Salivary gland enlargement and sialorrhoea in dogs with spirocercosis: a retrospective and prospective study of 298 cases

Spirocerca lupi Proteomics and Its Role in Cancer Development: An Overview of Spirocercosis-Induced Sarcomas and Revision of Helminth-Induced Carcinomas

Spirocerca lupi is a parasitic nematode of canids that induces a myriad of clinical manifestations in its host and, in 25% of infections, leads to the formation of sarcomas. The description of the protein composition of the excretory and secretory products (Sl-ESP) of S. lupi has shed light on its possible interactions with the host environment, including migration within the host and mechanisms of immunomodulation. Despite this, the process by which S. lupi induces cancer in the dog remains poorly understood, and some hypotheses have arisen regarding these possible mechanisms. In this review, we discuss the role of specific ESP from the carcinogenic helminths Clonorchis sinensis, Opisthorchis viverrini and Schistosoma haematobium in inducing chronic inflammation and cancer in their host’s tissues. The parasitic worms Taenia solium, Echinococcus granulosus, Heterakis gallinarum, Trichuris muris and Strongyloides stercoralis, which have less-characterized mechanisms of cancer induction, are also analyzed. Based on the pathological findings in spirocercosis and the mechanisms by which other parasitic helminths induce cancer, we propose that the sustained inflammatory response in the dog´s tissues produced in response to the release of Sl-ESP homologous to those of other carcinogenic worms may lead to the malignant process in infected dogs.

A review of the traditional use of southern African medicinal plants for the treatment of selected parasite infections affecting humans

ETHNOPHARMACOLOGICAL RELEVANCE

Worldwide, more than three billion cases of parasitic disease are reported yearly and it is likely that this figure is substantially under-estimated. Approximately one in six people globally are estimated to be infected with at least one parasite species annually. In South Africa, the prevalence of Schistosoma haematobium (bilharzia) and intestinal worms and helminths are particularly high, especially in children and in crowded or poorer rural communities with inadequate sanitation and nutrition. Despite alarmingly high estimates, medical research into parasitic diseases remains neglected and only malaria receives significant attention and funding. Traditional medicines have been used for centuries in Africa by multiple ethnic groups and many people rely on these healing systems as their primary healthcare modality. The traditional use of South African medicinal plants to treat parasite infestations is relatively well documented, and it is important to link these traditional uses to scientific evidence validating efficacy.

AIM OF THE STUDY

To document the medicinal plants used for parasitic infections and critically review the literature on the anti-parasitic properties of South African plants against some neglected parasitic diseases.

MATERIALS AND METHODS

A review of the literature (ethnobotanical books and publications documenting traditional plant use) was undertaken related to specific medicinal use for parasitic infections in Southern Africa. Inclusion criteria focused on human use. Exclusion criteria included veterinary use and malaria due to the extensive nature of these subject matters. An in-depth analysis of previous studies was undertaken and future prospectives are considered.

RESULTS

In particular, bilharzia, gastrointestinal worms and helminths, ectoparasites, trichomoniasis, leishmaniasis and trypanosomiasis are reviewed with special emphasis on the gaps in research.

CONCLUSIONS

Despite the availability of relatively extensive ethnobotanical records on the anti-parasitic properties of southern African medicinal plants, the antiparasitic properties of many plants have been poorly examined. There was in many instances a lack of evidence to support traditional use of many species towards some parasites and research is urgently needed in this area.

Evaluation of a spot-on imidacloprid-moxidectin formulation (Advocate®) for the treatment of naturally occurring esophageal spirocercosis in dogs: a double-blinded, placebo-controlled study

Background

Dogs are the definitive hosts of Spirocerca lupi. Spirocercosis is treated by prolonged avermectin administration by injection or daily oral doses. In this prospective, double-blinded, placebo-controlled, clinical trial, the efficacy of imidacloprid and moxidectin spot-on formulation (Advocate®) was compared to injectable doramectin (Dectomax®). Dogs diagnosed with benign esophageal spirocercosis were divided randomly into doramectin (400 μg/kg IM) or moxidectin and imidacloprid spot-on (2.5–6.25 mg/kg and 10–25 mg/kg, respectively) groups and treated weekly for 12 consecutive weeks. Dogs were followed for 20 weeks by physical examination, owners’ questionnaire, blood work, fecal floatation, PCR and endoscopy.

