Acute Collapse in Dogs

Overview of Acute Collapse in Dogs

Acute collapse is a sudden loss of strength causing your dog to fall and be unable to rise. In acute collapse, your pet falls to the ground either into a sitting position (hind limb collapse) or a lying position (complete collapse). Some dogs that suddenly collapse will actually lose consciousness. This is called fainting or syncope. Some dogs recover very quickly and look essentially normal just seconds to minutes after collapsing, whereas others stay in the collapsed state until helped.

Acute collapse is usually caused by a disorder of one of the following:

• The nervous system (brain, spinal cord, nerves)
• The musculoskeletal system (bones, joints, muscles)
• The circulation (heart, blood vessels, blood)
• The respiratory system (mouth, nose, throat, lungs)
• What To Watch For
• If your dog suffers an acute collapse, he will sit down suddenly or lie down and won’t be able to get back up. Call or take your pet to your veterinarian immediately.

Diagnosis of Acute Collapse in Dogs

Veterinary care should include diagnostic tests to determine the cause of acute collapse so that subsequent treatment recommendations are specific and most likely to be successful.

There are dozens of diseases that can cause acute collapse. In order to pinpoint which is responsible, your veterinarian may perform one or more of the following evaluations:

• A complete physical examination and history
• Routine blood tests (complete blood count and serum biochemical profile)
• Specialized blood tests that measure endocrine (hormone) function or identify antibodies against muscle cells
• Measurement of arterial blood pressure
• X-rays of the thorax and the abdomen (the chest and belly)
• Electrocardiogram (ECG) or ambulatory electrocardiogram (Holter ECG or event monitor)
• Ultrasound of the abdomen or heart

Treatment of Dogs with Acute Collapse

Treatment of acute collapse is dependent upon the underlying cause. Initially, emergency treatments may be necessary if the blood pressure is too low or if bleeding has occurred. The following are possible treatment options that your veterinarian may choose to implement.

• Reversal of the problem if the cause of collapse is known. Examples include removing an object that is obstructing airflow in the throat, giving an antidote if poisoning has occurred, or administering glucose (sugar solution) in cases of low blood sugar.
• Intravenous fluids (an “IV”). These fluids can rehydrate and support the blood pressure.
• Surgery if the underlying problem is operable, such as a bleeding abdominal tumor.
• Intravenous drugs. The exact drug selection depends on the underlying or suspected problem.
• Blood transfusion or blood substitute if anemia or hemorrhage contributed to the collapse.

Home Care

• When acute collapse occurs, do not panic. Observe your dog carefully. Notice if there has been a loss of consciousness. Remember what – if anything – precipitated the collapse, how long your pet was collapsed, and how he acted immediately afterwards. If your dog is unconscious, see if you can feel the heartbeat on the left side of the chest. If your pet seems dazed or aggressive, be very careful not to be bitten. Call your veterinarian and explain what has happened.
• If your dog cannot rise, prepare to transport the collapsed animal immediately after speaking with the veterinary hospital personnel. USE CAUTION. Animals that collapse may be disoriented, confused, or aggressive during the collapse and during recovery. Consequently, they may bite aimlessly and can injure even the people most familiar to them.
• Dogs that have collapsed often act normally within a few minutes. In such cases, a veterinary examination is still warranted to find the cause and try to determine if future collapse is likely.
• If your pet appears completely recovered, try to make some notes. Remember the events surrounding the collapse. Was there an obvious cause (e.g. choking on a ball or toy)? Did it happen during normal activity or during vigorous exercise? How long did the collapse last? Was there a loss of consciousness? How did your pet behave afterward? These pieces of information can help the veterinarian tremendously.
• When a collapse persists, generally, it is best to go immediately to the nearest veterinarian rather than spend time on “life-saving” measures. Inappropriate cardiopulmonary resuscitation (CPR), for example, may be ineffective and can also cause internal organ damage if done improperly.

In-depth Information on Acute Collapse in Dogs

A collapse may involve extreme weakness of the front or rear limbs, falling to the ground, or unconsciousness, in which case the dog does not respond to sound or touch. The severity and symptoms are often related to the cause of collapse.

Often consciousness is maintained, but the dog has an expression of confusion or anxiety or a “glassy-eyed” appearance. The collapse may last for only a few seconds, or it may take many minutes to hours before your pet can stand again.

