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.     

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).     

Sensitivity of cytopathological examination in the diagnosis of feline sporotrichosis

Sporotrichosis is caused by Sporothrix schenckii. The cat is the animal species most affected by this mycosis and plays an important role in the zoonotic transmission of this disease. The definitive diagnosis is made by isolation of the fungus in culture; however, cytopathological examination is frequently used in cats. Medical records from cats treated at Instituto de Pesquisa Clínica Evandro Chagas/Fiocruz, Rio de Janeiro, Brazil, between 2004 and 2006 were reviewed. Criteria for inclusion were a diagnosis by isolation of S schenckii in culture and cytopathological examination of the same lesion as that used for collection of the culture material. Eight hundred and six cats were included in the study. Yeast-like structures suggestive of S schenckii were observed in 636 cases. The sensitivity of the method was 78.9%. Its practicality, low cost and sensitivity validate cytopathology as a safe technique for the presumptive diagnosis of sporotrichosis in cats.     

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.     

Correlation between fine-needle aspiration cytopathology and histopathology of the lung in dogs and cats

Medical records from 28 patients having fine-needle aspiration (FNA) cytopathology and histopathology of pulmonary lesions were reviewed. Clinical signs, thoracic radiographs, cytopathology, histopathology, and complications associated with FNA were evaluated. Correlation between cytopathological and histopathological diagnoses was determined. Cytopathological specimens were classified as neoplastic, inflammatory, or nondiagnostic. Histopathological diagnoses were categorized as neoplastic or inflammatory. No complications were observed following FNA. Diagnoses obtained by FNA cytopathology accurately reflected the diagnosis obtained on histopathological examination in 82% of cases. Fine-needle aspiration cytopathology of the lung is a useful and safe diagnostic tool in dogs and cats with pulmonary parenchymal lesions.     

Effect of topical application of fipronil in cats with flea allergic dermatitis

OBJECTIVE: To determine whether topical application of a 10% fipronil solution would control signs of flea allergic dermatitis in cats housed under natural conditions. DESIGN: Multicenter open clinical trial. ANIMALS: 42 client-owned cats with flea allergic dermatitis. PROCEDURES: Study cats along with all other cats and dogs living in the same houses were treated with 10% fipronil solution topically on days 0, 30, and 60. Flea counts and clinical assessments were performed on study cats on days 0, 14, 30, 60, and 90. RESULTS: Percentage reductions in geometric mean flea counts on days 14, 30, 60, and 90, compared with day-0 geometric mean count, were 75, 73, 85, and 94%, respectively. Pruritus score was significantly improved at each examination after day 0, and pruritus was reduced or eliminated in 31 of 40 (78%) cats at the final examination. Similarly, scores for severity of miliary dermatitis and alopecia were significantly improved at each examination, except for alopecia score on day 14. Overall treatment efficacy, assessed on day 90, was excellent for 28 (70%) cats, good for 6 (15%), moderate for 3 (7.5%), and poor for 3 (7.5%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that monthly topical application of fipronil is effective for treatment of flea allergic dermatitis in cats housed under natural conditions.     

Efficacy of itraconazole as a combined continuous/pulse therapy in feline dermatophytosis: preliminary results in nine cases

This study evaluated the efficacy of itraconazole as a combined continuous/pulse therapy for feline dermatophytosis. Nine cats with dermatophytosis caused by Microsporum canis were treated with itraconazole at 10 mg kg(-1) orally once daily for 28 days and then on an alternate week regimen (1 week off, 1 week on) at the same dosage. Cats were re-evaluated by physical examination and fungal culture at days 28, 42, 56 and 70 if necessary. Treatment was stopped when two consecutive negative fungal cultures were obtained. Eight cats were cured after 56 days, with two negative cultures obtained at days 28 and 42. In one case, a positive culture was obtained at day 28, but negative cultures were achieved at days 42 and 56. This protocol appears to be effective in the treatment of feline dermatophytosis, although these preliminary results should be confirmed by a controlled study.     

