Histopathological study of feline eosinophilic dermatoses

A retrospective study was conducted on skin specimens from 24 cats with eosinophilic granuloma complex. The specimens were stained with haematoxylin and eosin and Gallego's trichrome stain. In all specimens, flame figures and/or large foci of so-called "collagen degeneration" were detected and histopathological features were not predictive of the clinical picture. Use of the term eosinophilic dermatosis was advocated in diagnostic dermatopathology. On trichrome-stained sections, normally stained collagen fibres were identified in the middle of both flame figures and large foci of "collagen degeneration" and the debris surrounding collagen bundles showed the same tinctorial properties as eosinophil granules. Eosinophil degranulation around collagen bundles seemed to represent the major pathogenetic event in these lesions, analogous with human flame figures. The term flame figures might therefore be more accurately used to designate those foci of eosinophilic to partly basophilic debris commonly referred to as "collagen degeneration".     

Bovine nasal eosinophilic, granuloma with blood eosinophilia caused by Nocardia species.

OBJECTIVE: To describe a case of nocardial nasal granuloma in a Holstein heifer. CLINICAL FEATURES: The heifer showed laboured respiration and occasional coughing with granulomatous excrescences on the bilateral nasal mucosa, and a marked leucocytosis with eosinophilia. NECROPSY: Severe granulomatous inflammation with eosinophils, epithelioid cells, giant cells and Nocardia sp obstructed both nasal passages completely. CONCLUSION: This lesion resulted from chronic infection with Nocardia sp and is distinct from other forms of bovine nasal granuloma, also called atopic rhinitis or chronic granular rhinitis, which we propose should be classified as bovine allergic granular rhinitis. The most appropriate name for the present disease is bovine nasal eosinophilic granuloma.     

Clinical and histological evaluation of an analogue of palmitoylethanolamide, PLR 120 (comicronized Palmidrol INN) in cats with eosinophilic granuloma and eosinophilic plaque: a pilot study

Fifteen cats with eosinophilic granuloma or eosinophilic plaque were given PLR 120 at the dosage of 10 mg kg⁻¹ twice daily for one month. PLR-120 down-modulates mast cell degranulation via a receptor-mediated mechanism. No other drugs were permitted and cats were kept free of parasites throughout the study. A clinical evaluation and skin biopsies were performed before and after the treatment. Clinical improvement was assessed at 15 and 30 days. Mast cell numbers were counted and their granular content was assessed by densitometric analysis on toluidine blue-stained sections before and after the treatment. Ten of 15 (67%) cats showed clinical improvement of signs and lesions. There was no significant difference between mast cell numbers in skin biopsies taken before and after the trial, whereas the number of granules was significantly increased ( P < 0.009). This pilot study suggests that PLR-120 might be a useful drug for the treatment of eosinophilic granuloma and eosinophilic plaque.     

Expression of RANTES mRNA in skin lesions of feline eosinophilic plaque

Abstract One of the mechanisms of eosinophil infiltration is its induction by chemoattractants such as regulated upon activation, normal T-expressed and secreted (RANTES) which is a cysteine–cysteine chemokine that mediates chemotaxis and activation of eosinophils in humans and mice. Skin lesions of feline eosinophilic plaque are characterized by a predominant infiltration of eosinophils. The mechanism(s) of eosinophilic infiltration in the skin and/or mucosa of cats is unknown. It is possible that RANTES is involved. To investigate the presence of RANTES in the skin of cats with eosinophilic plaques and nonaffected skin, we cloned and sequenced the full-length feline RANTES cDNA gene, in order to determine whether it is present in the skin of cats with eosinophilic plaques and/or if it is present in normal adjacent skin. We were able to document the the expression of RANTES mRNAs in skin with feline eosinophilic plaque as well as in normal cat skin. The full-length cDNA sequence of the RANTES gene (742 bp) contained a single open reading frame of 276 bp encoding a protein of 92 amino acids. The amino acid sequence of feline RANTES shared 67 and 74% sequence identity with that of bovine and mouse RANTES genes, respectively. RT–PCR analysis on RANTES mRNA in the skin of cats with eosinophilic plaque revealed that its expression was higher in the eosinophilic plaque skin lesions than in the normal skin. The result suggested that RANTES might play a role to induce eosinophil infiltration in feline eosinophilic plaque lesions.     

