Brain Tumors in Dogs and Cats
Cancer that affects different tissues that make up the brain, is underdiagnosed in elderly dogs and cats. A relative tendency for brain tumors has been found in young animals (Boston Terrier and Boxer breeds). The development of a brain tumor usually has serious consequences in patients, generating impotence in the majority of guardians. However, these tumors vary widely in their level of malignancy and some can be treated effectively. Unfortunately there are many things that are still not known about the development and evolution of the different types of brain tumors in dogs and cats.
- The term brain tumor means simply a mass of cells in the brain. Brain tumors are classified as primary or secondary according to the origin of the tumor cells.
- Primary brain tumors: this category includes meningiomas, gliomas, papilloma of choroid plexus, adenomas, and pituitary adenocarcinomas, among others.
- Meningiomas are primary brain tumors of most common presentation in dogs, cats and humans. These tumors are originated in the membrane arachnoid meninges. Meningiomas should not be considered as brain tumors in the strict sense, but they are classified together because of their location within the cranial cavity and action invading and compressing the nervous tissue. These tumors occur more frequently in dolichocephalic breeds such as the Golden Retriever. Meningiomas tend to grow relatively slowly and are susceptible to be treated (although malignant forms can be found).
- Gliomas: these tumors originate in the glial cells and include ependymomas, astrocytomas, oligodendrogliomas and glioblastomas Multiforme. They are common in certain brachycephalic breeds, such as the Boxer, the Boston terrier and the Bulldog French and English.
- Papilloma of the Plexus choroid: choroid Plexus tumors are relatively common in dogs. Due to the location of their cell of origin, they tend to arise within the ventricular system, and can block the drainage of cerebrospinal fluid; therefore, a small tumor can cause very severe neurological signs.
- Adenoma or pituitary adenocarcinoma: the pituitary gland lies beneath the forebrain and is attached by a stalk to the hypothalamus. Pituitary adenomas are common in dogs causing hyperadrenocorticism (central origin Cushing’s disease).
- Others: There are other forms of brain tumors whose discovery is exceptional.
- Secondary brain tumors: these tumors spread to the brain tissue from a tumor present in another part of the body. Tumors that commonly secondarily affect the brain are: Hemangiosarcomas, Mammary carcinomas and Melanomas. The prognosis in these situations is usually very bad since they have already spread through the body. Whenever you suspect or confirm a diagnosis of brain tumor, routine practice should be to take chest x-rays and even carry out ultrasound of abdomen to check that there is no evidence of tumors in other parts of the body.
Signs caused by brain tumors
Symptoms and signs caused by brain tumors are due to the mechanical compression or invasion of surrounding tissues. The resulting signals are directly related to the area of the brain affected and are not tumor-specific since any disease that affects the area of the brain will produce similar symptoms.
The forebrain is responsible for thoughts, behavior and the final integration of sensory information. Therefore, the tumors in the tissues of the forebrain, can cause:
- Abnormalities in behavior, such as loss of learned behavior, depression, etc.
- Increase or decrease in appetite and thirst
- Constant movement or walking in circles
- Sometimes, affected animals behave as if they suffered pain
- Onset of seizures is the most common sign in animals with affections of the forebrain. These seizures can occur along with any of the other signs listed above, or present themselves as sole anomaly. Whenever a dog or a cat older than five or six years of age has a seizure, it is important to take into account the possibility of a brain tumor. (Note: the case of the ‘Micky’ is within the preceding description).
The Brain plays various vital functions, including the regulation of motor function, the level of wakefulness, respiratory and cardiovascular systems. The sense of balance also arises in the brain stem. The nerve paths that control movements and the sensitivity of the face, eyes, throat, larynx, tongue and the muscles of mastication originate in this portion of the brain. The tumors in this region can be rapidly fatal if, for example, they affect the control of respiration. Usually the first manifestations of disorders of the brain stem are the vestibular signs and weakness in one side of the body. There are a wide variety of additional signs, such as difficulty swallowing, change in phonation and involuntary movements of the eyes. The progression of symptoms can lead to paralysis, coma, and death.
The cerebellum controls coordination of movements and interacts closely with the vestibular system for balance and posture control.
It should be suspected that there might be a brain tumor when there have been neurological signs in an animal of more than 5 years old. It is important to understand that, with rare exceptions, brain tumors are tumors of soft tissue and not become manifest in x-rays of the skull. Magnetic Resonance Imaging (MRI) or Computerized Tomography (CT) is used with excellent diagnostic methodologies.
The following consecutive steps are recommended to arrive at a diagnostic presumption before an MRI or a CT
- Full general objective examination and neurologic examination, particularly in order to identify other health problems and locate neurological signs in a particular area of the brain.
- Blood routine to rule out a systemic problem and step count to assess anesthetic risks.
- Chest x-rays to check that there is no evidence that the cancer has spread to the lungs (a common site of metastases) .
Conventional brain tumors treatment options include surgical removal, radiotherapy, chemotherapy and palliative treatment of the symptoms.
