrhea, generalized erythema, pruritic urticaria and conjunctival hyperemia after ingestion of peanut. The history, clinical signs, and histopathology of the lesions were compatible with a hypersensitivity reaction. The clinical signs resolved rapidly after treatment with prednisolone and antihistamine. This is the first report of urticaria caused by peanut ingestion in a dog.     

Equine exudative canker: an (auto-)immune disease?

Equine canker is a chronic, hyperplastic, exudative pododermatitis affecting one or more feet. Although many causes and treatments have been suggested, the cause of the disease is still unknown and most probably multifactorial. Local treatments include radical surgical debridement of the diseased hoof tissue and application of caustic substances, antibiotics, and pressure bandaging. Nevertheless, the number of recurrences is high (45%). This article presents a 3-year-old New Forest pony-cross mare in which all horny structures (frogs, coronets, spurs, chestnuts) of all feet were affected. Bacteriological and fungal cultures of the frogs were found negative for the pathogens tested. Papilloma virus was not found. Clinical findings raised the hypothesis that the non-specific hyperplastic inflammation of these horn-like structures might have been caused by an (auto-)immune reaction. On the basis of the clinical findings, the pony was treated with surgical debridement of the frogs of a diagonal pair of feet and oral administration of prednisolone (1 mg/kg sid). The frogs, coronets, spurs, and chestnuts of all four feet healed completely within 8 weeks, thus making an (auto-)immune reaction more likely. In conclusion, this case report raised the hypothesis that an aspecific, hyperplastic inflammation of all four feet ('equine canker') and other horny structures may be caused by an (auto-)immune reaction, and that corticosteroids (prednisolone 1 mg/kg sid per os) are effective as treatment.     

Salmeterol or doxycycline do not inhibit acute bronchospasm and airway inflammation in cats with experimentally-induced asthma

The objective of this study was to determine if inhaled salmeterol, a long-acting β(2)-adrenergic agonist, and oral doxycycline, a tetracycline antibiotic displaying matrix metalloproteinase (MMP) inhibitory activity, reduce airway inflammation and obstruction in cats with experimentally-induced asthma. Eight Ascaris suum (AS)-sensitised cats were enrolled in a prospective study in which they underwent four AS-challenges at 1 month intervals. The challenged animals were given no treatment or were treated on 4 consecutive days with either: (1) oral prednisolone (1mg/kg twice daily), (2) inhaled salmeterol (50 μg twice daily), or (3) oral doxycycline (5mg/kg twice daily), according to a randomised cross-over design. Inhibition of allergen-induced early (EAR) and late (LAR) asthmatic reactions were assessed by barometric whole-body plethysmography. Cytology and measurement of MMP-2 and -9 activities were carried out on bronchoalveolar lavage fluid (BALF). Although none of the treatments prevented the EAR, prednisolone treatment inhibited the LAR. Relative to untreated cats, the eosinophil percentage and MMP-2 activity in BALF were significantly reduced following prednisolone treatment (P<0.05). Short-term therapy with either salmeterol or doxycycline had no effect on the EAR or LAR or on airway inflammation. Given the chronic nature of this disease in cats, long-term therapy may be required to produce more favourable functional and clinical outcomes.     

Comparison of an antifungal agent with a mixture of antifungal, antibiotic and corticosteroid agents for the treatment of Malassezia species otitis in dogs

Twenty dogs with otitis externa in both ears and numerous Malassezia species yeasts on cytological examination were treated in one ear with a combination product containing clotrimazole, marbofloxacin and dexamethasone, and in the other ear with a topical antifungal containing miconazole. The effects of the treatments were analysed on the basis of the scores for pruritus, erythema and amount of cerumen, and the number of yeasts on cytological smears. There were reductions in the counts of Malassezia species after both treatments, but the combination product gave significantly greater reductions in erythema, cerumen and pruritus.     

