Amyloidosis describes the build-up of an abnormal protein called amyloid in organs and tissues throughout the body. It can affect people and cats; wild and domestic. There is a distinct overlap between domestic and wild cats here which I find interesting. There is a study on amyloidosis in caracals (March 2020), which is a medium-sized, highly athletic wild cat species which mainly feeds on rodents and is very prevalent in South Africa. In this study they assessed nine cases of amyloidosis in caracals from three different institutions in Europe. I presume that these were zoos. Anyway, they were captive caracals; six males and three males who died between 2008 and 2018 at an average age of six years and 2.5 months. This is well short of a typical lifespan that this species.
In 7/9 of the cats there was acute renal failure due to the amyloidosis. The symptoms were weight loss, lethargy, anorexia, dehydration and azotaemia plus increased BUN and creatinine. Azotaemia is a higher-than-normal blood level of urea and other nitrogen-containing compounds.
The researchers did not know what caused the amyloidosis (“etiology of the amyloidosis remains unknown”). They speculated that it may be due to a familial trait i.e. inherited but in conclusion they said that amyloidosis “should be considered as a significant disease in the caracal”.
On the domestic cat front, amyloidosis is rare in domestic cats generally except for Abyssinians, Siamese, Burmese, Tonkinese, Devon Rex and Oriental shorthair cat breeds.
VCA animal hospitals say that “certain family lines of Siamese cats identified as predisposed”. It seems that they too are talking about familial inheritance within certain bloodlines. Normally it affects cats older than seven years of age although it can affect cats between the ages of one and 17 years. The risk of developing the disease increases with age and Siamese cats with “familial amyloidosis” can be diagnosed as early as 1-4 years of age.
The signs are the same as those caracals with “kidney involvement” being common. I take that to mean the kidneys are damaged resulting in kidney failure. The affected cats lose their appetite and become lethargic. They drink more and urinate more (signs of kidney failure). They suffer from weight class, vomiting and diarrhoea. Sometimes fluid builds up under the skin and in the abdomen and chest cavity.
In Siamese and Oriental shorthair cats the symptoms include severe hepatic amyloidosis which leads to haemorrhaging and rupture of the liver.
Because the kidney fails, cats can suffer from mouth ulcers, dehydration, vomiting and extreme weight loss. Some cats develop blood clots.
VCA hospitals say that the cause of amyloidosis is chronic infection and chronic inflammation and certain types of cancer are implicated.
The study: AMYLOIDOSIS IN CARACALS (CARACAL CARACAL).