moxidectin and Eye-Diseases

Thelazia callipaeda (Spirurida, Thelaziidae) has been documented as agent of ocular infection in domestic animals (dogs and cats), wildlife (e.g., foxes, hares, rabbits), and humans. In the last two decades, this parasitosis has been increasingly reported in several European countries. Both adult and larval stages of the eyeworm are responsible for symptoms ranging from mild (e.g., lacrimation, ocular discharge, epiphora) to severe (e.g., conjunctivitis, keratitis, and corneal opacity or ulcers). The present study evaluated the clinical efficacy and safety of imidacloprid 10% and moxidectin 2.5% spot on (Advocate(®), Bayer Animal Health) in comparison to milbemycin oxime/praziquantel tablets (Milbemax(®), Novartis-Animal Health), as positive control, in the treatment of canine thelaziosis in naturally infected dogs and, a third group was used as an untreated control. Forty-seven dogs (27 females and 20 males) harbouring at least one live adult worm of T. callipaeda in one eye were enrolled from an endemic area of southern Italy. Each dog was then weighed and assigned in accordance with a random treatment allocation plan to one of the treatment groups (G1: imidacloprid 10% and moxidectin 2.5% spot on, G2: Untreated control and G3: milbemycin oxime/praziquantel tablets). On Day (D) 7, 14, 28 and 35 dogs were physically examined and the infection level was assessed by examination of both eyes, including conjunctival pouch and third eyelid for live adult T. callipaeda count and clinical scores. Dogs in G1 were treated on D0 and D28, whereas those in G3 on D0 and D7. Efficacy in G1 was 100% at each day post treatment (p<0.01). For the G3 group efficacy was 57.39% on D7 (p<0.05), 92.79% on D14 and 100% on D28 and D35 (p<0.01). The application of the spot on formulation moxidectin 2.5% and imidacloprid 10% was highly effective in the treatment of canine thelaziosis caused by T. callipaeda. Advocate(®) spot on can be recommended for the control of T. callipaeda infection, considering that this formulation is currently licensed in Europe for the treatment of a wide range of parasites affecting dogs.

Topics: Administration, Cutaneous; Animals; Anthelmintics; Cholinergic Agents; Dog Diseases; Dogs; Eye Diseases; Female; Imidazoles; Macrolides; Male; Neonicotinoids; Nitro Compounds; Spirurida Infections; Thelazioidea

The present study evaluated the therapeutic effectiveness of moxidectin 1.0% (w/v) and imidacloprid 10% (w/v) (Advocate® spot-on solution for cats, Bayer Animal Health) against natural infections with the eyeworm Thelazia callipaeda in cats. This study was conducted as a GCP, negative-controlled, blinded and randomised field study in privately owned cats living in an area in southern Italy where T. callipaeda is enzootic.. The study was carried out in 30 cats (19 females and 11 males, aged from 8 months to 5 years, weighing 1.2-5.2 kg) of different breeds, naturally infected by T. callipaeda. At study inclusion (Day 0), animals were physically examined and the infection level was assessed by examination of both eyes for clinical score and live adult T. callipaeda count. Each cat was weighed and randomly assigned to one of the treatment groups (G1: Advocate, G2: untreated control). Clinical assessments and T. callipaeda adult counts were performed on Day 14. At the study completion visit on Day 28, clinical assessments and counts of T. callipaeda adults and larvae were performed. All cats were daily observed by their owners and general health conditions were recorded during the entire period of the study.. The primary effectiveness variable was the percentage of animals in G1 group (Advocate) showing a complete elimination (parasitological cure) of adult eye worms at Day 14 and Day 28 . The effectiveness of the treatment in the G1 group was 93.3 and 100% at Day 14 and Day 28 , respectively, when compared to group G2. Total worm count reduction from both eyes for Advocate was 96.3% on Day 14 and 100% on Day 28. Clinical data were confirmed by the examination of conjunctival pouch flushing. An overall reduction in the number of cats with lacrimation and conjunctivitis was observed following treatment despite the fact that in a few cats treated with Advocate clinical signs persisted due to the chronic nature of the disease.. Based on the results of the present trial, a single dose of Advocate was found to be safe and highly effective in the treatment of natural T. callipaeda infection in cats.

Topics: Administration, Topical; Animals; Cat Diseases; Cats; Drug Combinations; Eye Diseases; Macrolides; Neonicotinoids; Nitro Compounds; Spirurida Infections; Thelazioidea

Ocular thelaziosis caused by Thelazia callipaeda is a vector-borne disease affecting dogs and humans. We report a case of thelaziosis in a 10-year-old German Shepherd dog from Vila Real city (Portugal). Ophthalmological examination revealed bulbar and nictitating membrane conjunctival hyperemia with serous discharge noted at the left medial canthus and blepharitis. Schirmer tear test value and intraocular pressure were within the reference ranges in both eyes, and biomicroscopy showed a transparent cornea without lesions or edema and no inflammatory reaction in the anterior chamber. No funduscopic alterations were detected by direct and indirect ophthalmoscopic examination. When testing the nasolacrimal patency, two white worms were observed on the caruncle conjunctival surface with undulating movements that increased with light intensity. In total, eight worms were collected and morphologically identified as T. callipaeda (seven mature females and one male). PCR amplification of a 689 sequence of partial cytochrome c oxidase subunit 1 target gene confirmed the nematodes were T. callipaeda, haplotype 1. The dog was treated with a single subcutaneous injection of ivermectin combined with additional topical application of ophthalmic fusidic acid drops and oral milbemycin oxime. One week after treatment, no worms were detected and the ocular clinical signs resolved. The most recent reports of canine thelaziosis in the Iberian Peninsula should alert local health authorities to the zoonotic potential of infestation with T. callipaeda, which should be included in the differential diagnosis of conjunctivitis in dogs and humans.

Topics: Animals; Anti-Bacterial Agents; Antiparasitic Agents; Dogs; Eye Diseases; Female; Fusidic Acid; Ivermectin; Macrolides; Male; Portugal; Spirurida Infections; Thelazioidea