A retrospective study of canine and feline cutaneous vasculitis

Twenty-one cases of cutaneous vasculitis in small animals (dogs and cats) were reviewed, and cases were divided by clinical signs into five groups. An attempt was made to correlate clinical types of vasculitis with histological inflammatory patterns, response to therapeutic drugs and prognosis. Greater than 50% of the cases were idiopathic, whereas five were induced by rabies vaccine, two were associated with hypersensitivity to beef, one was associated with lymphosarcoma and two were associated with the administration of oral drugs (ivermectin and itraconazole). Only the cases of rabies vaccine-induced vasculitis in dogs had a consistent histological inflammatory pattern (mononuclear/nonleukocytoclastic) and were responsive to combination therapy with prednisone and pentoxifylline, or to prednisone alone. Most cases with neutrophilic or neutrophilic/eosinophilic inflammatory patterns histologically did not respond to pentoxifylline, but responded to sulfone/sulfonamide drugs, prednisone, or a combination of the two.     

Isolated lepromatous conjunctivo-corneal granuloma in a cat from Italy

Objective  To describe a case of a conjunctivo-corneal mass in a cat associated with acid-fast bacilli.
Methods  A 2-year-old female black European Short-Hair cat, living outdoors in a suburban environment in Italy, was referred for evaluation of a nodular, vascularized mass of 2 weeks duration. The mass involved the dorsal bulbar conjunctiva at the temporal canthus of OS and invaded the sclera and cornea. Routine ophthalmic and systemic examination, serologic testing, cytology and histology of the mass were performed. Mycobacterium specific polymerase chain reaction (PCR) of variable regions 1, 2 and 3 of the 16S ribosomal RNA (rRNA) gene was also performed.
Results  Neutrophils, lymphocytes, macrophages and giant cells with intracytoplasmic acid-fast bacilli were seen on cytological examination. The histological examination confirmed the presence of a granulomatous lesion with acid-fast bacilli within macrophages. Bacteriological culture of the material from the lesion was negative for Mycobacterium spp. Mycobacterium 16S rRNA gene specific PCR was positive.
A diagnosis of feline leprosy was made. The owners refused any treatment, and 1 year later the lesion was still present.
Conclusions  Veterinary ophthalmologists should be aware of conjunctivo-corneal leproma as an unusual symptom of leprosy.     

Treatment of proliferative feline eosinophilic keratitis with topical 1.5% cyclosporine: 35 cases

Objective  Proliferative feline eosinophilic keratitis is a chronic keratopathy caused by a suspected immune mediated response to an unknown antigenic stimulus. The purpose of this study is to demonstrate the efficacy of topical 1.5% cyclosporine solution in proliferative feline eosinophilic keratitis.
Methods  Thirty-five cats were treated topically with 1.5% cyclosporine A between 1997 and 2007. Eosinophilic keratitis was diagnosed by clinical appearance and evidence of eosinophils and/or mast cells in corneal cytology. The patients were treated with topical cyclosporine (1.5%) twice (26 of 35, 74.3%) and three times (9 of 35, 25.7%) daily. The minimum period for follow-up was 5 months.
Results  The age of the patients ranged from 2 to 13 years with a mean age of 6.0 years. Twenty-two were neutered males, and 13 were females. The represented breeds were 30 DSH, 3 DLH, one Siamese and one Maine Coon. Cytologic examination of a corneal scrape revealed the presence of eosinophils in 34 of 35 specimens, and mast cells in 25 of 35 specimens. Improvement in the treated eyes was seen in 31 cats (88.6%). Four animals (11.4%) did not respond to the treatment with topical cyclosporine. Recurrences were seen in seven (22.6%) cases. Blepharitis was noted as an infrequent side effect.
Conclusion  Based on our findings, topical cyclosporine (1.5%) is an effective treatment of proliferative feline eosinophilic keratitis in the vast majority of cases. Recurrences were mainly associated with poor owner compliance. Chronic, often lifelong therapy with medications is thus recommended.     

