Fritz's diagnosis - Saddle Thrombus

In trying to cope with the loss of our cat Fritz, I did some research on the cause of his death - Saddle Thrombus. I needed to know if there was something I had missed or could have done to prevent the horrible sudden end to his life. And I'm sure it is upsetting to my cat-loving readers who are now worrying about their own cats. So following is what I discovered.

Saddle Thrombus, also known as Aortic Thromboembolism, is rare and one of the most difficult and frustrating feline diseases for veterinarians, as the onset is quite sudden and often there are no warning signs. It is known as the silent killer in cats. 90 percent of the cases are related to a heart condition, and believed to be most common in cats with pre-existing cardiac problems such as an enlarged heart, cardiomyopathy or valvular disorders, and often goes undetected. It usually occurs in middle-aged to older cats, but is rarely seen in younger cats, even kittens, and occurs twice as often in male cats as in female cats. It is caused by a defect in the heart walls, allowing a clot to form. If the clot breaks loose, it can block blood flow to any area of the arterial system. With Saddle Thrombus, the clot lodges at the split in the aorta by the hind legs, causing paralysis and extreme pain.

Regular veterinary checkups are recommended to detect heart murmurs which are a warning sign. If a heart murmur is detected, therapy such as blood thinners can be started if needed. Other warning signs of heart problems are loss of appetite, weight loss, lethargy and a change in personality. Fritz's last vet appointment was in October and there was no sign of any problems. Right up to the event on Saturday morning, he showed none of these signs.

The symptoms of Saddle Thrombus are vomiting, panting and hyperventilation, extreme pain, vocalization of their pain, rapidly developing lameness in rear legs, rapid heart rate, lack of femoral pulse in either rear leg, and foot pads and nails turning blue. The cat will often chew at his back legs trying to relieve the pain caused from lack of blood flow to the legs.

It is rare for a cat to recover from the condition. In some cases, if treatment is started within minutes of the event, there's a chance they can survive and regain use of their hind legs. Surgery is usually performed to remove the clot, and blood thinners are given for the rest of the cat's life to prevent future problems. It can take months for the cat to regain use of their back legs, along with physical therapy, and amputation is sometimes necessary. A study was conducted between 1977 to 1998, in which approximately 1/3 of the cats died from the event, another 1/3 of them were euthanized as there was no hope of recovery, and a final 1/3 survived on average approximately 1 additional year.

Fritz was the only surviving member of his litter, born to a sickly mother cat who wasn't able to give him proper nourishment. When we took him in at around 5 weeks old, he was in poor health, but we hoped with a high quality diet and pampering he would overcome his hard beginning in life. And he did respond well. He overcame his mal-nourished beginnings and was the picture of health. I never saw a cat with such a silky and shiny coat, and his eyes were as clear and bright as can be. He had boundless energy for play and for mischief. He lived each day to the fullest. In hindsight, we have concluded he was born with this problem and what happened to him was inevitable, and if he had remained on the farm, he would have died much earlier. We're just thankful we were able to give him a happy year and a half of life and share that time with him. So my fellow cat lovers, remember that this is a rare disease. Give your kitty a hug and treasure every day you have together.

I took this picture just last week - Fritzy in his favorite napping spot.