RETROSPECTIVE EVALUATION OF A NOVEL SUSTAINED-RELEASE IVERMECTIN VARNISH FOR TREATMENT OF WOUND MYIASIS IN ZOO-HOUSED ANIMALS.

Myiasis is a major disease condition in human and veterinary medicine. Domestic, free-ranging, and zoo-housed animals can be severely affected by myiasis. Depending on case severity, multiple treatment episodes may be indicated and can lead to recurrent capturing, handling stress, and anesthetics, all of which increase the risk of adverse responses (including death) individually and also in the herd. As an insecticide, ivermectin is often used for larval control. A total of 28 individual myiasis cases were retrospectively evaluated, out of which 11 cases were also treated using an ivermectin sustained-release varnish (SRV). The clinical outcome of all cases was assessed and the results suggest that the use of a topical ivermectin SRV (with or without concurrent injectable ivermectin) can reduce handling and treatments, has no adverse effects, and has minimal recurrence of the disease when compared with cases treated without it.

Changes in blood pressure following escalating doses of phenylpropanolamine and a suggested protocol for monitoring.

This prospective, cross-over, blinded study evaluated the effect of various doses of phenylpropanolamine (PPA) on blood pressure in dogs. Dogs were randomized to receive a placebo or 1 of 3 dosages of immediate release PPA, q12h for 7 days [1 mg/kg body weight (BW), 2 mg/kg BW, or 4 mg/kg BW] in a cross-over design. Blood pressure was recorded every 2 h, for 12 h, on days 1 and 7. There were significant increases in systolic, diastolic, and mean blood pressure following administration of PPA at 2 mg/kg BW and 4 mg/kg BW. A significant decrease in heart rate was also noted at all PPA dosages, but not in the placebo. Administration of PPA was associated with a dose response increase in blood pressure. Dosages of up to 2 mg/kg BW should be considered safe in healthy dogs.

Changements de la pression artérielle après des doses progressives de phénylpropanolamine et suggestion d'un protocole de surveillance. Cette étude prospective à l'insu et à plan d'étude croisée a évalué l'effet de diverses doses de phénylpropanolamine (PPA) sur la pression artérielle des chiens. Les chiens ont reçu au hasard un placebo ou 1 de 3 doses de PPA à action immédiate, q12h pendant 7 jours (1 mg/kg de poids corporel [PC], 2 mg/kg PC ou 4 mg/kg PC) dans un plan d'étude croisé. La pression artérielle a été consignée toutes les 2 h, pendant 12 h, aux jours 1 et 7. Il n'y a pas eu de hausses significatives de la pression artérielle systolique et diastolique ni de la pression artérielle moyenne après l'administration de PPA à 2 mg/kg PC et à 4 mg/kg PC. Une baisse significative de la fréquence cardiaque a aussi été notée dans toutes les doses de PPA, mais non avec le placebo. L'administration de PPA a été associée à une hausse de la pression artérielle en fonction de la dose. Des doses jusqu'à 2 mg/kg PC devraient être considérées sûres chez des chiens en santé.(Traduit par Isabelle Vallières).

Giardiasis and diarrhea in dogs: Does the microbiome matter?

BACKGROUND: Giardia duodenalis (Gd) causes intestinal parasitosis. The involvement of the intestinal microbiome in determining the infection's clinical phenotype is unknown. OBJECTIVE: Investigate the fecal microbiome features in dogs with giardiasis. ANIMALS AND METHODS: Cross-sectional study, including fecal samples of kenneled dogs with Gd diagnosed by fecal Giardia antigen dot ELISA. The fecal microbial compositional characteristics and dysbiosis index (DI) were compared between diarrheic and nondiarrheic dogs. RESULTS: Fecal samples of 38 Gd-infected dogs (diarrheic, 21; nondiarrheic, 17) were included. No differences were found in Faith's phylogenic diversity and beta diversity (weighted UniFrac distances) and in specific taxa abundances at the phylum, genus, and species levels, as well as in alpha and beta diversities between diarrheic and nondiarrheic dogs, and also when divided by sex or age. Among diarrheic dogs, alpha diversity was higher in males than in females (pairwise Kruskal-Wallis, q = 0.01). Among males, fecal abundances of the genus Clostridium (W = 19) and Clostridium spiroforme species (W = 33) were higher in diarrheic compared to nondiarrheic dogs. In diarrheic dog fecal samples, Proteobacteria were more prevalent (W = 1), whereas Verrucomicrobia were less prevalent in dogs <1 year of age than in older dogs. The fecal sample DI of 19 diarrheic and 19 nondiarrheic dogs was similar (median, -0.2; range, -4.3 to 4.5 and median, -1.0; range, -4.3 to 5.8, respectively). CONCLUSIONS: The fecal microbial composition of symptomatic and asymptomatic dogs with giardiasis is similar. Based on fecal DI, giardiasis is not characterized by prominent dysbiosis. Other host and parasite characteristics might determine the severity of giardiasis in dogs.