Results

All the doramectin group dogs (n = 10) completed the treatment and follow-up, and the disease had completely resolved in all by week 12. Of the Advocate® group (n = 10), four had complete resolution at week 12, four had partial resolution, one dog did not respond to treatment, and one dog was switched to the doramectin protocol on week 5 due to persistent severe clinical signs. PCR analysis was more sensitive in detecting S. lupi eggs compared to fecal floatation. Discrepancies were detected on 22 occasions, of which on 20 occasions, the PCR was positive while fecal floatation was negative, and only on two occasions the PCR results were negative while fecal flotation was positive.

Conclusions

The present results indicate that weekly Advocate® spot-on administration may be effective for treating benign esophageal spirocercosis, but is less effective than the currently used injectable doramectin therapy at the dose and duration used herein.

Canine Trichomonas tenax mandibular gland infestation

Background

Several species of trichomonads are intestinal or urogenital parasites of humans and animals, with only a few species typically being located in the oral cavity. The prevalence of oral trichomoniasis in dogs is approximately 15–25 %, although the prevalence varies among different populations and depends on age, sex and the health of the oral cavity.

Case presentation

A case of mandibular gland infestation by trichomonads in a 13-year-old female Dachshund with advanced periodontal disease and oral trichomoniasis is reported. The dog was referred due to a history of a painless swelling over the left submandibular region that increased in size over time. Based on physical and ultrasound examinations, a final diagnosis of mandibular gland cyst was established and transcutaneous needle aspiration was carried out. Numerous mobile trophozoites of trichomonads were found by microscopy and culturing for trichomonas was performed. The species was finally characterized as Trichomonas tenax by polymerase chain reaction and sequencing.

Conclusions

Studies have shown that T. tenax can be found in humans in atypical locations such as the salivary glands and upper and lower respiratory tracts. According to our knowledge this is the first report of T. tenax being present in the salivary glands of a dog. Because of the relatively high prevalence of trichomoniasis in dogs with periodontal diseases, these parasites should be considered together with bacterial and viral agents in salivary gland infections, especially in individuals with compromised oral health.

Spirocercosis in dogs in Israel: A retrospective case-control study (2004-2009)

This case-control retrospective study (years 2004-2009) investigated the epidemiological, clinical, and diagnostic test findings of dogs with esophageal spirocercosis (ES) presented to the Hebrew University Veterinary Teaching Hospital (HUVTH) and coproscopy-positive dogs at the Kimron Veterinary Institute (KVI), Israel. It included 133 dogs with ES and 133 negative controls diagnosed at the hospital, and 343 dogs diagnosed at the KVI. The average incidence of ES at the HUVTH was 22.5/year, and the percentage of spirocercosis cases was stable at both institutions (HUVTH, 0.67-1.23%; KVI, 5-8%). Dogs aged > 5 years old had 100-fold likelihood to be infected compared to dogs aged ≤ 1 year of age (P < 0.001). Mean body weight (P = 0.0004), proportion of Retrievers (P = 0.002) and sporting breed dogs (P = 0.006) were higher, while proportion of toy breeds (P = 0.004) was lower in the ES group compared to the control group. The proportion of cases from Greater Tel-Aviv decreased (P = 0.002), while that of those from Judea and Jerusalem increased (P = 0.01) compared to the 1990 s. Spirocercosis occurred in 22 dogs despite past prophylactic avermectin treatment. Vomiting and regurgitation were the most common clinical signs of ES. Coproscopy was S. lupi-positive in 33/60 dogs (55.0%). The median number of esophageal nodules was two (range 1-8), with a median diameter of 3.5 cm (range 1.0-11.0). Malignant esophageal lesion transformation was confirmed in 29 dogs (22%). Despite preventive attempts, spirocercosis has spread in Israel over time, compared to previous findings, raising questions about the efficacy of the currently accepted prophylactic protocol is incompletely effective.