Staining abnormalities of dermal collagen in eosinophil- or neutrophil-rich inflammatory dermatoses of horses and cats as demonstrated with Masson's trichrome stain

A retrospective study was performed on skin biopsy specimens from horses and cats having eosinophilic granulomas with 'collagen degeneration', eosinophilic skin diseases without 'collagen degeneration' and pyogranulomas without 'collagen degeneration'. Neither the appearance of collagen fibres nor the dominant polymorphonuclear cells, as seen in H & E-stained sections, were predictive of Masson's trichrome findings. Hence, a Masson's trichrome staining abnormality of collagen fibres was no more likely to be present in lesions with 'collagen degeneration' than in those lesions without 'collagen degeneration'. In addition, evaluation of trichrome-stained specimens suggested that there is no collagen degeneration in equine and feline eosinophilic granulomas and that the areas previously referred to as collagen degeneration are more appropriately called flame figures.     

Squash-prep cytology in the diagnosis of canine and feline nervous system lesions: a study of 42 cases

BACKGROUND: The increased sophistication of imaging techniques in veterinary medicine allows the detection of a wide variety of intracranial and intraspinal lesions; however, imaging often does not provide a definitive diagnosis for nervous system (NS) lesions. Cytology is emerging as a useful diagnostic tool for obtaining a fast and accurate assessment of NS lesions, but little information is available for dogs and cats. OBJECTIVES: The purpose of this study was to assess the accuracy of cytologic evaluation of squash samples from NS lesions in dogs and cats and to consider cytology-based diagnostic guidelines and sources of misdiagnosis. METHODS: Cytologic specimens from masses localized in the central and peripheral NS taken during surgery or postmortem examination were classified into 3 groups according to the final histopathologic diagnosis: Group 1 = completely correct diagnosis, when the cytologic diagnosis and final histologic diagnosis were exactly correlated; Group 2 = partial correlation, when the cytologic diagnosis only partially correlated with the final histologic diagnosis, and Group 3 = no correlation, when the cytologic diagnosis was incorrect and there was no correlation with the general histologic type of lesion. The diagnostic accuracy of cytopathology was calculated by considering the histopathologic diagnosis as the "gold standard," and calculating a 95% confidence interval (CI). RESULTS: A total of 42 animals (33 dogs and 9 cats) were included in the study. The cytologic diagnoses were classified in Group 1 for 32 cases (76%; 95% CI 0.63-0.89), in Group 2 for 6 cases (14%; 95% CI 0.04-0.25), and in Group 3 for 4 cases (10%; 95% CI 0.006-0.18). Considering both complete and partial correlation as an adequate result, cytologic diagnosis was satisfactory in 90% of biopsies. CONCLUSIONS: Although the current series of cases is relatively small, cytologic evaluation of squash preparations can be considered a fairly accurate and reliable tool in the diagnosis of NS lesions.     

Equine cutaneous fungal granuloma: a study of 44 lesions from 34 horses

Forty-four nodular and noninvasive cutaneous fungal granulomas were identified in 34 horses over a 14.5-year period. Cutaneous fungal granulomas were most common in young horses (mean age 6.1 +/- 4.2 years; range 1-19 years). There was no apparent breed or sex bias. Granulomas were either single or multiple, and most often occurred in the skin of the head and neck. The characteristic histological finding was a nodular dermal mass with a mean diameter of 7.3 mm (range 2.5-20 mm) and an intact overlying epithelium. Lesions most often exhibited intense lymphocytic inflammation, with admixed pyogranulomatous inflammation associated with a small to moderate number of fungal elements. Causative fungi were both pigmented and nonpigmented organisms of variable morphology. Penetrating plant material was identified in three cases. Granulomas caused by nonpigmented fungi were most common in horses from wet regions. Both pigmented and nonpigmented fungi were found in granulomas from horses in dry regions. Cutaneous fungal granulomas occurred in February through November, with peaks in April and July. No correlation of yearly incidence with annual average temperature or rainfall was detected. This study confirms that equine cutaneous fungal granuloma is relatively common in horses in the Pacific Northwest. Morphology of causative fungi was variable, but the signalment, history, and clinical and overall histological features were very similar. Surgical excision was curative.     

Idiopathic eosinophilic colitis lesions of the equine small (descending) colon

Five horses with a primary surgical lesion of the small (descending) colon were diagnosed with eosinophilic colitis based on visual and histopathological examination. These were evident as visibly striking, hyperaemic, focal lesions of the small colon, with serosal petechiation, oedema and marked thickening of the intestinal wall at the site. Areas of focal necrosis were also evident. The gross appearance of the lesions were considered to be sufficiently severe in all cases to merit resection, due to concerns about intestinal necrosis and septic peritonitis. An inability to fully exteriorise the affected portion of intestine to perform a resection and anastomosis necessitated intraoperative euthanasia of one horse. A total of three horses survived to hospital discharge. Eosinophilic colitis lesions are a rare cause of severe small colon disease, but should be considered in cases with similar visual characteristics.     

