Are there many tumors in cats?

Cats do develop neoplastic diseases. There are many cancer diseases in cats, especially in older cats. The most common ones are mammary tumors in female cats, which can be benign (called benign tumors) or malignant (called cancer).

What are the symptoms of cat tumors and how to treat them?

Tumor classification is generally based on the tissue from which it originates. Each category is divided into benign and malignant tumors according to the degree of differentiation of tumor cells and their impact on animal health. Cats have a high incidence of tumor diseases. Because the lifespan of cats continues to extend, the incidence rate in cats is significantly higher than that in domestic animals. Tumors are abnormally occurring tissues (or cell groups) that grow faster than normal tissues. Malignant tumors have a great impact on tissues and animal life.

Worldwide, cutaneous mastocytoma and squamous cell carcinoma are the most common in cats; there is no reliable statistical data on the incidence, breed factors and regional impact of small animal tumors in China. Judging from the current clinical tumor cases in small animals in my country, many types of cat tumors can be seen, such as: gland tumors (especially mammary tumors), squamous cell carcinoma, various sarcomas, basal cell tumors, lipomas, fibromas, tumors, melanomas, hemangiomas, enchondromas, and ovarian implant tumors. In clinical tumor surgery, breast tumors account for the largest proportion.

The naming of tumors is mainly based on the following method: benign tumors are named by adding the word "tumor" after the name of the tissue from which the tumor originates, such as parotid gland tumor, hemangioma, lipoma, etc. The nomenclature of malignant tumors is more complicated. Malignant tumors derived from mesenchymal tissue are called "sarcomas", such as lymphosarcoma, rhabdomyosarcoma, angiosarcoma, osteosarcoma, etc. Sarcomas formed from epithelial tissue are called "carcinomas", such as : Ear adenocarcinoma, squamous cell carcinoma, etc.; for the naming of malignant tumors derived from neural tissue and immature embryonic tissue, the word "成" is usually added in front of the tissue or organ where the tumor occurs, or it can be Add the four words "blastoma" after the source tissue, such as renal cell tumor, neuroblastoma, etc.; for some malignant tumors whose origin is still controversial, usually add "malignant" before the name of the tumor. " to complete the naming, for example: malignant melanoma, etc.

The clinical diagnosis methods of tumors include the following:

Biopsy: referred to as biopsy. Biopsy is a rapid and accurate clinical diagnosis method that takes tumor tissue blocks, punctures, scrapings orThe cell fragments shed by the patient were identified under a microscope by a veterinary pathologist. Before taking a biopsy, you should understand the basic information of the animal being examined, such as animal species, gender, breed, age, tumor growth location, growth rate, appearance, palpation conditions, etc., so that you can make a precise decision.

Instrumental diagnosis: X-ray fluoroscopy and taking X-rays are effective methods to determine the location of tumors and are often used clinically; if necessary, B-ultrasound diagnosis can assist veterinarians in making judgments on abdominal tumors. The use of various speculums is an accurate means of clinical diagnosis, such as esophagus, gastroscope, colonoscopy, laparoscopy, etc., which have begun to be used in domestic veterinary clinics. CT diagnosis has good accuracy, but the equipment is expensive.

Immunopathological examination: performed by examining tumor-related antigens and antibodies.

Histochemical examination: used to identify tumors that are similar in structure and morphology to normal tissue, and is performed in the pathology laboratory.

Clinical differential diagnosis: refers to the traditional method that combines inspection, palpation and questioning. When veterinarians lack the necessary instruments, this method can only be used for clinical identification. The main purpose is to ask about the growth rate and surface condition of the tumor. Whether the boundary with surrounding tissue is clear, growth pattern, whether bleeding continues, whether metastasis occurs, etc. It should be noted that when a mass appears within 2-3 days with tenderness and fever, it is usually a bacterial infection. After treatment with anti-inflammatory drugs, the fever subsides and the mass shrinks.

Tumor treatment can only be carried out after the nature and location of the tumor have been determined. The age and functional status of the animal should be considered. The treatment method used can be one or a combination of multiple methods.

Drug therapy: Used for tumors that are not suitable for surgery or that cannot be cured by surgery. Drug chemotherapy is a common treatment method that has developed rapidly in clinical practice, but it is not yet a good solution to the problems in most cases. It is also used as a coordinating measure for surgical treatment.

Instrumental therapy: Magnetic therapy, radiotherapy and ultrasound therapy are measures to treat tumors that are difficult to cure by surgery.

Surgical removal: For most benign tumors (the scope of the tumor has been determined), surgical removal of the tumor is the most effective clinical treatment method and is widely used. For some non-benign tumors, if the cat owner requires surgery, the scope of surgical resection should be larger than the size of the tumor, generally at least 1 cm beyond the edge of the tumor. Note: During surgery, blood vessels and lymphatic vessels should be ligated first, and then the tumor tissue mass should be removed.

