A melanoma is a tumor that develops from the pigment cells of the skin, known as melanocytes. The tumor produces cells that contain melanin, the dark pigment in the skin. If the tumor is benign, it is referred to as a melanoma; if it is malignant, it is referred to as a melanosarcoma. In human medicine, melanomas are commonly referred to as "black skin cancer."
The exact cause of tumor formation is unknown. However, there is a genetic predisposition in certain breeds and coat colors. Arabian, Percheron, and Lipizzaner horses are particularly affected. Melanomas can occur in horses of all coat colors, but are significantly more common in gray horses. According to several scientific studies, melanomas occur in an estimated 80% of all gray horses over the age of 15, although most of these are benign.
Melanomas can occur anywhere on the body, but are most common on the underside of the tail, in the perianal region (around the anus and, in mares, around the vulva) and on the head below the ear. In the early stages, they appear as isolated, firm, small lumps, which are black in most cases and lie under the skin. However, the surface of the tumors may also be hairless and ulcerated. As the disease progresses, secondary tumors usually develop in the immediate vicinity under the skin. These lumps, which can grow to the size of walnuts, may remain seemingly unchanged for years and, in this form, are merely cosmetic blemishes.
Occasionally, melanomas can also form in the pelvic cavity. If they are large enough, they can constrict nearby organs such as the rectum or vagina. Melanomas can be divided into different groups based on their growth rate and degree of malignancy (i.e., how cancerous they are). Many melanomas grow very slowly and do not metastasize (spread). Other melanomas also grow very slowly and appear virtually unchanged for years until sudden metastasis occurs. This transformation from a benign to a malignant tumor can be caused by both mechanical irritation and certain stressful situations. The third group includes all melanomas that grow very quickly from the outset and metastasize immediately. The cancer cells of the original tumor can spread throughout the body via the lymphatic system. Metastases primarily affect the breast and abdominal lining, liver, lungs, spleen, and lymph nodes of internal organs.
External signs of metastasis that has already occurred can include neurological symptoms, weight loss, and problems with eating and defecation. Therefore, have even a harmless-looking lump on your horse examined by a veterinarian as soon as possible and treated if necessary.
The diagnosis of melanoma can usually be made by the veterinarian based on the externally visible clinical signs. Only in rare cases with atypical appearance are biopsies (= tissue samples) necessary.
Benign, non-metastatic melanomas on the tail root or head have a good prognosis and are merely cosmetic blemishes. If no skin changes are visible on the surface of the tumor, they should not be touched or treated. Surgical treatment is only recommended for isolated melanomas if they cause problems due to their location (girth, halter or bridle) or their altered surface. However, this operation is only promising if the associated lymph node is also removed to prevent or contain metastasis.
If there are multiple tumors merging into one another in the perianal region or in the facial area below the ear, the veterinarian will usually not perform surgery, as manipulation of an otherwise dormant tumor could activate it and lead to subsequent metastasis. In some cases, it is possible to remove the lymph nodes, giving these animals a survival rate of 3-5 years. Otherwise, there is no prospect of a cure. The animals live with the tumors for as long as they can without any disturbance to their general well-being.
A novel therapy method currently under development is immunotherapy. This involves administering the body's own immune messengers to stimulate the immune system to curb tumor growth. Scientific studies are currently underway at veterinary universities.
The development of melanoma cannot be prevented. However, in the case of existing slow-growing melanomas, activation of the tumor cells and subsequent spread can be prevented by refraining from any manipulation.
Castration of stallions is one of the most common medical procedures performed on horses and refers to the surgical removal of the male sex organs or gonads (testicles). This is an amputation permitted under animal welfare legislation. A castrated stallion is referred to as a gelding and is permanently infertile.
Everyone has probably heard the term "mangy dog" before. But what exactly is mange? Mange is a contagious skin disease in dogs caused by various types of mites. Classic mange in dogs is caused by the Sarcoptes mite (scabies mite). However, there are other types of mites that cause similar skin changes.
Fungal diseases are among the most common skin diseases in horses. They occur regardless of the season, are easily transmissible, and cause circular, scaly, non-itchy skin lesions. Young horses whose immune systems are not yet fully developed are particularly affected. Humans can also become infected with a skin fungus from horses, meaning that it is a zoonosis.
Horse influenza, similar to influenza in humans, is a highly contagious viral disease of the upper and lower respiratory tract. Its classic progression makes it easy to distinguish from other respiratory diseases. With the exception of New Zealand and Australia, it occurs worldwide. It is the most common viral respiratory disease in horses. Despite almost universal vaccination, outbreaks of the disease continue to occur.
Cats communicate through various channels. Their behavior, body language, vocalizations, and scent markings, which are largely invisible to humans, speak volumes. But how can "cat language" be translated into "human language"?
Have you ever wondered whether your dog can see the magnificent colors that nature sometimes presents us with? Have you ever thought about how your dog sees you and how it perceives its environment with its eyes?
Cryptorchidism refers to the absence of one or both testicles in the scrotum of a stallion. It is a relatively common developmental disorder in horses and can occur in all horse breeds. These stallions are also colloquially referred to as "Klopp-, Spitz- or Urhengste" (clop, pointed or original stallions). Since the majority of cryptorchid stallions are infertile, this condition also has economic significance in relation to horse breeding.
X-ray fluoroscopy is an imaging examination method that uses X-rays to create a series of moving images of the part of the body being examined. The X-ray machine is freely movable thanks to a C-shaped arm (= C-arm), allowing the body part or organ to be viewed from all angles in real time on the monitor.
Distemper is a long-known and highly contagious viral infection that can affect various carnivorous wild animals as well as dogs and ferrets. It is also known as Carré's disease, after its discoverer, Henri Carré. Since the introduction of protective vaccination in 1960, outbreaks and mortality rates have been significantly reduced. However, with declining vaccination rates and the constant increase in dog imports from Eastern Europe, distemper is once again on the rise in Germany.
Gastritis is an inflammation of the stomach lining that can occur in dogs as a result of superficial or deep injuries. Persistent irritation of the stomach lining can lead to chronic inflammation and ultimately to a stomach ulcer. The disease can take an acute or chronic course.
Like humans and dogs, horses can also suffer from poor heart performance. In heart failure, the heart is unable to pump enough blood through the body, resulting in a lack of oxygen supply to the cells and a backup of blood in the body and pulmonary circulation.
Giardiasis is a diarrheal disease in dogs and cats caused by single-celled parasites in the small intestine. There are different types of Giardia, most of which are harmless to humans. However, some rare forms can also be transmitted to humans, making it a zoonosis. Young children and immunocompromised individuals are particularly at risk, which is why strict hygiene measures are essential when dealing with giardiasis.
