Pets and Diseases

Pet Related Diseaess

Many human infections can pass between humans and animals. A study done in 1987 suggested there were about 4 million pet related infections in the United States that year. The number of household pets has only grown since that time. In 2002 the number of dogs was estimated at 62 million and the number of cats at 68 million in the United States. Exotic animals present even more of a problem because they can transmit disease from one area of the world to another. This makes diagnosis very difficult at times. This article will take a brief look at various pet related diseases from some of the more common parasites, bacteria, viruses.

Parasites are organisms that live in or on other organisms. Toxoplasmosis is a very common parasitic infection. Cat feces are the vector to humans due to the excretion of the spores in the cat feces. Thus, cleaning the litter box and gardening in contaminated soil are the main risks in developing the disease. Toxoplasmosis in adults is usually asymptomatic, but may cause a mono-like illness. Pregnant women should avoiding cleaning the litter box because infection in the third trimester can cause serious congenital problems.

Round worms are found in both dogs and cats. Puppies are often born infected. Children are especially prone to infection because they often handle animal feces or soil contaminated with animal feces. The immature stage of the round worms is called larvae. The larvae may migrate from the intestine to the liver, lungs or eyes. This may result in serious illness.

Hookworms cause an infection of the skin. Fecal material from infected dogs or cats gets into the soil in the form of cysts. Walking barefoot in this contaminated soil allows the cysts to gain access through a break in the hosts skin. The larvae cause a reddish itchy raised area at the site of the infection. The larvae then migrate under the skin leaving a reddish irritated track through the skin.

Tape worms are common in both dogs and cats. Humans become infected through fecal contamination or through fleas. Human infections are usually not serious but can on occasion cause serious heart and liver problems.

Fungal infections with ring worm are the most common shared infection among humans and domestic pets. It appears to be most common in children. It usually results in a minor superficial infection that can be treated with topical medication.

Bacterial infections are another common source of infection spread between humans and animals. Salmonella is common in turtles, iguanas, chicks, ducklings, dogs and cats. Campylobacter is found in cats and dogs. Both of these bacteria are common causes of gastroenteritis in humans. In fact there are about 200,000 cases of gastroenteritis per year related to these bacteria in humans per year. Cat scratch fever is related to a bacteria carried in cat saliva. This bacterium is called Bartonella henselae. The infection is usually caused from a scratch after the cat has been licking its claws. The infection may show up weeks later and often presents with fever, malaise and swollen lymph nodes. Methicillin resistant staphylococcus aureus ( MRSA ) can be passed to humans from cats and dogs. In cases of recurred infections in households the pet may be the carrier that causes the recurrences. Psittacosis is also known as parrot fever. It presents in humans as a flu like syndrome and occasionally pneumonia. It can be found in parrots, cockatiels, parakeets and macaws. Mycobacterium marinum is an infection of the skin resulting from exposure to fish tank water. It usually causes cutaneus granulomas but can become life threatening in immunocompromised individuals.

Viral infections such as rabies are uncommon in properly cared for pets because of vaccinations. However, pets interact with local wildlife and may develop these more serious infections. Lymphocytic choriomeningitis is a virus that hamsters, guinea pigs and mice carry. This virus in humans usually presents as flu-like syndrome. This disease has caused more serious infections in those humans with a weakened immune system.

The best way to prevent pet related diseases is good flea/tick control and good veterinary care for pets. Good hand washing after handling pet waste and proper disposal of the waste are also important ways to minimize pet related disease. Pregnant women, infants, HIV patients, transplant patients, patients on chemotherapy or chronic steroids, and the elderly should avoid contact with any pet waste, reptiles, chicks, ducklings, kittens, puppies and any animal that appears ill. Any sick pet should be seen by a vet for proper diagnosis and treatment. If you become ill while caring for a sick pet you should see your family doctor and let him know of the ill pet.

Pets provide great companionship to millions of families in the United States. They have been shown to reduce stress and depression. However, on occasion they may carrier certain infections that can be spread to their human house mates. Good cleaning techniques and proper veterinary care can prevent the vast majority of these infections.families in the United States. They have been shown to reduce stress and depression. However, on occasion they may carrier certain infections that can be spread to their human house mates. Good cleaning techniques and proper veterinary care can prevent the vast majority of these infections.

