Mycobacterial disease in cats in Great Britain: I. Culture results, geographical distribution and clinical presentation of 339 cases

This study investigated 339 cases of feline mycobacterial disease from cats with cutaneous lesions or masses found at exploratory laparotomy. Tissue samples were submitted to the Veterinary Laboratories Agency for mycobacterial culture over a 4-year period to December 2008. The study assessed which species of culturable mycobacteria were involved, where the cats lived, and their clinical presentation (physical findings, serum biochemistry, radiography, feline leukaemia virus and feline immunodeficiency virus status). Mycobacterium microti was cultured from 19%, Mycobacterium bovis 15%, Mycobacterium avium 7%, non-M avium non-tuberculous mycobacteria 6%, with no growth in 53% of samples. M microti, M bovis and M avium were found in almost mutually exclusive clusters within Great Britain (GB) (ie, M bovis in South-West England/Wales/Welsh Border, M avium in eastern England and M microti south of London and in South-West Scotland). While differences were seen in the clinical presentation and distribution of lesions caused by the different infections, these were not sufficiently different to be diagnostic. Cats commonly presented with single or multiple cutaneous lesions (74%), which were sometimes ulcerated or discharging, located most frequently on the head (54%). Lymph nodes were usually involved (47%); typically the submandibular nodes. Systemic or pulmonary signs were rarely seen (10-16%). When a cat is suspected of having mycobacteriosis, accurate identification of the species involved helps to determine appropriate action. Our findings show that knowing the cat's geographic location can be helpful, while the nature of the clinical presentation is less useful. Most cases of feline mycobacterial disease in GB are cutaneous.     

Experimental transmission of a feline mycobacterial skin disease (feline leprosy)

Non-culturable acid-fast bacteria from two spontaneous cases of so-called feline leprosy were transmitted to rats and cats and further passaged in rats or cats. Two to six months after infection, cats developed cutaneous lesions that were indistinguishable from spontaneous cases, including the occurrence of nasal granulomata in one cat. When injected into rats, the mycobacteria caused a generalized mycobacteriosis and the granulomatous reaction was composed chiefly of macrophages without polymorphonuclear granulocytes. Infection of cats with Mycobacterium lepraemurium did not produce any lesions. The feline disease may be a suitable model for the study of human leprosy (Hansen's Disease).     

Adaptation of IFN-gamma ELISA and ELISPOT tests for feline tuberculosis

There are currently no reliable immunodiagnostic tests for feline tuberculosis. Infection of domestic cats in the UK is thought to occur via their contact with the relevant reservoir of infection, e.g. cattle and badgers for Mycobacterium bovis, and rodents for M. microti. In the African National Parks, where M. bovis infection of Bovidae is an increasing problem, transmission to big cats is occurring via their ingestion of infected carcasses. We have adapted feline ELISA and ELISPOT assays to potentially provide the first cell-based diagnostic test for the detection of tuberculosis in cats. We tested peripheral blood mononuclear cell antigen-specific IFN-gamma responses of 18 cats suspected of mycobacterial infection for which biopsy material was co-submitted to the Veterinary Laboratories Agency for mycobacterial culture and identification. Seventeen cats were tested by ELISA while seven cats were tested by ELISPOT (six cats were tested by both ELISA and ELISPOT). Six healthy control cats provided baseline data for these tests. Responses to bovine and avian tuberculins (PPDB and PPDA) and a protein cocktail of ESAT6 and CFP10 were measured, together with positive mitogen (PMA and calcium ionophore) and negative (medium) controls. Overall, both ELISPOT and ELISA tests were found to be suitable for generating rapid results (2 and 4 days, respectively), which provided good predictive information for M. bovis and M. microti infections, but were unable to reliably discern M. avium infection.     

Treatment of opportunistic mycobacterial infections with enrofloxacin in cats.

Marked improvement was observed in the condition of 6 cats with opportunistic mycobacterial infections during treatment with enrofloxacin, a fluoroquinolone antibiotic. Complete remission was achieved in 3 cats after 3 to 7 weeks of treatment. The other 3 cats were euthanatized after 1 to 2 weeks of treatment for reasons not related to the treatment. Lesions did not recur within the follow-up period, which ranged from 9 to 16 months. Treatment of opportunistic mycobacterial infection in cats is complicated because many mycobacteria are resistant to antituberculosis drugs, which also can be toxic to cats, and because results of susceptibility testing with other antimicrobials do not always correlate with clinical response. Often, neither satisfactory nor long-term response is observed in cats treated surgically or with the antibiotics currently recommended. These findings suggested that enrofloxacin is effective in the treatment of infections caused by Mycobacterium smegmatis and M fortuitum var fortuitum in cats.     