Other methods: including non-resection surgical treatment, vector-oriented treatment, traditional Chinese medicine, immunotherapy, etc., all of which have different clinical therapeutic effects for different cases and different stages of the case.

Stereotactic tumor killing: Three-dimensional stereotactic radiotherapy is a new treatment method, and its effect and impact on surrounding tissues are better than two-dimensional stereotactic radiotherapy.The method of dimensional plane radiation. Three-dimensional stereotactic radiotherapy has been clinically combined with traditional treatment methods for the treatment of nasopharyngeal cancer, prostate cancer, lung cancer, liver cancer and pancreatic cancer, improving the treatment effect.

Cat skin tumors are relatively easy to detect clinically. Due to the direct contact between the skin and the outside world, chemical factors, radioactive factors, viral factors, hormones and genetic factors are all causes of skin tumors. Due to the diversity of skin tumors, skin tumors are generally divided into the following categories clinically: moles, benign tumors, mild malignant tumors and malignant tumors. The so-called mild malignant tumors show local infiltration in the skin and can be removed through surgery. They often recur after resection, but they rarely metastasize.

Basal cell tumor is a benign tumor that mainly occurs in middle-aged and older cats (the incidence is higher in dogs). Feline basal cell tumors generally originate from the epidermis but lack epidermal appendages and can occur in sebaceous glands, apocrine glands, and hair follicles.

Basal cell tumors are pigmented, oval, smooth, hairless or ulcerated; the tumor grows expansively, has a pedicle, is clearly demarcated from the surrounding tissue, can move in the tissue under the epidermis, and is solid in texture. The site of occurrence in cats is variable, with higher incidence rates in Angora cats, Siamese cats, and Himalayan cats.

Surgical removal of the tumor is the treatment of choice. Recurrence after surgery for multicentric basal cell tumors is occasionally seen in cats only.

Squamous cell carcinoma originates from epidermal spinous cells or the epithelium of the hair root sheath. It penetrates the germinal layer and invades the underlying connective tissue. It can further spread to surrounding tissues and even bone tissue, but it does not occur quickly.

Squamous cell carcinoma of the skin in cats is generally related to chronic sun damage, with a higher incidence in the (white) skin of the auricles and eyelids, while non-actinic cancer mainly occurs in the toes. The initial symptoms of the disease are similar to those of canine actinic keratosis. The lesions are small but highly invasive, with locally raised skin and hard edges. Photoallergic dermatitis is common in cats, primarily on the ear tips and other exposed areas of white cats, but the development of tumors may persist for several years.

Surgical total resection and cryosurgery are the two most commonly used methods. Well-differentiated cutaneous squamous cell carcinomas can be surgically removed, but poorly differentiated tumors may have local recurrence or metastasis after surgery; radiotherapy can also be used.

Collagen fiber nevus is a localized skin development defect caused by excessive deposition of collagen. Mainly found in middle-aged and elderly cats, it is common on the head, neck and lower parts of the limbs. It has nodular bulges and a papillary surface. The lesions are occasionally found in the subcutaneous and fatty tissues. Surgery can remove it.

Cat skin melanoma: The incidence of cat skin melanoma is not high. It mainly occurs in middle-aged and elderly cats. It is common on the head and distal parts of the body. It is shallow in location and close to the surrounding tissues.The boundaries are clear, sometimes up to several centimeters in diameter; they are mostly benign, and the tumors can be removed through surgery.

Cat cutaneous mast cell tumors are small in size and have a unique histiocytic type; mast cell tumors in cats are mainly found on the head and neck and appear as single hairless nodules with a diameter of 2-3 cm. They occur frequently. In cats over 4 years old, it sometimes spreads to subcutaneous fat tissue. Feline mast cell tumors of the histiocytic type are more common in Siamese cats under 4 years old. The tumors are located under the skin and are protruding. The diameter is generally less than 0.5 cm, but the number is large, the distribution area is wide, and the shapes are different.

Cat skin mast cell tumors can be removed surgically, but metastasis occurs in a few cases after surgery. Feline mast cell tumors of the histiocytic type can recover naturally without treatment.

The digestive system tumors of cats are mainly in the oral cavity. Squamous cell carcinoma is common in cats. Adenomas and adenocarcinomas mainly occur in the stomach and rectum. Leiomyomas or smooth muscle cancers can also occur. Tumors in the lower digestive tract also often occur. .

