Parasitic outbreak of the copepod Balaenophilus manatorum in neonate loggerhead sea turtles (Caretta caretta) from a head-starting program

BACKGROUND

Diseases associated to external parasitosis are scarcely reported in sea turtles. During the last decades several organism have been documented as a part of normal epibiont community connected to sea turtles. The copepod Balaenophilus manatorum has been cited as a part of epibiont fauna with some concern about its parasitic capacity. This study serves three purposes, i.e. (i) it sheds light on the type of life style that B. manatorum has developed with its hosts, particularly turtles; (ii) it makes a cautionary note of the potential health risks associated with B. manatorum in sea turtles under captivity conditions and in the wild, and (iii) it provides data on effective treatments against B. manatorum.

RESULTS

We report for the first time a massive infestation of the copepod B. manatorum and subsequent acute mortality in a group of loggerhead sea turtle hatchlings. Four-month-old turtles from a head-starting program started exhibiting excitatory and fin rubbing behavior preceding an acute onset of lethargy, skin ulceration and death in some animals. All the individuals (n = 57) were affected by severe copepod load and presented different degrees of external macroscopic skin lesions. The ventral area of front flippers, axillar and pericloacal skin were mostly affected, and were the main parasite distribution regions. Copepods were also detected on plastron and carapace sutures. The gut contents of B. manatorum reacted positively for cytokeratin, indicating consumption of turtle skin. Severe ulcerative necrotic dermatitis and large amount of bacteria presence were the major histopathological findings.

CONCLUSIONS

Individual fresh water immersion for 10 min and lufenuron administration (0.1 ppm) to the water system every 2 weeks proved effective for removing turtle parasites and to control re-infestation, respectively. The results from our study clearly indicated that B. manatorum individuals consume turtle skin. The pathological effects of this agent and the potential implications in sea turtle conservation and management are discussed.

Comparison of immune response to lipopolysaccharide of rabbit does selected for litter size at weaning or founded for reproductive longevity

To evaluate differences in maternal lines to the immune response of reproductive rabbit does, a total of 64 animals of two different lines: (1) founded for hyper-longevity and litter size criteria (LP) and (2) selected for litter size at weaning (V) were used. Females were subjected to three different reproductive efforts: post-partum (PP) mating at first lactation and 9 kits during the second; post-weaning (PW) mating at first lactation and 9 kits during the second; and PW mating at first lactation and 5 kits during the second. At second weaning (30 days PP), an acute response was induced by intravenous infusion of lipopolysaccharide (LPS). LP females seemed to be lower affected during the hyper-acute phase than V females, showing lower plasma glucose content at 1.5 h post infusion (pi) and rectal temperature at 6 h pi; and showed higher ulterior immune response, with higher levels of C-reactive protein at 48 h pi and haptoglobin in plasma from 24 h pi. Survival test conferred a higher risk of culling for V than for LP females during the first hours after challenge. These results may suggest that, regarding immune response to LPS challenge, foundation by hyper-longevity productive criteria lead to obtain a more robust population of rabbit does, characterized by improved response ability.

Strains of Staphylococcus aureus and pathology associated with chronic suppurative mastitis in rabbits

Staphylococcal mastitis is one of the main reasons for culling adult does from commercial rabbitries. The aim of this study was describe the spectrum of gross and microscopic lesions in 178 cases of chronic staphylococcal mastitis in adult does and to determine whether there is a correlation between Staphylococcus aureus genotypes and pathology. On the basis of histopathology, chronic mastitis was differentiated into abscesses (66.3%), suppurative mastitis with a lobular pattern (7.9%), cellulitis (19.6%) and mixed lesions (6.2%). Pathological presentations were not related to S. aureus genotype.

Uterine leiomyoma in a sheep

Leiomyomas are benign tumours, which are frequently found in animal species. However, the presence of leiomyomas in domestic ruminants has been rarely reported, especially in sheep. This report describes the pathological and immunohistochemical characteristics of a leiomyoma in the uterine body of a sheep and discusses the different aetiological causes. This is the first description of a leiomyoma in sheep in Spain.