Therapeutic efficacy and pharmacokinetics of liposomal-cannabidiol injection: a pilot clinical study in dogs with naturally-occurring osteoarthritis.

Introduction: Osteoarthritis is a common disease in dogs resulting in chronic pain and decreased wellbeing. Common analgesics such as non-steroidal anti-inflammatories may fail to control pain and can produce major adverse effects. Study objectives were to evaluate pharmacokinetics, therapeutic efficacy, and safety of subcutaneous liposomal-cannabidiol (CBD) as an additional analgesic therapy in dogs suffering from naturally-occurring osteoarthritis. Methods: Six such dogs were recruited following ethics approval and owner consent. Dogs were administered a single subcutaneous injection of 5 mg/kg liposomal-CBD. Plasma concentrations of CBD, blood work, activity monitoring collar data, wellbeing questionnaire (owners) and pain scoring (veterinarian) were performed at baseline and monitored up to six weeks following intervention. Data overtime were compared with baseline using linear-regression mixed-effects. P-value was set at 0.05. Results: CBD plasma concentrations were observed for 6 weeks; median (range) peak plasma concentration (Cmax) was 45.2 (17.8-72.5) ng/mL, time to Cmax was 4 (2-14) days and half-life was 12.4 (7.7-42.6) days. Median (range) collar activity score was significantly increased on weeks 5-6; from 29 (17-34) to 34 (21-38). Scores of wellbeing and pain evaluations were significantly improved at 2-3 weeks; from 69 (52-78) to 53.5 (41-68), and from 7.5 (6-8) to 5.5 (5-7), respectively. The main adverse effect was minor local swelling for several days in 5/6 dogs. Conclusion: Liposomal-CBD administered subcutaneously produced detectable CBD plasma concentrations for 6 weeks with minimal side effects and demonstrated reduced pain and increased wellbeing as part of multimodal pain management in dogs suffering from osteoarthritis. Further placebo-controlled studies are of interest.

Zinc chloride is effective as an antibiotic in biofilm prevention following septoplasty.

Biofilm-state bacterial infections associated with inserted medical devices constitute a massive health and financial problem worldwide. Although bacteria exhibit significantly lower susceptibility to antibiotics in the biofilm state, the most common treatment approach still relies on antibiotics, exacerbating the phenomenon of antibiotic-resistant bacteria. In this study, we aimed to assess whether ZnCl2 coating of intranasal silicone splints (ISSs) can reduce the biofilm infections associated with the insertion of these devices and prevent the overuse of antibiotics while minimizing waste, pollution and costs. We tested the ability of ZnCl2 to prevent biofilm formation on ISS both in vitro and in vivo by using the microtiter dish biofilm formation assay, crystal violet staining, and electron and confocal microscopy. We found a significant decrease in biofilm formation between the treatment group and the growth control when ZnCl2-coated splints were placed in patients' nasal flora. According to these results, infections associated with ISS insertion may be prevented by using ZnCl2 coating, thereby obviating the overuse and abuse of antibiotics.

A novel bacterial symbiont in the nematode Spirocerca lupi.