Comparison of postmortem techniques for the detection of Mycobacterium bovis in white-tailed deer (Odocoileus virginianus).

A retrospective study of various diagnostic postmortem techniques used in a 4-year surveillance program for detection of Mycobacterium bovis infection in wild white-tailed deer (Odocoileus virginianus) was conducted. The tests evaluated were routine histopathology, acid-fast staining, detection of acid-fast bacilli in culture, and an M. tuberculosis group-specific genetic probe applied to pure cultures. Each of these techniques were compared with a reference or "gold standard" of mycobacterial culture and identification. Histopathology, the most rapid form of testing for M. bovis infection in white-tailed deer samples, had a sensitivity of 98% and a specificity of 87%, resulting in a positive predictive value of 94%. The detection of acid-fast bacilli by staining was less sensitive than histopathology (90%), but its higher specificity (97%) resulted in a positive predictive value of 99%. The detection of acid-fast bacilli on culture was both highly specific (93%) and sensitive (100%). The group-specific genetic probe had the highest sensitivity and specificity and produced results in complete agreement with those of mycobacterial culture, suggesting that this technique could be used as the new "gold standard" for this particular wildlife tuberculosis surveillance program.     

Comparisons between cats with normal and increased fPLI concentrations in cats diagnosed with inflammatory bowel disease

Objectives : The aim of this study was to compare age, serum albumin and cobalamin concentrations, serum alanine amino transferase and alkaline phosphatase activities, feline inflammatory bowel disease clinical disease activity index, pancreatic ultrasound findings, intestinal histopathology scores, outcome, treatment and clinical response between cats diagnosed with inflammatory bowel disease with normal or increased serum feline pancreatic lipase immunoreactivity concentrations. Methods : Medical records for 23 cats diagnosed with inflammatory bowel disease and with serum feline pancreatic lipase immunoreactivity concentrations available were reviewed. Three groups were compared; cats with serum feline pancreatic lipase immunoreactivity concentrations 2·0 to 6·8 µg/l (group A), 6·9 to 11·9 µg/l (group B) and ≥12·0 µg/l (group C). Results : Sixteen of the 23 cats had increased serum feline pancreatic lipase immunoreactivity concentrations; 9 cats in group B and 7 cats in group C. The remaining seven cats were in group A. Cats with serum feline pancreatic lipase immunoreactivity concentrations ≥12·0 µg/l had significantly lower median serum albumin and cobalamin concentrations. No significant differences were identified between the three groups for age, serum alanine amino transferase and alkaline phosphatase activities, feline inflammatory bowel disease clinical disease activity index, pancreatic ultrasound findings, intestinal histopathology scores, clinical outcome, treatment or clinical response. Clinical Significance : Hypoalbuminaemia and hypocobalaminaemia were more frequently observed in cats with serum feline pancreatic lipase immunoreactivity concentrations ≥12·0 µg/l.     

PCR studies of feline leprosy cases

16S rRNA gene sequence analysis provided evidence for two different mycobacterial species, Mycobacterium lepraemurium and a potentially novel species, as causative agents of 'feline leprosy'. Comparison of 16S rRNA gene sequence data obtained for M. lepraemurium and the potentially novel species indicated 12 nucleotide differences over a 446 bp region encompassing the V2 and V3 hypervariable regions. From available 16S rRNA gene sequence data, M. lepraemurium shared greatest nucleotide identity with M. avium subsp paratuberculosis and M. avium. The novel species had a long helix 18 in the V3 region and shared greatest nucleotide identity with M. leprae, M. haemophilum and M. malmoense. The novel species had an additional 'A' nucleotide at position 105 of the aligned 16S rRNA gene sequence, the only other mycobacterial database sequence having this same extra nucleotide being M. leprae. This nucleotide variation was exploited to develop specific PCR assays for the two species. These were found to be effective and specific when tested against a panel of mycobacteria including species found in feline leprosy lesions and closely related mycobacteria and also when applied directly to formalin-fixed, paraffin-embedded tissues from feline leprosy cases.     

