Feline non-flea induced hypersensitivity dermatitis: clinical features, diagnosis and treatment

The Pharmacokinetic and Absolute Bioavailability of Cyclosporine (Atopica for Cats®) in Cats

This study aimed to evaluate the absolute bioavailability of cyclosporine in cats by investigating the pharmacokinetic profile after intravenous and oral administration, respectively. Twenty-four clinically healthy cats were enrolled in this study and randomly divided into four groups, namely the intravenous group (3 mg/kg), low oral group (3.5 mg/kg), medium oral group (7 mg/kg), and high oral group (14 mg/kg). Whole blood was obtained at the scheduled time points after a single dose administration and cyclosporine was determined using ultra-performance liquid chromatography-tandem mass spectrometry technology (UPLC-MS/MS). Pharmacokinetic parameters were calculated using the WinNonlin 8.3.4 software via compartmental and non-compartmental models. As a result, the bioavailability values for the low, medium, and high oral groups were 14.64%, 36.98%, and 13.53%, respectively. The nonlinear pharmacokinetic profile was observed in the range from 3.5 mg/kg to 14 mg/kg in cats following oral administration. Whole blood concentrations taken 4 h after oral administration were better correlated with the area under the blood concentration-time curve AUC_0-24 with a high regression coefficient (R² = 0.896). This concentration would be a greater predictor in the following therapeutic drug monitoring. No adverse effect was observed in the whole study process.

Oral dexamethasone sodium phosphate solution significantly reduces pruritus and clinical lesions in feline hypersensitivity dermatitis: an open-label study

BACKGROUND

There are no liquid oral glucocorticoids labelled for management of pruritus and clinical lesions of feline hypersensitivity dermatitis (feline HD).

HYPOTHESIS

First, to demonstrate that dexamethasone sodium phosphate (DexSP, DexajectSP, Henry Schein; Dublin, OH, USA; 4 mg/mL), an intravenous glucocorticoid, can be absorbed by healthy cats when administered orally. Second, to demonstrate the efficacy of orally administered DexSP for reducing pruritus and clinical lesions in patients with feline HD.

ANIMALS

Seven healthy and 12 client-owned cats with HD.

METHODS AND MATERIALS

Healthy cats were administered a single dose of 0.2 mg/kg DexSP p.o. and serum concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Feline HD patients were assessed with SCORing Feline Allergic Dermatitis (SCORFAD) and pruritus Visual Analog Scale (pVAS) at Visit 1 (V1) and after 20-31 days of receiving 0.2 mg/kg/day DexSP p.o. (V2). Complete blood cell counts, serum chemistry profile, and urinalysis were performed in 50% of feline HD patients at both visits.

RESULTS

Healthy cats had detectable serum concentrations of DexSP following oral administration; concentrations ranged from 0.7 to 92.3 ng/mL. Feline HD patients showed significant decreases in SCORFAD and pVAS scores from V1 to V2.

CONCLUSIONS

DexSP was absorbed when administered orally to healthy cats and 0.2 mg/kg/day DexSP is an efficacious dose to rapidly improve the pruritus and clinical lesions associated with feline HD.

Atopic Dermatitis in Domestic Animals: What Our Current Understanding Is and How This Applies to Clinical Practice

Atopic dermatitis is a clinical syndrome that affects both people and animals. Dogs closely mimic the complexity of the human skin disease, and much progress has been made in recent years in terms of our understanding of the role of skin impairment and the identification of new treatments. Cats and horses also develop atopic syndromes which include both cutaneous and respiratory signs, yet studies in these species are lagging. It is now recognized that atopic dermatitis is not a single disease but a multifaceted clinical syndrome with different pathways in various subgroups of patients. Appreciating this complexity is clinically relevant as we develop more targeted treatments which may work well in some patients but not in others. Different phenotypes of atopic dermatitis have been described in dogs, and it is possible that phenotypes related to breed and age may exist in other animals similar to how they are described in people. The awareness of different mechanisms of disease leads to the desire to correlate different phenotypes with specific biomarkers and responses to treatment. In this review, the current understanding and updated information on atopic syndrome in animals are described, highlighting opportunities for further studies in the future.