Mark Smith, MD

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Trigeminal Neuralgia

Trigeminal Neuralgia

Trigeminal neuralgia (TN) is an uncommon condition characterized by intense recurrent attacks of piercing facial or jaw pain. The disorder was first described back in the Roman times. The nerve most affected is a cranial nerve called the Trigeminal Nerve. This nerve has three branches: 1) ophthalmic branch which innervates the area of the forehead and the eye, 2) maxillary branch which innervates the area around the nose, cheek and upper lip, and 3) mandibular branch which innervates the area around the jaw. The attacks may involve any one of the branches or all 3 branches at once. The maxillary branch is the most commonly affected. The right side is the more commonly affected than the left side. Trigeminal neuralgia affects about 4.5 people out of every 100,000 population. There is a slight female predominance. TN is unusual under the age of 40 years old with a peak incidence between the ages of 60-70 years of age. There does not appear to be a racial predilection.

The exact cause of TN is unknown but current theories believe that the superior cerebellar artery may cause compression of the nerve root. This compression of the nerve root causes a loss of the myelin insulation between the nerve fibers within the nerve bundle. This would be similar to all the insulation coming off the individual phone lines in the phone cable. The results of this would be chaos for the phone systems served by this phone cable. When the nerve becomes dysfunctional intense episodic pain appears to be the results.

The diagnosis of TN is difficult since there is no specific test for the condition. The history usually includes paroxysmal episodic attacks lasting 1 second to 2 minutes. They must occur in the trigeminal nerve distribution. They are usually intense stabbing or sharp pains. Sometimes specific triggers such as smiling, chewing, brushing teeth or talking can set off an episode. The history is important to rule out other causes of facial pain. TN is almost never associated with vertigo, vision changes, or hearing loss. TN is almost always on one side. The physical exam is usually normal since the patient is almost always asymptomatic when seeing the physician. Tests like MRI are not very useful in diagnosing TN.

Treatment maybe medical or surgical. Medical treatment usually involves carbamazepine, an antiseizure medication. If carbamazepine  fails or the patient is intolerant to this medication, other anti seizure medications have been found to be effective. Some of include gabapentin, Lamictal, Depakote, and Topamax. More recently Botox injections have been shown to help control TN. Topical Zostrix and transcutaneous nerve stimulation (TENS) are two  treatments being tested for the treatment of TN. Treatments to decompress the nerve root include a gamma knife (a form of radiation), radiofrequency ablation and balloon compression.

In summary, TN is a relatively uncommon neurological disorder, but due to its intense symptoms can be quite debilitating. It is due to the intensity of the pain that treatment is often required.

Mark Smith, MD

Restless Leg Syndrome

RLS: Restless Leg Syndrome

RLS is a neurologic condition that affects sleep and daytime functioning. The underlying cause is believed to involve abnormalities of iron and dopamine metabolism. Patients with RLS may have a compelling urge to move their legs, which worsens at night. Patients with RLS may have difficulty describing their symptoms and may present with daytime fatigue and general sleep difficulties.

The prevalence of RLS is believed to occur in 5-10% of the U.S. population. The prevalence increases with age and women are more likely to report symptoms. RLS is likely an under reported cause of insomnia related symptoms, chronic fatigue and mood disturbance.

Diagnostic criteria include- unusual urge to move limbs, active movement of limbs relieves the urge, rest brings on the urge and nighttime symptoms are worse than daytime symptoms. Most people report that the urge to move the limb is a sensation deep in the leg, but not a cramp. The legs are the primary focus, but the arms, back, and head can be involved. The spouse is often the one that forces the patient to seek help for the nighttime jerky movements. The history is often all that is needed to make the diagnosis of RLS. Medication history is helpful since some medications can aggravate RLS. Some of the common medications that may worsen the condition are: Reglan, SSRI antidepressants, the TCA antidepressants, calcium channel blocker anti hypertensives and anti seizure medications. Alcohol and caffeine may worsen the condition. Moderate exercise before bed may decrease symptoms.

Treatment of RLS includes avoidance of medications, alcohol and caffeine. The four main groups of medications found to be useful in the treatment of RLS are: Dopamine agents (Mirapex and Requip), Benzodiazepines (Klonopin, which is clonazepam), Opioids (Codeine, Methadone), and anitepileptics (Neurontin, which is gabapentin,  and Topomax). The dopamine agents are considered to be the first line treatment for RLS. They appear to be the most effective for mild, moderate or severe RLS. This class of medications is also used in the treatment of Parkinson’s disease. However, no link between RLS and Parkinson’s disease has been discovered.

Mark Smith, MD

Lab Tests – What Do They Mean?

WHAT DO MY LAB TESTS MEAN?

The tests we discuss below have links to a website that can give you more information than the brief information here; the site also discusses tests not reviewed below, and symptoms that can be associated with the abnormalities. Another source of information about lab tests is at http://www.nlm.nih.gov/medlineplus/laboratorytests.html.

