This then quickly progresses to shock, difficulty breathing, and even death. If your cat ingests portions of a broken thermometer or light bulb, they will often develop severe gastrointestinal signs, such as vomiting and diarrhea, anorexia, and pain. Where Are the Signs of Mercury Poisoning? Those causes are extremely rare in both cats and humans. Other causes of mercury poisoning can occur if your cat ingests mercury from a broken thermometer or pieces of a broken thermostat or light bulb. Not only is feeding exclusively tuna completely unbalanced, but it can also put a cat at a much higher risk for developing mercury poisoning. Conversely, there have been no documented cases of mercury toxicity in cats eating only commercially made cat food. However, feeding exclusively tuna is not recommended. Some veterinarians even recommend putting tuna juice in water or on top of food to tempt anorexic cats to eat or drink more. Tuna is generally considered safe by veterinarians to serve to cats, especially plain canned tuna in water. If you feed your cat canned tuna, it’s recommended not to do it daily and to ensure it does not make up more than 10% of your cat’s diet. If you feed your cat only canned tuna, their risk of ingesting a toxic level of mercury is much higher. While tuna is a common ingredient in commercial cat food, it’s often mixed with other types of fish with historically lower levels of mercury and other ingredients. The most likely cause of mercury poisoning in cats is ingesting a large amount of canned or fresh tuna. Image by: P Maxwell Photography, Shutterstock What Are the Causes of Mercury Poisoning? While other fish may also contain mercury, tuna is commonly fed to cats based on its availability (in cans or pouches), cheap cost, and ease of administration. With cats, we would suspect this to occur most commonly after ingesting tuna. It typically takes days to weeks of high mercury ingestion to develop any abnormal signs and suffer from the effects of mercury toxicity. The most common source of mercury poisoning is the ingestion of fish or other seafood containing high levels of the toxin in their tissues. The mercury levels then build up in the body, causing signs of toxicity or poisoning. Mercury poisoning occurs when an animal eats a toxic level of mercury.

Mercury poisoning from tuna