Cervical, mandibular, and parotid lymph nodes of dogs naturally infected with Leishmania infantum: a histopathologic and immunohistochemistry study and its correlation with facial skin lesions

The parasite load in cervical, mandibular, and parotid lymph nodes and in the skin of the nose and the pinna from dogs infected with Leishmania infantum were investigated by histologic and immunohistochemical studies. Twenty-two infected dogs with and without signs of infection were examined to demonstrate correlation of signs with parasite load and the correlation of facial skin lesions with parasites in regional lymph nodes. Chronic inflammation of the skin was demonstrated in infected dogs that had no gross skin lesions, confirming that normal-appearing skin can harbor the parasite, likely playing a role in transmission. Dogs with facial skin lesions showed a higher parasite load in parotid lymph nodes than dogs without lesions of the facial skin, based on Leishman-Donovan unit analysis. Based on immunohistochemical analysis, parasite load in parotid and cervical nodes was correlated with that of skin of the nose and pinna, as was the parasite load in mandibular lymph nodes and skin of the external nose. We demonstrated a logical involvement of the lymphatic vessels and their specific anatomic draining sites.     

Investigation on the use of 0.3% tacrolimus lotion for canine atopic dermatitis: a pilot study

The efficacy of 0.3% tacrolimus lotion (maximum dosage: 0.3 mg kg-1 per day) for treatment of atopic dermatitis (AD) was evaluated. Systemic absorption and effects on complete blood cell counts (CBC) and chemistry panels were also investigated. Eight dogs were assigned randomly to either a tacrolimus or a vehicle lotion treatment group. Both owners and investigator were blinded to the treatment. After 4 weeks, there was a 2-week wash-out period and treatments were reversed. Owners scored pruritus weekly while the investigator scored pruritus and erythema at the beginning and end of each treatment period. Investigator scores for pruritus in the tacrolimus group significantly decreased by the end of the study (P = 0.03). Investigator scores for erythema in the tacrolimus group were significantly lower than those in the placebo group at the end of the study (P = 0.005). There was no difference between groups with respect to owner scores for pruritus. No changes in the CBC and chemistry panels were noted. Mean blood concentrations of tacrolimus were below toxic levels.     

Erythema multiforme possibly triggered by food substances in a dog

A 5-year-old female border collie presented with erythematous skin lesions at the axillae, groin, mucocutaneous junctions, and pinnae. Biopsy revealed lymphocytic interface dermatitis with hydropic degeneration of basal cells and keratinocyte apoptosis. Based on gross and histological features, diagnosis of erythema multiforme was made. The disease was resolved by treatment with azathioprine, prednisolone, and a hypoallergenic diet. Finally, the skin lesion was controlled without drug therapy but recurred easily every time commercial foods except the hypoallergenic diet were used, suggesting that food substances triggered this outbreak.     

A chondropathy of the pinna in rabbits associated with rabbit haemorrhagic disease

AIMS: To investigate the relationship between loss of parts of the pinna in rabbits and rabbit haemorrhagic disease (MD). METHODS: A case-control study design was employed. Rabbits with ear lesions were shot on farms in various locations in the South Island of New Zealand. For each case, an attempt was made to obtain a sex and size-matched control rabbit from the same farm on the same day. Serum samples were collected immediately after shooting. The serum samples were tested for RHD titres from 1:lO to 1:640. A selection of affected ears was examined histologically. Odds ratios and their 95% confidence intervals were calculated to assess the relationship between ear loss and RHD antibody status at various serological cut-off levels. RESULTS: Affected ears were characterised by firm cartilaginous nodules and ridges, folding of the ear or loss of pinna to form a notch or complete loss of the outer pinna from about 052.0 cm above the intertragic notch. Histological changes in affected ears consisted mostly of focal mineralisation in the auricular cartilage, proliferation of cartilaginous tissue and loss of cartilage. The serological findings showed a significant association between rabbits with ear lesions and elevated RHD titres. CONCLUSION: The loss of the outer pinna in the rabbits under study was due to degenerative and hyperplastic changes in the auricular cartilage with distortion of the pinna, withering and loss of the outer pinna. The serological findings suggests that RHD is a likely factor in the development of the ear lesions.     

