What Is Canine Heartworm Disease?
Heartworm disease is a serious and potentially fatal condition that affects dogs, cats, and up to 30 other species of animals. It is caused by parasitic worms (heartworms) living in the major blood vessels of the lungs and, occasionally, in the heart. These worms are transmitted (as microscopic larvae) through the bite of an infected mosquito. The scientific name for the heartworm parasite is Dirofilaria immitis.
Heartworm disease can cause a variety of medical problems affecting the lungs, heart, liver, and/or kidneys. Any of these problems, alone or in combination, can lead to death. Although safe and effective treatment is available, it can be a costly and complicated process depending on how long the dog has been infected and how severe the infection is.
How Is Heartworm Testing Performed?
Heartworms are spread through the bite of a mosquito. When a mosquito bites an infected dog, it withdraws blood that contains immature heartworms (called microfilariae [pronounced micro-fill-air-ee-ay]). These microfilariae mature inside the mosquito to become infective larvae. When the mosquito bites another dog, the larvae enter the dog and (in many cases) mature to become adult heartworms, which produce more microfilariae and continue the heartworm’s life cycle. Current testing practices can detect several stages of heartworm infection:
No test is accurate 100% of the time, and sometimes your veterinarian may recommend performing tests more than once, or performing additional tests to learn more about your dog’s overall health.
When Should My Dog Be Tested for Heartworm Disease?
Dogs should be tested for heartworms before beginning a heartworm prevention program, or when changing from one heartworm preventive to another. Dogs that are already on heartworm preventive medication should also be tested periodically.
The “prepatent period” for heartworm disease (the amount of time it takes for microfilariae to be produced) is approximately 6 months in a dog. During this time, heartworm tests will be negative even if a dog is actually infected. Therefore, puppies younger than 7 months old are generally not tested for heartworms. Instead, puppies should be started on heartworm preventive medication (usually during their puppy checkup visits) and tested when they are older than 7 months.
Ask your veterinarian about the recommended heartworm testing schedule for your dog.
What Are the Benefits and Risks of Canine Heartworm Testing?
There are very few risks associated with heartworm testing. Drawing blood takes only a few seconds, and your veterinary team will take precautions to ensure that your pet is not injured during this procedure. Once blood is obtained, all further processing is performed at the veterinarian’s office or at a diagnostic laboratory, so there is no risk of harm to your pet.
The benefits of heartworm testing are enormous. If your dog is infected with heartworms, early diagnosis and treatment are the best ways to help ensure that the infection is cleared before permanent damage is done to the heart, lungs, or associated blood vessels. Heartworm disease can be fatal if left untreated, so early diagnosis and treatment can literally save your dog’s life! Be sure to keep your dog on heartworm preventive medication and follow your veterinarian’s recommendations regarding heartworm testing.
What Is It?
Canine distemper is a serious contagious disease caused by canine distemper virus (CDV), which attacks the respiratory, stomach/intestinal, and brain/nervous systems of dogs. It can also infect ferrets and many wild animals, including raccoons, skunks, minks, weasels, foxes, and coyotes. The death rate can reach 50%, and animals that do recover are often left with permanent disabilities. There is no effective treatment, but virus-associated disease is largely preventable through vaccination.
While the disease is less common than it was before the first effective vaccines became available in the 1960s, it is still present in wildlife populations that might have contact with domestic animals.
The incubation period of CDV is typically 1 to 2 weeks but can last up to 5 weeks. CDV is shed (spread) through all body secretions. It can also be carried on the hands and feet. Warm, dry, or sunny conditions will kill CDV, but it is resistant to cold and can survive in near-freezing, shady environments.
Signs of Distemper
The first sign in infected dogs typically is a watery or pus-like eye discharge.
Additional initial signs include:
In later stages, the disease affects the brain and nerves, and dogs may show the following signs:
Because of the importance of canine distemper and its severity, the CDV vaccine is considered a “core” vaccine by organized veterinary medicine, meaning that all dogs should be protected from this disease. Vaccination is the most effective way to prevent illness and death associated with CDV infection. The CDV vaccine is typically given in a combination vaccine that also protects against other serious diseases, such as canine parvovirus and canine adenovirus-2 infections.
Your veterinarian will advise you of what vaccination schedule you should follow for your pet, but in general, all puppies should receive the CDV vaccine every 3 to 4 weeks between the ages of 6 and 16 weeks, followed by a booster 1 year after the last dose. Thereafter, booster vaccinations are typically recommended every 1 to 3 years.
It is important to remember that a vaccination, even a routine one like a CDV vaccine, is a medical procedure, and you should follow your veterinarian’s instructions on how to monitor your pet for signs of a reaction. Vaccine reactions are rare, but knowing the associated signs is important.
