Clinical differentiation between dogs with benign and malignant spirocercosis

Spirocerca lupi is a nematode infesting the canine oesophagus, where it induces the formation of a nodule that may transform into a malignant sarcoma. The current, retrospective study compared the clinical presentation, haematology, serum albumin and globulin and radiology of benign cases (n=31) and malignant cases (n=31) of spirocercosis. Dogs with spirocercosis-induced sarcoma were significantly older (6.4+/-1.91 years) than benign cases (4.93+/-2.87). In the malignant cases there were significantly (p=0.03) more sterilized females (10/31) and fewer intact males (4/31) compared to 2/31 and 13/31, respectively, in the benign cases. Hypertrophic osteopathy was observed in 38.7% of malignant cases and in none of the benign cases (p=0.0002). Common clinical signs included weight loss, regurgitation, anorexia, pyrexia (T>or=39.5 degrees ), respiratory complications and salivation but did not differ in prevalence between groups. On haematology, the malignant group had significantly (p<0.05) lower haematocrit (0.34+/-0.08 vs. 0.41+/-0.07) and higher white cell count (31.6+/-27.83 vs. 17.71+/-13.18 x 10(3)microl(-1)), mature neutrophil count (26.06+/-26.08 vs. 12.23+/-9.96 x 10(3)microl(-1)) and thrombocyte count (493.15+/-151.61 vs. 313.27+/-128.54 x 10(9)microl(-1)). There were no differences in the mean corpuscular volume and immature neutrophil count. On radiology, the mass length was not significantly different, but the height and the width of the malignant masses were significantly larger (62.59+/-15.15 mm and 73.93+/-20.94 mm) compared to the benign group (46.43+/-23.62 and 49.29+/-25.56, respectively). Spondylitis was more prevalent in the malignant group (67.86% vs. 38.46%, p=0.03). Examining secondary pulmonary changes revealed significantly higher prevalence of bronchial displacement in the malignant group (52% vs. 17%, p=0.008). Hypertrophic osteopathy appeared to be a very specific but relatively rare (poor sensitivity) marker of malignancy. Female gender, anaemia, leukocytosis, thrombocytosis, spondylitis and bronchial displacement are significantly more common in malignant cases, but appear in benign cases as well. However, if found together in a specific case, they should increase the index of suspicion for malignancy in a diagnosed spirocercosis case.     

Evaluation of Salmonella-lytic properties of bacteriophages isolated from commercial broiler houses

Because of recent interest in bacteriophage therapy in poultry, information regarding the interaction of bacteriophages and potential host bacteria in the environment should be collected. The present studies were initiated with a rather typical commercial broiler integrator within the south-central United States to examine environmental Salmonella levels in two broiler complexes, attempt to isolate Salmonella-lytic bacteriophages, and elucidate a possible reason for differing apparent Salmonella prevalence. Significantly (P < 0.05) less Salmonella was isolated from houses in complex 1 (15/44 [34%] Salmonella-positive drag swabs) as compared to houses in complex 2 (22/24 [92%]). A total of seven Salmonella-lytic bacteriophages were isolated from Salmonella-positive environments, and two bacteriophages were isolated from a single Salmonella-negative house. During the initial bacteriophage isolation, individual bacteriophages did not replicate in the Salmonella host isolated from the same environment, and lysis of additional Salmonella hosts relied on high numbers of bacteriophage to be present. This suggests that the presence of these bacteriophages in the environment of a commercial broiler house had little to no effect on the presence of Salmonella. This study highlights the need to find additional bacteriophage sources, more effective isolation methods, and more innovative approaches to using bacteriophages to treat enteric disease.     

Antimicrobial resistance in Salmonella enterica subspecies enterica serovar Dublin from dairy source calves in the central San Joaquin Valley, California (1998-2002)

The present study describes antimicrobial resistance patterns of Salmonella enterica subspecies enterica serovar Dublin (S. Dublin) in clinical submissions from calves and temporal and farm-type trends in antimicrobial resistance patterns of the isolates. A total of 300 isolates of S. Dublin were obtained from fecal or internal organs of calves fewer than 120 days of age originating from 84 dairies and 18 calf ranches from July 1998 to December 2002. The isolates were susceptibility tested to a panel of 10 antimicrobials using the disk diffusion assay. Temporal and farm-type trends in individual antimicrobial inhibition zone sizes were assessed and antimicrobial resistance patterns were described using cluster analysis. Isolates obtained from calf ranches compared with dairies exhibited decreased susceptibility to florfenicol, gentamicin, neomycin, sulfisoxazole, sulfamethoxazole/trimethoprim, and tetracycline. During the years 1998-2002, decreasing susceptibility was seen for ceftiofur, enrofloxacin, and sulfamethoxazole/trimethoprim. There were 20 different antimicrobial resistance patterns in the isolate set, indicating that S. Dublin has the ability to transfer and pick up resistance genes with relative ease. The trends seen in antimicrobial resistance in S. Dublin may likely be linked to antimicrobial drug use in young calves.     