Numerous diseases can cause acute collapse. Often a disease is fairly advanced when something this extreme occurs. However, there may not have been prior symptoms.

Causes of Collapsing in Dogs

Examples of illnesses that may cause canine collapse include:

• Heart disease. This includes congenital heart disease (birth defects in the heart), acquired valvular heart disease (leaky heart valves), heartworm disease, tumors of the heart, pericardial disease (disease of the lining of the heart) and primary cardiac arrhythmias (erratic heart beat). When blood is not pumped through the body properly, the brain is most vulnerable. It can be momentarily “starved” of oxygen, causing collapse or fainting.
• Fainting (syncope). Fainting can occur due to abnormal blood pressure control mechanisms (neurocardiogenic syncope). It can be difficult to diagnose without a full evaluation.
• Diseases of the blood. These include internal hemorrhage from a ruptured tumor or organ, severe anemia, leukemia and polycythemia (abnormally thick blood caused by an excess of red blood cells). The brain and the muscles need an appropriate amount of blood to function (and the oxygen carried by red blood cells). Failing this, collapse can occur.
• Respiratory diseases, This also includes blockage of the throat by a foreign object or by laryngeal paralysis, which is the inability to open the voice box so that air can enter the lungs. Other causes include respiratory disease such as bronchitis, collapsing trachea, pneumonia, or pulmonary edema (fluid in the lungs). BE CAREFUL! Many conditions cause gasping during collapse, but without a foreign object in the mouth or throat. Do not risk being bitten by trying to remove from the throat an object that is not there. “Choking on something” is a common owner’s description of animals that have respiratory problems without any foreign body in the mouth or throat.
• Diseases of the nervous system. These are common reasons for collapsing. These include fibrocartilagenous emboli (when clots in the bloodstream damage the spinal cord), intervertebral disk disease (“slipped disk” in the neck or back), degenerative myelopathy (degeneration of the spinal cord), and myasthenia gravis (defective conduction from the nerves to the muscles). In diseases of the spinal cord and muscles, the animal’s consciousness and mental abilities are generally unchanged during collapse, whereas in brain diseases disturbances of consciousness such as seizures can occur during collapse.
• Musculoskeletal diseases. These include hip dysplasia (arthritis of the hips), lumbosacral disease (arthritis of the lower back), and others. Generally, with the musculoskeletal causes of collapse, symptoms such as limping, difficulty getting up, or inability to sit up or jump have been present and getting worse for days, weeks or months before collapse occurs.
• Toxicity. Poisonings of many kinds can cause sudden weakness and collapse. Any known exposure to substances that are deliberately poisonous, like rat poison and snail/slug poison, should be reported to your veterinarian, even if the poisoning may have taken place several days earlier.
• Drugs and medications. A simple example would be an overdose of insulin causing an excessively low blood sugar. Many human drugs that might be mistakenly eaten by your dog, or maliciously administered by someone, could lead to low blood pressure. Similarly, some veterinary prescription medicines can lead to low blood pressure and collapse.
• The most serious cases of collapse are life threatening.

Diagnosis In-depth

If your pet is still in a collapsed state when he is brought to the veterinarian, tests will be done immediately and hospitalization with continuous monitoring may be recommended, particularly if the situation is perceived as life threatening.

Your veterinarian will determine the underlying problem and the immediate threat it poses to your pet. Alternatively, if your pet’s condition improves spontaneously, and your dog seems well when you reach the veterinary hospital, tests will still be performed. These will be aimed at determining the cause of the problem in order to assess the risk of future collapse and to see whether medication is warranted.

Numerous diseases can lead to acute collapse. Therefore, your veterinarian may perform one or more of the following tests:

