Overview

This is a lay term used to describe a condition that is both simple and yet at the same time complex and only poorly understood. The simplest explanation is that this disorder results from a chronic compression of the spinal cord in the neck caused by multiple factors. These factors include being born with a bony canal that is slightly too narrow, together with subsequent degenerative changes like disc herniations and overgrowth of other soft tissues. These structures cause compression of the spinal cord, often at several different levels within the neck. Instability between certain vertebrae may also play a factor in this disorder. There are therefore three major factors in this disorder, namely abnormalities that the animal is born with, abnormalities that the animal develops as it ages and the effect of instability. What is only poorly understood is what role each of these three factors plays in … Continue reading

Overview

The vestibular system is the primary sense that governs balance. Just like vision depends on the eyes to convert light to electrical impulses and then requires a specialized region of the forebrain to interpret the information correctly, the vestibular system also depends on two components. These are the inner ear structures that convert information about head position into electrical impulses and then an area of the brainstem that interprets this information. An animal can have a disturbance of balance due to either a problem affecting the inner ear, such as a severe and deep-seated ear infection, or the problem could be caused by either a tumor or an infection in the vestibular center of the brainstem. The signs of vestibular disease include not only a loss of balance but also a head tilt and nystagmus. Nystagmus is a specific, involuntary eye movement where the eyes flick rapidly in one … Continue reading

Overview

This condition is not common in dogs and cats as they are quite resistant to the tetanus toxin. As in people, animals get tetanus when a cut gets infected by a bacterium called Clostridium tetani that produces tetanus toxin. The causes the muscles of one or more limbs, and usually those of the entire body and the head, are caused to contract forcefully and continuously. The result is that the animal goes very stiff. Animals also develop a characteristic facial expression as all the muscles of the head contract as well.  The prognosis is guarded but many animals will recover with long-term, intensive care. Complications relate mainly to the risk of pneumonia or, in a few cases, that the animal becomes so stiff and rigid that it is unable to breathe on its own and requires ventilation.

Further Resources

• Tetanus. REQUIRES LOGIN; FOR VETERINARIANS In Clinical Neurology in Small

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Syringohydromyelia, also known as COMS or Caudal Occipital Malformation Syndrome, is a condition where there is insufficient room for cerebrospinal fluid (CSF) to pass out of the back of the skull and down around the spinal cord. Instead of flowing gently as CSF should do normally, it seems as if the lack of space affects CSF flow in similar fashion to putting ones finger over the end of a hose and so CSF tends to jet out. This jet-effect damages delicate nervous tissue and forms cavities within the spinal cord that are the hallmark of syringohydromyelia. This condition was first described in Cavalier King Charles spaniels but has since been reported in a number of breeds. Animals are usually born with the malformation predisposing them to this condition and some develop signs within the first year of life whereas others only show signs considerably later. The main clinical sign is … Continue reading

Brain infarcts, or strokes as they are more commonly known, occur in dogs as well as in people. Just like in people, strokes tends to occur in older individuals and those with risk factors such as high blood pressure, Cushing’s disease, adrenal tumors called phaeochromocytomas, kidney disease and some types of heart disease. They also occur in animals with bleeding disorders, such as immune-mediated thrombocytopenia (IMTP). Strokes are classically sudden in onset and do not usually progress for more than 24 hours before stabilizing or improving. One common site is the cerebellum and these cases are often mistaken as idiopathic geriatric vestibular syndrome. Diagnosis can be confirmed only by an MRI. There is no treatment other than giving the animals time, good nursing care and physical therapy. The prognosis depends to some extent on the part of the brain involved but is more dependent on the size of the stroke. … Continue reading

Overview

Seizures are common in dogs and also occur occasionally in cats as well. A seizure is a neurological episode that is sudden in onset, repeatable in nature and that usually involves some disturbance in consciousness along with uncontrolled movements and unintended visceral functions such as urination. Seizures have a wide variety of causes, which can include birth defects such as hydrocephalus, metabolic defects like liver dysfunction, brain tumors, brain infections such as encephalitis, or a brain abscess, toxins such as lead and vascular disorders such as strokes and high blood pressure. Perhaps the best-known cause of seizures in dogs is idiopathic epilepsy, which is probably caused by either a genetic mutation, a microscopic brain malformation or possibly a birth injury. Epilepsy in dogs usually causes seizures to start between one and five years of age. If a dog starts to have seizures before one year of age … Continue reading