Michele Corazza

Dermatophytes isolated from symptomatic dogs and cats in Tuscany, Italy during a 15-year-period

Between January, 1, 1986 and December, 31, 2000, dermatological specimens from 10.678 animals (7.650 cats and 3.028 dogs) were examined for dermatophytes. All the animals presented clinical signs of ringworm. Two thousand-four hundred fifty-six of the 10.678 (23%) examined animals scored positive for dermatophytes, 566 out of 3.028 canine (18.7%) and 1890 out of 7.650 feline specimens (24.7%). Microsporum canis constituted 83% and 97% of the isolated dermatophytes respectively in dogs and cats, M. gypseum represented 13% and 2.6% and T. mentagrophytes 5.5% and 0.2%. A sexual predisposition for mycotic infections was not observed. The animals with less than 1 year of age were more frequently infected. Canine toy breeds showed a significantly higher (P < 0.001) prevalence of infections by M. canis. Microsporum gypseum was mostly recorded from sporting (hunting) breeds [such as T. mentagrophytes (6.7%)]. Microsporum canis was isolated from long-haired cats with a ratio of 2:1 versus short-haired cats, while M. gypseum and T. mentagrophytes were never recovered from Persian cats. The annual distribution of the infections in dogs showed a significantly higher incidence for M. gypseum in summer versus winter and spring, while the recovery rate of M. canis from cats was very significantly higher in fall and winter than in summer and spring. Trichophyton mentagrophytes did not show a similar seasonal distribution.

Environmental detection of Microsporum canis arthrospores in the households of infected cats and dogs

Microsporum canis is the dermatophyte most frequently recovered from canine and feline ringworm cases. The household environment can be contaminated both by symptomatic animals and through asymptomatic M canis carriage, resulting in a potential human health risk. The load of M canis arthrospores was determined in households harbouring infected pets, in order to evaluate the infectivity of the animals versus the environment. The environments inhabited by 30 symptomatic animals (21 cats and 9 dogs) infected by M canis were examined by sampling both surfaces and indoor air. The surfaces were examined by means of contact plates; the air sampling was performed with a Sas super-100 AIR SAMPLER (PBI, Italy). Environmental contamination was detected in all households with cats, while only four out of nine houses harbouring dogs were found positive. The frequence of isolation in each sampling, and the results in terms of colony forming units per plate in the different houses appeared to be quite homogeneous. Heavily infected environments harboured kittens only. Infected owners were observed in eight households, in all of which at least one infected cat was present. No history of human dermatophytosis in households harbouring dogs was found. On the basis of our results, infected cats appear to cause substantial environmental contamination, and provoke a substantial presence of viable airborne fungal elements. Dogs seem to be of lower importance in the spread of M canis: they contaminated surfaces, but they never contaminated the air. The results of this study confirm the potential leading role of the feline species in the environmental spread of M canis.

Occurrence of Malassezia species in healthy and dermatologically diseased dogs

The presence of Malassezia spp. yeasts was investigated in dermatological specimens of 224 dogs, 164 dermatologically diseased and 60 normal dogs. Subjects included in the study were of different breed, age, sex and habitat. Malassezia spp. positive cultures were obtained in 142 (63.4%) specimens: 67.6% from dermatologically diseased subjects and 51.6% from healthy dogs. Malassezia pachydermatis, either as a pure culture or in association with lipid-dependent species, was identified in 138 (97%) specimens. Malassezia furfur was identified in 69 (48.6%) specimens and was associated with other Malassezia species in 68 dogs, as a pure culture in one subject: at the best of our knowledge, this species was identified before as the sole species from canine dermatitis. Malassezia sympodialis was identified in 11 (7.7%) specimens, always in association with other species: it was never isolated from kennel dogs. Statistical analysis of data showed a very significant difference (P < 0.01) in the prevalence of isolation of Malassezia spp. between animals with and without dermatological signs, and in the distribution of cultural burden between diseased and healthy dogs. A statistically significant difference (P<0.05) was also detected in the group of animals between 1- and 5-years of age. No significant difference was found between male and female dogs.