Staphylococcal infections in rabbit does on two industrial farms

The main reasons for culling adult rabbit does on two Spanish rabbit farms were investigated for a year. The most important conditions were mastitis (33.3 per cent), followed by subcutaneous abscesses (9.9 per cent) and pyometra (8.7 per cent). Staphylococcus aureus infections were the most severe problem, the organism being isolated from 69.2 per cent of infected animals. Pasteurella species were more prevalent in cases of pyometra and pneumonia. Two strains of S aureus were identified by using polymorphism of the coagulase gene as the criterion. One of these strains was responsible for the majority of the staphylococcal infections and was isolated from several pathological processes.

Genotypic characterization of Staphylococcus aureus strains isolated from rabbit lesions

Since staphylococcal infections are the main pathological problem in rabbit does, the objective of this study was to characterize epidemiologically Staphylococcus aureus isolates from different lesion types in rabbits. Using 3 genetic markers (coagulase, staphylococcal protein A and clumping factor B genes), 22 different genotypes were identified among 301 isolates recovered from 259 rabbit does with 10 different kinds of chronic purulent lesions. These infected rabbits were obtained from 30 herds located in the Valencia province on the Spanish Mediterranean coast. The most frequent genotype was designated A1/II1/delta (coa/spa/clfB combination genotype) and represented 70.76% of the isolates. Although most genotypes were previously identified in other countries, novel types were also documented. No specificity between genotypes and nature of the pathologic process could be identified. After genetic comparison between strains from different origins, the results may suggest that rabbit, bovine and human S. aureus isolates are not clonally related, suggesting that specific host-dependent pathogenic factors may have evolved independently in these species. These differences indicate that a rational and effective strategy to control infections caused by rabbit-specific isolates may be advantageous.

Pathological and aetiological studies of multifocal interstitial nephritis in wasted pigs at slaughter

Multifocal interstitial nephritis in pigs has been associated with several infectious agents. The objective of the present study was to investigate several different potential infectious agents associated with "white-spotted" kidneys in pigs suffering from wasting at slaughter (aged 6-8 months). Twenty-nine case kidneys (with a "white-spotted" gross appearance) classified into 3 macroscopic lesional grades, and 15 control kidneys (lacking gross lesions), were obtained from a pig abattoir. Laboratory analyses to detect potential associations with the aforementioned pathological condition with Leptospira spp., porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), and bacteria, were carried out. Microscopically, interstitial nephritis with a lymphofollicular inflammatory pattern (follicular nephritis) was observed in both case and control kidneys, with a higher frequency seen in the former ones. No leptospires were identified, although antibodies to the Pomona and Bratislava serovars were detected. Some pyogenic bacteria were also isolated from both case and control kidneys. PCV2 nucleic acid was only detected in 1 case kidney. PRRSV antigen was not found in any tested sample. Some pigs were tested positive for PPV by serology. Apparently, none of the studied agents were specifically associated as being the potential cause of the renal lesions in the studied wasted pigs. The fact that these chronic lesions may have been the consequence of a previous infection with one of these studied microorganisms, or more, and eventually with other non-tested infectious agents during the growing-finishing period, cannot be ruled out.

Histopathological Classification of Lesions associated with Natural Paratuberculosis Infection in Cattle