Mycobacterium microti infection in the cat: a case report, literature review and recent clinical experience

OVERVIEW: Mycobacterium microti infection is infrequently described in cats in the veterinary literature. It can be one of a large number of possible differential diagnoses in a feline patient with dermal nodules and non-healing draining ulcers, and can occasionally spread to involve the lungs and/or other areas of the body. CASE SUMMARY: This report describes the clinical signs, eventual diagnosis and variable response to treatment in a cat in Switzerland with recurrent cutaneous M microti infection. Only after several diagnostic and therapeutic attempts, over more than 2 years, was the species of Mycobacterium finally identified and targeted therapy given. PRACTICAL RELEVANCE: For any cat in which there is even a low suspicion of mycobacterial infection, the authors recommend that an aggressive diagnostic approach is taken. Tissue specimens should be collected and frozen early on, and, as soon as acid-fast bacilli are detected, samples should be sent to a mycobacterial reference laboratory for definitive identification. LITERATURE REVIEW: A review of the literature relating to the aetiopathogenesis, diagnosis and management of M microti infection in cats and dogs is included. This is supplemented with clinical and therapeutic experience gained from this case and other, unpublished cases managed over the past 15 years by one of the authors (DGM).     

Infection by Leishmania infantum in cats: epidemiological study in Spain

More than 40 cases of feline leishmaniasis have been reported in the scientific literature. The influence of some immunodepressive conditions of viral origin, such as leukemia and feline immunodeficiency, are still unknown. The purpose of this study was to assess the prevalence of Leishmania infection in cats and possible relations with these viral infections. Markers of Leishmania infection were searched in 183 cats from Southern Spain by IFAT, PCR, Giemsa stain and culture, with a follow-up of positive cats. Seropositivity was 60.0% (Ab titer > or =10) and 28.3% of animals presented Ab titers > or =40. Around 25.7% of the cats studied were parasitemic and some of them remained positive for months. Combining both data, 70.6% of the feline population was, or could be, infected. We observed a negative association between seropositivity to Leishmania and infection by FeLV. Hence, production of antibodies against the parasite appears to be compromised in cats with leukemia, which have a prevalence of 36% in our study. In contrast, we found no association with feline immunodeficiency. The results makes us doubt the value of conventional serological methods to detect active Leishmania infection in cats.     

Ulcerated and nonulcerated nontuberculous cutaneous mycobacterial granulomas in cats and dogs

Background –  Mycobacterial granulomas of the skin and subcutis can be caused by one of a number of pathogens. This review concentrates on noncultivable species that cause diseases characterized by focal granuloma(s), namely leproid granuloma (in dogs) and feline leprosy (in cats). Clinically indistinguishable lesions can be caused by tuberculous organisms (Mycobacterium bovis and Mycobacterium microti) and members of the Mycobacterium avium complex. Rapidly growing mycobacterial species that cause infection of the subcutaneous panniculus associated with draining tracts are not discussed. Disease caused by Mycobacterium ulcerans is an important emerging differential diagnosis for ulcerated cutaneous nodules in certain localized regions. Clinical lesions –  Lesions comprise one or multiple nodules in the skin/subcutis. These are generally firm and well circumscribed, and typically become denuded of hair. They may or may not ulcerate, depending on the virulence of the causal organisms and the immune response of the host. Diagnosis –  The most inexpensive, noninvasive means of diagnosis is by submission of methanol‐fixed, Romanowsky‐stained smears to a Mycobacterium Reference Laboratory after detecting negatively stained or acid‐fast bacilli on cytological smears. Scrapings of material from slides usually provide sufficient mycobacterial DNA to enable identification of the causal organism using sequence analysis of amplicons after PCR using specific mycobacterial primers. Therapy –  Therapy relies upon a combination of marginal resection of easily accessible lesions and treatment using two or three drugs effective against slowly growing mycobacteria, choosing amongst rifampicin, clarithromycin, clofazimine and pradofloxacin/moxifloxacin.     

Feline mammary carcinoma: a retrospective evaluation of 17 cases

Seventeen biopsies of feline mammary carcinoma submitted to the Veterinary Pathology Laboratory, Nova Scotia Department of Agriculture and Marketing were reviewed. All 17 cases were female cats. Data on age, reproductive status (sexually intact vs. neutered), therapy, outcome of the cases and histological features were consistent with data on feline mammary carcinoma previously reported. Four of these 17 cats had a history of receiving exogenous progestin prior to tumor development. The possible role of progestins as initiators or promoters of feline mammary carcinoma was discussed. The use of feline mammary carcinoma as a model for carcinoma of the breast in women was reviewed.     

