You want to save money whenever you can so when you see the usual brand of flea treatment for your cat listed at half the normal price, you click “buy”. It arrives and you apply it to your pet, but they fall ill and you have to rush to the vet for treatment. It emerges that the medicine you bought was a fake and that it contained dangerous chemicals that triggered vomiting and seizures . You are lucky that the cat survived, but have ended up with a large vet bill. Pet owners have been warned when buying flea treatments online after toxic pesticide traces were found in counterfeit products. The Veterinary Medicines Directorate (VMD), the UK government agency that oversees pet medication, says the fakes often lack proper active ingredients, making them ineffective. But in the worst cases, they contain harmful substances that can cause vomiting, muscle tremors, breathing difficulties, seizures and even death. Last year, the VMD cited the case of a cat that had to have extensive surgery after its owner used …