Has your vet examined him? Has he had a fecal done yet? Is the animal emaciated? Although fenbendazole covers a broad range of parasites, WC animals often have such a multitude that is not always covered under the spectrum that fenbendazole can treat. Have you tried assist-feeding before? Tube-feeding is typically used as a last resort... after assist-feeding and forcefeeding (which should be done by someone who has experience with this or guided by them for the first time...) have failed. All of the above mentioned methods are highly stressful on the animal, tubing being the most stressful of them all. Good luck with your snakie