When guinea pigs get thinner and thinner

Guinea pigs are by nature smart, cheerful animals, sociable and willing to communicate; both with each other and with their owners. They quickly become trusting, soon listen to their name and enjoy it a lot. The greater the consternation, if one of these animals gets sick. Since we are repeatedly asked by readers, in which concern about a continuous weight loss of the guinea pig is expressed, we have the specialist for small pets of the University of Veterinary Medicine Vienna, Dr. med. Frank Künzel, asked about the topic.

Question: Mr. Künzel, what can be the cause of guinea pigs becoming thinner and thinner?

Dr. Künzel: One possible cause of progressive weight loss in guinea pigs is an overactive thyroid gland. It is typical that the animal decreases, although it eats with great appetite and often shows cravings.

What other symptoms are the pet owner with this disease?

Dr. Künzel: The pet owner noticed changes in guinea pig behavior. Guinea pigs with hyperthyroidism become hyperactive, are nervous and show violent defensive movements when arrested. They take for this species abnormal body postures, sleep, for example, in a lateral position and are difficult to wake. Striking is also that the diseased animal separates from the group, although just guinea pigs are herd animals. Even the shaggy, partly matted hair dress jumps in the eye. But the main reason for the vet visit is in most cases the continuous emaciation of the animal.

How can the vet diagnose "hyperthyroidism"?

Dr. Künzel: The vet first makes a palpation. Since the cause of hyperfunction is often one or more tumors of the thyroid gland, a tumor is felt on the underside of the neck; this can be from the size of a passer-by to a chicken egg. In addition, the veterinarian notices that the animal is breathing too fast, the number of heart beats per minute is too high and the pulse is abnormally strong. Blood must be taken from the guinea pig to determine the amount of thyroid hormone - called total T4. Different methods exist for the determination of this hormone, but it is important that the same method with existing reference levels for guinea pigs is used for the investigations; This is possible, for example, in the central laboratory of the Veterinary University.

Are these tumors on the thyroid gland more benign or malignant?

Dr. Künzel: Studies here at the University have shown that the percentage of benign tumors on the thyroid gland with the malignant scales; About 50% of cases are adenomas and 50% are carcinomas, or cancerous tumors.

Are guinea pigs affected at any age?

Dr. Künzel: No, not at any age, but only animals from the age of three to four years, so middle-aged to older animals.

What treatment options are there?

Dr. Künzel: We have three options: drug therapy, surgery and radioiodine therapy. However, according to the current state of knowledge and the empirical values ​​that we currently have, in most cases drug therapy is to be preferred. The once or twice daily administration of tablets with the active ingredient "Felimazole" inhibits the overproduction of thyroid hormone and affected guinea pigs usually show a rapid improvement. The tablets must be given for life and initially regular veterinary checks must be performed every two to three weeks. Since guinea pigs with hyperthyroidism are often brought to the vet only in advanced disease state, the drug setting difficult and a referral to a special clinic may be necessary. For the surgical removal of the thyroid, there is little experience, the operation involves many risks. The reasons for this are: The risk of anesthesia in the weakened guinea pigs is high and because the thyroid gland is a well-perfused organ, there is also the risk of bleeding. Against the operation also speaks that scattered tumor foci - for example, in the chest - are not detected and therefore it can come to relapse after the surgery has been over. The scintigraphy allows the graphical representation of altered thyroid tissue. For this purpose radioactive pertechnetium is injected intravenously. It accumulates in the tumor and you can see how many "active nodes" are present. The radioiodine therapy takes place immediately after the scintigraphy. The experience with this treatment in guinea pigs is still low, but the results are promising. A disadvantage of this method is that the animals must remain in hospital for up to two weeks after treatment until their radioactivity falls below the legally prescribed limit again. In summary, it can be said that the drug therapy of hyperthyroidism in guinea pigs is well established in practice, as it shows rapid success and is inexpensive and low in risk.