Paratuberculosis-associated lesions in 116 naturally infected adult cows, with or without clinical signs, were classified histopathologically. Tissue samples obtained focused on gut-associated lymphoid tissue. Lesions were divided into five categories. Focal lesions (n=68 cases), consisted of small granulomas in the ileal and jejunal lymph nodes or the ileocaecal lymphoid tissue. In the multifocal type (n=13 cases), small granulomas or scattered giant cells appeared in some intestinal villi, as well as in the lymph nodes. Diffuse multibacillary lesions (n=15 cases), associated with severe granulomatous enteritis affecting different intestinal locations and lymph nodes, were formed by macrophages containing large numbers of acid-fast bacilli. In diffuse lymphocytic lesions (n=3 cases), lymphocytes were the main inflammatory cells, with some macrophages or giant cells containing few if any mycobacteria. In diffuse intermediate forms (n=17 cases), the infiltrate was formed by abundant lymphocytes and macrophages, and mycobacteria were present to varying degrees related to the number of macrophages. Clinical signs and gross lesions were mainly associated with diffuse forms. Thickening of the intestinal wall, which was the most common macroscopical finding, was related to the degree of submucosal change. Mycobacterium avium subsp. paratuberculosis was identified by culture or PCR in all cows with diffuse lesions, and in 55.5 and 37% of those with multifocal or focal forms, respectively. The importance of sampling the ileal and caudal jejunal lymph nodes to find histological lesions of paratuberculosis in cattle is emphasized.

Pneumatosis cystoides intestinalis in a rabbit doe (Oryctolagus cuniculus)

Pneumatosis cystoides intestinalis (PCI) is an infrequent condition of animals characterized by the existence of numerous thin-walled, gas-filled cystic structures within the intestinal wall and adjacent lymph nodes. Microscopically, the cystic structures appear to be dilated lymphatics located in the lamina propria, submucosa, muscularis, subserosa, mesentery, and mesenteric lymph nodes. This report describes a case of pneumatosis cystoides intestinalis in a rabbit doe from an organic farm where 20 rabbit does were fed ad libitum with a natural diet consisting of whole barley, pea beans, alfalfa hay, and a pelleted vitamin-mineral blend. A combination of nutritional, bacterial, and other factors are hypothesized as possible predisposing factors in the development of PCI.

Gastric hypersecretion associated to iodoacetamide-induced mild gastritis in mice

Disturbances of gastric motor, secretory and/or sensory functions are frequently associated with gastritis. The aim of this study was to characterize motor and secretory alterations associated to chemically-induced gastritis in mice. Mild gastritis was induced with 0.1% iodoacetamide administered intragastrically and added to the drinking water for a 6 days period. A significant loss of body weight and a reduction in food and water intake was observed in iodoacetamide-treated animals compared with those receiving vehicle. At the end of the treatment period, no macroscopic alterations were observed in the gastric mucosa of iodoacetamide-treated mice. However, histological sections revealed a mixed inflammatory infiltrate, with a predominance of mast cells in the submucosa; suggesting a mild gastritis. Gastric emptying rate of a nutrient solid meal was not modified in mice with gastritis compared with normal controls. In animals with gastritis, basal gastric acid secretion was increased compared with normal controls. Basal gastric acid secretion was not modified by either indomethacin or compound 48/80. Secretory response to secretagogues (pentagastrin and histamine) was enhanced during gastritis. Hypersecretory responses to both gastrin and histamine in iodoacetamide-treated mice were blocked by the mast cell stabilizer sodium cromoglycate, and enhanced by indomethacin, without affecting the secretory response in normal mice. These results suggest that mild gastritis alters gastric acid secretory responses through a mechanism related, at least partially, to mast cells activation. Moreover, prostaglandins also modulate secretory responses during mild inflammation. This animal model of gastritis might be useful to characterize pathophysiological changes and potential therapeutic targets in secretory-related gastric pathologies.

Distribution of lymphocyte subsets in the small intestine lymphoid tissue of 1-month-old lambs

Distribution of lymphocyte subpopulations along the small intestine lymphoid tissue has been examined in 1-month-old lambs using flow cytometric and immunohistochemical techniques. Monoclonal antibodies against CD4, CD8, gamma delta, CD45R and B receptors have been employed in samples from continuous ileal Peyer's patch (IPP), discrete jejunal Peyer's patches (JPP), ileocaecal valve lymphoid tissue (ICVPP), mesenteric lymph node (MLN) and intra-epithelial (IEL) and lamina propria (LPL) lymphocytes. Histological studies were also done. Differences in the lymphocyte distribution have been observed between some of the regions examined, especially between IPP and JPP for most of the markers. A remarkable feature was the existence of morphological and lymphocyte distribution differences between ICVPP and IPP, locations that had been traditionally considered as similar. The antibody against CD45R receptor used in this study, that was supposed to mark B cells and some T cells, detected cell populations located in the dome of the follicles in all the samples, whereas the centre was negative. Lymphocytes positive to the B marker employed were located mainly in the centre, suggesting that both antibodies would mark B cells in different maturation status.