Risk factors for epiploic foramen entrapment colic: an international study

REASON FOR PERFORMING STUDY: Epiploic foramen entrapment (EFE) is one of the most common causes of small intestinal strangulation in the horse. Identification of risk factors would generate hypotheses about causation and may suggest preventive strategies. HYPOTHESIS: Horses exhibiting certain behavioural patterns and those exposed to particular management practices are at increased risk of EFE. METHODS: A matched case-control study was conducted on EFE cases admitted to hospitals in the UK, Ireland and USA. Data on 109 cases and 310 control horses were obtained by telephone questionnaire and conditional logistic regression was used to identify associations between horse- and management-level variables and the risk of EFE. RESULTS: Crib-biting/windsucking behaviour was strongly associated with increased risk of EFE (OR 67.3, 95%CI 15.3-296.5). A history of colic in the previous 12 months (OR 4.4, 95%CI 1.5-12.7) and horses of greater height (OR/cm 1.05, 95%CI 1.01-1.08) were also at increased risk. The person(s) responsible for horses' daily care (nonowner/relative/spouse OR 5.5, 95%CI 2.3-13.3) and a number of behavioural features, including response to a stimulus causing fright (easily frightened OR 0.4, 95%CI 0.1-1.0) or excitement (sweats up easily/occasionally OR 0.3, 95%CI 0.1-0.8), reaction to their surroundings (inquisitive OR 0.4, 95%CI 0.2-0.8) and feeding behaviour when stressed (goes off food in full/part OR 0.3, 95%CI 0.1-1.0) were also associated with altered risk of EFE. CONCLUSIONS: The association between horses of greater height and those with a previous history of colic and increased risk of EFE suggests that some horses may be inherently predisposed to EFE. Furthermore, a behavioural pattern has been characterised that is common to horses at increased risk of EFE. Further research is required to investigate the causal pathway linking behavioural traits with gastrointestinal dysfunction and to determine whether behavioural modification reduces the risk of EFE. POTENTIAL RELEVANCE: The findings of the present study have relevance to horses in the UK, Ireland and USA.     

Evaluation of immunoglobulin G concentration in colostrum of mares by ELISA, refractometry and colostrometry

In 360 samples of colostrum and 36 samples of blood of warmblood mares, the concentration of immunoglobulin G (IgG) was evaluated in the post partal period with an ELISA and the results were compared to values obtained with 2 field methods--refractometry and colostrometry. A significant correlation (p < 0.0001) was determined between ELISA and colostrometry (r = +0.88) and between ELISA and refractometry (r = +0.93). So both field-methods seem suitable for evaluation of the colostral IgG-concentration in mares. Further the kinetic of the IgG concentration in colostrum, the volume of colostrum and the total amount of IgG was measured in the 12 hours post partum (p.p.) in each half udder of 36 mares of different parity. Immediately p.p. primiparous mares have a greater mean concentration of IgG (68 mg/ml) than multiparous mares (51 mg/ml). However, multiparous mares have a mean colostral volume of 1020 ml whereas, in primiparous mares, a mean volume of 527 ml was determined within the first three hours p.p. As a result of this the total amount of IgG was lower in primiparous (31.5 g) than in multiparous mares (48.5 g). A significant decrease of IgG concentration was measured in multiparous mares in the 1.5 hours following partum versus 3 hours in primiparous mares. The mean IgG concentration in the blood serum of the 36 mares immediately p.p. was 13.4 +/- 3.6 mg/ml. No significant correlation was observed between values of IgG concentration in the blood and in the colostrum of the mares.     

Natural postnatal Neospora caninum infection in cattle can persist and lead to endogenous transplacental infection

A serological follow-up study of 3.5 years duration was done of a dairy herd that had experienced a mass seroconversion to Neospora caninum following a point source exposure shortly before the 17th of January 2000. A total of 913 blood samples of 244 animals at seven sampling dates were used to investigate the seroprevalence dynamics in the herd. Most postnatally infected cattle remained seropositive during the period of investigation but 11 animals became seronegative after 6-27 months indicating transient infection. Six animals seroconverted later than the main group of 45 animals and 5 animals became seronegative after at least two seropositive records possibly due to a low infection dose or difference in the haplotypes of the infected animals. In total 58% (14/24) of the offspring of postnatally infected dams was seropositive. Nine of 16 (56%) daughters originating from inseminations after the postnatal infection of their dams were seropositive indicating endogenous transplacental infection.     