Liver Tests: (ALT, AST, ALK Phosphatase, Bilirubin)

http://www.labtestsonline.org/understanding/analytes/liver_panel/glance.html

Alkaline Phosphatase is an enzyme (protein) found in the liver, bone, and intestinal tissues. In the liver, it is mainly located in the ducts (tubes) that run throughout the liver. Some causes of elevated levels include:

  • Medication side effect
  • Anticonvulsant use (phenytoin/Dilantin, Phenobarbital)
  • Alcoholism
  • Diabetes mellitus
  • Liver Disease (especially obstruction of the ducts), including hepatitis, cirrhosis
  • Gallstones
  • Bone Disease, including Paget’s Disease
  • Bone Cancers, pancreas cancer, some blood cancers (multiple myeloma), other cancers
  • Hyperthyroidism, Hyperparathyroidism
  • Lymphoma
  • Leukemia
  • Cancer metastases to the bone
  • Kidney disease, severe
  • Infection of the bone (osteomyelitis)
  • Pregnancy
  • Fractures, extensive, associated with healing
  • Infections involving the liver (tuberculosis, abscess)
  • Mono

Some causes of decreased levels include:

  • Anemia from B-12 deficiency
  • Celiac Disease
  • Hypothyroidism
  • Malnutrition
  • Zinc or Magnesium Deficiency
  • Vitamin D Intoxication

ALT (Alanine Transaminase) is an enzyme found in the liver, pancreas, and skeletal muscle. It acts as a catalyst in the process necessary for amino acid production; the body uses amino acids to make proteins. Some causes of elevated levels include:

  •   Medication effect
  •   Obesity
  •   Liver Disease (obstruction and infection)
  •   Fatty liver (steatosis)
  •   Liver Cancer
  •   Congestive Heart Failure
  •   Reye’s Syndrome
  •   Mononucleosis
  •   Muscular Dystrophy

Some causes of decreased levels include:

  •   Cancer

AST (Aspartate Transaminase) is a catalytic enzyme found in the liver, skeletal muscle, and cardiac tissue. Often both the AST and ALT will be elevated for the same reason. Some causes of elevated levels include:

  • Medication effect
  • Alcoholic hepatitis
  • Liver Disease (including infection, especially hepatitis; cirrhosis)
  • Blockage of the bile drainage, including gall stones in the bile duct
  • Liver Cancer
  • Congestive Heart Failure
  • Myocardial infarction (heart attack)
  • Pancreatitis
  • Stroke
  • Reye’s Syndrome
  • Mononucleosis

Some Causes of decreased levels include:

  • Dialysis

Bilirubin (Total) is produced in the liver, spleen, and bone marrow. It is a by-product of hemoglobin breakdown. Bilirubin is found in direct (conjugated) and indirect (unconjugated) fractions. Some causes of elevated levels include:

  • Hepatitis (viral, alcohol-related, toxin-related, medication-related)
  • False elevation due to medications/chemicals in the blood
  • Inherited (genetic) disorders, such as Dubin-Johnson syndrome, Gilbert’s disease
  • Obstruction of the bile system
  • Cancer
  • Infection (abscess)
  • Anemia, including B12 deficiency and sickle cell anemia
  • Alcoholism
  • Destruction of red blood cells (inherited, severe infections, immune diseases)
  • Mononucleosis
  • Pulmonary Embolism
  • Transfusion Reactions
  • Malaria
  • Toxic Shock Syndrome
  • Certain Medications

Some causes of decreased levels include:

  • Certain Medications (but not considered to be clinically significant)

Lipids

Cholesterol is a fat. It is found in all body tissues and plays a vital role in cell membranes. Over 90% of the cholesterol in our blood is made in our liver. This cholesterol is made primarily from saturated fats. One type of cholesterol subfraction (LDL) is associated with damage to the inner lining of the blood vessels. Optimally, the total cholesterol should be under 200. More important than the total cholesterol are the subfrations, noted below. Note that low cholesterol is unknown to cause any disease, although it can be seen in some diseases.
Some causes of increased levels include:

  • Genetics (most common cause)
  • Celiac disease
  • Pancreatitis
  • Hypothyroidism
  • Liver/gallbladder disease
  • Kidney failure
  • Certain medications, including beta blockers, contraceptives, anabolic steroids

Some causes of decreased levels include:

  • Acute illness
  • Malnutrition
  • Liver disease
  • Certain cancers
  • Certain medications, especially those used to treat cholesterol

http://www.labtestsonline.org/understanding/analytes/cholesterol/glance.html

HDL Cholesterol is a protective subfraction of cholesterol. The higher the level, the better.

http://www.labtestsonline.org/understanding/analytes/hdl/glance.html

LDL Cholesterol is a sub fraction of cholesterol associated with heart disease and stroke. There are different cutoffs for “normal”, depending on risk factors for heart disease (like diabetes, high blood pressure, smoking, and more.)