• A complete medical history and a thorough physical examination. Particular attention should be paid to auscultation of the heart, or listening with a stethoscope. Your veterinarian should also measure your pet’s blood pressure, palpate or feel the abdomen and assess the neurologic status of your dog.
• Routine blood tests. Abnormalities in blood test results can pinpoint certain causes of collapse such as anemia or hypoglycemia (low blood sugar). Blood tests can also help evaluate the state of many internal organs.
• Specialized blood tests. These may include examination of some hormones to exclude Addison’s disease (hypoadrenocorticism) or severe hypothyroidism.
• Blood tests for myasthenia gravis. Blood tests for this disease of the muscle may be recommended if the clinical symptoms suggest this problem. This tests for antibodies against acetylcholine receptors.
• X-rays of the chest and the abdomen. X-rays generally show the outlines of internal organs, which helps determine their size, shape and position. Fluid accumulation or bleeding may be evident if moderate to severe.
• X-rays of the back and limbs. If a spinal problem or a leg problem is suspected on physical examination, X-rays are the best way to evaluate the bones. Often these X-rays need to be taken with the animal under general anesthesia or heavy sedation.
• Electrocardiogram (ECG or EKG). If a cardiac problem is suspected, the rhythm of the heart beat is analyzed with an ECG recording. This can be as simple as a routine EKG or more advanced such as an ambulatory EKG that your pet wears while at home. These specialized EKGs are sometimes called Holter monitors and event recorders.
• Ultrasound of the abdomen or of the heart. While X-rays show the outlines of organs, ultrasound makes it possible to see inside the individual organs. Therefore, X-rays and ultrasound examinations are often complementary. Ultrasound is frequently performed by a specialist, which may require referral to a specialty veterinary hospital.
• Neurologic evaluation. If a disease of the brain, spinal cord or nerves is suspected, a consultation with a neurologist may be recommended.
• Spinal or brain procedures. Examples include a myelogram, which is an X-ray of the spine taken with a special dye injection to evaluate the spinal cord; a CT scan (“CAT” scan); or an MRI scan. Sometimes a neurologist will recommend specialized tests of the nerves and muscles called an electromyogram (EMG).
• Additional, tests may be recommended from the results of any of the tests listed above. Therefore, the initial tests may find the cause of collapse outright or may direct the veterinarian to pursue other causes of collapse.

Treatment In-depth

At the time of initial collapse, it is best to go immediately to the nearest veterinarian rather than spend time on “life-saving” measures. Inappropriate cardiopulmonary resuscitation (CPR), for example, can be ineffective and cause internal organ damage if done improperly.

The most beneficial treatment for acute collapse is the elimination of its cause. Finding the cause can be complicated and time-consuming because so many potential explanations are possible. Therefore, treatments often are general (“supportive”) at first and then become more specific as new information is obtained from test results.

The following are examples of treatments the veterinarian may provide.

• Immediate reversal of the problem if possible. Examples include removing an object that is obstructing airflow in the throat or giving an antidote if poisoning was known to have occurred.
• Intravenous fluids (“IV’s”). These fluids may rehydrate, provide nutrition, and bring the blood pressure back towards normal if collapse was associated with low blood pressure.
• Surgery. Many of the causes of acute collapse involve abnormal tissue that should be removed. Examples include tumors in the abdomen that cause internal bleeding, and intervertebral disk problems that cause stiffness or paralysis of the legs. If and when to perform surgery requires a careful decision that is based on weighing the risk of general anesthesia against the risk of delaying surgery.
• Intravenous drugs. A number of emergency drugs can be given intravenously, including drugs to control blood pressure, regulate the heartbeat, reduce inflammation, stimulate respiration in an emergency, and so on. Naturally, the exact drug selection depends on the underlying problem.
• Blood transfusion. If severe anemia or a loss of blood from injury or internal hemorrhage is the cause of collapse, then giving whole blood, blood components, or blood substitutes may be lifesaving. Many veterinary hospitals do not have a blood bank on-site and a blood transfusion may require transfer to a specialty veterinary hospital.

Many of the diseases that cause acute collapse are progressive, which means they can get worse. Once a diagnosis has been reached and the cause of collapse is known, you should discuss with your veterinarian the frequency of rechecks.

Follow-up Care for Dogs with Acute Collapse

Follow-up care may include:

• Giving any medications prescribed.
• Scheduling re-evaluations as recommended.
• Monitoring your pet for weakness. Often this is apparent as an unwillingness or difficulty in rising, stumbling when walking, or recurrence of collapse.
• Monitoring for breathing difficulties such as labored or rapid breathing. This may indicate a problem in the circulation, lungs, or blood, or suggest your dog is feeling discomfort or pain.
• Preparing a plan should collapse recur. This is a significant issue if transportation is not immediately available. Also consider if the collapsing pet is a large dog and too heavy for one person to carry alone. If two people are available, even a large dog can be carried if the dog is carefully laid on a sturdy blanket and the blanket is pulled taut by the corners to serve as a stretcher.
• Exact recommendations depend on the precise cause of the collapse.