The use of a caudal auricular axial pattern flap for repair of a degloving pinna wound in a dog

A 3-year-old male neutered French bulldog was presented for an anatomical degloving injury of the left pinna following a conflict with a larger dog at a park. Approximately 2/3 of the dorsal skin was removed from the convex surface of the left pinna along with an irregular, full thickness injury on the lateral aspect of the pinna distal to the cutaneous marginal pouch. A caudal auricular axial pattern flap (CAAPF) was used to reconstruct the pinna. The flap healed with no noted necrosis over the long-term. Postoperative cellulitis was noted for approximately 3 mo. The dog was medically managed for bilateral otitis externa multiple times over the course of recovery. Long-term function and cosmesis at 1.5 y after surgery revealed adequate functional movement of the pinna and acceptable cosmesis. It is concluded that, rather than a pinnectomy, a CAAPF can be offered as a surgical option in dogs that have injuries localized to the pinna.Key clinical message:A CAAPF is an alternative to pinnectomy for reconstruction of the pinna after degloving injury and yields a functional and cosmetically acceptable outcome.     

Pharmacological effects of a C-phycocyanin-based multicomponent nutraceutical in an in-vitro canine chondrocyte model of osteoarthritis

Multicomponent nutraceuticals are becoming increasingly popular treatments or adjunctive therapies for osteoarthritis in veterinary medicine despite lack of evidence of efficacy for many products. The objective of this study was to evaluate the anti-inflammatory and antioxidant activities of a commercially available C-phycocyanin-based nutraceutical and select constituent ingredients in an in-vitro model of canine osteoarthritis. Normal canine articular chondrocytes were used in an in-vitro model of osteoarthritis. Inflammatory conditions were induced using interleukin-1β. The nutraceutical preparation as a whole, its individual constituents, as well as carprofen were evaluated at concentrations of 0 to 250 μg/mL for reduction of the following inflammatory mediators and indicators of catabolism of the extracellular matrix: prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TFN-α), interleukin-6 (IL-6), metalloproteinase-3 (MMP-3), nitric oxide, and sulfated glycosaminoglycans (sGAGs). Validated, commercially available assay kits were used for quantitation of inflammatory mediators. The antioxidant capacities, as well as cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and lipoxygenase (LOX) inhibitory activities of the whole nutraceutical preparation and select constituents, were also assessed using validated commercially available assay kits. The antioxidant capacity of the nutraceutical and constituents was concentration-dependent. The nutraceutical and constituents appear to display anti-inflammatory activity primarily through the inhibition of COX-2. The nutraceutical displayed similar strength to carprofen in reducing TNF-α, IL-6, MMP-3, nitric oxide, and sGAGs at select concentration ranges. The C-phycocyanin (CPC)-based nutraceutical and constituents may be able to mediate 3 primary pathogenic mechanisms of osteoarthritis: inflammation, chondral degeneration, and oxidative stress in vitro. The nutraceutical may be clinically useful in veterinary medicine and its efficacy should be further investigated in vivo.     

Anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils

Because of the development of anthelmintic resistant populations, the search for new drugs is essential to maintain the productivity of small ruminants. The aim of this study was to evaluate the anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils and their major constituents, anethole and thymol. The effects of these oils and their constituents were determined by in vitro assays with the eggs and larvae of the sheep gastrointestinal nematode Haemonchus contortus. The two essential oils were evaluated on intestinal nematodes of mice at 800 mg kg(-1) dose. In the last experiment, the mice were treated with larger doses of L. sidoides, 1200 and 1600 mg kg(-1). The essential oils and their constituents prevented more than 98% of the H. contortus eggs from hatching at a concentration of 1.25 mg ml(-1) and inhibited more than 90% of H. contortus larval development at a concentration of 10 mg ml(-1). At a concentration of 800 mg kg(-1), the two essential oils were 46.3% and 11.64% effective against Syphacia obvelata and Aspiculuris tetraptera. At 1200 and 1600 mg kg(-1), L. sidoides essential oil's efficacy on the mouse worm burden was 57.6% and 68.9%, respectively. The fact that L. sidoides essential oil was almost 70% effective against mouse intestinal nematodes indicates it should be evaluated against gastrointestinal nematodes of sheep and goats.