http://www.labtestsonline.org/understanding/analytes/ldl/test.html

Triglycerides (TG) are a long chained fatty acid. TG are absorbed through the intestines and stored in fat cells. TG are also synthesized in the liver from fatty acids as well as from proteins and glucose above the body’s current needs and then stored in fat cells. The levels vary, and are especially high after a meal. Even levels after fasting can change from day to day.
Some causes of elevated levels include:

  • Alcoholism
  • Diabetes out of control
  • Genetics
  • Pancreatitis
  • Hypothyroidism
  • Renal (kidney) failure

Some causes of decreased levels include:

  • Malabsorption
  • Malnutrition

http://www.labtestsonline.org/understanding/analytes/triglycerides/faq.html

Electrolytes

Potassium is a positively charged cation found mostly inside our cells. It is involved with water balance, ph balance, membrane transplant, and electrical conduction in the muscle and nerve cells. Potassium levels too high or too low may cause problems with our nerves and muscles. Some causes of elevated levels include:

  • Lab error (a common cause, due to red cells “leaking” potassium after they die)
  • High potassium diet (including certain fruits, substitute salt)
  • Renal (kidney) failure
  • Abnormal adrenal gland function (Addisons’s disease and hypoaldosteronism)
  • Muscle injury
  • Dehydration
  • Diabetes
  • Fever
  • Breakdown of red blood cells
  • Lab error (a common cause, due to red cells “leaking” potassium after they die)
  • Diuretics of a certain type (such as triamterene, spironolactone, amiloride)
  • ACE inhibitors (the “prils” – lisinopril, benazepril, captopril, fosinopril and others)
  • ARB’s (the “sartans” –  valsartan, losartan, olmesartan, irbesartan, others)
  • Anti-inflammatories including Advil/ibuprofen, Aleve, many others
  • Beta blockers

Some common causes of decreased levels include:

  • Diuretics of a certain kind, such as furosemide, and HCTZ (hydrochlorothiazide)
  • Diarrhea, vomiting and other causes of dehydration
  • Less common causes of low levels:
  • Abnormal adrenal gland function
  • Renal (kidney) disease
  • Malabsorption
  • Low magnesium
  • Laxatives

http://www.labtestsonline.org/understanding/analytes/potassium/glance.html

Sodium is a positively charged electrolyte found mostly outside cells. It is involved with water balance, pH (acid/base) balance, and nerve and muscle function. It’s found in table salt, but blood levels are not usually related to salt intake.
Some common causes of elevated levels include (almost always due to excess fluid loss):

  • Dehydration
  • Vomiting

Some uncommon causes of high sodium:

  • Abnormal adrenal gland function (Cushing syndrome)
  • Congestive Heart Failure
  • Renal (kidney) failure
  • Too much salt intake with too little water intake
  • Inadequate levels of the hormone ADH
  • Some common causes of decreased levels include:
  • Loss of sodium – diarrhea, excess sweating, diuretics
  • Abnormal adrenal gland function (Addison’s disease)
  • Kidney disease
  • Some less common causes of low sodium:
  • Too much water intake
  • Congestive heart failure
  • Liver failure/cirrhosis
  • Diabetes
  • Thyroid Disease
  • Bowel Obstruction
  • Some brain and lung diseases with abnormal levels of hormone (ADH)

http://www.labtestsonline.org/understanding/analytes/sodium/glance.html

Other

Sedimentation Rate (Sed Rate) is a simple measure of how fast the red blood cells settle down to the bottom of a tube of blood. The cells settle faster when certain proteins are in the serum part of the blood. These proteins are elevated in infection and inflammatory conditions of the body. The elevated level of these proteins increase the sed rate. The sed rate is a very sensitive test, but not very specific. In other words it tells you something is going on, but not what that something is. (A related test is C-Reactive Protein). A normal sed rate, however, does not mean you do not have an inflammatory disease. In other words, a high sed rate is a useful test result; a normal or mildly elevated sed rate is not helpful. Some causes of elevated levels include:

  • Anemia
  • Arthritis
  • Infection
  • Autoimmune diseases like Lupus
  • Specific inflammatory diseases: temporal arteritis and polymyalgia rheumatica
  • Certain cancers, and especially multiple myeloma
  • Allergies
  • Old age
  • Pregnancy
  • Kidney failure
  • Certain medications

Some causes of decreased levels include:

  • Congestive Heart Failure
  • Certain red blood cell diseases, including sickle cell anemia and polycythemia

http://www.labtestsonline.org/understanding/analytes/esr/glance.html

Mark Smith, MD
Dennis Oliver, MD