Proximal aortic dissection (dissecting aortic aneurysm) in a mature ostrich

The gross and histopathologic lesions observed in a case of spontaneous proximal aortic dissection (dissecting aortic aneurysm) in a mature ostrich are reported. At necropsy, a dissecting intramural hematoma was seen in the proximal aorta, extended about 12 cm distally from the aortic valves. Histopathologic changes in aortic dissection included fragmentation and disruption of elastic laminae, presence of cystic extracellular spaces, and pooling of ground substance in the tunica media. Hepatic copper levels were measured, and the low concentration found suggested that a copper deficiency together with other risk factors such as the elevation of blood pressure may have been implicated in the development of the aortic dissection seen in this ostrich.

Differences in the immune responses in lambs and kids vaccinated against paratuberculosis, according to the age of vaccination

In order to evaluate and compare the peripheral immune responses induced by the vaccination against paratuberculosis in relation with the age of immunization, two groups of lambs and goat kids were vaccinated at 15 days and 5 months old, respectively. A heat-killed commercial vaccine was inoculated subcutaneously and humoral and cellular immune responses were measured by an ELISA and IFN-gamma assay, respectively, at 0, 30, 90, 180, 270 and 360 dpv in the lambs and 0, 30, 90 and 180 dpv in the caprine. IFN-gamma values did not show statistically significant differences between both groups, but when compared to the unvaccinated controls, this cytokine response tend to disappear earlier in animals vaccinated at 15 days old. The antibody response was always higher and more persistent in animals vaccinated at 5 months. The possibility of the incomplete degree of maturation of the immune system in 15 days old animals as the cause of the differences in the immune response to vaccination is suggested.

Classification of lesions observed in natural cases of paratuberculosis in goats

Sixty-eight adult goats with clinical or sub-clinical paratuberculosis, from naturally infected flocks, were subjected post mortem to a pathological examination that focused on the intestinal lymphoid tissue. The lesions were divided into four categories. Focal lesions, found in 16 goats, consisted of small granulomata in the ileocaecal Peyer's patches or related lamina propria. Diffuse multibacillary lesions (34 goats) consisted of a granulomatous enteritis, affecting different intestinal sites. Numerous macrophages containing many mycobacteria were present, resulting in macroscopical changes in the normal gut morphology; in the ileum of nine of the 34 animals, however, these changes were confined to the apex of the villi and the intestinal wall was not thickened. In diffuse lymphocytic lesions (10 goats), the lymphocyte was the main inflammatory cell, with some macrophages (containing few if any mycobacteria). In diffuse mixed lesions (eight goats) the infiltrate consisted of numerous lymphocytes and macrophages, with small numbers of mycobacteria. The three types of diffuse lesion were often associated with necrosis in the lymph vessels of the mucosa, mesentery and lymph nodes, and with greater thickening of the jejunum than of the ileum. Mycobacterium avium subspecies paratuberculosis was cultured from 69% of goats with diffuse lesions and from 44.4% of those with focal lesions.

Generalized aspergillosis in dairy sheep

Two cases of systemic aspergillosis are described in dairy sheep from a flock in which fungal mastitis appeared subsequent to the antibiotic treatment of animals before parturition. Lesions characterized by necrosis and a pyogranulomatous exudate were observed in the mammary glands, supramammary and mediastinal lymph nodes, kidneys, lung, liver, heart, forestomachs and brain. The intense vasculitis with thrombosis observed in various organs, but especially in the mammary glands, suggested a haematogenous dissemination of the infection from this organ. The aetiological diagnosis was accomplished by the immunohistochemical staining of the fungal structures seen in the histological sections by the specific Aspergillus monoclonal antibody Mab-WF-AF-1 together with the isolation of Aspergillus fumigatus in pure culture from affected tissues.