Feline systemic reactive angioendotheliomatosis: eight cases and literature review

A rare, multisystemic intravascular proliferative disorder was identified postmortem in eight cats. The majority of these cats died or were euthanized following episodes of dyspnea, lethargy, and anorexia. Microscopic examination revealed occlusive, intraluminal proliferations of spindle cells within small vessels. The heart was consistently involved, and myocardial dysfunction was the probable cause of illness in all cats. Immunohistochemically, the majority of intravascular cells expressed von Willebrand factor, and a smaller number expressed smooth muscle actin, compatible with a dual population of endothelial cells and pericytes, suggesting a reactive rather than a neoplastic process. Four cases of a similar feline vascular disorder from the veterinary literature are reviewed. The histopathology resembles reactive angioendotheliomatosis in humans, a benign cutaneous intravascular endothelial and pericytic proliferative condition. However, in contrast, this feline disease is multisystemic and fatal. We propose the name "feline systemic reactive angioendotheliomatosis" for this unique, idiopathic disorder of domestic cats.     

Mycobacterial dermatitis.

Mycobacterial skin disease in cats associated with atypical mycobacteria is an uncommon disease in small animal practice, and the disease is rarely encountered in dogs. A mycobacterial etiology should be considered in cases of chronic nodular dermatitis, draining tracts, and panniculitis. Cats and dogs affected with atypical mycobacterial infections are usually otherwise healthy, and systemic illness is unusual. In most cases, a diagnosis is made based on histopathological findings and growth of a causative organism. Group IV atypical mycobacteria can usually be grown following submission of affected tissue. Treatment should be based on antibiotic sensitivity test results. Treatment is prolonged and is unsuccessful in many cases. In cases of feline leprosy and canine leproid granuloma syndrome, organisms are difficult if not impossible to grow, and clinical and histopathological findings should be used to make a diagnosis. Spontaneous resolution of disease has been reported in atypical mycobacteriosis, feline leprosy, and canine leproid granuloma syndrome.     

Polymerase chain reaction detection of Mycobacterium tuberculosis complex and Mycobacterium avium organisms in formalin-fixed tissues from culture-negative ruminants

In the US eradication program for bovine tuberculosis, a definitive diagnosis depends on the isolation of Mycobacterium bovis. However, in some cases bacterial culture is unsuccessful, even though the tissue is considered suspicious by histopathology because granulomatous lesions and acid-fast organisms are present. The purpose of this study was to determine if polymerase chain reaction (PCR) tests on formalin-fixed tissue would successfully identify the organisms observed in suspect lesions from culture-negative animals. Diagnostic laboratory records were used to select paraffin blocks of tissue from 102 ruminants that had suspect microscopic lesions but no bacterial isolation. Sections from these blocks were examined with PCR primers for IS6110 to detect Mycobacterium tuberculosis complex infection, or with 16S ribosomal RNA and IS900 primers for detection of Mycobacterium avium. The PCR tests successfully identified a mycobacterial infection in 58 of 102 tissues, including 41 M. tuberculosis complex and 17 M. avium (11 subspecies paratuberculosis). These results demonstrate that PCR testing of formalin-fixed tissue, in combination with bacterial culture, may increase the effectiveness of laboratory diagnostic efforts to detect and identify the most common mycobacterial diseases of ruminants.     

Periocular cutaneous mast cell tumors in cats: evaluation of surgical excision (33 cases)

Objective  To describe feline periocular cutaneous mast cell tumor (CMCT) clinical features, rates of local tumor recurrence and metastases, and cat survival time following surgical excision.
Animals studied  Thirty-three cats with periocular CMCTs.
Procedures  Medical records of cats diagnosed with periocular CMCTs were reviewed; cats were included if CMCTs were surgically excised and the diagnosis confirmed by histopathology. The appearance, size, location and histopathology findings of CMCTs were recorded. Rates of local recurrence, metastasis, and survival time following surgical excision were collected when available.
Results  All periocular CMCTs were restricted to the eyelids. In addition to surgical excision, three cats were treated with adjunctive therapy (strontium-90 irradiation or cryotherapy) intraoperatively. Local tumor control was achieved in 22/23 cats with a minimum follow-up of 30 days (median follow-up time of 711 days); one cat developed disseminated CMCTs but no local recurrence. Cats with periocular CMCTs had a median survival time of 945 days. Metastatic disease involving peripheral lymph nodes or abdominal viscera was not detected in any cat at any time during the study. All periocular CMCTs were classified as low-grade based on histopathology, and complete excision was achieved in approximately 50% of cases.
Conclusions  Surgical excision of periocular CMCTs in cats is an effective treatment option with rare local recurrence and metastases, even following incomplete surgical excision.     