Successful Treatment of a Multi-Drug-Resistant Severely Pruritic Hypersensitivity Dermatitis in a Cat

A 3-year-old neutered female domestic shorthair cat was presented with a severely pruritic dermatitis. After exclusion of flea allergy dermatitis, ectoparasite infestation, retroviral infection, neoplasia, and cutaneous adverse food reaction, a diagnosis of nonflea, nonfood hypersensitivity dermatitis (NFNFHD) was made. The resolution of complicating bacterial infection and yeast overgrowth did not improve the animal's condition. Numerous antipruritic treatment modalities used during the investigation proved unsuccessful, including anti-inflammatory and immunosuppressive prednisolone doses, oclacitinib, antihistamines, ciclosporin A, and supplementation with essential fatty acids. Allergen-specific serology test results were negative. Treatment with oral dexamethasone allowed a complete resolution of clinical signs. The cat has been successfully maintained in remission for over 12 months. To the author's knowledge, this is the first case report of a cat with multi-drug-resistant NFNFHD treated successfully with dexamethasone.

A blinded, randomized, placebo-controlled trial of the safety of oclacitinib in cats

Background

Oclacitinib is a Janus kinase (JAK) 1 enzyme inhibitor and blocks JAK1-dependent cytokines and is used to control pruritus. Studies available in cats are very limited and as there is a potential role for oclacitinib in the control of pruritus in this specie, the aim of this study was to evaluate the safety and clinical effects of oral oclacitinib maleate in healthy cats.

Results

Thirty mixed-breed cats weighing from 2.1 to 5.3 kg each were randomly allocated to three treatment groups of 10 animals each. Cats in two groups received oclacitinib at 1 mg/kg or 2 mg/kg q 12 h orally for 28 days. Cats in the third group were given placebo tablets (cornstarch) q 12 h orally for 28 days. Oclacitinib maleate was well tolerated during the study and few adverse events were observed in treated cats. Clinical signs of toxicity were not observed in any animals treated at 1 mg/kg. Gastrointestinal clinical signs observed in the 2 mg/kg group included vomiting in two of the 10 cats and soft stools in two cats. One cat treated with placebo also exhibited soft stools. No significant differences were observed between the groups for hematologic analyses performed during the study. There was a slight increase in neutrophils and monocytes and a decrease in eosinophil mean counts in treated cats. Mean renal and liver enzymes remained normal throughout the entire study. A small, but significant increase in fructosamine levels was observed for both treated groups compared with placebo; however, values remained within the normal reference range. There were no significant difference between treated groups and the placebo group for urine specific gravity, pH, or urine protein to creatinine ratio mean values.

Conclusions

Oclacitinib maleate was well tolerated by cats at 1 mg/kg and 2 mg/kg and appeared to be safe for this species when administered orally twice daily for 28 days. More studies would be needed to demonstrate if oclacitinib maleate may be a suitable alternative to treat pruritic cats.

Cutaneous Hypersensitivity Dermatoses in the Feline Patient: A Review of Allergic Skin Disease in Cats

Feline allergic skin disease presents a unique set of challenges to the veterinary practitioner. Although there is some similarity to what is seen in the allergic canine patient, cutaneous hypersensitivity dermatoses in cats can manifest with strikingly different clinical signs, treatment options and outcomes, and secondary complications/disease entities. Additionally, less is known about the pathogenesis of feline allergic skin diseases, particularly "feline atopic syndrome" when compared to dogs or people. This article aims to review what is currently known in regards to allergic skin disease in the feline patient, with focus on non-flea, non-food hypersensitivity dermatitis.