Other forms of prevention include the following:
Diagnosis and Treatment
Diagnosis of CDV infection is difficult because there are few reliable tests for the disease and, in the initial stages, clinical signs can mimic those of other conditions, such as kennel cough. Diagnosis is generally based on clinical signs.
Treatment is limited to supportive care: providing fluids, administering medications to reduce vomiting and diarrhea, and administering antibiotics to prevent subsequent infections, such as pneumonia.
Caution: Some of the clinical signs of both rabies and canine distemper can be similar, so use caution when handling sick animals.
What Is Diabetes Mellitus?
Diabetes mellitus is an illness caused by the body’s inability to either make or use insulin, which is a hormone produced and released by specialized cells in the pancreas. Insulin permits the body’s cells to take sugar (glucose) from the blood and use it for their metabolism and other functions. Diabetes mellitus develops when the pancreas doesn’t make enough insulin or when the body’s cells are unable to use available insulin to take glucose from the blood.
Type 1 diabetes mellitus (referred to as “insulin dependent” diabetes) occurs when the pancreas doesn’t make enough insulin. Type 2 diabetes (more common in cats and humans) has been called “relative insulin deficiency”; it occurs when the body’s cells develop “insulin resistance,” meaning that they are unable to effectively use available insulin, or when the pancreas is producing some insulin, but not enough to serve the body’s needs. Most diabetic dogs have type 1 diabetes mellitus. Lifelong administration of insulin is generally required to control this illness.
What Are the Clinical Signs of Diabetes in Dogs?
Diabetes can exist for a while before it begins to make an animal obviously ill. Clinical signs may vary depending on the stage of disease, but they can include the following:
How Is Diabetes Diagnosed?
Your veterinarian may suspect that your dog has diabetes if any suspicious clinical signs, such as increased drinking and/or urinating, have been observed at home. After performing a thorough physical examination, your veterinarian may recommend some of these tests to help confirm a diagnosis:
How Is Diabetes Treated?
Because dogs tend to have type 1 diabetes mellitus, insulin injections are generally started at diagnosis and continued for the rest of the pet’s life. Your veterinarian may also recommend dietary changes to help control your dog’s diabetes. It is very helpful to write a medication schedule for your pet on the calendar, including the date and time that the medication needs to be administered, and to maintain accurate records. This will help you to avoid forgetting to give insulin to your pet and allows you to track your pet’s treatment.
After treatment begins, periodic blood and urine tests are generally recommended. This helps ensure that the insulin dosage is right for your dog. Your dog’s weight, appetite, drinking and urination, and attitude at home can all provide useful information that helps determine if his or her diabetes is being well managed. Your veterinarian will consider all of these factors when making recommendations for continued management.
Many dogs live active, happy lives once their diabetes is well regulated. However, insulin therapy and regular monitoring at home and by your veterinarian are necessary for the rest of your dog’s life.
What Is Canine Coronavirus?
Coronavirus infection is a highly contagious infection of puppies and older dogs that primarily attacks the intestinal tract. The disease is spread from dog to dog through contact with feces. After coronavirus has been transmitted to a dog, the incubation (development) period of the disease can be as short as 1 to 4 days.
Signs of Coronavirus Infection
Coronavirus infections are typically mild and self-limiting (resolving without treatment), and infected dogs may have several days of diarrhea that resolves without treatment. Other signs may include:
Diagnosis and Treatment
Coronavirus infection is typically diagnosed based on clinical signs, although definitive laboratory testing is available. Because the clinical signs can be similar to those of more serious diseases (such as parvovirus infection), your veterinarian may recommend testing to rule out other illnesses.
Because coronavirus infection is caused by a virus, there is no cure. Treatment is typically limited to supportive care, such as fluid therapy, rest, and antibiotics to prevent secondary infections. If vomiting or diarrhea is severe, medications may be prescribed to manage the problem.
Coronavirus is spread through contact with fecal material from infected dogs, so separating sick dogs from healthy ones can help reduce disease spread. Coronavirus can be killed by many types of household disinfectants (including diluted bleach solution), so cleaning contaminated areas and bedding can also help reduce disease spread.
A vaccine is available to prevent canine coronavirus infection. The coronavirus vaccine is not required for all dogs, but it may sometimes be included in combination vaccines for other, more serious diseases, such as infections with canine distemper virus, canine parvovirus, and canine adenovirus type 2.