Most oral squamous cell carcinomas in cats metastasize after surgery. Clinically, metastasis is common to local lymph nodes or lungs. Most cats that undergo surgery die within 3 months after surgery. Dogs suffering from oral squamous cell carcinoma may experience local recurrence or metastasize to the retropharynx, superficial cervical lymph nodes or even the lungs on the same side. Although squamous cell carcinoma of the gums does not metastasize often, serious symptoms may occur at the affected site. Ulcers and erosions, therefore, euthanasia is an important option for this disease.

Cholecystocarcinoma in cats is mainly a primary tumor of the liver. When abdominal distension, pain, ascites and loss of appetite appear clinically, the tumor has developed to an advanced stage. At this time, some liver tissue has been replaced by tumor cells, and Scattered nodular tumors several centimeters in diameter may be seen in the liver parenchyma.

Because this disease has multiple characteristics, it is necessary to identify whether tumors occur in other organs at the same time. Whether it is a highly differentiated tumor (vesicle-like structure) or a poorly differentiated tumor (highly invasive and composed of small irregular acini), tumors have basically already occurred in the liver when clinical diagnosis is made. Metastasis, so the prognosis of this disease is generally poor.

The incidence of pancreatic cancer is relatively high in cats with abdominal tumors. Clinically, the symptoms are mainly lethargy and loss of appetite, and sometimes the abdominal circumference increases. If the tumor compresses the bile duct at the entrance of the duodenum, obstructive jaundice will occur. .

During palpation and examination, you should pay attention to the difference between this disease and intestinal lesions, because pancreatic cancer appears in the form of a hard mass. Radiological examination can detect the presence of masses, and laparoscopy can find that part of the pancreatic tissue is multi-layered. The nodules are replaced by masses and adhere to surrounding tissues and the greater omentum. The surface of the tumor may be necrotic.

When pancreatic cancer is diagnosed, the cancer cells have basically metastasized to the liver, and sometimes to the kidneys or spleen, so the prognosis of this disease is poor..

The clinical incidence of kidney tumors is not high. Malignant primary kidney tumors are generally found in middle-aged and elderly cats, with no breed differences; kidney tumors include adenomas, lipomas, fibromas and papillomas, most of which are It was discovered at autopsy.

50% of these tumors cause pathological changes in the cat's kidneys, causing kidney enlargement and deformation; note that feline lymphosarcoma is mostly related to feline leukemia virus infection.

Due to the physiological functions of the kidneys, animals with kidney tumors experience decreased weight and appetite, poor spirits, elevated body temperature, and in severe cases, an enlarged abdomen; due to the occurrence of varying degrees of renal uremia, it is common in urine examinations Hematuria, an increase in red blood cells in the blood.

The basic methods for diagnosing kidney tumors are ultrasonic diagnosis and radiological examination, which are used to determine the size and location of renal masses, and at the same time, chest radiography is performed to check whether tumor metastasis has occurred. Examination of the urine sediment may reveal tumor cells. Biopsy is the basic method to determine the nature of the tumor; depending on the case, urography and renal arteriography may be required.

Treatment methods include conservative therapy and surgery, and the clinical treatment effects of different tumors vary.

There are two types of ovarian tumors: adenoma and adenocarcinoma. They often cause abdominal enlargement and are accompanied by ascites, but generally do not cause functional changes. Ultrasound diagnosis or laparoscopy can reveal that tumors are generally unilateral and relatively large. Exploration of the abdominal cavity can reveal the presence of ovarian tumors, which appear as cyst-like masses of different sizes and in large numbers, with fluid inside the cyst and a capsule outside the cyst.

Surgery is the main treatment. However, ovarian cancer is highly metastatic. If a large number of tumor nodules are found on the serosa of the organs surrounding the ovary during surgery, the lungs, liver and other organs should be monitored for tumor metastasis; if ovarian cancer has metastasized to a large area, Animals should be euthanized.

Feline lymphosarcoma is more common in digestive and thymic types. Symptoms of peptic lymphosarcoma include: severe diarrhea and dysentery, anorexia and vomiting, and anemia; thickened intestinal segments (intestinal tumors) can be felt by palpation of the abdominal cavity, and enlarged mesenteric lymph nodes.

Feline lymphosarcoma is caused by a reverse-transcribing RNA virus. When the peripheral blood smear or bone marrow smear of a cat is treated with fluorescein-labeled rabbit anti-feline leukemia virus serum, bright green fluorescence will appear, which is very effective for this disease. The diagnosis has clinical significance.

Treatment: Drug treatment includes prednisolone (which can improve symptoms and cause lymph node tumor regression, but cannot reduce mortality), cyclophosphamide, vincristine, levophenylalanine mustard, and cytosine arabinoside and asparaginase, etc. However, generally speaking, after clinical diagnosis, sick cats generally only live for a few dozen days, and euthanasia is the preferred method.