BACKGROUND: The parasitic nematode Spirocerca lupi (Spirurida: Thelaziidae), the canine esophageal worm, is the causative agent of spirocercosis, a disease causing morbidity and mortality in dogs. Spirocerca lupi has a complex life cycle, involving an obligatory coleopteran intermediate host (vector), an optional paratenic host, and a definitive canid host. The diagnosis of spirocercosis is challenging, especially in the early disease stages, when adult worms and clinical signs are absent. Thus, alternative approaches are needed to promote early diagnosis. The interaction between nematodes and their bacterial symbionts has recently become a focus of novel treatment regimens for other helminthic diseases. RESULTS: Using 16S rDNA-based molecular methods, here we found a novel bacterial symbiont in S. lupi that is closely related to Comamonas species (Brukholderiales: Comamonadaceae) of the beta-proteobacteria. Its DNA was detected in eggs, larvae and adult stages of S. lupi. Using fluorescent in situ hybridization technique, we localized Comamonas sp. to the gut epithelial cells of the nematode larvae. Specific PCR enabled the detection of this symbiont's DNA in blood obtained from dogs diagnosed with spirocercosis. CONCLUSIONS: The discovery of a new Comamonas sp. in S. lupi increase the complexity of the interactions among the organisms involved in this system, and may open innovative approaches for diagnosis and control of spirocercosis in dogs.

A Case Report of Subcutaneously Injected Liposomal Cannabidiol Formulation Used as a Compassion Therapy for Pain Management in a Dog.

A 14-year-old intact mixed breed dog (26 kg) was submitted for a novel cannabidiol (CBD) analgesic treatment. The dog was cachectic and had a testicular neoplasia, hip and elbow osteoarthritis and severe cervical pain. Analgesic treatment included canine osteoarthritic supplement, robencoxib and gabapentin. An additional liposomal CBD injectable formulation at 5 mg/kg was administered subcutaneously between the shoulder blades. The dog was monitored using an activity monitoring collar (PetPace), owner wellbeing questionnaire (Canine Brief Pain Inventory; CBPI), pain interactive visual analog scale (iVAS), blood work and CBD plasma concentrations. A week from the injection and up to 3 weeks afterwards the dog had improved CBPI and iVAS pain scores, and increased collar activity scores. CBD was quantified in plasma for 28 days. Due to disease progression, further difficulty to rise and walk, and relapse to pain after 3 weeks, the owners requested a second liposomal CBD injection, which was performed 4 weeks following the first injection using 3 mg/kg dose. Two days later, the dog was found dead in the yard under direct sun, while environmental temperature was 37°C. Major findings on necropsy revealed evidence of heat stroke and severe cervical disc protrusion with spinal hematoma, none related to liposomal CBD. In conclusion, subcutaneous liposomal CBD produced quantifiable CBD plasma concentrations for 28 days and may be an effective additional treatment as part of multimodal pain management in dogs.

Aspects in controlled drug delivery for topical applications in veterinary medicine.

The controlled release of drugs is an appealing area of research as it provides numerous benefits in veterinary and human medicine. In this paper we attempt to analyze certain aspects related to topical drug delivery systems, their successes and failures, and their place in veterinary medicine. Some emphasis is given to the pharmaceutical aspects of the delivery systems, where the material available made it possible. Purely topical devices, such as cattle ear tags and various collars, as well as some topically administered bioavailable delivery systems are discussed. Special attention is given to hitherto under-evaluated delivery systems, such as topical varnishes. A carefully selected bibliography aims to lead the reader easily to the facts, without providing overwhelming data of varying quality. We believe that the paper may be of interest to practicing veterinarians as well as to pharmaceutical scientists working or considering practice in the area.

Use of a sustained release chlorhexidine varnish as treatment of oral necrobacillosis in Macropus spp.

Oral necrobacillosis or lumpy jaw is a common cause of morbidity and mortality affecting captive macropods. This article describes several cases of a new treatment regimen using a sustained release chlorhexidine varnish applied locally to the teeth and the gingivae of two Macropus species, eastern grey kangaroos (Macropus gigantus) from Gan-Garoo Australian Park and a red-necked wallaby (Macropus rufogriseus fruticus) from The Tisch Family Zoological Gardens in Jerusalem. The varnish was applied using a horsehair paint brush as three 1- to 2-mm thick layers. The active ingredient in the varnish was the disinfectant chlorhexidine. Results indicated that use of an intraoral sustained release varnish significantly shortens the treatment time and may prevent recurrence.

Prognostic markers and assessment of a previously published clinical severity index in 109 hospitalised dogs with acute presentation of pancreatitis.