Evaluation of the efficacy of oral lufenuron combined with topical enilconazole for the management of dermatophytosis in catteries

The efficacy of oral lufenuron, a chitin synthetase inhibitor, combined with topical enilconazole, was evaluated for the management of Microsporum canis infection in 100 cats housed in two catteries in France. The cats were treated with weekly rinses with enilconazole (0.2 per cent) for four weeks and, in each cattery, one group (A) was also treated with micronised griseofulvin (25 mg/kg administered orally twice a day for five weeks) and a second group (B) was treated with 60 mg/kg lufenuron administered orally once on day 0 and again after 30 days. All the cats were examined individually for cutaneous lesions and mycological cultures were made when the treatment began and after 15, 30, 60 and 90 days. In the first cattery, the cats' clinical scores after 30 and 60 days were significantly lower in group B than in group A. In both catteries and both treatment groups, the mean number of fungal colonies decreased rapidly during the first 15 days of treatment, remained stable for the following 45 days but increased from day 60 to the end of the experiment on day 90.     

Sporotrichosis: a retrospective evaluation of 23 cases seen in northern California (1987–2007)

Sporotrichosis is an uncommon to rare cutaneous and subcutaneous mycosis of animals and humans caused by the dimorphic fungus Sporothrix schenckii . Twenty-three mammalian cases of sporotrichosis examined between 1987 and 2007 at the University of California, Davis – Veterinary Medical Teaching Hospital, were retrospectively evaluated with regard to the historical, clinical, diagnostic and treatment findings. Cats were the most common species affected ( n  = 14). In addition, sporotrichosis was diagnosed in four dogs, four horses and a donkey. Six of 23 cases were diagnosed with the localized cutaneous form of sporotrichosis (four cats, one dog, one horse), 10 with the cutaneous-lymphatic form (four cats, two dogs, three horses and a donkey), and seven with the disseminated form (six cats, one dog). Two of 23 cases did not have skin lesions at the time of diagnosis (one cat, one dog). The most common mode of diagnosis was demonstration of S. schenckii on histopathological evaluation of tissue. In contrast with most previously described sporotrichosis infections in cats, few to no fungal organisms were seen in histopathological samples (haematoxylin and eosin and special stains) in five of the 14 cats. Treatments received included itraconazole (12 cats, one dog), ketoconazole (three dogs), fluconazole (one cat, one donkey), sodium iodide (four horses, one cat) and potassium iodide (one cat, one horse, one donkey). The prognosis for successful treatment was good in all species. Fluconazole was successful in inducing resolution of the cutaneous lesions and controlling the infection in one cat with disseminated sporotrichosis.     

Efficacy of selamectin in the treatment of naturally acquired cheyletiellosis in cats

The purpose of this study was to evaluate the efficacy of a topical formulation of selamectin in the treatment of cheyletiellosis in cats. Fifteen adult domestic cats from the same household with naturally occurring Cheyletiella sp. infestation were enrolled in the study. On each cat, 45 mg of selamectin was applied on days 0, 30, and 60. No other treatment or environmental decontamination was performed during the trial. On days 0, 30, 60, and 120, all cats were examined, epidermal debris was collected over the dorsal area of the body with flea combs for microscopic examination, and fecal flotations were done. Clinical signs had subsided by day 60 in all 15 cats and no signs of recurrence were apparent on follow-up 1 year later. All epidermal and fecal samples were negative by day 60. No adverse reactions were observed. Under the conditions of our study, topical selamectin was a practical and well-tolerated means of treatment for cheyletiellosis in cats.     

Experimentally induced infection of cats with Borrelia burgdorferi.