Characterisation of the inflammatory reaction in equine idiopathic focal eosinophilic enteritis and diffuse eosinophilic enteritis

REASONS FOR PERFORMING STUDY: Idiopathic focal eosinophilic enteritis (IFEE) and diffuse eosinophilic enteritis (DEE) are primary eosinophilic intestinal conditions without a known cause that are associated with an increasing number of surgical colic cases. Histology may be helpful in defining disease aetiology and pathogenesis. OBJECTIVES: To characterise further the inflammatory infiltrate in equine IFEE and to compare the condition with DEE. METHODS: Twenty-three IFEE cases and 5 DEE cases were examined by light microscopy including immunohistology to identify infiltrating leucocytes. Inflammatory infiltrates in mucosa and submucosa were characterised in IFEE lesions (Group 1), the intestine distant from the lesions in IFEE (Group 2) and DEE (Group 3). RESULTS AND CONCLUSIONS: IFEE lesions represented an accumulation of leucocytes in submucosa and muscularis, with dominance of eosinophils and macrophages and smaller numbers of lymphocytes, plasma cells and neutrophils. T cells represented the dominant lymphocytes. The mucosa overlying the lesion and both mucosa and submucosa in IFEE nonlesion sites and in DEE exhibited a similar composition, with different prevalence of various cell types. Macrophages were significantly more prevalent in the mucosal and submucosal infiltrates in IFEE nonlesion sites than in DEE, and lymphocytes significantly more prevalent in the mucosa in DEE than in IFEE nonlesion sites. The findings confirm IFEE as a primary eosinophilic intestinal disorder and indicate that IFEE represents a focally exacerbated inflammatory reaction in horses with DEE, possibly due to functional changes in the macrophage and T cell components, with subsequent excessive recruitment of both eosinophils and macrophages.     

Pulmonary and hepatic eosinophilic granulomas and epistaxis in a horse suggestive of multi‐systemic eosinophilic epitheliotropic disease

Multi‐systemic eosinophilic epitheliotropic disease (MEED) is a relatively uncommon disease characterised by eosinophilic infiltration of more than one organ system, with the skin and gastrointestinal tract most commonly affected. This case report describes a gelding that presented for weight loss, increased respiratory rate and effort and chronic intermittent epistaxis. During post mortem examination diffuse eosinophilic granulomatous lesions were identified in the lung and liver, leading to a diagnosis of MEED. Veno‐occlusive pulmonary remodelling was also discovered, believed to be the cause of the chronic epistaxis and a result of the pulmonary fibrosis and eosinophilic granulomas.     

Subcutaneous granuloma caused by Mycobacterium avium complex infection in a cat

A localised subcutaneous swelling developed on the nasal bridge of a cat receiving chemotherapy for alimentary tract lymphosarcoma. Cytological and histological examination of representative samples of the lesion demonstrated pyogranulomatous inflammation and abundant acid-fast bacilli. A Mycobacterium sp was cultured from tissue excised from the lesion. Extensive testing at three reference laboratories indicated the strain was a member of the Mycobacterium avium complex. The infection was treated successfully by cytoreductive surgery and a 6 weeks course of orally administered clofazimine.     

Prevalences of feline leukaemia virus and feline immunodeficiency virus infections in cats in Sydney

