Disease #3
Arthritis is simply defined as an inflammation of any joint in the body. A joint is any bone that meets with another bone. Examples of joints are the elbow, hip, knee and even joints exist in the craneum (skull). Arthritis can occur in any joint. Causes can be due to: trauma, congenital, aging process, immune-mediated, septisemia amongst others. The size of the dog does matter. Hip Dysplasia is more common in large dogs while cruciate ailments of the knee joint (stifle) are more commonly seen in small dogs. Obesity is another predisposing factor in developing arthritis. Excess weight over time puts tremendous forces on the majority of joints in the animals body.
As the animal ages or via some other cause, cartilage starts to wear down over the joint. This causes bone to grind against bone. Over time, this causes inflammation and pain in the affected joint. The joint can not function normally at that time. This inflammation and pain are the hallmarks of arthritis.
Inflammation and pain cause the majority of symptoms associated with arthritis. The animal will limp or favor the affected limb. Touching the joint elicits pain in the animal. Dogs are often reluctant to move around and cats are reluctant to jump up onto sofas and other objects that they did before. The joint itself is often swollen and warm to touch. Clinical signs can be seen gradually over time in the case of the aging process or suddenly when associated with trauma such as a bite wound over a joint or hit by car associated trauma.
Lab Work used to help diagnose osteoarthritis usually revolves around imaging processes. This includes standard xrays of the joint as well as ultrasound imaging. Other tests may be warranted depending upon the cause of arthritis. For example, older dogs, septic arthritic cases as well as trauma induced arthritis warrant a CBC and Chemistry Profile.
Diagnosis is based on a history, physical exam and pertinent lab data. Understanding breed differences also helps to diagnose the condition at hand.
There have been tremendous advances in veterinary medicine regarding the treatment of osteoarthritis (arthritis). In general terms, treatment of the disease is based upon treating the primary cause of arthritis. The medical treatment of the pain and discomfort is the same regardless of cause. Restriction of exercise, the use of anti-imflammatories such as Rimadyl®, employing nutraceuticals such as glucosamine/chondroitin and corticosteroids in acute cases are the hallmark of medical treatment. Some animals with chronic hip dysplasia often require a complete hip replacement. Small dogs with cruciate injuries require surgical repair of the knee joint. Antibiotics are needed in treatment of bite wound or septic arthritis. Soaking in a circulating water pool or swimming helps with inflammation. Support bandages are very difficult to keep on animals as they slide around and or are chewed off by the patient. Home care is crucial. Take care that the animal has enough support on slippery tile or wood floors, provide cushioned bedding for sleep plus it makes it easier for the pet to get up. In winter time, watch out for ice and snow that can cause slippage injuries to the animal. For cats, provide a stool or chair that will split the height difference needed to jump on a favorite bed or sofa.
The prognosis for arthritic patients varies with the cause of the disease process as well as how long the arthritic process has been going on. Most older dogs do quite well with anti-inflammatories and other supportive care. Animals that lose weight on an appropriate weight loss diet will also improve. Regardless, the majority of patients undergoing medical or surgical care usually warrant a guarded to favorable medical prognosis and quality of life; as long as the owner provides a lot of TLC and love.
Asthma is akin to a severe allergic reaction also known as allergic bronchitis. Asthma is caused by a myriad of agents including: dust, dust mites, pollen, smoke and many other irritants. Anything can trigger an asthmatic attack and figuring out what that anything is, is the hard part. Asthma also has a genetic route, being seen in Pomeranians and Himalayan cats. Asthma is exacerbated in obese animals plus those that have a bracheocephalic skull type; like the Pug, Bulldog or Persian cat.
When an irritant enters the respiratory tree via inhalation it sets up a severe allergic reaction which translates into a dramatic inflammatory response once histamine takes over. This sort of inflammation via a flea bite may be innocuous but when it is present in the airway (trachea, brochi and lungs) it can be life threatening.
The most common clinical signs are coughing and shortness of breath. The pet is reluctant to move and is weak because insufficient oxygen is being sent to body tissues. Breathing is labored and difficult. In severe cases the tongue and mucous membranes turn a shade of blue known as cyanosis. This means a severe depletion of oxygen in the body. Many cats will open mouth breathe when in distress. Excitation and panic can exacerbate these signs.
X-Rays and other imaging procedures are the first diagnostic procedures done. This assesses the degree and severity of asthma. A CBC and Chemistry profile are done to rule out infectious components and internal organ involvement.
Asthma is diagnosed by clinical appearance, physical exam and a good medical history. The time of year is important as certain irritants (allergens) are predominant at certain times of the year. The pet may have had a prior history about the same time of year. Trying to figure out the exact allergen causing the asthma can be difficult but blood allergy tests can be performed such as provided by Heska®.
The first order of business is insuring a patent airway. Make it easier for the animal to breathe. This involves the use of parenteral and oral corticosteroids, bronchodilators (theophylline), adrenalin and nebulization therapy. Some animals are so panicked that to decrease oxygen demand, they have to be lightly sedated (Telazol®). Pure oxygen is administered to patients that are cyanotic. Once the animal is stable antibiotics and other supportive measures may be prescribed depending on the results of the blood work. Home care involves administering inhaled or oral corticosteroids and avoidance of suspect allergens. This means using air conditioning, changing the air handler filters more often and cleaning any bedding the animal lies on. Vacuuming more often is recommended as well as losing weight if obesity is an issue. Some veterinarians will supply several injectable doses of adrenalin to be administered in acute home cases that reoccur.
The prognosis for acute asthma, that is uncomplicated, and recognized early, is quite good. With chronic asthma, there is a scarring of the respiratory tract which narrows any openings through which oxygen passes; all the way from the bronchus down to the alveoli (final exchange of oxygen in the blood). Prognosis for these patients is guarded. Sometimes the sclerosis and over reactive inflammatory response may be fatal.
An auricular hematoma is the accumulation of blood and blood by-products between the ear cartilage and skin of the ear. It is most commonly caused by ear infections, trauma, ear mites and anything else that can irritate a dog or cats ear pinna (flap).
With the infection or irritant present in the affected ear, the animal constantly shakes its head trying to alleviate the discomfort in the ear. Constantly doing this causes the rupture of capillaries in the ear allowing blood to flow in the area. This produces a heavy, pendent ear. This makes the dog feel even worse so it shakes its head even more. A vicious cycle ensues.
All pets are bothered by auricular hematomas. When presented, they will constantly shake their heads. A swollen ear will be noticed. An otic exam of the ear will show an infection, ear mites or the owner may mention that the pet was involved in a car accident while the owner was driving. Some pets will also have a mild infection. Blood is a magnet for bacterial growth hence often producing an additional infection to deal with.
A CBC is required to assess the degree of infection and or elevated white cell count. Since the majority of these cases require repair under a light general anesthetic, a chemistry profile is in order to make sure the internal organs are functioning well before putting the animal under.
Diagnosis is by simply noticing the enlarged ear pinna. Sometimes one ear is involved or both at the same time. Sometimes one ear is affected than months later, the other.
Surgical repair is the only way to correct auricular hematomas. Just draining the blood from the ear by using a syringe is a waste of time. It might provide temporary relief but the ear fills up with blood again. The goal in surgery is to relieve the pressure and contents of the blood buildup plus to allow drainage to continue post operatively. The ear is bandaged tightly to prevent blood from flying all over the owners car and home. It also cushions the ear making it more comfortable for the animal. Antibiotics are always provided and an ear culture is taken at the same time. If ear mites are present, they can be treated with ivermectin or other preparations. Surgery is curative. Sutures are removed in two weeks.
The prognosis for auricular hematomas are excellent. They are all different but with surgical intervention all animals respond well.
Autoimmune hemolytic anemia is a disease involving the animal's immune system. Autoimmune disorders create antibodies to normal body tissues such as red cells. These disorders could potentially effect any cell type but in this disorder the red cell antigens lock horns with circulating anti red cell antibodies. The body is essentially attacking itself! Most cases are caused by a mix up in the dogs immune system. Erroneously, it targets normal red cells. In a less common version the surface antigens of the red cell change tricking the immune system into thinking they are foreign, hence development of antibodies against them. This can occur in cancers as well as parasitic disorders of the blood.
When circulating anti-red cell antibody confronts the surface antigen of a red cell, the two combine with the eventual destruction of the red cell in the blood vessel itself or in the spleen or liver. This destruction releases the red cell hemoglobin where it is converted into bilirubin in the liver and than circulates in the animal's circulatory system. This destruction of red cells and accompanying metabolism of hemoglobin produces the majority of clinical signs seen in the dog. Cats rarely develop this disease.
Clinical signs are associated with the resultant anemia. Animals become debilitated early. Signs of weakness, anorexia, pale mucous membranes, jaundice, dehydration and clotting difficulties (DIC) are common. Oxygen depletion also makes the dog depressed and often acts like it is in another world. Excess bilirubin spills over into the tissue giving it a yellow appearance (jaundice). It is also secreted in urine giving it a dark yellow/orange appearance. Since the red count is so low, the heart and respiratory rate elevate trying to compensate for a low saturated amount of oxygen.
The definitive lab work needed is: CBC and Chemistry profile, Coombs test, clotting panel & urinalysis to start. Most dogs have a hematocrit of about 18-20 when diagnosed and it creeps downward, even though treatment has commenced, eventually bottoming out. Serum bilirubin is elevated and the urine is 4+ direct (conjugated) bilirubin. Liver enzymes are often elevated and a CBC will show a marked regenerative anemia with spherocytes often present in a blood smear. Because of the altered blood chemistry, DIC (Disseminated Intravascular Coagulopathy) is present. The blood appears watery and will not clot. This can be life threatening in itself.
Diagnosis of AIHA is made by a complete physical exam, blood work and the acute onset of the disease. This is very common in tiny or small breeds such as: maltese, toy poodles and wheaten terriers.
Treatment of AIHA is geared towards stopping the autoimmune destruction of red cell and clinical signs associated with red cell destruction. Many of these animals are vomiting and intravenous doses of Cerenia® are required. This condition is a medical emergency and all patients are hospitalized. Intravenous fluids help maintain circulatory pressure and perfusion of vital organs plus maintain renal function. Corticosteroids (usually dexamethasone SP) are administered daily to break the immune mediated red cell destruction. Other supportive measures such as adding dextrose to the fluid line, caloric replacement and B12 vitamin supplementation are done. Antibiotics may be administered if an infection is suspected. Blood transfusions are contraindicated until the animals immune system has been suppressed. Premature blood transfusion is like throwing gasoline on a fire. Excess red cell antigen is thrown in and further red cell destruction ensues. Under such conditions, it is not unusual for a transfusion to cause a drop of 4-5 points in an animals already low hematocrit. Once the emergency has been alleviated (often taking several days) the animal's red cell destruction tapers off and over time the dog starts feeling better. In time animal's start to drink on their own and develop a ravenous appetite! It is very rewarding to turn these animals around. Animals are discharged on oral prednisone and Azathioprine (Imuran®). The latter is extremely effective at suppressing the immune system and allows a lower dose of prednisone to be used so as to prevent iatrogenic Cushing's syndrome. At home, owners need to maintain a weekly CBC visit to the hospital, insuring that the hematocrit continues to climb. Post hospital management usually takes about 4 months. The long term goal is to wean the dog off of all drugs with monthly or quarterly CBC's for the duration of the animal's life.
The prognosis for AIHA is guarded until the immune mediated reaction stops and the hematocrit starts to rise. It becomes more favorable as the animal responds to therapy and starts to eat and drink on its own. With continued therapy at home and periodic CBC evaluations the prognosis is good as long as the dog stays in remission and its immune system stays quiet. A normal high quality of life can be expected.
Babesiosis is caused by a protozoan (uni-cellular) organism that lives and reproduces in red blood cells. The most common species are Babesia canis and Babesia gibsoni. In the U.S. it is most common in the southern states such as Florida. Genetic PCR testing has opened the floodgates on potential Babesia species differentiation.
The organism is transmitted to dogs by ticks. The most common ticks involved are Ixodes sp, Rhipicephalus sanguineus (common dog tick) and Dermacentor sp. The sporozoites are injected into the dog via the insects saliva while feeding on blood. The sporozoites penetrate the red cell, reproduce and burst the host red cell causing destruction of it and hence a hemolytic anemia. Clinical signs bounce off of this fact and the continual sub clinical presence of the organism even after treatment. In 1981 this author did his doctoral thesis for his DVM degree on "Canine Babesiosis in the Dominican Republic".
Clinical signs are based upon the hemolytic anemia. Many of these cases are acute but some are chronic. In acute cases circulatory collapse due to severe anemia will lead to extreme pallor of the mucous membranes. The animals urine is orange due to the presence of bilirubin in the urine; secondary to the metabolism of the red cell hemoglobin. Dogs are weak and distressed. The spleen is often enlarged as well as some peripheral lymph nodes.
A CBC will illustrate the regenerative anemia that is always present. This disease can be insidious as some cases develop slowly over time. A Giemsa stained red cell smear may or may not show the typical pleomorphic (multiple forms) shapes of Babesia. In slowly developing or chronic cases, detecting the organism on smears can be futile. A Chemistry profile is necessary to look at internal organ functions. Further lab work is being offered such as the fluorescent antibody test and ELISA test for the more common B. canis.
Definitive diagnosis of Babesiosis is by finding the typical pleomorphic organism inside an infected red cell on a Giemsa stained blood smear. There are other indirect ways such as ELISA and FA testing but they are not always accurate.
Treatment of babesiosis is not curative as a sub-clinical infection will persist that will allow the organism to reside in red cells without causing initial clinical signs. This may lead to a relapse of the disease. Dogs such as these should never be used as blood donors. Veterinarians have used: imidocarb and azithromycin (Zithromax®) for treatment of the disease. Treatment is complicated with the presence of other red cell parasites such as Ehlichia canis.
The prognosis for babesiosis is never favorable. The prognosis is variable depending upon whether the dog is in a full blown hemolytic crisis or a more sub acute form. Making things more dicey is that dogs never fully recover so a relapse is fully possible plus the dog can serve as a further source of infection to other dogs.