To determine whether cats could be infected experimentally with Borrelia burgdorferi, 15 cats were inoculated with approximately 1,000 B burgdorferi. Seven cats were inoculated by the IV route, 2 by the oral route, 2 by the ocular route, and 4 by the oral-ocular route. Six control cats were inoculated with phosphate-buffered saline solution by the IV, oral, and ocular routes. Prior to the start of the study, all 21 cats were seronegative for B burgdorferi on the basis of results of the indirect fluorescent antibody (IFA) test, and their blood was B burgdorferi culture negative. All of the IV, orally, and ocularly inoculated cats developed IgG antibodies to B burgdorferi as detected by IFA testing. Of 4 oral-ocularly inoculated cats, 2 developed IFA-detectable antibodies and the remaining 2 cats developed low-titer response (1:128) on postinoculation (PI) day 10 only. All control cats remained seronegative. The organism was detected in blood smears from 2 of the IV inoculated cats on PI days 10 and 24 and from 2 oral-ocularly infected cats, 1 on PI days 17 and 24 and 1 on PI day 10. Spirochetes were not detected in the blood after PI day 24. The organism was isolated from tissues of only 1 cat (the lung of an ocularly inoculated cat necropsied at 7 months after inoculation). Spirochetes were not isolated from control cats. Neither clinical signs of infection nor gross or histologic abnormalities were found in any of the inoculated or control cats. Results indicate that cats are susceptible to infection with B burgdorferi, but clinically apparent disease may not be common.     

Marbofloxacin for the treatment of experimentally induced Mycoplasma haemofelis infection in cats

BACKGROUND: Administration of tetracyclines or fluoroquinolones is associated with improvement in clinical and laboratory abnormalities in cats infected with Mycoplasma haemofelis. No treatment protocol has consistently eliminated the organism, and antimicrobial susceptibility may vary among M. haemofelis isolates. Continued search for effective therapies is warranted. HYPOTHESIS: Marbofloxacin administered at the onset of clinical illness will be safe and effective for the treatment of M. haemofelis. ANIMALS: Fourteen young adult, laboratory-reared cats housed together in a specific pathogen-free facility. METHODS: Twelve cats were inoculated IV with 2.0 mL of blood from 2 M. haemofelis positive cats. Clinical parameters were assessed daily. CBC and hemoplasma polymerase chain reaction (PCR) assay were performed before inoculation, weekly for 1-3 weeks postinoculation (PI) and twice weekly 3-6 weeks PI. Treatment with marbofloxacin (2.75 mg/kg PO daily for 14 days) was initiated in 6 randomly selected cats when PCV was <30% or fever was >102.5 degrees F (39.2 degrees C). Cats that were PCR positive on day 7 of therapy were treated for 28 days. Cats that were PCR negative on day 42 PI were treated with 20 mg/kg methylprednisolone acetate IM on day 50 PI. RESULTS: Significant differences between groups on some days after inoculation included higher PCV and red blood cell counts, lower mean cell volume, and higher mean cell hemoglobin content in marbofloxacin-treated cats. No differences in PCR assay results were noted between groups. CONCLUSIONS AND CLINICAL IMPORTANCE: Marbofloxacin was safe and resulted in more rapid hematologic improvement in M. haemofelis-infected cats, but did not change clinical scores and did not consistently eliminate infection.     

Evaluation of the comparative efficacy of selamectin against flea (Ctenocephalides felis felis) infestations on dogs and cats in simulated home environments

The comparative efficacy of monthly administration of selamectin or lufenuron against Ctenocephalides felis felis on dogs and cats was evaluated over a 5-month period in flea-infested environments. Twenty-four dogs and 32 cats were randomly allocated to receiving a topical treatment with selamectin or an oral administration of tablets containing lufenuron/milbemycin oxime (for dogs) or lufenuron only (for cats). Each product was administered in accordance with the manufacturer's label recommendations. Eight dogs and four cats served as untreated sentinels. Treatments were administered on days 0, 30, 60, 90, and 120. Each animal received an application of 100 fleas on days -28 and -21, and then weekly applications of 20 fleas from days 91 through 147. Flea comb counts were performed on day -6, and every 2 weeks after day 0. From day 29 (dogs) or day 44 (cats) to day 150, geometric mean flea counts for selamectin were < or =0.4. Mean flea counts for animals assigned to treatment with selamectin were significantly lower (P=0.0001) than for animals assigned to treatment with lufenuron at all assessments after day 0.     