Relation between pathologic findings and cellular immune responses in sheep with naturally acquired paratuberculosis

OBJECTIVE

To investigate the relation between lesions and cellular immune response-based tests in sheep with naturally acquired paratuberculosis and to evaluate efficacy of an interferon-gamma (IFN-gamma) assay and the intradermal skin test.

ANIMALS

110 and 88 adult sheep were used to evaluate the IFN-gamma assay and skin test, respectively.

PROCEDURE

Before euthanasia, heparinized blood was collected and incubated with avian purified protein derivative (PPD). Interferon-y production was assessed, using a commercial enzyme immunoassay. Skin testing in the caudal fold also was performed, using avian PPD. Sensitivity and specificity of these techniques were evaluated, using histopathologic findings as reference.

RESULTS

Of the sheep examined, 61 (55.4%) had lesions that were classified in 5 categories, according to location, extension, cellular types, and presence of acid-fast bacilli. Regarding cellular immunity test results, 55.4% of sheep with and 6.1 % without pathologic changes had positive results of the IFN-gamma assay. Skin test sensitivity (55.6%) and specificity (100%) were slightly greater.

CONCLUSION

Close association between pathologic findings and cellular immune response was apparent. Most sheep with focal (tuberculoid) and some with diffuse lesions (borderline tuberculoid), all with scant or no acid-fast bacilli in the intestine, had positive results of the IFN-gamma assay and skin test. Most sheep with diffuse lesions and high numbers of bacilli (borderline lepromatous) were test negative.

CLINICAL RELEVANCE

Cellular immune response-based and serologic tests are useful tools for seeking evidence of paratuberculosis. Each technique detects different types of immune-reacting sheep, and their simultaneous use may detect most infected animals.

Adenocarcinoma of the small intestine in a goat

A case of intestinal adenocarcinoma is described in a 4-year-old dairy goat with progressive emaciation. At necropsy, a tumour was found in the middle part of the jejunum as an annular, firm white mass which resulted in stenosis and dilation of the intestine proximal to the lesion. Spread of the tumour, with thickening of the contiguous mesentery, and metastasis to the mesenteric lymph nodes were observed. Microscopically, the tumour was characterized by nests or sheets of mucin-rich cuboid or columnar epithelial cells, which formed irregular acinar structures that infiltrated all layers of the intestinal wall. In the mesentery, neoplastic cells were surrounded by an intense fibrous reaction. A diffuse inflammatory infiltrate of lymphocytes was observed both in the mesentery and in the intestinal layers. These findings are compared with those observed in sheep, in which this type of tumour occurs more frequently.

Mammary and systemic aspergillosis in dairy sheep

Mammary aspergillosis was diagnosed in four flocks of dairy sheep, comprising a total of 1,750 ewes. These animals had been treated prophylactically by intramammary infusion with cloxacillin 5 months prior to lambing. Mammary aspergillosis with concomitant spread to the regional lymph nodes was present in these flocks in a percentage ranging from 2% to 36.4% of treated sheep. Pathologic, bacteriologic, and mycologic studies were performed in seven of the affected ewes. Some of them also had lung, kidney, and liver involvement. The pathologic reaction within lesions ranged from the acute to subacute type, dominated by necrosis and vasculitis with thrombosis, to the chronic granulomatous type, with macrophages and giant cells. The distribution of lesions and the presence of a remarkable vasculitis with fungal thrombi in the mammary gland suggested a hematogenous dissemination of the infection from this organ. Immunologic staining with monoclonal antibody MAb-WF-AF-1, which reacts specifically with Aspergillus hyphae, identified the causative agent in histologic sections of the different affected tissues. The etiologic diagnosis was further supported by the isolation of Aspergillus fumigatus in pure culture from affected tissues and from eight samples of mammary secretions.