Eradication of feline dermatophytosis in a shelter: a field study

Enzootic dermatophytosis in a shelter with approximately 140 cats was treated according to a protocol combining identification, isolation and treatment of subclinical carrier and affected animals in accordance with a three‐area system: healthy animals (no lesions and negative cultures), subclinical carrier animals (no lesions but with positive cultures) and clinically affected animals (lesions and positive cultures). The cats were examined and inspected under a Wood’s lamp and had samples taken for fungal culture every 2 weeks. Thirty‐three per cent of the cats had a positive fungal culture at the start of the study. Clinically affected animals and carriers were treated with a 0.2% enilconazole lotion (Imaverol^®) twice a week and given itraconazole (Itrafungol^®) 5 mg/kg SID orally every other week. The environment was treated once a day with a 1% bleach solution and once a week with a 0.6% enilconazole (Clinafarm^®) solution. Treated animals were considered cured after two consecutive negative fungal cultures. All cats were cured within 56 days. Prophylactic measures against dermatophytosis were implemented for new arrivals consisting of individual quarantine and the systematic taking of fungal cultures. No relapses were observed based on the fungal cultures taken from the animals and the environment over the first 10 months.     

Use of lime sulphur and itraconazole to treat shelter cats naturally infected with Microsporum canis in an annex facility: an open field trial

Dermatophytosis is the most common contagious and infectious skin disease of cats. It is of particular importance in animal shelters because it is a known zoonosis, highly contagious, and easily transmitted. In this open clinical trial, 58 cats with confirmed Microsporum canis dermatophytosis and 32 uninfected bonded pairs or littermates were treated with a combination of 21 days of oral itraconazole (10 mg kg(-1)) and twice weekly lime sulphur rinses until cured. Cats were not clipped in this treatment programme. Fungal cultures were obtained once weekly on all cats, and cats were considered cured when they had two consecutive negative weekly fungal cultures. Cats were held in the facility and received continued topical treatment until the fungal cultures were finalized. None of the cats developed oral ulcerations as a result of grooming the lime sulphur rinses. Oral ulcerations only developed in cats with clinical signs associated with upper respiratory disease. None of the uninfected cats living in contact with infected cats became culture positive or developed skin lesions. When data were examined retrospectively and the number of days to finalize the cultures was subtracted (21 days) from the total number of days the cats were housed in the annex, the mean number of days of treatment required for cure was 18.4 +/- 9.5 SEM (range 10-49 days). Cats with more severe infections required longer therapy. In this shelter, the combination of oral itraconazole and topical lime sulphur rinses for the treatment of dermatophytosis was effective and safe.     

P-15 Identification of Malassezia spp. isolated from a cat and cattle, including a new species, M. nana

Preliminary studies showed that lufenuron inhibits chitin synthesis, a dermatophyte cell wall constituent, and may be effective in the treatment of dermatophytosis. Our purpose was to evaluate the efficacy of lufenuron in the treatment of feline dermatophytosis. Forty-six cats (Persians and mixed-breed cats from 1-month to 4-years old) naturally infected with Microsporum canis were included in this study. Fifteen cats were treated isolated in cages in the veterinary hospital and 31 were treated in their home environment (some with access to the outdoors). Dermatophyte skin lesions were seen in 29 animals while 17 other cats were asymptomatic carriers. Wood's lamp, direct microscopic examination of hairs, fungal culture and skin biopsies were used for the diagnosis. Affected cats and all in-contact animals received lufenuron at a dose of 120 mg/kg every 21 days for four treatments. Of the 29 symptomatic cats treated with lufenuron, 70% recovered within 21 days and 28% within 42 days of initiation of therapy. One cat had only partial recovery and another was euthanized. Negative fungal culture was recorded only after the fourth dose of lufenuron in 98% of affected cats and 100% of asymptomatic carriers. There was no difference in clinical response to lufenuron between the cats treated in their home environment and those treated in the veterinary hospital. Side effects were not observed, thus the drug proved to be safe and effective for the treatment of dermatophytosis.
Funding: Novartis.     

