Last week, a much-improved Amy returned to the clinic. Amy is a white and grey petit cat I had first seen a couple of weeks ago. At the time, she was severely underweight. Amy was brought in because she had gone off her food, had become much quieter than usual and had started to vomit.
Cats are stoics when it comes to illness. They suffer quietly and do not readily show how unwell they are. From a medical point of view, this tends to work against them since, all too often, owners do not realise how unwell their cat is. This was certainly the case with Amy.
On the surface, Amy’s clinical examination did not reveal much. So, bearing in mind what her owner had told me about her lethargy and vomiting, I carried out some blood tests, which quickly revealed that the problem was Amy’s liver.
The liver is the largest organ in the abdomen of your cat or dog. It starts to perform critical functions even during the foetal stage of the kitten or puppy by contributing towards the production of its red blood cells and growth hormones until other organs take over this task. Once the kitten or puppy is born, it continues in its role as a vital organ performing a multitude of critical functions.
As generally happens with other large organs, when signs and symptoms of liver disease manifest themselves, this usually indicates that there has already been quite a major malfunction of the liver. Depending on the ailment, sometimes even as much as two-thirds of the liver might be compromised before external symptoms start to show.
Primarily, the liver sorts through (metabolises) all digested food and nutrients which pass through the intestine – be they proteins, carbohydrates or fats. To achieve this, the circulation system is optimally designed so that all the veins from the intestine have to pass by the liver on their way back to the heart. Together with these nutrients, vitamins and minerals that are transferred to the liver are similarly metabolised. But the liver does not process only the good stuff.
All toxic substances or excesses of particular substances that may be harmful to the body are also pushed through and mostly dealt with by the liver after being absorbed. This detoxifying function of the liver is also used to break down toxic substances produced inside the body itself. These substances include ammonia, which is a breakdown product of protein and which is converted into urea. The urea is then excreted by the kidneys as urine.
Apart from blood tests, additional investigations such as X-rays, ultrasound and biopsies will all contribute towards a better understanding of the liver disease
Another major function of the liver is the production of bile acids which are secreted through bile ducts and gall bladder into the intestine. Bile acids are extremely important in the emulsifying and breaking down of fats, which are then secreted into the digestive process. Due to this secretion function, the liver is considered not only as the largest organ in the abdomen, but also as the largest gland in the body.
Other very important functions of the liver include the synthesis (production) of certain proteins that are fundamental to blood clotting as well as certain hormones that regulate blood pressure.
There are a number of different liver ailments which cats may suffer from. These may be of infectious origin caused by viruses or bacteria or inflammatory in nature, as sometimes happens especially to the bile ducts; or neoplastic, as may happen as part of the feline leukemia complex. They may also be toxic in nature due to, for example, poor quality diets or adverse reaction to certain medications.
Toxicity is of particular importance since the cat’s liver has certain limitations when metabolising drugs which other species can handle. It is therefore vitally important that you administer to your cat only medication that have been specifically been prescribed by your veterinarian and in the quantities prescribed. Fatty liver (hepatic lipidosis) is another ailment common to cats that have stopped eating for a length of time.
When hepatic lipidosis occurs, the body would need to use more of its own fat than is normal and this excess of fats in the blood may also result in an over-deposit of fats in the liver.
Apart from blood tests, additional investigations such as X-rays, ultrasound and biopsies will all contribute towards a better understanding of the liver disease and the best-indicated type of treatment needed.
With Amy, we found that her liver enzymes were very high. These enzymes are produced by the liver and are generally more or less elevated, depending on the particular liver problem and location. Further blood tests showed no sign of an infectious condition and X-rays showed no hint of the presence of a tumour.
A form of toxic liver damage was the tentative diagnosis at the time and within a few days she responded extremely well to supportive treatment, a special diet and medication –all of which are intended to reduce pressure on the liver and improve detoxification to restore the functions of Amy’s liver.
thisweekwiththevet@gmail.com
Dr Martin Debattista is a veterinary surgeon.