Drug Efficacy of Terbinafine Hydrochloride (Lamisil®) During Oral Treatment of Cats,Experimentally Infected with Microsporum canis

Cats represent a primary source of Microsporum canis infections in humans. Terbinafine hydrochloride (Lamisil^®) is commonly used in the treatment of microsporosis in humans as its fungicidal action permits short periods of treatment. The aim of the present study was to estimate the efficacy of the drug in cats. Nine cats were experimentally infected with M. canis and treated with terbinafine hydrochloride at a dose of 10–20 mg/kg (once daily, SID; low‐dose group, LDG). Another nine cats were similarly infected and treated with 30–40 mg/kg SID (high‐dose group, HDG) and a further nine cats were also infected and left untreated (control group, CG). The general condition of the cats was observed daily and their clinical symptoms evaluated weekly. The cats recovery was monitored using the Wood's lamp illumination test and microscopic and fungal culture examinations. The general condition of the cats during the study was good. The cure rates of the LDG were not significantly different from the CG at any period during the treatment. However, the HDG cure rates differed significantly from the other two groups. After 109 days of treatment, when all nine cats of the HDG were healed, seven cats of the LDG and all the cats in the CG were still M. canis‐positive. This study shows that dosages of 10–20 mg/kg SID of terbinafine hydrochloride are not sufficient to terminate an experimental M. canis infection in cats within an acceptable period of time. Terbinafine hydrochloride can be used to treat dermatophytosis in cats, but a higher dosage, 30–40 mg/kg SID, should be used to achieve a cure.     

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.     

Cerebral phaeohyphomycosis caused by Cladosporium spp. in two domestic shorthair cats

Two domestic shorthair cats presented for clinical signs related to multifocal central nervous system dysfunction. Both cats had signs of vestibular system involvement and anisocoria, and one had generalized seizure activity. Cerebrospinal fluid analysis revealed a neutrophilic pleocytosis with protein elevation in one cat and pyogranulomatous inflammation in the second. Electroencephalography and brain-stem auditory-evoked potentials in the first cat confirmed cerebral cortical and brain-stem involvement. Euthanasia was performed in both cats, and postmortem diagnoses of phaeohyphomycosis secondary to Cladosporium spp. were made based on histopathology and fungal culture in both cats.     

Efficacy of selamectin in the treatment and control of clinical signs of flea allergy dermatitis in dogs and cats experimentally infested with fleas

OBJECTIVE: To determine whether treatment with selamectin would reduce clinical signs of flea allergy dermatitis (FAD) in dogs and cats housed in flea-infested environments. DESIGN: Randomized controlled trial. ANIMALS: 22 dogs and 17 cats confirmed to have FAD. PROCEDURE: Animals were housed in carpeted pens capable of supporting the flea life cycle and infested with 100 fleas (Ctenocephalides felis) on days -13 and -2 and on alternate weeks with 10 to 20 fleas. On day 0, 11 dogs and 8 cats were treated with selamectin (6 mg/kg [2.7 mg/lb]). Dogs were retreated on day 30; cats were retreated on days 30 and 60. All animals were examined periodically for clinical signs of FAD. Flea counts were conducted at weekly intervals. RESULTS: Throughout the study, geometric mean flea counts exceeded 100 for control animals and were < or = 11 for selamectin-treated animals. Selamectin-treated cats had significant improvements in the severity of miliary lesions and scaling or crusting on days 42 and 84, compared with conditions on day -8, and in severity of excoriation on day 42. In contrast, control cats did not have any significant improvements in any of the clinical signs of FAD. Selamectin-treated dogs had significant improvements in all clinical signs on days 28 and 61, but in control dogs, severity of clinical signs of FAD was not significantly different from baseline severity at any time. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that topical administration of selamectin, even without the use of supplementary environmental control measures and with minimal therapeutic intervention, can reduce the severity of clinical signs of FAD in dogs and cats.     