P‐13 Dermatophytosis in domestic cats: treatment with lufenuron

Preliminary studies showed that lufenuron inhibits chitin synthesis, a dermatophyte cell wall constituent, and may be effective in the treatment of dermatophytosis. Our purpose was to evaluate the efficacy of lufenuron in the treatment of feline dermatophytosis. Forty‐six cats (Persians and mixed‐breed cats from 1‐month to 4‐years old) naturally infected with Microsporumcanis were included in this study. Fifteen cats were treated isolated in cages in the veterinary hospital and 31 were treated in their home environment (some with access to the outdoors). Dermatophyte skin lesions were seen in 29 animals while 17 other cats were asymptomatic carriers. Wood's lamp, direct microscopic examination of hairs, fungal culture and skin biopsies were used for the diagnosis. Affected cats and all in‐contact animals received lufenuron at a dose of 120 mg/kg every 21 days for four treatments. Of the 29 symptomatic cats treated with lufenuron, 70% recovered within 21 days and 28% within 42 days of initiation of therapy. One cat had only partial recovery and another was euthanized. Negative fungal culture was recorded only after the fourth dose of lufenuron in 98% of affected cats and 100% of asymptomatic carriers. There was no difference in clinical response to lufenuron between the cats treated in their home environment and those treated in the veterinary hospital. Side effects were not observed, thus the drug proved to be safe and effective for the treatment of dermatophytosis. Funding: Novartis.     

Use of lufenuron for treating fungal infections of dogs and cats: 297 cases (1997-1999)

OBJECTIVE: To evaluate use of lufenuron for treating cutaneous fungal infections in dogs and cats. DESIGN: Retrospective study. ANIMALS: 156 dogs and 201 cats with dermatophytosis or superficial dermatomycoses. PROCEDURE: Medical records were reviewed for dogs and cats that had been treated for dermatophytosis or other fungal infections by administration of lufenuron and 18 dogs and 42 cats that were not treated and served as a control group. RESULTS: Dogs were treated once by oral administration of lufenuron tablets at doses ranging from 54.2 to 68.3 mg/kg (24.6 to 31.0 mg/lb) of body weight. Samples of skin, scrapings, and hair were obtained daily from 14 dogs with dermatophytosis; mean durations from time of treatment to time of negative fungal culture results and resolution of gross lesions were 14.5 and 20.75 days, respectively. In all treated dogs, gross lesions resolved within approximately 21 days. Cats were treated once by oral administration of lufenuron suspension in doses ranging from 51.2 to 266 mg/kg (23.3 to 120.9 mg/lb). Samples were obtained daily from 23 cats; mean durations from time of treatment to time of negative fungal culture results and resolution of gross lesions were 8.3 and 12 days, respectively. Time to resolution of lesions in most untreated control animals was approximately 90 days. Adverse effects of treatment were not detected. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study suggest that lufenuron provides an effective, convenient, and rapid method for treating fungal infections in dogs and cats.     

Use of itraconazole and either lime sulphur or Malaseb Concentrate Rinse® to treat shelter cats naturally infected with Microsporum canis: an open field trial

In an open non‐randomized study, 90 cats with severe dermatophytosis were treated with 21 days of oral itraconazole at 10 mg/kg and one of three topical antifungal rinses applied twice weekly: lime sulphur (LSO); reformulated lime sulphur with an odour‐masking agent (LSR); or a 0.2% miconazole nitrate and 0.2% chlorhexidine gluconate rinse (MC). Weekly examinations and fungal cultures were used to monitor the cats’ response to therapy. If at day 42 of treatment cats were still strongly fungal culture positive and/or developing new lesions, they were retreated with oral itraconazole and LSO. Cats were not prevented from licking the solutions and none developed oral ulcerations. Thirty‐one cats were treated with LSO, 27 with LSR and 32 with MC. The median number of days to cure was 30 (range 10–69 days) and 34 (range 23–80 days) for LSO and LSR, respectively. Thirty‐two cats were treated with MC, and 13 of 32 cats required repeat treatment because of persistent culture‐positive status and development of new lesions. Median number of days of treatment for the 19 cats that cured with MC was 48 (range 14–93 days). When the number of days to cure was compared between the groups, there was a significant difference between cats treated with LSO and LSR (P = 0.029) and cats treated with LSO and MC (P = 0.031), but no significant difference between the number of days to cure for cats treated with LSR and MC (P = 0.91).     