In cold weather, some dogs may be more comfortable in outerwear (sweaters or coats). Some dog breeds (like malamutes, huskies, Newfoundlands, and other breeds with thick coats) thrive in cold temperatures, so these dogs don’t need outerwear. However, outerwear can help short-haired dogs (like boxers, greyhounds, and vizslas) stay comfortable longer in the cold, allowing them to conserve body heat as well as energy for walking and running. When it’s cold, outerwear is recommended for dogs recovering from surgery (anesthesia can disrupt a dog’s ability to regulate his or her body temperature). If your dog seems to be reacting poorly to cold temperatures (such as prolonged shivering), contact your veterinarian right away.
Dog boots are recommended if your dog will be outdoors for a long time or will be walking on ice, which can injure paws.
Dogs of any breed can benefit from canine raincoats, which can help keep your dog and house dry. Many canine raincoats have the added benefit of reflective material for safety.
Tips for Dressing Your Dog
What Is a Bladder Infection?
The bladder is an expandable sac, like a balloon, that lies toward the back of the abdomen and is part of the system that removes waste from the body. Urine flows from the kidneys through the tube-shaped ureters and into the bladder, where it is stored before being eliminated from the body through a tube called the urethra.
Urine in the bladder is normally sterile unless microbes (usually bacteria) travel up the urethra and proliferate, causing an infection. These bacteria may come from the nearby rectal area or from the genital tract. Conditions such as diabetes can increase the risk of developing bladder infections, as can medications that depress the immune system, including high-dose or long-term corticosteroids.
In long-standing infections, the bladder tissue can thicken and scar, creating more places for bacteria to grow. Long-term infection also increases the chances that infection will spread upstream to the kidneys or cause bladder stones to form.
What Are the Signs of a Bladder Infection?
Urinary infections irritate the walls of the bladder, so pets with bladder infections have the urge to go even when there is little urine present. They frequently pass small amounts of urine that are often tinged with blood. Constant squatting and straining without passing much urine and having urinary accidents in the house are typical signs of potential bladder infection. Bladder infections are more common in females than in males; however, any dog can have a bladder infection.
Bladder infections change the chemical makeup of the urine, which makes it easier for minerals in the urine to crystallize and form stones. Bladder stones add to the irritation and create places for bacteria to hide from bodily defenses and antibiotics.
On some occasions, bladder stones can block the outflow of urine, which is a serious emergency situation. Pets with urinary obstruction can have a swollen, painful abdomen and strain repeatedly without passing urine. This is a medical emergency!
How Is a Bladder Infection Diagnosed?
Your veterinarian can usually diagnose an uncomplicated bladder infection based on your pet’s history and a urinalysis. In some cases, a urine sample might be sent to a laboratory to determine the specific bacteria involved (through a culture and sensitivity test) as well as an effective antibiotic for treatment. Abdominal radiography (x-rays) or ultrasound imaging is sometimes needed to look for stones, tumors, or other abnormalities involving the bladder.
How Are Bladder Infections Treated?
Treatment for a simple bladder infection usually consists of 1 or 2 weeks of antibiotics. Chronic or severe infections may require longer treatment. Infections that clear up and then come back may suggest an underlying problem requiring additional diagnostic testing and treatment.
If bladder stones are present, there are several options for eliminating them:
What Is It?
Arthritis is a joint problem that can reduce mobility and cause pain. Often seen in older dogs, arthritis can by caused by injury, infection, the body’s own immune system, or developmental problems. The most common form of arthritis is called osteoarthritis (osteo = bone; arthr = joint; itis = disease) or degenerative joint disease. Normally, joints form smooth connections between bones. Osteoarthritis involves thinning of joint cartilage (a protective cushioning between bones), buildup of fluid within the joint, and the formation of bony growths within the joint. Over time, this can lead to reduced joint mobility as well as pain. Osteoarthritis affects one of every five dogs.
Signs and Diagnosis
Recognizing arthritis in dogs can be difficult because the condition progresses slowly and dogs don't complain about their aching joints. Also, some owners assume that signs of arthritis are “normal” in older animals.
Bringing your dog in for an annual checkup can help your veterinarian identify clinical signs early. Radiography (x-rays) can reveal bony growths and joint abnormalities.
Regular, moderate exercise and a high-quality diet can help delay aging, manage body weight, and keep your dog’s musculoskeletal system in good shape. Ask your veterinarian to recommend an exercise program and a diet that are appropriate for your dog.
Many human and canine pain relievers are poisonous to cats.
Aids for Arthritic Dogs
What Is Canine Otitis?
Canine chronic otitis is recurrent or persistent inflammation of the ear. One or both ears may be affected. Inflammation of the ear often leads to secondary infection caused by yeast or bacterial overgrowth. This condition can be quite painful.
Chronic otitis is most often caused by allergies to fleas, certain foods, or substances in the environment. Sometimes medical problems like thyroid disease can cause a dog to develop otitis. Certain breeds such as cocker spaniels and golden retrievers are more prone to ear infections.
