Determination of anthelmintic efficacy against Toxocara canis in dogs by use of capsule endoscopy

Deworming Schemes’ Efficacy for Adult Dogs with Mixed Gastro-Intestinal Helminthoses

Mixed gastrointestinal helminthoses, which combines Toxocara canis, Trichuris (T.) vulpis, Toxascaris leoninа, Uncinaria stenocephala, Ancylostoma caninum, and Dipylidium caninum in various combinations, are very common pets’ problems worldwide. It is unlikely necessary to choose between 100 % efficiency and for the patient’s body to heal the infected animals safely. The present work aims to develop an affordable scheme for adult dogs’ deworming, which will create a minimum load on the body due to the low drugs’ toxicity. Mixed breed dogs, 1—5 years old, representing both sexes, spontaneously infected with T. vulpis (100 % prevalence) in combination with other gastrointestinal helminths (from 12.7 to 45.1 %) were selected for study. Regimens combining Caniquantel® Plus (fenbendazole + praziquantel) and fenbendazole with a 24-hour interval were tested. After a single treatment of experimental animals with Caniquantel® Plus, no helminth eggs were detected in their faeces after three days, except for T. vulpis. Seven days after the start of the experiment, the intensity of infection of this nematode decreased by only 22.0 % (P < 0.001). Bodies and fragments of dead helminths were found in faeces 1—4 days after de-worming, with T. vulpis isolated only in 2 days in small quantities (4.54 ± 0.21 specimens per 100 g of faeces). Two-stage deworming with Caniquantel® Plus and fenbendazole after 24 hours resulted in 100 % efficiency against eggs of all parasites after five days. Helminths’ bodies stopped excreting after four days, and T. vulpis was detected within three days in substantive quantities (from 10.03 ± 0.45 to 36.8 ± 1.2 specimens per 100 g of faeces).

Feasibility, complications, and quality of visualization using video capsule endoscopy in 40 dogs with overt or questionable gastrointestinal bleeding

Background

Prospective studies describing video capsule endoscopy (VCE), its feasibility, and complications in dogs are limited.

Objective

To assess VCE, quality of visualization, complications, and risk factors for incomplete studies in dogs with overt or questionable gastrointestinal bleeding (GIB).

Animals

Forty dogs with overt or questionable GIB.

Methods

Prospective, multicenter, interventional study. From August 2017 to March 2020, dogs were examined by VCE (ALICAM) because of overt or questionable GIB. Reported outcomes included diagnostic results of VCE study, quality of visualization, and complications. Risk factors for incomplete studies were evaluated using logistic regression.

Results

In total, 40 dogs (13 overt, 27 questionable GIB) were included. The capsules were administered PO in 29 and endoscopically in 11 dogs (6 duodenum, 5 stomach). One capsule was not retrieved. In 24 of 39 recordings, bleeding lesions were identified (10 overt GIB, 14 questionable GIB). Overall, the quality of visualization was poor to limited in the stomach and colon, and adequate to good in the small intestine. The most common complication was an incomplete study in 15/39 studies, particularly after oral administration (13/28). Risk factors for incomplete study after oral administration included administration of simethicone or opioids, chronic enteropathy, and capsule gastric transit time >6 hours.

Conclusions and Clinical Importance

Video capsule endoscopy can be used to diagnose a variety of lesions causing bleeding in the gastrointestinal tract of dogs with questionable GIB. Incomplete studies are the most common complications in dogs after oral administration of capsules.

A pilot study on the effect of fat loading on the gastrointestinal tract of healthy dogs

OBJECTIVE

To assess the effect of a high fat meal (fat loading) on gastrointestinal motility and the appearance of intestinal villi using video capsule endoscopy and ultrasound.

MATERIALS AND METHODS

Four healthy staff-owned dogs were included in a prospective blinded crossover study. Dogs had initial baseline video capsule endoscopy to measure gastrointestinal transit times and allow for visual assessment of intestinal mucosa. Abdominal ultrasound was also performed to obtain intestinal wall measurements and assess for the presence of mucosal hyperechoic speckling. All dogs had diagnostics repeated twice between one and two hours after ingestion of either corn oil or dairy cream for a total of four control and 16 fat loaded studies.

RESULTS

Dogs in the corn oil group had greater mean gastric emptying times (740.3 ± 187.6 minutes vs. 237.9 ± 155 minutes) and total transit times (54.50 ± 22.2 hours vs. 23.25 ± 6.1 hours) than controls. Feeding of a fatty meal resulted in substantial retention of the capsules (10 of 16) within the stomach. While intestinal wall thickness of fat loaded dogs did not differ from control dogs, mucosal hyperechoic speckling scores of the duodenum of dairy cream dogs were greater when compared to control dogs (1.625 ± 0.518 vs. 0.500 ± 0.577).

CLINICAL SIGNIFICANCE

Data from this pilot study provides further evidence that feeding of a small high fat meal results in ultrasonographic as well as visual changes to the intestinal mucosa of healthy dogs. This data suggests that previous recommendations to feed fatty meals to dogs with lymphangiectasia might not allow differentiation with healthy individuals. In addition, due to the marked effect on gastric emptying time, video capsule endoscopy should be avoided in dogs fed a high fat meal.

The 3Rs Concept: Time to Change How We Evaluate the Efficacy of Anthelmintics in Companion Animals

Experimental infections are required by current guidelines for investigating the efficacy of anthelmintics in dogs and cats. Recently, alternatives to experimental infections and the sacrificing of research dogs and cats have been evaluated, and novel conceptual investigations and methods of examination have been explored. Several of these approaches could potentially be used in efficacy studies for anthelmintics in dogs and cats. Here, we provide food for thought towards using new tools for evaluating the efficacy of anthelmintics in companion animals, for promoting the value of field trials, and for updating the existing guidelines for the efficacy testing of anthelmintics in dogs and cats.