Evaluation of topically applied enilconazole for the treatment of dermatophytosis in a Persian cattery

Many Persian catteries have long-standing dermatophyte infections and are particularly difficult to treat. Enilconazole is a topical antifungal agent that has demonstrated good efficacy in recent studies. Twenty-two Persian cats naturally infected with Microsporum canis in a breeding cattery were treated with topical 0.2% enilconazole and monitored for 180 days. The treatments were repeated every 3 days for a total of eight applications. All the cats improved clinically and became culture negative by day 28. By day 180, four cats had developed clinical dermatophytosis and all cats had positive fungal cultures. In this study, topical 0.2% enilconazole was generally well tolerated but may have caused hypersalivation, idiopathic muscle weakness and slightly elevated serum alanine aminotransferase (ALT) concentrations. This study suggests that enilconazole may be used safely with little risk to the young, aged and gravid animals.     

Four cats with fungal rhinitis

Fungal rhinitis is uncommon in the cat and cases of nasal aspergillosis-penicilliosis have been rarely reported. Signs of fungal rhinitis include epistaxis, sneezing, mucopurulent nasal discharge and exophthalmos. Brachycephalic feline breeds seem to be at increased risk for development of nasal aspergillosis-penicilliosis. Computed tomography (CT) imaging and rhinoscopy are useful in assessing the extent of the disease and in obtaining diagnostic samples. Fungal culture may lead to false negative or positive results and must be used in conjunction with other diagnostic tests. Serological testing was not useful in two cats tested. The cats in this study were treated with oral itraconazole therapy. When itraconazole therapy was discontinued prematurely, clinical signs recurred. Hepatotoxicosis is a possible sequel to itraconazole therapy.     

Treatment of dermatophytosis in dogs and cats: review of published studies

The recent literature on the treatment of dermatophytosis in dogs and cats was reviewed. Based upon in vitro studies using isolated infected hairs and controlled or field in vivo studies, the following topical treatments were consistently found to be antifungal (i.e. antidermatophyte): lime sulfur (1:16), 0.2% enilconazole rinses, and a combined 2% miconazole/chlorhexidine shampoo. Animals or hairs were either bathed or rinsed once or twice weekly. Itraconazole, griseofulvin and terbinafine were evaluated in controlled or field studies, most commonly involving cats. Griseofulvin (50 mg kg(-1)) was reported to cure infected animals in 41-70 days. Itraconazole (10 mg kg(-1) once daily or in a combined daily/pulse therapy 10 mg kg(-1) once daily for 28 days and then week on/week off) was reported to cure infected animals in 56-70 days. Low-dose itraconazole (1.5-3.0 mg kg(-1)) in 15-day cycles required 1-3 cycles (15-45 days). Various doses of terbinafine (5-40 mg kg(-1)) were reportedly used to treat dogs or cats. The higher doses of terbinafine (> 20 mg kg(-1)) were required to achieve a mycological cure; the number of treatment days to cure varied from 21 to > 126 days. Lufenuron was reported anecdotally to be an effective cure, however, this was not substantiated in controlled studies. Finally, fungal vaccines were not found to be effective against challenge exposure, however, there is evidence that they may be useful in treatment protocols.     

Platelet-bound antibodies detected by a flow cytometric assay in cats with thrombocytopenia

In cats, primary or secondary immune-mediated thrombocytopenia have rarely been described or characterised. The objective of this study was to determine platelet-bound antibodies (PBA) by a flow cytometric assay in both healthy and thrombocytopenic cats. Direct PBA testing was performed in 42 thrombocytopenic cats (platelet counts 6-179 x 10(9)/l, median 56 x 10(9)/l). Of these 42 cats, 19 had positive PBA test results, 17 of which were considered to have secondary immune-mediated thrombocytopenia (sITP). Underlying diseases included fat necroses (four cases), feline infectious peritonitis (three), feline leukaemia virus (two) or feline immunodeficiency virus (two) infections, lymphoma (two), leukaemia (one), hepatitis (one), pyelonephritis (one), or hyperthyroidism (one). In two cats, no underlying disease was found suggesting a primary immune-mediated thrombocytopenia (pITP). The PBA test was negative in 23 cats diagnosed with varying underlying diseases and in 47 healthy control cats with platelet values within the reference range. Only seven of the 42 cats with thrombocytopenia (platelet count 10-57 x 10(9)/l, median 34 x 10(9)/l) had spontaneous bleeding. This study suggests that immune-mediated destruction of platelets might be an important pathological mechanism for feline thrombocytopenia caused by various underlying diseases. In cats, pITP appears to be rarely diagnosed.     