BACKGROUND: Acute pancreatitis (AP) is common in dogs. Nevertheless, validated clinical severity index (CSI) scoring systems to assess severity and guide treatment in current, large-scale studies are unavailable. METHODS: This is a retrospective study including 109 dogs. Pancreatitis was diagnosed based on clinical signs, abdominal sonographic evidence, positive pancreatic lipase assays and experts' assessment consensus. RESULTS: The survival rate was 75 per cent (82 dogs). Azotaemia and presence of local complications (ie, ascites) and secondary complications (ie, acute kidney injury and acute respiratory distress syndrome) were significantly associated with death. In agreement with the previously published CSI, respiratory anomalies were significantly associated with death. However, in disagreement with that study, high scores in the kidney and local abdominal complication categories and the sum of scores of all nine categories, but not high gastrointestinal category score, were also significantly associated with death. A final CSI score of at least 4 was associated with death. CONCLUSIONS: This study has validated a nine-category CSI, proven a useful assessment tool in dogs with AP. Several previously reported and novel prognostic markers were assessed.

Effect of mode of administration on guaifenesin pharmacokinetics and expectorant action in the rat model.

AIM: Guaifenesin is a very commonly used and prescribed oral expectorant drug. However, its mechanism of action is not completely elucidated and the available information is limited. The purpose was to evaluate whether guaifenesin action on respiratory tract secretion is mediated through a reflex stimulation of the gastric mucosa or by the systemic exposure due to the absorption of the drug to the blood circulation. METHODS: Guaifenesin was administered to rats by various routes: intravenous bolus, oral gavage, and gastric, jejunal or cecal infusions (through surgically implanted catheters). Phenol red respiratory tract secretion (after intraperitoneal or intravenous injection) was used as a marker for degree of expectorant action. Administration of saline by gavage was used as control. RESULTS: Respiratory secretion following oral bolus was approximately 2-fold higher (p<0.05) than that of control. Following IV administration the increase of respiratory secretion did not occur despite the fact that systemic exposure to guaifenesin was 1.5-fold higher than following oral administration. The abdominal surgery was found to eliminate the effect of guaifenesin although it did not change systemic absorption. Guaifenesin was equally absorbed from all parts of the gastrointestinal tract. CONCLUSIONS: It was demonstrated that expectorant action of guaifenesin is mediated by stimulation of the gastrointestinal tract and not by the systemic exposure to the drug.

Copromicroscopic and molecular assays for the detection of cancer-causing parasitic nematode Spirocerca lupi.

Spirocerca lupi (Nematoda, Spirurida) is a life-threatening parasitic nematode of dogs that is presently emerging in several countries. Nonetheless, canine spirocercosis is neglected and underestimated, mainly due to diagnostic limitations inherent to clinico-pathologic, diagnostic imaging and laboratory methodologies. Given the significant benefit of improved diagnosis, the present work evaluated the reliability of a recently described copromicroscopic approach, the FLOTAC technique, as well as a PCR-based assay with that of traditional coproscopic techniques to diagnose S. lupi infection. Ninety-four faecal field samples were collected from two endemic areas (i.e. 29 and 65 from Kenya and Israel, respectively) and processed using different coproscopic examination techniques. In particular, set I (Kenyan samples) comprised the modified flotation with Sheather's sugar solution and merthiolate-iodine-formalin technique, while set II (Israeli samples) comprised a flotation technique with zinc sulphate solution, a modified sugar flotation procedure and the FLOTAC method. All samples were also subjected to a semi-nested PCR protocol specific for a region internal to the mitochondrial cytochrome c oxidase subunit 1 gene of S. lupi. The coproscopic examinations showed low sensitivity and high variability, demonstrating the unreliability of the conventional methods for detecting S. lupi eggs. Nonetheless, the FLOTAC technique scored the highest number of positives and significantly higher number of S. lupi eggs per microscopic field compared to the other coproscopic methods. Additionally, of the coproscopically negative samples, 9 (45%) Kenyan and 21 (38.2%) Israeli samples scored molecularly positive using the PCR-based approach. The potential implications and perspectives for canine spirocercosis of these coproscopic and molecular diagnostic methodologies evaluated herein are discussed.

Oesophageal sarcomas in dogs: histological and clinical evaluation.