- Surgery: in the case of tumors located in the forebrain, they can be extracted along with the tumor, some surrounding tissue without causing undesirable effects in the long run. Meningiomas tend to be housed in surface areas and therefore are the best candidates for surgical removal. Gliomas are more difficult to remove, since they are deeply included within the cerebral network.
- Radiation therapy: since nervous tissue cannot tolerate large doses of radiation, the total applied dose is limited and must be done under general anesthesia. If the animal is affected by a very large tumor mass, it is preferable to remove it surgically if possible in order to initially decompress and then make chemotherapy sessions.
Chemotherapy: the brain is protected by the blood-brain barrier of various potentially harmful molecules that circulate in the blood. This protective barrier limits the effectiveness of chemotherapeutic agents. As a result, chemotherapy has not been advocated for the treatment of brain in dogs and cats tumors and very little is known about the efficacy of such drugs in these patients.
- Palliative treatment: if any of the treatments mentioned above is a viable option, it is possible to treat only secondary symptoms caused by a brain tumor. For example seizures, edema, etc. As many clinical signs are due to the presence of edema, some animals show a dramatic improvement within 24 hours of starting treatment with corticosteroids. This response is often of short duration, since this drug is not removing the tumor, but you can certainly give patients a variable time of good quality of life.
It is important to understand that the majority of brain tumors can be treated, but not cured. Therefore the main goal of treatment is to achieve a good quality of life, the longest time possible. Another critical point is to understand exactly what is meant when we present data on the efficacy of the treatment. Progression-free survival is the time that the animal survived without worsening of clinical signs. This gives a better idea of the meaning of quality of life.
- When symptoms are more intense and severe the worse is the prognosis and outcome (“Micky” case).
- The bigger the tumor, the result is expected to be worse. (Mickey’s case).
• Supratentorial tumors (tumors of the anterior brain) have a better prognosis than Infratentorial tumors (tumors in the brainstem and cerebellum) .
- With Meningiomas the therapeutic results obtained are better than with tumors that are within the brain tissue (e.g. gliomas)
Dr. Natasha Olby and Dr. Matthew Breen of the Group of genomics Neurology of canines at State University College of Veterinary Medicine in North Carolina, are conducting research on different types and degrees of brain tumors in dogs and recognize that very little is known about how long is the survival rate in dogs without treatment, compared to those treated with surgery, radiation therapy and/or chemotherapy.
Brain tumor, chronic disease, suppression, Homeopathy vs. Allopathy
A successful clinical case will be discussed to demonstrate the virtues and scope of Homeopathy
Detailed Description of the Clinical Case
Patient: “Micky”. 12 year-old neutered male, Poodle dog.
- Reason for inquiry: 13/04/13 – Brain Tumor (Adenocarcinoma?, Meningioma?), in the left frontal region, measuring 2 cm Long by 0.8 cm wide. Nuclear Magnetic Resonance was requested by M. V. F. Pellegrino, specialist in Veterinary Neurology and performed on 17/01/13. See annex 1
- BiopatographyHistory: “Micky”, can be considered the “symbolic son” of a childless couple. They have Mickey since he was 45 days old. As a puppy he was very restless.
- Previous illness:
–Recurrent itchy Dermatitis.
-Recurrent, chronic Otitis, every 3 months! Owners have always a gel with (dexamethasone, norfloxacin, ketoconazole). 2 months ago he was medicated with (dexamethasone, norfloxacin, ketoconazole
-Prolapse and anal redness.
-On March 30, 2013 “Micky” presented a strong convulsion which ended up “spinning in a circle”. He later suffered a severe epileptic status, forced to admit him in an emergency clinic. Once he recovered from the status epilepticus, he remained lying down, still with opisthotonos for 4 days. During two intermitent opportunities he had to be induced into a coma with barbiturics due to the intensity of the seizures. When he regained consciousness, “Micky” did not recognize anyone, he raved and gave turns in a circle. Given the severity of the clinical picture and with evidence of a brain tumor, the forecast was reserved to severe.
- V. specialist, F. Pellegrino after a week of hospitalization without clear clinical improvement recommended euthanasia. You have to understand that in terms conventional medicine “Micky” had reached a very advanced, near-terminal state of the disease. With this said it seemed like it would not predicted any other possibility from the medical paradigm…
- The keepers of ‘Micky’, as it was mentioned above, are a childless couple. Being a puppy’ Micky’ occupied the place of the son that they could not have. Therefore, they hoped someone could find a solution to the problem. In addition, to the treatment that the specialist had stated: dexamethasone, clonazepam and phenobarbital.
- On 13/04/13 they got in touch with me by the telephone, asking me for a home consultation. I remember entering the Department and seeing the patient lying down. ‘Micky’ had very bad overallstate, dull, poorly connected with the environment., I had to pick him up and to hold him; he stood up with difficulty and only gave turns in a circle to the left.
- Behavioral symptoms (historical)
-“Anxious”, when visits arrived he would not stop barking