Confirmatory field study for the evaluation of ciclosporin at a target dose of 7.0 mg/kg (3.2 mg/lb) in the control of feline hypersensitivity dermatitis

Objectives This study was designed to confirm the efficacy and tolerability of a daily dose of 7.0 mg/kg (3.2 mg/lb) ciclosporin (CsA) in the treatment of feline hypersensitivity dermatitis (HD), as this includes some of the most frequently suspected skin diseases in cats and recent publications have reported the successful use of CsA in the treatment of feline HD. Methods In total, 217 cats with feline HD were treated daily for 42 days with a target dose of 7 mg/kg CsA (n = 144) or a placebo control (n = 73) administered either in the food or directly in the mouth following feeding. Clinical and dermatological evaluations were conducted on days 0, 21 and 42, or study exit. Safety was evaluated through physical examinations, clinical pathology and the monitoring of adverse events (AEs). Results Administration of CsA at 7.0 mg/kg produced a significant improvement in the total lesion score ( P <0.0001). The average reduction from visit 1 to visit 3 was 65.1% in the CsA group (9.2% for the placebo). In addition, owners assessed 78.3% of the cases in the CsA group as a success. Statistically significant recoveries were also seen in extent of lesions, investigator assessment of overall improvement, and mean improvement in both the investigators' and owners' assessment of pruritus. Mild gastrointestinal disorders were the most common AEs but did not require cessation of therapy. Conclusions and relevance Results confirm that 7.0 mg/kg CsA dosed daily in food or orally for up to 6 weeks is effective and well tolerated by cats with feline HD.

Effect of high-dose ciclosporin on the immune response to primary and booster vaccination in immunocompetent cats

Ciclosporin (Atopica oral solution for cats 100 mg/ml; Novartis Animal Health) was recently approved for use in cats with feline hypersensitivity dermatitis. The immunosuppressant effect of ciclosporin on the ability of cats to mount an immune response following vaccination was determined. Thirty-two healthy, immunocompetent adult cats (16 cats/group) were treated with either ciclosporin for 56 days at a dose of 24 mg/kg once daily or sham dosed. Prior to treatment, cats had an adequate antibody response to primary vaccination against feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), feline panleukopenia virus (FPV), feline leukemia virus (FeLV) and rabies. Booster vaccination or novel vaccination with feline immunodeficiency virus (FIV) was administered 28 days after initiation of treatment with ciclosporin. There were no differences between the ciclosporin-treated and control cats for FCV and FPV antibody titers following booster vaccination. There were delays/reductions in antibody response to FHV-1, FeLV and rabies in treated cats; however, adequate protection was achieved in response to all booster vaccinations. Following primary vaccination with FIV, control cats showed a response, but treated cats showed no antibody production. Adverse events commonly associated with ciclosporin treatment, including diarrhea/loose stool, vomiting, salivation and regurgitation, were reported. In adult cats treated with 24 mg/kg/day of ciclosporin (more than three times the therapeutic dose), vaccine titer levels were adequate for protection following booster vaccination. In contrast, treated cats failed to mount a humoral response to a novel (FIV) vaccination, suggesting that memory B-cell immune responses remain intact during repeated high-dose ciclosporin administration in cats, but that primary immune responses are impaired.

Feline familial pedal eosinophilic dermatosis in two littermates

In cats, the most common eosinophilic dermatoses are feline miliary dermatitis and eosinophilic granuloma complex. The most commonly identified underlying cause is a hypersensitivity reaction. Few cases of familial forms of eosinophilic dermatoses are reported in the literature. Two young adult cats from the same litter presented 2 years apart with a severe and chronic fluid or tissue infiltration of the distal part of several limbs. Lesions started on the forelegs and developed on the other limbs. Cytological and histopathological examinations showed lesions consistent with an atypical form of feline eosinophilic dermatosis associated with secondary bacterial infection. In both cats, antibiotics combined with immunosuppressive treatment partially improved the lesions, which continued to progress on a waxing and waning course, even in the absence of treatment. Allergy work-up did not permit the identification of an underlying allergic triggering factor. The severity of the lesions, the unusual presentation and the unsatisfactory response to immunosuppressive therapy in two feline littermates suggested a genetic form of eosinophilic dermatosis.