Diagnosis of avian mycobacteriosis: comparison of culture,acid-fast stains,and polymerase chain reaction for the identification of Mycobacterium avium in experimentally inoculated Japanese quail (Coturnix coturnix japonica)

In this study we compared culture, acid-fast stains, and polymerase chain reaction (PCR) for the detection of acid-fast organisms in fecal and tissue samples from Japanese quail (Coturnix coturnix japonica) that were experimentally inoculated intravenously with Mycobacterium avium. For culture, three different culture media (modified Herrold egg yolk with mycobactin; Lowenstein-Jensen [L-J]; and L-J with cyclohexamide, naladixic acid, and lincomycin) were tested to determine which medium had the greatest success in isolating mycobacteria. Acid-fast staining methods included Zichl-Neelsen (Z-N) and Truant. The PCR assay detected mycobacterial DNA with primers specific for the 65-kD heat shock protein gene. Culture was considered the "gold standard." Compared with other culture media, L-J yielded more positive cultures and greater numbers of colonies on positive tubes, and incubation times were shorter. Mycobacterium avium was isolated from all of the harvested tissue samples (liver, spleen, and intestine) of inoculated birds. Mycobacteria were isolated from 53% (69/130) of fecal samples from inoculated birds. As the disease advanced, fecal culture was positive on more culture days, indicating that the culture-positive rate was higher later in the course of the disease. Compared with culture, all of the laboratory methods had 100% specificity for the tissue samples. Sensitivities for the tissue samples were 82.6% (Z-N), 95.7% (Truant), and 100% (PCR). For the fecal samples, the specificity was >95% for all methods. Sensitivities compared with fecal culture were 7.2% (Z-N), 30.4% (Truant), and 20.3% (PCR). Tissue and fecal samples from the two control birds were negative for acid-fast organisms by any method. These results were comparable with clinical cases of avian mycobacteriosis where culture and PCR of tissue samples seem to be the most sensitive and specific laboratory tests and evaluation of fecal samples still remains challenging. On the basis of the results of this study, identification of mycobacteria in fecal samples from Japanese quail can be optimized by repeated cultures and Truant acid-fast staining of fecal smears.     

Feline non-ocular melanoma: a retrospective study of 23 cases (1991-1999).

Non-ocular melanoma is considered to be a rare neoplasm in cats; however, more than 150 cases have been reported in the literature since 1961. The objective of this study was to characterise this tumour better by evaluating case outcome and survival data for cats with melanoma and to compare clinical and histopathological findings with those of previous reports. Twenty-three feline non-ocular melanomas were identified, the most common locations being the nose, digit and pinna. Cats with digital melanomas had survival rates similar to their canine counterparts. Histological assignation of benignity, malignancy or junctional activity was not found to be an accurate predictor of clinical behaviour. Melanoma should be considered as a differential diagnosis for cats presenting with pigmented or non-pigmented masses and histopathology is essential for definitive diagnosis, as other tumours may clinically appear quite similar. Regular follow-up examinations are recommended indefinitely for benign or malignant feline melanomas.     

Infection of Eurasian badgers (Meles meles) with Mycobacterium bovis and Mycobacterium avium complex in Spain

The prevalence, distribution and pathology related to infection with Mycobacterium bovis and other mycobacteria were determined in trapped (n=36) and road-killed (n=121) badgers in Spain from 2006 to 2010. The prevalence of M. bovis based on bacteriological culture from road-killed badgers was 8/121 (6.6%) and from trapped badgers was 0/36 (0%). Tuberculosis/M. bovis infection was evident in 15/121 (12.4%) road-killed badgers when bacteriology and histopathology were combined. Mycobacterium avium complex was isolated by culture from the tracheal aspirate of 1/36 (2.8%) trapped badgers and from tissue pools from 8/121 (6.6%) road-killed badgers.     

2018-2019年南京某宠物医院2 249例宠物猫疾病调查与统计分析

本文对2018年和2019年于南京市艾贝尔宠物医院龙江店就诊的2 249例宠物猫病例进行调查与统计分析,以评估近年来南京地区宠物猫疾病的发生情况,同时补充国内猫疾病发生情况调查的相关资料.统计结果显示:内科疾病641例,占总病例数的28.50％,其中最常见的为消化系统疾病;外科疾病749例,占总病例数的33.30％,其...