A histological grading system of oesophageal sarcomas has not been established. Thirty-two cases of oesophageal sarcomas have been reviewed for tumour characteristics and clinical outcome. Nineteen dogs underwent surgical intervention to remove oesophageal tumours; ten of them survived (median 278 days). Primary tumour types included osteosarcoma (47%), osteosarcoma with tumour giant cells (7%), fibroblastic osteosarcoma (13%), chondroblastic osteosarcoma (7%) fibrosarcoma (23%) and undifferentiated sarcoma (3%). Histological grade evaluation revealed 33% grade 1 sarcoma, 50% grade 2 and 17% grade 3. No correlation could be found between survival and signalment, duration of clinical signs, tumour type, tumour grade and chemotherapy. Chemotherapy was found to reduce lung metastases' histological scores in three cases (P=0.0007). Surgery seems to be the treatment of choice but the effect of chemotherapy warrants further investigation. Additional research of cases should be performed in order to further define prognostic factors of oesophageal sarcomas.

Transient megaoesophagus and oesophagitis following diaphragmatic rupture repair in a cat.

A 6-month-old domestic shorthair female cat was presented with suspected diaphragmatic hernia (DH) that was later confirmed by thoracic radiography. The cat underwent exploratory celiotomy with a diaphragmatic rupture (DR) repair and recovered. Six days later, it was represented with vomiting and anorexia. Megaoesophagus (MO) and gastric dilatation were diagnosed by contrast radiography. A second celiotomy revealed no abnormalities and gastropexy was performed. Endoscopy demonstrated MO, oesophagitis and gastro-oesophageal reflux. MO persisted for several weeks and was an unexpected complication as no association between DR (or DH) and MO has never been described in the veterinary literature. The cat was treated medically with aggressive prokinetic and antacid therapy along with prolonged temporary oesophageal diversion (percutaneous endoscopic gastrostomy tube) with an excellent outcome.

Use of a sustained release preparation of clotrimazole to treat dermatophytosis in a siamang (Hylobates syndactylus).

In November 2004, an adult male siamang (Hylobates syndactylus) from The Tisch Family Zoological Gardens-Jerusalem Biblical Zoo (Israel) presented with skin lesions on various body parts. Lesions consisted of alopecia and dry, crusty areas of hyperkeratosis. A diagnosis of dermatophytosis due to Microsporum canis was determined by fungal culture of skin scraping taken from the edge of several lesions. Treatment with various oral and topical antifungal agents such as griseofluvin, itraconozole, and lufenuron resulted in the resolution of most lesions and a decrease in size of the single remaining lesion, which continued to be culture positive for M. canis. The animal was anesthetized and an experimental sustained-release clotrimazole varnish was painted directly on the lesion. Initially there was no change in the lesion, and 2 months later a slightly altered formula was applied under anesthesia. One month later, the lesion began to reduce in size; 3 months after the start of treatment, although 2 years after the onset of clinical signs, the lesion resolved. Minimizing the number of treatments is always an advantage when dealing with exotic animals or zoological collections.

Chlorhexidine sustained-release varnishes for catheter coating - Dissolution kinetics and antibiofilm properties.

Catheter-associated urinary tract infections are difficult to eradicate or prevent, due to their biofilm-related nature. Chlorhexidine, a widely used antiseptic, was previously found to be effective against catheter-related biofilms. For the present study, we developed sustained-release chlorhexidine varnishes for catheter coating and evaluated their antibiofilm properties and chlorhexidine-dissolution kinetics under various conditions. The varnishes were based on ethylcellulose or ammonio methacrylate copolymer type A (Eudragit® RL). Chlorhexidine was released by diffusion from a heterogeneous matrix in the case of the ethylcellulose-based formulation, and from a homogeneous matrix in the case of Eudragit® RL. This dictated the release pattern of chlorhexidine under testing conditions: from film specimens, and from coated catheters in a static or flow-through system. Momentary saturation was observed with the flow-through system in Eudragit® RL-based coatings, an effect that might be present in vivo with other formulations as well. The coatings were retained on the catheters for at least 2weeks, and showed prolonged activity in a biological medium, including an antibiofilm effect against Pseudomonas aeruginosa. The current study demonstrates the potential of catheter coatings with sustained release of chlorhexidine in the prevention of catheter-associated urinary tract infections.

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.

A retrospective study of 157 hospitalized cats with pancreatitis in a tertiary care center: Clinical, imaging and laboratory findings, potential prognostic markers and outcome.