Isolation of Malassezia species from healthy cats and cats with otitis

Lipid-dependent Malassezia species have recently been cultured from veterinary specimens. The identification of Malassezia species isolates from animals is important to clarify the epidemiology of these lipophilic yeasts. Malassezia species were cultured from the external ear canals of 63 out of 99 cats with otitis and 12 of 52 (23%) healthy control cats. The rate of isolation in affected animals versus controls was highly significant (P<0.01). Malassezia pachydermatis was isolated as a pure culture in 33 (45.2%) cats, associated with Malassezia globosa and Malassezia furfur in 20 (50%) and 17 (42.5%) animals, respectively. Three different species were isolated simultaneously in three cats (two cats with M pachydermatis, M globosa and M furfur, one subject with M pachydermatis, M furfur and Malassezia sympodialis). M globosa was isolated as the sole species in two animals. The present work confirms the presence of some lipid-dependent species of Malassezia in both healthy and otitic cats.

Proliferation activity in oral and cutaneous canine melanocytic tumours: correlation with histological parameters, location, and clinical behaviour

A total of 62 canine melanocytic tumours (10 melanocytomas and 52 primary malignant melanomas) were investigated to compare the accuracy of prognosis provided by MIB-1 proliferation index (MIB-1-PI) with classical histological criteria and location. MIB-1-PI was assessed by means of quantitative image analysis of sections immunostained with MIB-1 monoclonal antibody. Tumour location, histological cell type, stromal or lymphatic vessel invasion, maximum tumour thickness, and presence of inflammation or necrosis were recorded for each case. Thirty-eight dogs were submitted to a 1-year follow-up and the clinical outcome of the disease determined. MIB-1-PI in melanocytomas differed significantly from that detected in primary malignant melanomas (P=0.0001). A significant difference in MIB-1-PI was revealed between oral and cutaneous malignant melanomas (P=0.015), and between presence and absence of lymphatic vessel invasion (P=0.05). MIB-1-PI was not correlated with the other parameters. In univariate analysis, only tumour location (oral vs cutaneous), presence of lymphatic vessel invasion, and MIB-1-PI were associated with decreased overall survival (P=0.0001,P=0.0144, and P=0.0489, respectively). In conclusion, the results of our study confirm that the assessment of the MIB-1-PI may be of additional prognostic value for dogs with primary malignant melanomas.

Extracellular enzymatic activity of Malassezia spp. isolates

Extracellular enzymatic activity of different species of Malassezia spp was evaluated. Thirty-three isolates of animal origin (dogs and cats) and stock culture samples were studied. Twenty isolates of M. pachydermatis, 8 of M. furfur, 2 of M. sympodialis and M. globosa and one of M. restricta, M. obtusa and M. slooffiae were examined. The enzymatic activity was investigatedusing Api Zym system. The enzymatic patterns showed light differences. Esterase lipase, Phosphatase acid and Naphtol-AS-BI-phosphohydrolase were produced in significant amounts from most isolates excepted for M. restricta, confirming the limited enzymatic activity of this species. Data obtained from the other new species described after the revision of the genus, appear to be quite homogeneous. Dixon’s broth appeared to be a valid medium for the growth of all Malassezia spp.

Occurrence of fungi from conjunctiva of healthy horses in Tuscany, Italy

The fungal flora of the normal conjunctival fornix has been described for many animal species (Urban et al., 1972; Samuelson et al., 1984; Moore et al., 1988; Davidson et al., 1994; Cooper et al., 2001) and many environmental factors, such as age, geography, habitat and husbandry are reported to influence its composition (Samuelson et al., 1984; Andrew et al., 2003). Equine keratomycosis can be caused by saprophytic fungi following an underlying corneal pathology or improper use of topical antibiotics and/or topical corticosteroids (Andrew et al., 1998; Brooks, 1999). Knowledge of differences in geographic prevalence of fungi and their frequency in the conjunctiva of the horse could allow the identification of risk factors for the development of keratomycosis. The purpose of the present paper was to culture, describe and quantify moulds and yeasts from the conjunctival fornix of healthy horses living in Tuscany (Italy), and to identify the most common fungal species.