Evaluation of praziquantel for treatment of experimentally induced paragonimiasis in dogs and cats

Praziquantel was used successfully for treatment of a small number of dogs and 1 cat infected with Paragonimus kellicotti. To further evaluate the usefulness of this drug in treating such infections, 7 cats and 7 dogs were inoculated orally with metacercariae (12 and 20 to 22, respectively) obtained from crayfish, then were treated after the infections became patent; 2 cats and 2 dogs served as noninfected controls. Beginning 1 week before infection, and continuing weekly thereafter, physical, hematologic, and fecal examinations were performed on each animal; thoracic radiography was performed every other week. By postinoculation week 6, all dogs given metacercariae had patent infection diagnosed on the basis of positive results of fecal examination. By postinoculation week 7, 5 cats had confirmed patent infection, but 2 cats given metacercariae never had patent infection or had signs of infection. Clinical signs of infection were minor and included increased respiratory tract noise, slight inducible cough, or mild dyspnea. Transient eosinophilia was detected in dogs around postinoculation week 3. Pretreatment radiography revealed cavitated lesions in cats only; pleural lines and patchy infiltrates in cats and dogs; or pneumothorax in dogs only. The treatment regimen consisted of 23 mg of praziquantel/kg of body weight given every 8 hours for 3 days; 1 infected cat and dog were not treated. By 11 days after treatment, eggs had disappeared from the feces of infected animals, and marked resolution of lung lesions was evident radiographically.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental Bovine Genital Ureaplasmosis II. Granular Vulvitis, Endometritis and Salpingitis Following Uterine Inoculation

Twenty-three virgin Holstein heifers received uterine inoculations with ureaplasma and were necropsied one to thirteen days later. Three heifers inoculated intracervically were necropsied on days 3, 5 and 11.

Granular vulvitis was produced on average by 3.6 days in fourteen of sixteen uterine inoculated heifers monitored for four or more days. Two cervically inoculated heifers monitored for over four days also developed granular vulvitis by the fourth day.

At necropsy, ureaplasma was recovered from 94% of uterine horn cultures for the first four days postinoculation and 50% during days 5 to 7. Thereafter all uterine cultures were negative. The percentage of positive ureaplasma recoveries from uterine tube flushings was lower than for uterine horns but remained positive for a longer period. By day 7, three of four uterine tube flushings were still positive. No bacterial pathogens were isolated from the uterine horns or uterine tube flushings.

On histopathology 50% of uterine inoculated heifers had endometritis up to six days postinoculation and a slightly higher percentage (58%) had salpingitis. Endometritis was not found in any heifers after day 6. Residual salpingitis was present in one heifer on day 7. Endometritis was present in cervically inoculated heifers necropsied on days 3 and 5 but not on day 11. Salpingitis was not found in any of the three cervically inoculated animals.

The study concluded that some strains of ureaplasma are pathogenic for the upper reproductive tract of the cow and should be considered significant when isolated from cases of granular vulvitis, endometritis or salpingitis.

     

Efficacy and safety of selamectin against Sarcoptes scabiei on dogs and Otodectes cynotis on dogs and cats presented as veterinary patients

A series of randomized, controlled and masked field studies was conducted in veterinary patients to evaluate the efficacy of selamectin, a novel avermectin, in the treatment of naturally occurring Sarcoptes scabiei infestations on dogs and Otodectes cynotis infestations on dogs and cats. A total of 342 dogs and 237 cats participated in these studies, which were conducted at 40 veterinary practices in the USA and Europe. Animals were randomly assigned to treatment with selamectin or a positive-control product (existing approved products). Selamectin was administered as a unit dose providing a minimum of 6mgkg(-1) (range: 6-12mgkg(-1)) in a topical preparation applied to the skin in a single spot on day 0 (O. cynotis in cats, n=144), or on days 0 and 30 (O. cynotis and S. scabiei in dogs, n=83 and n=122, respectively). The presence of parasites was assessed before treatment and at 30 days (for all studies) and 60 days (for O. cynotis and S. scabiei dog studies) after first treatment. The animals were also evaluated clinically at each assessment period. Based on skin scrapings, the efficacy of selamectin against S. scabiei infestations on dogs was >95% by day 30, and 100% by day 60. Against O. cynotis, selamectin eliminated mites in 94-100% of cats by day 30, and in 90% of dogs by day 60. The positive-control products achieved similar results. Thus, selamectin was safe and effective against ear mites in dogs and cats and sarcoptic mange in dogs when used in field (veterinary patient) studies in dogs and cats of a wide variety of ages and breeds.