Article in English: Watch for excessive scratching, which may be indicative of fleas. If you see your cat scratching himself often, you will need to perform a spot check. Get a fine toothed comb and run it through your cat’s fur. Look for little, fast-moving brown specks (which are fleas) particularly around your cat’s neck and tail.  You can also check for fleas by grooming the cat over a sheet of blank white paper. You may see fleas in the comb's teeth or flea dirt on the paper. Flea dirt is black and comma shaped. If placed on damp cotton wool it dissolves into bloody streaks. Many commercial products are available to kill fleas and remove them from your home. Ask your vet for specific recommendations. Hairballs can also cause bad breath or low appetite. Serious hairball problems may become Trichobezoars (hard lumps of matted hair and undigested foul-smelling food) and extreme cases may require surgery. Regularly groom your cat to reduce hairballs.  Other effective home remedies include adding supplements to their diet such as: Slippery Elm Bark to lubricate the hairball passage or pumpkin pulp (canned) which adds bulk fiber to stools, easing the hairball out. These items can periodically be added to treats like fish or cooked chicken/livers as a preventative for hairballs. You should consult with the veterinarian to be certain that a more serious problem is not the cause. Symptoms include increased appetite or thirst, unexplained weight loss (particularly muscle mass), nervousness or irritability, frequent vomiting, lethargy and weakness, diarrhea, or a messy coat. If two or more symptoms are present, your cat will need to see the veterinarian. Hyperthyroidism typically occurs in middle-aged to older cats and is rare in a young cat. Increased appetite is a handy warning sign that your cat needs veterinary attention. The thyroid hormone that triggers appetite also raises the metabolic rate and puts organ function under strain. Signs of diabetes include vomiting, dehydration, weakness and loss of appetite, increased thirst and...

Summary in Vietnamese:
Phát hiện bọ chét. Quan sát hiện tượng ho khan và nôn mửa là dấu hiệu của dị vật lông dạ dày. Phát hiện bệnh cường giáp, hoặc tuyến giáp hoạt động quá mức. Quan sát dấu hiệu tiểu đường ở mèo. Quan sát dấu hiệu viêm đường tiết niệu ở mèo (FLUTD).