The prevalence of immediate and delayed type hypersensitivity reactions to Microsporum canis antigens in cats

Spontaneous recovery from Microsporum canis infections in cats is thought to be dependent on the development of a competent immune response. The purpose of this study was to determine the prevalence of positive delayed type hypersensitivity reactions in cats with and without dermatophytosis. Four groups of cats were intradermally skin tested with M canis extract and test sites were evaluated both subjectively and objectively at 0, 24 and 48 h after injection. Delayed intradermal testing (IDT) reactions were absent in cats not exposed to dermatophytosis (n=20); infected-recovered cats (n=38 culture negative lesion negative and n=43 lesion negative but culture positive) had significantly larger IDT reactions than unexposed cats and cats that were still actively infected (n=18). Based on the results of this study, IDT with M canis extract can be used to assess the cellular immune response of cats with dermatophytosis.     

Immunologic responses in healthy random-source cats fed N,N-dimethylglycine-supplemented diets.

The immunomodulatory capacities of N,N-dimethylglycine (DMG) were examined in random-source cats. Blood mononuclear leukocytes of healthy adult cats that had negative results to tests for FeLV and feline immunodeficiency virus were exposed in vitro to various concentrations of DMG (10 to 1,000 micrograms/ml) and were evaluated for proliferative responses to T- or B-cell phytomitogens. Although increased, mean lymphocyte blastogenic responses to phytolectins in DMG-treated cultures did not differ significantly from responses of untreated cultures. For in vivo studies, cats were given a solution containing either 100 mg of DMG or a control solution without DMG orally at 8 AM and 6 PM for 40 consecutive days. On post-treatment day 24 and 25, mean blastogenic responses to phytolectins in DMG-treated and control cats inoculated 10 days earlier with an inactivated feline virus vaccine were similar. Cats given DMG and inoculated twice in a 3-week interval with a commercial vaccine containing inactivated feline herpesvirus-1 and feline calicivirus had significantly (P = 0.045) lower virus neutralizing serum antibody titers against feline herpesvirus-1, compared with titers of control cats, whereas feline calicivirus titers were similar in both groups. On day 25, mean serum interferon activity, induced after IV inoculation of Newcastle disease virus, was significantly (P = 0.021) lower in the DMG-treated cats. Results of this study of DMG in healthy cats failed to demonstrate enhancement of either specific or nonspecific immunity.     

Dermatophytosis (Trichophyton mentagrophytes) in a Coquerel's sifaka (Propithecus coquereli)

A 19-yr-old intact male Coquerel's sifaka (Propithecus coquereli) was evaluated for a crusting facial dermatopathy. Fungal culture and histopathology of skin biopsies were consistent with dermatophytosis caused by Trichophyton mentagrophytes, and treatment with the antifungal medication terbinafine was initiated. After 1 mo of treatment, all clinical signs had resolved and a fungal culture of the skin was negative. The sifaka was treated with terbinafine for a total of 81 days. Two additional fungal cultures were taken and found to be negative for the presence of dermatophytes, the last culture being taken 1 mo after discontinuation of terbinafine. To the authors' knowledge, this is the first reported case of dermatophytosis in a prosimian species and the first reported treatment of a prosimian with the antifungal drug terbinafine.     

Tumor necrosis factor alpha levels in cats experimentally infected with feline immunodeficiency virus: effects of immunization and feline leukemia virus infection.