Objective To determine prevalences of feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) infections in ‘healthy’ cats that, through acute misadventure or other circumstance, were presented to veterinary practitioners. Prevalences of FeLV and FIV in this population were compared to those in a population of predominantly sick cats. Design and procedures Serum specimens were obtained over a 2-year period from 200 cats oldeer than 1 year of age presented to veterinary clinics for routine procedures, including cat fight injuries or abscesses, vehicular trauma, neutering, dental scaling, vaccination, grooming or boarding. An additional 894 sera were obtained over approximately the same period from specimens submitted by veterinarians to a private clinical pathology laboratory, mainly from sick cats suspected of having immune dysfunction, but including some sera from healthy cats being screened prior to FeLV vaccination. FIV antibody and FeLV antigen were detected in samples using commercial enzyme immunoassays. Results Amongst 200 ‘healthy’ cats, the prevalence of FeLV infection was 0 to 2%, and the prevalence of FIV was 6.5 to 7.5%, depending on the stringency of the criteria used to define positivity. FIV infection was significantly more prevalent in cats which resided in an inner city environment (P = 0.013). Of the 894 serum specimens submitted to the laboratory by practitioners, 11/761 (1.4%) were FeLV positive, while 148/711 (20.8%) were FIV positive. The prevalence of FIV was significantly higher in these predominantly ‘sick’ cats than in cats seen for routine veterinary procedures (P < 0.00001), while there was no difference in the prevalence of FeLV (P = 0.75) Conclusions The prevalence of FeLV and FIV in healthy cats may have been substantially overestimated in some previous Australian surveys. FeLV infection would appear to be a rare cause of disease in Australian cats. The higher prevalence of FIV positivity in sick as opposed to healthy cats infers that FIV infection contributes to the development of disease.     

Emergence and multi-lineages of carbapenemase-producing Acinetobacter baumannii-calcoaceticus complex from canine and feline origins

The carbapenemase-producing Acinetobacter baumannii is an important opportunistic bacterium and frequently causes hospital-acquired infections in humans. It also has increasingly been reported in veterinary medicine. This study illustrates multiple clones of carbapenemase-producing A. baumannii disseminating and causing diseases in dogs and cats in Thailand. Between 2016 and 2020, 44 A. baumannii and two A. pittii isolates exhibiting imipenem resistance (MIC≥16 μg/mL) from diagnostic samples were characterized by Pasteur multilocus sequence typing (MLST), sequence grouping (SG), repetitive extragenic palindromic element (rep)-PCR fingerprint analysis and antimicrobial resistance (AMR) profiling. All isolates contained bla_OXA-23 in the Tn2006 family, and A. baumannii showed the sequence type (ST) 16 (14/44), ST149 (12/44), ST25 (6/44), ST2 (4/44), ST1581 (3/44), ST23 (2/44), ST1575 (1/44) and ST1576 (1/44). DNA fingerprint analysis and SG illustrated clonal relationships in the STs and its single locus variants, and AMR gene profiles, including tetracycline and aminoglycoside resistance genes, showed minor variations in the clones. The findings suggest that bla_OXA-23 has been spread in multiple clones of A. baumannii and A. pittii from canine and feline hosts. With the collection of multiple AMR genes and intrinsic resistance, antimicrobial options are limited for treatment, and pets can be a potential reservoir of extensively drug-resistant, carbapenemase-producing A. baumannii in the community. Epidemiological tracking by passive and active surveillance in animals, veterinary personnel and hospital environment and preventive measurements should be promoted to decrease the risk of infection and transmission to humans.     

Candida parapsilosis complex infection in a cutaneous lesion from a dog: Spotlight on an opportunistic pathogen of potential increasing importance

Fine-needle aspirates from a 1.5-cm cutaneous mass in a Cocker Spaniel were submitted for cytologic examination. Marked pyogranulomatous inflammation and fungal organisms were present, identified as Candida parapsilosis complex by MALDI-ToF following fungal culture. The fungal infection was considered secondary or an incidental finding, following the diagnosis of a benign keratinizing lesion by histopathologic examination of the excised mass. This case is presented to increase awareness and describe the cytologic features of a potential pathogen, which is of increasing importance in human medicine but has a limited presence in the veterinary literature despite the potential for a similar significance.     

Elevation of serum surfactant protein-A with exacerbation in canine eosinophilic pneumonia

A 7-year-old female spayed Labrador Retriever was admitted to our hospital, because ofcough with sputum. She was diagnosed as having canine eosinophilic pneumonia (CEP) basedon blood eosinophilia, bronchial pattern and infiltrative shadow observed on thoracicradiography, bronchiolar obstruction and air-space consolidation predominantly affectingthe right caudal lung lobe, as revealed by computed tomography (CT), predominanteosinophils in CT-guided fine needle aspiration and the clinical course. She exhibited agood response to steroid therapy, and the cough disappeared. The serum surfactant protein(SP)-A level increased with the aggravated symptom and decreased markedly with improvementcompared with the C-reactive protein level and the number of eosinophils. We propose thatserum SP-A level is a good biomarker in CEP.