BACKGROUND: Pancreatitis in cats (FP) has been increasingly diagnosed in recent years, but clinical studies of large numbers of affected cats are scarce. OBJECTIVES: To describe a large cohort of cats with FP requiring hospitalization. ANIMALS: One hundred and fifty-seven client-owned cats. METHODS: Retrospective study, including cats diagnosed with pancreatitis based on sonographic evidence, positive SNAP feline pancreatic lipase immunoreactivity test results, increased 1,2-o-dilauryl-rac-glycerol-glutaric Acid-(6'-methylresorufin ester)-lipase activity, histopathology, or some combination of these. RESULTS: One-hundred and twenty-two cats (77.7%) survived to discharge. Median time from onset of clinical signs to presentation was longer (P = .003) in nonsurvivors. Causes of FP included recent general anesthesia, trauma, hemodynamic compromise, and organophosphate intoxication, but most cases (86.6%) were idiopathic. Ultrasonographic findings consistent with pancreatitis were documented in 134 cats, including pancreatomegaly (81.3%), decreased (31.3%), or increased (14.9%) pancreatic echogenicity, extra-hepatic biliary tract dilatation (24%), and increased peri-pancreatic echogenicity (13%). Lethargy (P = .003), pleural effusion (P = .003), hypoglycemia (P = .007), ionized hypocalcemia (P = .016), azotemia (P = .014), parenteral nutrition administration (P = .013), and persistent anorexia during hospitalization (P = .001) were more frequent in nonsurvivors, whereas antibiotics were more frequently administered to survivors (P = .023). Nevertheless, when Bonferroni's correction for multiple comparisons was applied, none of the variables was statistically significant. CONCLUSIONS AND CLINICAL IMPORTANCE: Previously unreported, clinically relevant, potential prognostic factors, including hypoglycemia, azotemia, parenteral nutrition, and withholding antibacterial treatment were identified in this exploratory study. These preliminary results should be examined further in confirmatory studies.

Mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequence of Spirocerca lupi (Nematoda, Spirurida): avenues for potential implications.

Canine spirocercosis is a life-threatening parasitosis caused by Spirocerca lupi (Nematoda, Spirurida) that is presently emerging in several countries. This study characterised an informative region within the mitochondrial (mtDNA) gene encoding for the cytochrome c oxidase subunit 1 (cox1) of S. lupi by Polymerase Chain Reaction (PCR)-coupled sequencing. Specimens from five different countries in Europe, Asia and Africa were examined and two different sequence variants of cox1 (i.e. haplotypes) were determined, displaying nucleotidic variation at 6 of 689 positions. All of these positions were invariable among all the parasite individuals from Europe (haplotype 1) and among the African and Asian individuals (haplotype 2), but differed between Europe and Asia/Africa. The S. lupi cox1 sequences were consistent with those of other common Spirurida previously reported at both nucleotidic and phylogenetic levels. This study provides molecular information essential for identification of the nematode, irrespective of its life cycle stage. Crucial implications for the specific molecular diagnosis of clinical spirocercosis and investigation of the evolution, population genetics, ecology and epidemiology of S. lupi are discussed.

Chemotherapeutic treatment of xenograft Spirocerca lupi-associated sarcoma in a murine model.

To date, data are not available concerning the effectiveness of chemotherapy in the treatment of Spirocerca lupi-associated esophageal sarcomas. In the present study, we compared the effectiveness of 4 chemotherapeutic agents against S. lupi-associated osteosarcoma, using a xenograft murine model created in our lab. Samples of xenografted osteosarcoma were inoculated subcutaneously into 5 groups (n = 10 each) of 6-wk-old male and female NOD/SCID mice. Tumor-bearing mice were divided into treatment and control groups. The treatment groups were injected with either pegylated liposomal doxorubicin (6 mg/kg, intravenously, n = 9), doxorubicin (6 mg/kg, intravenously, n = 8), carboplatin (60 mg/kg, intraperitoneally, repeated twice at 1-wk intervals for a total of 2 doses, n = 9), or cisplatin (6 mg/kg, intraperitoneally, n = 8). The control group was injected with buffered saline (n = 9). Tumor size was determined by caliper measurements. Compared with the control group, the pegylated liposomal doxorubicin- and doxorubicin-treated groups, but not the carboplatin or cisplatin groups, showed significant inhibition of tumor growth. Our results indicate that doxorubicin-based drugs are effective against S. lupi-associated sarcomas in a mouse xenograft model. Because it is less toxic than doxorubicin, pegylated liposomal doxorubicin is likely the drug of choice for treatment of S. lupi-associated sarcomas. We suggest that combination of doxorubicin or its pegylated form with surgical excision will improve the prognosis of dogs with this disease.