dont push your dog to much, 4 since sunday, give him some time off,you could push him to far and he will spew best to go steady than over do it, not all fox dogs want to know cats, ive a bitch here that wont go any where near them, some times imo people push there dogs to far and then say its spewed, its not the dogs fault its the owners, im all for testing your dog but you must no when to ease off abit. example working a terrier still sore, same for lurchers, go steady and you muts will give years of sport,