Mycobacterium avium subspecies hominissuis disseminated infection in a Basset Hound dog

In the current report, a case in Italy of disseminated Mycobacterium avium subsp. hominissuis infection in a dog from an American lineage of Basset Hounds is described. A 2-year-old intact female Basset Hound presented with persistent lymphadenopathy, lameness, and a history characterized by coccidiosis, bacterial gastroenteritis, and alopecia. Lymphadenitis, with macrophages containing a few intracytoplasmic, negative staining, Ziehl–Neelsen-positive bacilli, was detected by a popliteal fine-needle aspirate leading to the diagnosis of mycobacteriosis. Ultrasound and X-ray examinations revealed visceral and mediastinal lymphadenopathy. Because of the extent of the disease, the dog was humanely euthanized. Significant gross abnormalities, such as enlargement of the cranial mediastinal lymph nodes with encapsulated areas of caseous necrosis and generalized lymphadenopathy, were observed at necropsy. Granulomatous lesions were histopathologically detected in the liver and spleen. Ziehl–Neelsen-positive bacilli were observed in all examined lymph node, liver, spleen, lung, and bone marrow smears. Lymph nodes and liver were collected in order to pursue speciation by bacterial culture and molecular biology; multiplex polymerase chain reaction results classified the pathogen as M. avium subsp. hominissuis. Although an immune system deficiency was not investigated, anamnesis suggests that the dog was immunocompromised. Furthermore, the dog came from an American stock of Basset Hound, and for some of this breed, a predisposition to this infection has been hypothesized.

Oral administration of tepoxalin in the horse: A PK/PD study

Tepoxalin is a non-steroidal anti-inflammatory drug with analgesic, anti-inflammatory, and antipyretic properties and has been recently introduced into veterinary medicine. The aim of this study was to evaluate the pharmacokinetic/pharmacodynamic (PK/PD) profile of tepoxalin to assess whether it would be suitable for clinical use in horses. Six female fasting/fed horses were given 10mg/kg tepoxalin orally in a cross-over study. After administration, tepoxalin underwent rapid and extensive hydrolytic conversion to its carboxylic acid metabolite RWJ-20142. In animals that had been fed, the plasma concentrations of tepoxalin were undetectable, whereas in fasting animals they were close to the limit of quantification of the method. No differences between the fasting/fed groups in RWJ-20142 plasma concentrations were shown. Tepoxalin showed a strong and long-lasting ex vivo inhibitory activity against cyclooxygenase (COX)-1, mainly due to its main metabolite RWJ-20142. Tepoxalin and RWJ-20142 do not seem to possess either COX-2 or 5-lipoxygenase inhibitory activity in the horse. These features suggest that the drug is a selective COX-1 inhibitor in horses, with no significant anti-inflammatory activity. Thus, its long term use in equine practice could be of concern.

Plasma Procalcitonin Concentration in Healthy Horses and Horses Affected by Systemic Inflammatory Response Syndrome

Background The diseases most frequent associated with SIRS in adult horses are those involving the gastrointestinal tract. An early diagnosis should be the goal in the management of horses with SIRS. Objective The objective of this study was to evaluate the plasma procalcitonin (PCT) concentration in healthy and SIRS horses to assess differences between the two groups. Animals Seventy‐eight horses (30 healthy and 48 SIRS). Methods Prospective in vivo multicentric study. Horses were classified as SIRS if at least 2 of the following criteria were met: abnormal leukocyte count or distribution, hyperthermia or hypothermia, tachycardia, tachypnea. Healthy horses showed no clinical or laboratory signs of SIRS. Plasma PCT concentrations were measured with a commercial ELISA assay for equine species. Results were expressed as mean±standard deviation. T‐test for unpaired data was performed between healthy and SIRS group. SIRS group was divided in 4 subgroups and t‐test was performed between healthy versus each subgroup. Results PCT concentrations in healthy and SIRS horses were 18.28 ± 20.32 and 197.0 ± 117.0 pg/mL, respectively. T‐test showed statistical differences between healthy versus SIRS group and between healthy versus all subgroups. Conclusions and Clinical Importance Results showed an increase in PCT concentration in SIRS horses as previously reported in humans and dogs. PCT could be used as a single assay in equine practice for detection of SIRS.