The role of phagocytic cells in enhanced susceptibility of broilers to colibacillosis after Infectious Bronchitis Virus infection

Colibacillosis results from infection with avian pathogenic Escherichia coli bacteria. Healthy broilers are resistant to inhaled E. coli, but previous infection with vaccine or virulent strains of Infectious Bronchitis Virus (IBV) predisposes birds for severe colibacillosis. We investigated whether IBV affects recruitment and function of phagocytic cells and examined NO production, phagocytic and bactericidal activity, and kinetics of peripheral blood mononuclear cells (PBMC) and splenocytes. Moreover, we measured cytokine mRNA expression in lung and spleen samples. Broilers were inoculated with IBV H120 vaccine or virulent M41 and challenged 5 days later with E. coli 506. A PBS control and E. coli group without previous virus inoculation were also included. Birds were sacrificed at various time points after inoculation (h/dpi). Inoculation with IBV induced extended and more severe colibacillosis than with E. coli alone. At 4dpi, the number of KUL-01(+) PBMC in all E. coli-inoculated groups was significantly higher than in PBS-inoculated birds, which correlated with lesion scores. From 1 to 4dpi, NO production by PBMC from all E. coli-inoculated animals was elevated compared to PBS birds. Bactericidal activity of PBMC in IBV-inoculated animals at 7dpi was lower than in PBS- and E. coli-inoculated birds, but phagocytic capacity and recruitment were not severely impaired. In spleen samples of IBV-infected animals reduced expression of IL-1beta, IL-6, IL-8, IL-10, IL-18 and IFN-gamma mRNA was found 1dpi. Our results suggest that enhanced colibacillosis after IBV infection or vaccination is caused at least by altered innate immunity and less by impairment of phagocytic cell function.     

Virulence factors and antimicrobial susceptibility of Escherichia coli isolated from calves in Turkey

Escherichia coli isolates from calves were investigated by multiplex PCR assays for the presence of genes encoding K99, F41, F17-related fimbriae, heat-stabile enterotoxin a (STa), intimin (eae) and Shiga toxins (stx1 and stx2). A total of 120 E. coli isolates, 75 isolated from diarrhoeic or septicemic calves and 45 from clinically healthy calves aged between 1 day and 2 months were tested. Each isolate was obtained from different calves in different herds. Among the isolates from diseased animals, 12 (16%) isolates from 1- to 7-day-old diarrhoeic calves were detected as enterotoxigenic E. coli which possessed K99, F41 and STa in combination; F17-related fimbriae genes were detected in 33 (44%) isolates and they were found in combination with K99 + F41 + STa in two isolates. Of 120 isolates, 16 carried eae, eight stx1 and five stx2 genes alone or in combination. None of the eae- or stx-positive strains was identified as O157:H7. However, results indicate that calves may be carrier of Shiga toxin-producing E. coli which have potential as a human pathogen. Antimicrobial susceptibility of 75 isolates from diseased calves was determined by agar disk diffusion method for 14 antimicrobial agents. In 77.3% of the isolates, multiresistance was detected. Higher resistance rates were detected for cephalothin (72%), tetracycline (69.3%), kanamycin (69.3%), ampicillin (65.3%), nalidixic acid (53.3%), trimethoprim-sulphamethoxazole (52%) and enrofloxacin (41.3%), respectively. No resistance was found for ceftiofur and cefoxitin.     

Agreement between ELISA and complement fixation test used for diagnosing of paratuberculosis in goats

An ELISA with a lipoarabinomannan as an antigen, developed for diagnosis of bovine paratuberculosis, has been adapted for use in goats, and compared with complement fixation test. Kappa value of 0.62 indicated good agreement between CFT and the adapted ELISA and proved that the investigated ELISA may be helpful in diagnosis of Mycobacterium avium subsp. paratuberculosis infection in goats. The ELISA has been used to screen a randomly selected representative sample of Polish breeding goat population (21.78% of herds, 21.33% of goats). It has been demonstrated that only 2.42% of animals coming from 15.79% of herds were seropositive. Within-herd seroprevalence varied from 1.69% to 38.10%. Most of the infected animals (67.07%) were 3- 4-years-old. No seropositive cases were found in group up to 1-year-old animals.     

Protothecal granulomatous meningoencephalitis in a dog

A case of central nervous system protothecosis in a dog is reported. A three-year-old male Maremma sheepdog was referred with a two month history of diarrhoea associated with progressive tetraparesis, depression and right circling. Stupor, severe proprioceptive deficits, bilateral decreased thoracic limb flexor reflexes and bilateral deficit of the menace reaction were detected on neurological examination and a multi-focal neurological localisation was suspected. Histopathological evaluation revealed multi-focal granulomatous foci in the thalamus, hippocampus and caudal brainstem containing numerous oval-rounded organisms with a thick, periodic acid-Schiff-positive and Gomori's methenamine silver-positive cell wall, a basophilic cytoplasm and one nucleus. Scattered sporangia containing two to four endospores were also observed. Morphological features were consistent with Prototheca species. Ultrastructurally, numerous degenerated algae were present within macrophages mainly lacking nuclei and cytoplasmic organelles. Generally, protothecosis in dogs is characterised by systemic signs because of a multi-organ involvement, and haemorrhagic colitis or ophthalmologic signs are the most frequent presenting signs. However, protothecosis should be added, also in Europe, to the list of the differential diagnoses in adult dogs with a multi-focal neurological localisation even in absence of other clinical signs.