Tumor necrosis factor alpha (TNF alpha) levels were determined by enzyme-linked immunosorbent assay (ELISA) and by cell culture bioassay in supernatants of lipopolysaccharide-stimulated feline monocyte cultures and in cat serum samples. There was a good correlation between the results obtained by the two methods. From the fact that TNF alpha was neutralized quantitatively by antibodies to human TNF alpha in feline monocyte supernatants and in feline sera, it was concluded that feline TNF alpha immunologically cross-reacts with human TNF alpha and that the human TNF alpha ELISA can be used to quantitate feline TNF alpha. During the first 6 months after experimental feline immunodeficiency virus (FIV) infection no differences in serum TNF alpha values were observed between infected and non-infected cats. TNF alpha levels increased significantly after primary vaccination with a feline leukemia virus (FeLV) vaccine in FIV infected cats over those in the non-infected controls. During secondary immune response TNF alpha levels rose transiently for a period of a few days in both the FIV positive and the FIV negative cats. After FeLV challenge, TNF alpha levels increased in all animals challenged with virulent FeLV for a period of 3 weeks. This period corresponded to the time necessary to develop persistent FeLV viremia in the control cats. It was concluded from these experiments that in the asymptomatic phase of FIV infection no increased levels of TNF alpha are present, similar to the situation in asymptomatic HIV infected humans. Activation of monocytes/macrophages in FIV infected cats by stimuli such as vaccination or FeLV challenge readily leads to increased levels of TNF alpha.     

Invasive Microsporum canis causing rhinitis and stomatitis in a cat

Microsporum canis is a pathogenic fungus that typically causes dermatophytosis in cats. This report describes a cat with a Microsporum canis infection causing invasive fungal rhinitis that extended through the hard palate, resulting in adjacent stomatitis. Treatment with itraconazole and terbinafine resolved the infection.     

Isolation of fungal flora from the hair coats of shelter cats in the Pacific coastal USA

Two-hundred shelter cats from the Pacific western coastal USA were sampled in four different geographical regions to determine the fungal organisms most commonly found on the hair coat and the prevalence of these organisms. Data on the cats' health, age, hair coat length, gender, and geographical location were collected and analysed. The overall prevalence of dermatophytosis was 5.5% (11 of 200 cats), with Microsporum canis isolated in 90.9% (10 of 11) of the samples from positive cats. This was a lower isolation rate or prevalence of dermatophytes than previous studies conducted on shelter cats in other regions of the USA. Ten of 11 of the cats were lesion free (either subclinical infection or mechanical carriage). Cats in the Los Angeles, California area ( P  = 0.001) and neutered male cats ( P  = 0.047) had a higher prevalence of a positive dermatophyte culture. The numbers and types of saprophytes isolated from cats in this study were found to be consistent with previous feline reports in the USA and with an equine study previously conducted in this area.     

Mycobacterial disease in a population of 339 cats in Great Britain: II. Histopathology of 225 cases, and treatment and outcome of 184 cases

This study investigated 339 cases of feline mycobacterial infection, with histopathology findings from 225 cases, and treatment and outcome information from 184 cases. Tissue samples from cats with cutaneous lesions or suspicious masses at exploratory laparotomy were submitted to the Veterinary Laboratories Agency for mycobacterial culture over a 4-year period to December 2008. The study reviewed the files for information about histopathology, treatment and outcome, and blindly reviewed histopathological changes (including staining for acid-fast bacteria [AFB]) in a sub-set of 45 cases. When a cat is suspected of having a mycobacterial infection, accurate identification of the species involved helps to determine possible treatment options and prognosis. The study confirmed that histopathology and the presence of AFB are useful tools in the recognition of mycobacterial infection. Unfortunately, they did little to help determine the species of mycobacteria involved. The study identified a group of cats that were negative for AFB at the primary laboratory, but from which mycobacteria could be cultured; commonly Mycobacterium bovis or Mycobacterium microti. The study also identified a group of cats which where culture negative, despite typical signs of mycobacterial infection and positive AFB staining. Many cases responded favourably to treatment (56% of the cases where information was available), and many cats gained complete remission (42%). However, relapses were common (64%) and often followed by pulmonary and/or systemic spread that may have resulted from treatment with short courses of single drugs. This study shows that the diagnosis and treatment of feline mycobacteriosis is complex and challenging.     