Signs of Canine Chronic Otitis
Signs of otitis include head shaking, scratching, and even head rubbing against floors and furniture. The normally pink skin of the ear appears very red, and dark debris or yellow to brown discharge may be present, along with a foul odor. In dogs with dark pigmented skin, the redness may not be apparent, but debris, discharge, odor, and discomfort will be evident. This condition will persist or get progressively worse if left untreated.
Signs of Canine Chronic Otitis
Diagnosis and Treatment
Diagnosis is based on history, clinical signs, swabs of samples taken from inside the ear canal, and physical examination, including examination with an otoscope (a special tool with a light and a cone for viewing the inside of the ear canal). Your veterinarian may perform cytology, which is an examination of the swab sample from the ear specially prepared on a slide for evaluation under a microscope. The slide is examined for the presence of yeast, bacteria, and white blood cells (which fight infection). Ear mites (microscopic mites that can live inside the ear canal) can cause ear infections and also can be identified when your veterinarian looks under the microscope.
Another test commonly used to help diagnose chronic otitis is a bacterial culture and sensitivity test. For this test, your veterinarian will use a sterile swab to obtain a sample of material from inside the ear. This swab is then placed in a special tube and sent to the lab for specific identification of bacteria and yeast.
The test result also lists the most effective antibiotics against the identified bacteria.
Treatment of chronic otitis most commonly includes medicated ear-drops or cream along with a prescribed ear-cleaning regimen. Most ear medications contain a steroid to reduce inflammation, an anti-fungal medication, and an antibacterial medication. Sometimes your veterinarian will recommend pill or liquid medication to be given by mouth to help treat otitis. If your veterinarian performs a bacterial culture and sensitivity test, the results of this test will guide in the choice of antibacterial and/or anti-fungal medication. It is very important to follow the prescribed treatment, since failure to complete treatment may result in recurrence and even bacterial or fungal resistance to treatment.
Another important element of diagnosis and treatment is to identify underlying allergies. Common allergies in dogs include flea allergies, food allergies, and environmental allergies (allergy to dust, mold, pollen, and other common particles found in the environment). Your veterinarian can guide you through the identification process, which includes regular flea prevention, possibly a “hypoallergenic” food trial, and allergy-testing using specialized skin and blood tests.
Because medical problems, such as thyroid disease, can sometimes cause otitis, your veterinarian may recommend specific blood tests to look for evidence of underlying illness.
Most cases of chronic otitis are treated or managed with medication. In some extreme cases, surgery may be recommended.
Identification of underlying allergies is very important for successful long-term management and preventing “flare ups” in the future. If food allergies are identified, a special diet may be recommended to avoid offending foods. Sometimes this involves a prescription diet or a good quality store-bought diet that does not contain any of the identified allergens. If environmental allergies are identified using skin and blood tests, allergy shots may be recommended to help reduce sensitivity to the named allergens. In the case of flea allergies, regular flea prevention with a product recommended by your veterinarian is very important.
Other forms of prevention include regular ear cleaning with an ear cleanser that will help to inhibit fungal and bacterial overgrowth. Most ear cleansers also break up and flush out wax and debris that accumulate in the ear. Your veterinarian can guide you in the appropriate choice of ear cleanser, and discuss frequency of cleaning along with proper technique.
What Is Anesthesia?
Anesthesia is defined as the loss of ability to feel pain. However, the term anesthesia is more commonly used to refer to a state of deep sedation or unconsciousness during which a patient is unable to feel pain.
Two forms of anesthesia are used in dogs. For some patients, local anesthesia is an option. This involves injecting the medication into a specific place in the skin (or applying it onto an area of the skin) to induce temporary localized numbness, allowing the veterinarian to perform a brief procedure.
The affected area can include the skin, underlying muscles, and nerves. The medication used for local anesthesia does not cause the patient to fall asleep; when deep sedation or unconsciousness is required, general anesthesia is a better option. Medications used for general anesthesia are available in many forms. Some are administered by injection, whereas other forms are inhaled through an anesthetic mask or breathing tube that is connected to an anesthesia machine.
When Is Anesthesia Used?
Anesthesia has many uses in dogs. Local anesthesia may be an option if your veterinarian needs to remove a small growth on your dog’s skin, perform a biopsy of a growth or an area of skin, use stitches to close a small cut or wound, or perform any type of minimally painful procedure during which unconsciousness is not required.
General anesthesia is used for more invasive types of surgeries or for procedures likely to be very painful. Examples include repairing a broken bone or performing surgery involving the abdominal or chest cavities.
Surgery is not the only time when anesthesia is recommended. Dogs generally require anesthesia or very heavy sedation before dental cleanings, dental x-rays, or complete dental examinations. