Common Diseases & Conditions in Pets L-O
Pneumothorax is the presence of air in the thoracic cavity. Atelectasis is when a lobe or part of the lung becomes airless and collapses on it own. This presentation will be on lung collapse due to pneumothorax. The most common cause of lung collapse in animals is blunt trauma to the chest. The pneumothorax may be caused by a fractured rib that punctures the thorax or a knife or other penetrating weapon that pentetrates the thorax. It may also be caused by primary or secondary lung disease. It may be open or closed. A penetrating wound into the thorax is open; meaning a direct opening from outside to inside. Lung disease produces a closed pneumothorax
Air pressure always goes from a high pressure environment to a low pressure environment. The thoracic cavity of mammals is under a NEGATIVE pressure environment while the air we breathe is under a POSITIVE pressure environment. If the thoracic cavity is exposed to the outside environment, high pressure goes to low (negative) pressure and the lungs collapse due to the pressure gradient. This explains the clinical signs and therapy that is provided.
The most obvious clinical sign is difficulty breathing (dyspnea). Because the lungs are collapsed, it is difficult bringing air into the lungs and breathing is always shallow and rapid. In most cases the left or right lung is involved unless there has been severe trauma to both sides of the thorax. With difficulty getting air into the lungs the animal may be cyanotic with its tongue and mucosal membranes turning a shade of blue. Dogs and cats will also sit upright making it easier to breathe.
Radiographs are always performed with pneumothorax. They will show the characteristic heart elevation. The base of the heart is normally anatomically close to the sternum (breast bone). In the case of pneumothorax, it may be an inch or two elevated!
Diagnosis is made by the presentation of a dog in dyspnea with traumatic wounds or lesions to the chest wall. Radiographs confirm the diagnosis.
The main goal of treatment is the correction of the trauma to the chest wall and recreating a negative chest pressure. The latter is accomplished by thoracocentesis. A large syringe is hooked to a stopcock and air is continually sucked out from the chest. Eventually difficulty doing this means the chest wall is becoming negative. This is repeated as necessary and the animal is confined for weeks with no exercise. Any tissue damage is repaired and the dog or cat is put on antibiotics. The animal is usually radiographed in a day or so to check the progress of the pneumothorax.
The prognosis for most pneumothorax corrections is very good as long as treatment is immediately sought and there is no severe crushing trauma to the pulmonary and heart vessels. Those cases have a poor prognosis.
The cause of lung tumors in dogs and cats is unknown. The most commonly seen lung tumor in the dog is an adenocarcinoma. This tumor is extremely malignant and metastasizes to other tissues such as the brain, liver and lymph nodes.
Lung tumors are very difficult to deal with. Since a cause is not known, it is very difficult to visualize them as they start. They are composed of cells that have undergone a harmful mitotic change. These cells and eventual tumor development are often diagnosed when the tumor is well established. This means when the tumor becomes calcified and visible on chest films. By that time, cancer cells have spread through the circulatory and lymphatic ducts. The lymphatic system is usually affected due to the proximity of the lungs to the lympatic thoracic duct.
Clinical signs are always respiratory related unless signs of other organ systems have developed due to metastasis. Dogs are seen with this condition more so than cats. Cases are most commonly seen in older dogs. Primary pulmonary neoplasia is less common than pulmonary lesions that have developed secondary to cancers elsewhere in the body. An example of this are mammary masses. Difficulty breathing and vomiting of blood are commonly seen. Lack of appetite, poor coat and associated weight loss are the most common respiratory signs. Lymphatic involvement will usually be associated with peripheral lymph node enlargement. Liver disease will show elevated liver enzymes and others such as jaundice.
If lung tumors are suspected radiographs are the first order of business as they may show calcified lesions. A CBC and Chemistry profile are performed to assess whether other organ systems have been affected by metastasis of the primary tumor. Animals may also have an ultrasound performed.
Diagnosis of lung tumors is made by the history and results of a physical exam. Many times an ultrasound and radiograph will show characteristic calcified lesions.
Lung Cancer patients are referred to a veterinary oncologist. Treatment protocols vary with the individual, severity of the primary disease and other organ systems affected. Surgical care may involve removing a lung lesion or lung lobe. To increase survival, radiation and chemotherapy may be offered.
The prognosis for lung tumors is poor. With metastasis of the tumor, most dogs will not live longer than a year. Even with treatment, survival is really not extended much at all. Owners need to be made aware of the very likely possibility that the animal’s quality of life will decline over time.
Lyme disease is a common world wide disease seen in humans and their companion animals. Lyme disease is named for Lyme, CT where the disease first was discovered. It is caused by the bacterial spirochete, Borrelia burgdorferi. In animals it causes a severe lameness due to joint inflammation.
Transmission of Lyme disease is by the bite of the larval form of the deer tick. Since the larval form is so difficult to see, most owners do not see the tick on the animal. After a day, the insect falls off and is gone. The disease in the United States is commonly diagnosed in New England and the Mid-Atlantic states. It is also seen in the Ohio Valley and Upper Midwest. In fact, most veterinarians in the northeast will screen ANY dog that comes in limping for Lyme disease.
The most common clinical sign noticed is lameness in any limb or combination of limbs! This is known as polyarthritis. The dog may be treated with an antibiotic and lameness shows up in another limb. It may disappear in a few days and a different joint is affected! Sort of like whack a mole. Later on in the disease acute renal failure, due to glomerulonephritis, may demonstrate itself as increased fluid and urination and associated halotosis. The central nervous system may be involved. Seizures or fascicular tics may be noticed.
A CBC and Chemistry profile should always be done on suspect Lyme disease patients. Involvement of other organs such as renal failure can be figured out via a profile. There are specific tests to pick up the spirochete. An antibody test can be performed that picks up antibodies to the spirochete. If this is positive it is a sure thing. If it is negative, the dog may still have the disease. Not enough time may have passed for the immune system to produce antibodies, the animal is immuno-suppressed or the animal has had the infection for eons with very little circulating antibody around anymore. A PCR (Polymerase Chain Reaction) test can truly identify the organism but it is not always around in the blood. To run this test, fluid is usually tapped from the affected joint.
A tentative diagnosis of lyme disease can be made by the presentation of an animal with a fever, swollen joints and lameness. A history of exposure to deer ticks in the environment is important. In some areas, there are more deer around than people! A diagnosis may be confirmed via a PCR or antibody test.
The primary treatment of Lyme disease is by antibiotics. One of the commonly used drugs is Doxycycline. Antibiotic therapy should last for at least 4-8 weeks. Sometimes clinical signs will reappear and other antibiotics may need to be used. Even when the disease is treated, the lameness may persist if there has been mechanical damage to the joint. Renal disease must also be treated. Glomerulonephritis caused by the Lyme circulating antigen/antibody complexes can be treated with fluids and oral benazepril.
The prognosis for treating Lyme disease successfully is very good but the animal can get bit by an infected tick at any time in the future. This will set up another infection. In this case, will a humoral antibody response to a prior infection protect a dog? Maybe.
The key is to prevent the animal from coming into contact with ticks in the first place. By removing the tick with tweezers and twisting counter clockwise will usually remove the head parts also. The big problem is that the larval deer tick is very small and naked to the eye. Best approach is to use one of the topical flea/tick preparations such as Frontline® Plus, a Preventic® or Seresto® collar. Environmental control of tick populations can be controlled in the home with sprays or foggers. Outdoor environmental control may be done with chemicals but the best approach is to cut down tall grasses and weeds. This is where most tick populations will reside.
There is a vaccine for Lyme disease available. It needs to be administered once and than again in about 3 weeks. It is than boostered annually. Talk to your veterinarian about the use of the vaccine in your area of the country.
Lymphomas are not that common in dogs. They involve neoplasms or cancers of the lymphatic system. The lymphatic system is crucial for humoral defenses plus the elimination of organisms as they are filtered through that system. The actual cause of the mitotic cellular changes that cause lymphoma is unknown.
Lymphocytes are just one type of white cell found in the blood of mammals. Their main function is involvement in the immune system of the animal. There are two types of lymphocytes; B-cell and T-cell. The B-cell lymphoma is more common in dogs and causes pathology in the lymph nodes, bone marrow and visceral organs.
The development of clinical signs depends upon the location of the lymphoma. If localized in the lymph nodes, peripheral lymph nodes may be enlarged. If in the digestive system, signs of diarrhea and associated weight loss may be seen. If in the liver, weight loss plus increased thirst and urination plus jaundice may be seen. General signs of weakness and anorexia may also be seen.
If lymphoma is suspected, a complete workup is in order. This means a CBC and Chemistry Profile to check for organ involvement. A CBC may show an anemia or a drop in platelets or other disorders due to bone marrow involvement. A urinalysis will be performed and radiographs or an ultrasound will be added to the list. If a lymph node is enlarged, a biopsy and histopathologic diagnosis will be obtained.
A tentative diagnosis of lymphoma may be made by the presence of a larger breed dog with associated lymph node enlargement. Other clinical presentations will be more difficult to diagnose. A diagnosis may be confirmed by a fine needle aspirate or biopsy of an enlarged lymph node. Biopsies may also be taken during an abdominal exploratory.
There is no cure or specific treatment of lymphoma in the dog. They may be referred to a veterinary oncologist where radiation or chemotherapy may be done. The COP (Cytoxin®, Oncovin®, Prednisolone) protocol also has been used along with other chemical approaches.
The long term prognosis for Canine Lymphoma is not good. The most important goal is to control the disease process as best as possible and to insure the best quality of life as possible. Everything should be done to make the animal’s life as fullfilling and comfortable as possible. Lots of kisses and a lot of TLC will go a long way. Including this veterinarian, it is a horrible disease to see an animal go through.
Lipomas are soft benign tissue that are commonly seen under the skin in animals as they age. The cause of lipomas is unknown but it seems to be more predisposed to in obese animals.
Lipomas can form anywhere on the body. They are usually about an inch in diameter but some can become massive to affect the animals mobility. In most cases they do not bother the animal but should be attended to. There are liposarcomas that are malignant and can metastasize to internal organs. However, the benign version is much more common in companion animals..
The most common finding is a fluctuant, soft mass over the skin but not normally attached to the subcutaneous tissue. This occurs most commonly in middle aged animals.
Most animals are healthy. Often a fine needle aspirate may be done to stain and visualize characteristic fat cells.
Diagnosis is made by the presence of a soft, golf ball sized, fluctuant mass anywhere on the animal’s body. They are seen most often on the trunk, ventrum and posterior areas. A biopsy can confirm the diagnosis.
Treatment is always surgical. An incision is made directly over the lipoma and they pop out looking like oysters! Dead space is closed and the wound is sutured shut with non-absorbable sutures. The mass is than sent out for histopathological diagnosis. It is important to get a pathological diagnosis so as to not overlook a liposarcoma.
The prognosis for lipomas are excellent. More may pop up on the animal’s body as it ages. The more infiltrative liposarcomas can be more invasive and a guarded prognosis is often given.
Mast cells are most commonly seen near the surface of the animal’s body. The skin and mouth are two of the common anatomical areas where mast cells live. They help build tissues and are involved in all allergic reactions in the body. Mast cells release histamine; which is the main chemical that initiates and plays havoc in animals with allergic reactions. The cause of Mast Cell Tumors is not known. The most commonly affected dog is the Boxer.
Mast cell tumors are extremely invasive. They are staged into 3 distinct types:
1. Stage 1: These mast cell tumors have a low chance of metastasis or spreading.
2. Stage 2: These mast cell tumors have a potential to be locally invasive.
3. Stage 3: These mast cell tumors are the most dangerous since they have the ability to metastasize.
The problem with Mast Cell tumors is that they can be chameleons when it comes to appearance. They can mimic many other different skin lesions. They can occur anywhere but are seen many times in the interdigital area of Boxers. They may be pigmented or non-pigmented. The masses may even be fluctuant. Signs of hepatic or splenic enlargement often suggests a metastasis to those areas. The site of the lesion may become inflamed and pruritic due to excess amount of histamine being produced by the tumor cells.
All animals should have a CBC and Chemistry profile performed to rule out (at least from a clinical pathological view) metastatic lesions in other body tissues. Ultrasound may also be used to detect liver or spleen involvement.
The most important test, prior to surgery, is the fine needle aspiration of cells from one of the tumors. In suspect animals, a proliferation of mast cells may be seen.
Diagnosis can be tentative with the detection of mast cells via a fine needle aspirate of a tumor but confirmed via histopathological diagnosis of a mass excisional biopsy to a lab. Bells and whistles should go off if the dog is a Boxer.
The majority of Mast Cell tumors are excised aggressively!! They are excised wide and deep! Care must be taken handling the tissues. Mast cell tumors can produce tremendous amounts of histamine while being excised. Many animals are treated with antihistamines prior to surgery. If lymph nodes are involved they can be excised at the same time. The key prognosticator of surgical success is the histopathological diagnosis. Even though it may show Mastocytoma as a diagnosis, the key for the animal are WIDE SURGICAL MARGINS between tumor and normal tissue. That is always good news. Animals may also undergo chemotherapy or radiation. The treatment of metastatic cases is usually not successful.
It is always a great prognosis when a mast cell diagnosis comes back with wide margins! The important thing is to always take the animal back to the veterinarian in case any other lesions may develop. It may end up being an innocuous sebaceous gland cyst but that is much more preferable than mastocytoma. Once an animal is diagnosed with the disease, ANY new growth is suspect and should be excised and sent for a pathological diagnosis. Metastatic mastocytomas have a poor long term prognosis due to the mestastasis to important visceral organs.
Megacolon is an over extension of the colon that leads to accumulation of feces and constipation. It is more commonly seen in cats and is often congenital or acquired. A common cause is loss of the nerve supply to the organ and a history of constipation that constantly distends the colon and inability hence to contract.
The colon is the part of the digestive tract that is responsible for absorption of water and sodium. Once those valuable resources have been absorbed, the other function is passage of the waste (feces) to the rectum and than outside of the body. Bouts of constipation lead to continuously dry, hard stools. The smooth muscle of the colon is stretched. Just like an incontinent urinary bladder, once continuously stretched for long periods of time, the organ stops working and feces accumulate. Clinical signs spring off of these concepts.
Clinical signs associated with megacolon are: straining to defectate, production of scanty, dry feces, passage of small amounts of mucous and blood. Once feces sit in the colon, the wastes begin to absorb water. This leads to dehydration, lethargy, vomiting and in severe cases, sepsis. It is important to make a distinction with cats. Straining of ANY type means an immediate visit to the veterinary hospital. The straining could be due to constipation or megacolon but also due to a urethral obstruction. The latter is a medical emergency! Obstipation (an obstruction to the flow of feces) can be caused by trichobezoars (hard hairballs) lodged in the descending colon.
Radiographs will show an abnormal volume of feces in a distended colon. Barium constrast studies will pick up obstructions and dilineate the stenosis of the actual lumen available for feces to pass. Ultrasounds will pick up the same thing but in greater detail. A CBC and Chemistry profile should be performed to assess organ function; particularly the white cell count. An elevated white cell count means an underlying infection, secondary to the megacolon, is starting to emerge.
Diagnosis is made by a history of constipation or obstipation over a period of time. It is much more common in cats. Radiographs, endoscopy, palpation of a hard colon from abdominal palpation are sufficient to make a diagnosis of megacolon.
Most megacolon cases are medically treated although surgery is often performed. A colectomy will remove as much of the colon that gets rid of the anatomy that was causing the problem in the first place. The big problem with this is the production of soft, frequent stools.
Medical therapy is geared to making feces easier to pass. This can be accomplished by dietary change to a food higher in roughage. Metamucil® can be added daily to the food. Lactulose may also be prescribed to loosen up stools in the colon by increased water absorption into the colon.
In severe cases, animals are extremely ill and need to be hospitalized. They are sedated and the lower bowel is manual emptied or flushed with enemas. Intravenous fluids are always given since most cats are severely dehydrated making colonic peristalsis even worse due to dehydration at the intestinal level. Antibiotics and other support care are administered.
The prognosis of megacolon is guarded at best. With either type of treatment, surgical or medical, there really is no win-win situation. The animal may feel better but the main problem is unresolved leading to recurrence of clinical signs. Many owners can not continue down that path. This eventually leads to euthanasia. Unfortunately, there is no cure for megacolon.
What I recommend is that cat owners give a small amount of a hairball preparation such as Laxatone®. This is mainly used to lubricate the gastrointestinal tract so that hair ingested by grooming can easily pass in the stool. Administering hairball prevention daily will keep stool from getting hard. Do not worry about loss of fat soluble vitamins in the stool. All hairball preparations are fortified with them. They may prevent obstipation and constipation; two of the biggest causes of acquired megacolon.
Megaesophagus is an over extension of the esophagus that leads to dilation of the organ and inability to propel, by perastalsis, food into the stomach. The causes can be either congenital or acquired. Congenital cases are seen in puppies just weaned. Acquired cases can be primary or secondary to another condition. The cause of primary megaesophagus is unknown. The most common cause of secondary megaesophagus is neurological in dogs; myasthenia gravis.
The esophagus is the tube that transfers food, after swallowing, to the stomach for digestion to commence. The organ is extremely muscular. Food is propelled by a muscular contraction known as peristalsis. What it looks like is like a snake swallowing a rodent. A person can actually watch the food pass through the snake. This is what is supposed to happen in the dog. In either cause, food becomes trapped and can not pass to the stomach. The esophagus becomes dilated and food is regurgitated up and often inhaled into the lungs causing inspiration pneumonia.
The most common sign of congenital megaesophagus in puppies is immediate regurgitation of solid food. The animal attempts to eat it over and over. Eventually it softens and it lands up in the stomach. By elevating the hind legs of the animal, one can often see the dilated esophagus through the cervical area. In acquired megaesophagus, animals will regurgitate undigested food, loose weight plus develop respiratory signs of inhalation pneumonia.
An ultrasound or barium series of the upper gastrointestinal tract will show dilitation of either the cervical or thoracic esophagus. Trapped food and or air will be seen. While examening the thoracic component, the lung fields can be studied for any signs of inspiration pneumonia.
Diagnosis is made by historical findings and clinical signs of megaesophagus. Radiographs will confirm the diagnosis with or without the presentation of inspiration pneumonia. The majority of dogs with megaesophagus are about 60-70 pounds. Miniature Schnauzers also will develop this.
This is where ladders come in handy. There is no cure for megaesophus. The best therapy for primary megaesophagus is feeding the animal a soft diet that is placed at an appropriate rung on a ladder. Elevating the food causes the animal to stand like a human so that gravity allows food to pass down to the stomach. You will have to experiment with the type and consistency of the food offered. It may be advantageous in puppies and adults to break down a meal into numerous small meals that can be passed easier than one big meal.
Acquired megaesophagus is very difficult to treat. Myasthenia gravis is an extremely debilitating disease in the dog that is diagnosed by the “Tensilon Test” (IV edrophonium chloride). Indirectly, megaesophagus may slightly improve by offering anticholinesterase drugs such as Mestinon® or Prostigman® to these patients.
The prognosis for idiopathic megaesophagus can be good if feeding instructions are followed exactly. Congenital megaesophagus has a much more guarded prognosis due to the immature anatomy in the puppy plus the constant threat of inspiration pneumonia. Secondary megaesophagus, due to myasthenia gravis, has a poor long term prognosis.
Melanoma is an extremely common cancer most commonly seen in dogs. The cause of melanoma is unknown. It is the most common cause of oral cancer in the dog and one of the most commonly diagnosed skin cancers in animals. They are extremely invasive lesions and require immediate medical care.
Most melanomas are pigmented. They are extremely invasive and metastasize rapidly to the bone and other visceral organs. Not all melanomas are pigmented. There are amelanotic melanomas that do not carry the dark pigmentation and look like any other cyst. These are often overlooked but can be just as dangerous. Humans can develop acute melanoma due to excessive UV sun exposure but this model in animals has not been proved.
Most melanomas are pigmented and found anywhere on the skin and oral cavity. They often start out as lesions that do not heal but fester and just sit there. They are often small. Melanomas on the distal (lower) extremity of a limb may cause lameness or swelling in the area. Oral melanomas will produce drooling and excessive salivation, presence of an oral mass, painful chewing and halitosis due to food particles lodged in the area of the melanoma. Metastasis is often to the liver and in some cases, a jet black urine is voided.
Radiographs and a CBC and Chemistry profile are performed to check bodily functions and pick up any metastatic lesions of the melanoma. Fine needle aspirates and or a biopsy may be obtained. Lymph node biopsies may be obtained to check for metastasis to the lymphatic system.
Diagnosis is made by the presence of lesions suspected of being a melanoma. A history of a mass that does not heal is suggestive. Diagnosis is confirmed via a fine needle aspirate or a biopsy.
Surgical treatment of oral melanomas is never satisfactory. There is no way the entire mass can be removed plus it comes back time after time again. Surgical treatment of cutaneous melanoma is made by a wide and deep excision being careful to preserve healthy margins. This is confirmed on examination of the biopsy by a pathologist. A melanoma on a toe is treated by surgically removing the toe. Radiation and chemotherapy have been also performed by veterinary oncologists.
Merial has come out with a veterinary melanoma vaccine named Oncept®. It has shown a lot of promise and is administered by oncologists.
The prognosis for dogs that do not receive medical care is poor. Their survival time is measured in months. Dogs that have been treated for oral melanoma and digit melanoma have a much greater chance for survival if Oncept® has been administered. In this instance the short term quality of life is good but survival ranges in the 1-2 year time frame.
Feline Miliary Dermatitis is a common skin condition in cats that causes excessive grooming, alopecia and pruritis (itch). The most common cause of miliary dermatitis is allergy. The most common cause of allergy in cats is to flea bites. Allergies to red plastics cause a “rodent ulcer” under the chin of the animal. Other causes can be autoimmune, parasitic or nutritional but allergy is, by far, the most common cause.
The skin in cats with miliary dermatitis is extremely sensitive. Just touching it in an exam room leads to immediate licking and grooming. I had one case, where after touching a lesion on a cats lumbar area, it literally flipped and turned circles around its own longitudinal axis! I wish I had a video of it! Cats that lick constantly will develop a secondary staph pyoderma and hairballs.
The most common clinical signs are the present of local or generalized skin lesions characterized by a scaly, pustular, inflamed raised reddish lesions over any body surface. They may also be seen under the cats chin or tail area.
A CBC and Chemistry profile are done to pinpoint an allergic condition such as a rise in the eosinophil levels. The latter are always elevated in parasitic or allergy cases. Skin scrapings are done to rule out parasites such as Cheyletiella and others. Flea combs are used to diagnose fleas or by finding the typical pepper looking flea dirt.
Diagnosis is made by the presentation of a cat with typical skin lesions associated with miliary dermatitis. An elevation in eosinophils found on lab data is helpful but doesn’t tell what the actual cause is.
Treatment is geared to finding and treating the cause of the miliary dermatitis. If it is flea related, animals are put on monthly preventatives such as Revolution® and the environment is treated for fleas. If a food allergy is suspected, a food trial is recommended employing many of the available hypoallergenic diets available for animals. If rodent ulcers are the problem, use ceramic food and water bowls instead of red plastic ones. (The red dye is the suspect allergen in this case.) If a secondary staph pyoderma is present most animals will be put on Clavamox® or facsimile. Most animals are intensely pruritic and are given an appropriate dose of DepoMedrol® to control clinical signs and make the animal feel better. Hairballs are taken care of by the many hairball preparations on the market.
The prognosis for miliary dermatitis is good and depends upon the elimination or control of the offending allergen or parasite. Many animals are extremely sensitive to the bite of just one flea so flea control is mandatory. The prognosis for immune-mediated miliary dermatitis depends upon the organ involved and pathology in that organ.
Nephritis is inflammation of the kidneys but the most common type of kidney inflammation is that called glomerulonephritis. This term refers to the inflammation of the glomerulous and renal parenchyma. The glomerlous is the first filtering device in the kidneys. The others are the proximal and distal tubules of the kidney. The term for the entire “factory” unit of waste disposal on a microscopic level is called the nephron. The most common cause of glomerulonephritis is the accumulation of antigen/antibody combinations. Other common causes of glomerulonephritis are heartworm, chronic dental disease, antifreeze poisoning and pyometra.
Think of the glomerulous as your kitchen drain. If the drain gets filled with food debris, the drain will not allow running water to pass through and it backs up and can even overflow and run over onto the floor! This is what happens in the glomerulous. Antigen-antibody combinations are the food debris. These combinations have a huge molecular weight and can not pass through the filtering device of the glomerulous. They clog it, impairing renal function.
Clinical signs development due to the poor filtering mechanism of the glomerulous and signs associated with renal disease. Animals may vomit, drink or urinate excessive amounts of water, have halitosis due to ammonia buildup and anorexia due to renal disease. There will often be visible blood in the urine as well as excessive protein due to poor filtration. Many dogs have glomerulonephritis secondary to another disorder and may develop chronic renal disease.
As with all renal diseases, a CBC and Chemistry profile are done to assess possible renal disease (elevated BUN and Creatinine) as well as a possible anemia. A urinalysis is always performed. Blood and excessive proteins are found on examination. The classical test to perform when suspecting glomerulonephritis is the UPC (Urine Protein Creatinine Ratio). This is extremely useful when deciding to treat it with Benazepril.
Diagnosis of glomerulonephritis is suspected when treating a primary disease that causes it. Clinical signs and lab data all go into making a diagnosis of glomerulonephritis.
Treatment is geared towards initially treating the primary cause of the glomerulonephritis. If the dog has heartworm, Immiticide® is used. If the dog has pyometra, the dog is spayed. Most animals need to be hospitalized for the treatment of the renal disease. There are varying degrees of glomerulonephritis so treatments may vary. Most animals receive intravenous fluids and diuretics to force as much fluid through the kidneys as possible, lowering the BUN and Creatinine in the process. Phosphate binders (Aluminum Hydroxide), antibiotics, vitamins and other dietary support measures will be offered. One of the most important ways to increase blood flow to the kidneys (glomerulous) is dilation of the renal blood vessels. This is done by the use of Benazepril, an ACE inhibitor. The use of this drug is based on the UPC results:
1. If the UPC is under 1, I rarely use Benazepril
2. If the UPC is between 1-2, I might use Benazepril
3. If the UPC is over 2, I always use Benazepril.
It is extremely effective in treating glomerulonephritis. The patient is discharged on it as well as diuretics, antibiotics and other supportive measures. Follow up visits including exams, blood work and urine exams are mandatory. The goal is to prevent chronic renal failure. If the urine can not concentrate, chronic renal failure will commence.
The prognosis for long term survival of glomerulonephritis depends upon successful treatment of the primary cause and preventing the animal from developing chronic failure. If those two goals are achieved the majority of animals do well as long as they are maintained on appropriate medical therapy and receive periodic exams, blood work and urine exams.
Notoedric Mange also goes by the name of Cat Scabies. It is an extremely irritating skin disease in the cat caused by the mite, Notoedres cati. Most people think that mange only can cause misery in dogs but any cat that has scaly, oozing lesions around the head and neck may have feline scabies.
All parasitic mites on dogs and cats cause damage to and reside in the hair follicle. This produces the typical scaly lesions seen. Most feline scabies will start as small oozing lesions on the ear tips but can easily extend to other parts of the body if left untreated. Feline scabies can be transmitted to dogs and humans by direct contact with an infested animal.
The most common sign is the development of oozing, scaly lesions on the ears that progress to the face and neck areas. They are extremely pruritic and cats will scratch and hyper-groom themselves resulting in hairballs. In chronic cases, the skin thickens and forms folds where secondary bacterial infections can take over.
The most commonly performed lab test is a deep skin scraping of the affected area on the cat. Under oil, the mite can easily be seen under a microscope.
Diagnosis is made by noticing the characteristic lesions around the face and by finding the mite on a deep skin scraping.
If one cat is diagnosed with the condition and it lives with other cats, all cats need to be treated. The most commonly performed treatment is shaving the affected areas of the cat and bathing it in a keratolytic shampoo such as benzoyl peroxide. A 3% lime sulfur dip is than applied and allowed to dry on the animal. Treatment can take months. Many chemicals used to treat dog scabies can be toxic to cats. Although they are off label; ivermectin, selamectin, (Revolution®) and moxidectin (Advantage Multi®) have been used successfully to treat feline scabies. It is much much easier to apply a topical than risk loss of limb trying to bathe the majority of cats! Lime sulfur dip also has an extremely offensive odor.
The prognosis for feline scabies depends upon the severity of the condition and or whether it is acute or chronic. Preventing cats from coming in contact with sick cats is important. Keeping your cats indoors is the best protection. Before any new cat is brought into the home, it should be taken to a veterinarian for a complete physical exam.
Oral injuries are a constant source of angst and pain for animals. People walk upright, animals walk on four legs. What this means is, is that their mouths are close to the ground surface. As I have said for years, dogs and cats are walking vacuum machines. They will get just about anything in their mouths. Common injuries such as: burns from chewing electrical cords, cuts and lacerations from ingesting glass and metal, severe oral infections from sticks wedged between the upper molars, needles that penetrate the soft palate, chewing rocks that fracture teeth, sharp objects that lacerate the tongue and the list goes on.
The mouth is the part of the body that is involved in prehension (the actual act of getting food into the mouth) and primary digestion by producing saliva. Other foreign bodies ingested can cause severe oral lesions that can lead to severe infections, loss of teeth and surgical repair of damaged tissue. The sinus cavities can be damaged or infected by objects that pierce the roof of the mouth.
The most common clinical sign with any foreign object lodged or damage to oral tissues is the animal constantly pawing at its face trying to extricate itself from a foreign body. If the object is sharp, such as metal or glass, there will be blood coming from the mouth mixed with saliva. If the object, such as a stick, has been in the mouth for days, there will be a foul odor. A lot of people think that is dental disease but on exam it is many times a stick lodged between the roof of the mouth and upper molars. Due to damage to the oral cavity, the animal may chew on one side of the mouth or not even eat at all if it is too painful to get food in the mouth.
Any lab work performed is proportionate to the type of oral injury. If an object penetrated the sinuses, radiographs will be taken to see if the sinuses have been infected. Most oral lesions can easily get infected so a CBC is warranted to keep an eye on the white cell count.
Tentative diagnosis of a foreign body is any dog or cat admitted that is pawing at its muzzle or face. Often the animal has to be sedated to get the diagnosis because it is too painful to open the mouth while awake. Many times the object has fallen out of the mouth yet trauma remains. At that point it is a good clinical guess that the animal had something in its mouth.
Treatment is geared towards treating the injury in the oral cavity and removing the object. Many animals are sedated to diagnose and than remove the foreign body from the mouth. Lacerations will need to be cleaned up and stitched. Burns from electrical cords will need to have the necrotic (dead) tissue removed so healing can occur. All animals are placed on antibiotics and soft, warm foods to make it easier for the animal to eat. Hamburger (chicken) and boiled rice is a good bet.
The prognosis for oral foreign body injuries is excellent once the foreign body is removed and the infection and tissue damage are dealt with.
The important thing is prevention. Walk around your home and yard and pick up anything that a dog or cat may find attractive. Dog and cat owners have to continually dog or cat proof their homes so animals can not injure themselves. They are toddlers for life!
Osteosarcomas are highly malignant bone tumors commonly seen in older, large breed dogs. The cause is unknown. There are many factors being studied that may predispose a dog to osteosarcoma but none yet has been conclusive. In most medical practices, it is the most common bone cancer seen in animals.
Osteosarcomas originate in bone tissue and their neoplastic growth causes damage to the bone itself. It literally eats the bone away making the bone very unstable. This leads to pathological fractures. Osteosarcomas are seen commonly in the distal (lower) part of the femur (long bone) of the dog. It also may occur in other long bones such as the tibia, radius and humerus.
The most common sign is the development of a lameness, particularly in the hind limbs, in the absence of trauma or self injury. They are extremely painful and animals are reluctant to move. There usually is a warm swelling over the affected joint. Any Rottweiler that is limping should be screened for osteosarcoma. They are one of the most commonly seen breeds that get osteosarcoma and chondrosarcomas. There are many diseases such as non-pathologic fractures, cruciate disease and others that cause signs similar to those of osteosarcoma.
The most important tool is radiographs of the affected limb. Differentiating it from other injuries is the “pitting” or bone lysis that is seen on films. The “eaten” areas of the bone are totally radiolucent (meaning black in appearance on films). All you will see are black markings all over the film indicating bone destruction. A CBC and Chemistry profile are also performed to observe if there has been any metastasis of the tumor to other bones or tissues such as the liver.
Diagnosis is made by the presentation of a large dog limping due to non trauma causes plus characteristic radiographic bone changes. In many cases, I have gone in to get bone biopsies to confirm the diagnosis by a veterinary pathologist. If the bone is totally lysed, a fine needle aspirate may be performed instead of the biopsy. By the time this condition is diagnosed, the majority of lesions have metastasized to the liver and lungs.
Whether dogs are treated or not, medical management of these animals is not successful in the majority of cases due to the metastasis of the primary disease to other tissues. Veterinary oncologists have attempted treating local bone lesions with Cysplatin beads. Surgical amputation of the limb is possible but in my opinion causes too much pain for the very little time the animal has left due to metastasis of the tumor. Radiation can be attemped also. Animals are in pain most of the time and will need to be put on analgesics such as Tramadol® or an opiate.
The prognosis for long term survival of osteosarcoma is poor. The survival rate depends upon the severity of the disease, presence of pathological fractures (fractures caused by a disease process) and or the metastasis of the primary lesion elsewhere in the body.
The crucial bottom line is maintaining the animal’s quality of life as long as possible before a decision is made to euthanize the pet. It is a very difficult decision to make but the most important thing to realize is that an animal should never be allowed to suffer. That really IS inhumane.
Home care is important. The affected bone will become weaker over time so be careful of dogs going up and down stairs. Slippery floors such as wood and tile can make it difficult for the dog to go outside or get to its food and water bowl. Provide a sling support (using an old bed sheet) to make it easier for the animal to move around. Provide thick comfortable bedding that will support the sore limb. Put food and water bowls close to the animal. Spoil the animal and give it a bouquet of TLC and kisses.
Otitis externa is one of the most common things treated in dogs and cats. It is a fancy word for an external ear infection. Ear infections are usually caused by a multitude of bacteria, yeast and parasitic organisms that produce a swelling and inflammation of the external ear canal. Bacterial infections can be difficult to deal with. The worst bacteria to find in the ear canal is Pseudomonas aeruginosa. It is resistant to almost all antibiotics except Zeniquin®. Other bacteria cultured are enteric bacteria! That is, bacteria normally found in the stool. Since dogs do not wear shoes, they step in fecal matter and scratch their ears hence introducing the bacteria in the ear canal. Wherever you find bacteria outside of its normal environment, it makes it difficult to treat. Ear infections can also be caused by a narrowing or stenosis of the external ear canal and food allergies. Dogs, such as all Retrievers, can develop “Swimmer’s Ears” from pond water accumulating in the external ear canal. Excess hair and ear wax in the canal also predisposes the animal to an external ear infection. They are seen much more common in dogs with floppy ears and those breeds that produce a lot of ear wax such as all the Spaniels.
The external ear canal of the dog and cat is composed of two parts. A vertical and horizontal ear canal. Humans just have a horizontal canal. What this means is that air circulation in the animal ear is not as good as in people. This is due to the curvature of the ear canal plus the presence of floppy ears that hang down in many breeds of dogs. This combination impedes air circulation making it easier for bacteria and yeast to reproduce and cause inflammation. It is this inflammation that leads to the majority of clinical signs.
The characteristic sign of otitis externa is head shaking and pawing at the affected ear. Many dogs will just have one nasty ear infection while the other is perfectly normal. My theory has been that the dog sleeps on the infected side more; making air circulation even worse. There is also a foul odor coming from the ear. It is painful. Owners will notice something is wrong just by petting the animal or stroking its ears when the animal cries out in pain. The ear canal is usually inflamed and dogs will tilt their head to alleviate discomfort. Many animals will present with an auricular hematoma that is secondary to the external ear infection.
To find the cause of the bacterial ear infection requires culture and sensitivity of ear debris. Yeast can be diagnosed by the characteristic stained microscope appearance. In severe cases, a CBC may be performed to check the white cell count.
Diagnosis of otitis externa is made by the medical history and clinical signs present.
Treatment of otitis externa has two facets. The treatment of the original cause of the infection and to create an ear environment that is resistant to future ear infections.
1. Bacterial Ear Infections: In the majority of basic cases, a topical antibiotic will be prescribed. In severe infections a topical and oral antibiotic such as Clavamox® will be prescribed. At the same time a culture is taken for the lab to grow.
2. Yeast (Malassezzia) Ear Infections: Can be treated with topical antifungals with or without oral ketoconazole.
3. Food Allergy Ear Infections: These are often treated with antihistamines such as hydroxyzine plus a food trial is offered.
4. Ear Mites External Ear Infections: There are many preparations such as Tresaderm®, pyrethrins and Acarexx® (ivermectins) that will do the job. Treatment for ear mites takes a minimum of three weeks.
In many animals the ear pain and head shaking is intense. If you do not stop the head shaking, an auricular hematoma will be the usual result. Topical and or injectable corticosteroids will often be used on a short term basis to control inflammation hence head shaking.
The ear canal needs to stay dry and acidic. These are normally bad conditions for yeast and bacteria to grow. Most veterinarians will send home a suitable preparation wash that is squirt in the ear, massaged in and removed with cotton balls. One of my favorites is EpiOtic®. Never use Q-Tips® to clean the ears. Animals may jerk and the cotton swab will penetrate the tympanic membrane causing intense pain and possible hearing loss. I have had to sedate numerous animals to remove the offending object. In cats, NEVER use ear cleaning products that contain salicylates! Salicylic acid is an astringent and is present in many canine ear cleaners. Cats are ultra sensitive to salicylates. For that reason, avoid the use of aspirin (acetylsalicylic acid) in cats. Use ear cleaning preparations that are made for dogs and cats or just cats.
The ear canal should be cleaned out first with a cleaner before the antibiotic drops are applied. Once the ear infection is cleared, use the cleaner at least once a week. For dogs that love to swim in the summer, clean the ears after each romp in the water.
It is crucial to keep acute ear infections under control. If they continue, a chronic ear infection develops. They cause a stenosis (narrowing) of the ear canal making ear infections even worse. Chronic cases are almost impossible to cure but possible to control.
The prognosis for acute ear infections is usually very good. Chronic cases can be controlled but are almost never cured. Ear infections can be prevented by using a professional grade ear cleaner available from your veterinarian.