Coccidioidomycosis in 48 Cats: A Retrospective Study (1984–1993)

Coccidioidomycosis was diagnosed in 48 cats. Forty-one cases were identified within a period of 3 years. Coccidioides immitis was revealed by cytological or histopathological examinations, or culture in 70% of cats. The remaining 30% of cases were diagnosed by appropriate clinical signs, radiographic lesions, and serological test results. The average age of affected cats was 6.2 years with a median age of 5.0 years. Fifty-four percent (n = 26) were female and 46% (n = 22) were male. Domestic shorthaired and longhaired breeds comprised 89% (n = 41) of affected cats. Sixty-seven percent of cases were diagnosed during the 6-month period of December through May. Cats infected with C immitis were presented for evaluation of dermatologic (56%), respiratory (25%), musculoskeletal (19%), and neurological or ophthalmologic signs (19%). Fever, inappetence, and weight loss were present in 44% of the cats. Duration of clinical signs before diagnosis was less than 4 weeks in 85% (n = 42) of cats, with an average of 3.8 weeks and a median of 2 weeks. Agar gel immunodiffusion tests were positive in all 39 cats tested at sometime during the course of their disease. Hyperproteinemia (greater than 7.9 g/dL) was present in 52% (10/23) of cases. The majority of cats (n = 39) were negative for feline leukemia virus. Antibodies to feline immunodeficiency virus were absent in the 19 cats tested. Ketoconazole was the most common antifungal agent used to treat cats with Coccidioidomycosis. Duration of treatment ranged from less than 1 week to 43 months. Thirty-two cats are currently asymptomatic, with or without treatment. Eleven cats died or were euthanized. Five cats were lost to follow-up. Ketoconazole likely is more suppressive than curative because relapses were common after discontinuing therapy.     

Development of an enzyme-linked immunosorbant assay (ELISA) for the serodiagnosis of canine dermatophytosis caused by Microsporum canis

Abstract In dogs, dermatophytosis should be considered in any case of alopecic, papular or pustular lesion. The aim of this study was to develop an enzyme-linked immunosorbant assay (ELISA) as an aid in the diagnosis of canine dermatophytosis. The antigen used was a whole fungal extract obtained from an isolate of Microsporum canis cultured on a liquid medium from the parasitized hair of a cat with patches of alopecia. To assess the ELISA performances, sera from 18 dogs with dermatophytosis caused by M. canis (group A, n = 18), 20 dogs with skin diseases other than dermatophytosis and 22 healthy dogs (group B, n = 42) were tested. Four further animals were tested: three with dermatophytosis caused by M. gypseum and one by T. mentagrophytes. A significant difference (P < 0.01, Wilcoxon's test, w = 364) was found between IgG-specific levels of sera of recently M. canis-infected dogs (infection < 15 days) and controls (although three dogs had negative titres at this stage). A highly significant difference (P < 0.001, w = 462) was noted between controls and dogs with infection of longer duration (> 30 days). All dogs had positive titres at this stage. A highly significant correlation (P < 0.001, Spearman's test, rho = 0.86) between duration of infection and IgG concentration was noted. The test has good sensitivity (83.3%) and high specificity (95.2%) but some dogs retained positive titres after elimination of infection. The sensitivity is higher than that of direct microscopic hair examination and similar to that of fungal culture with DTM (dermatophyte test medium).     

P-22 Mites of interest in canine and feline dermatology: evaluation of their survival and structural integrity in oil preparations for microscopy

The purpose of this study was to evaluate the clinicopathological aspects of experimental sporotrichosis in cats and compare the sensitivity of cytopathology, histopathology and culture as diagnostic tools in different phases of the infection. Twenty adult, mixed-breed cats (10 males and 10 females) were inoculated subcutaneously with 10⁶ fungal microorganisms. Clinical examination was performed weekly. Cytopathologic, histopathologic and culture examinations were performed at 15, 30 and 60 days postinoculation. Culture of multiple organs was performed after euthanasia at 30 (10 cats) and 60 (10 cats) days postinoculation. Friedman parametric and nonparametric statistical analysis were applied to the results. The nodular, tumoral and necrotic lesions progressed significantly until day 30 postinoculation, and partial spontaneous regression occurred at day 60, particularly in males. An intense inflammatory pyogranulatomous and lymphocytic infiltrate with rare giant cells and sparse fibrosis associated with numerous, pleomorphic, intra- and extracellular fungal cells were observed on day 30. These findings gradually decreased by day 60. Despite the inflammatory granuloma associated with feline sporotrichosis, a tendency for dissemination was observed, with fungal isolation in the lymph nodes, spleen and liver at the 30 and 60 days postinoculation. No significant differences were observed between cytopathology, histopathology and fungal culture during the different phases of the disease. Therefore, cytological examination was considered a simple, rapid and inexpensive diagnostic method at all stages of this disease.
Funding: Self-funded.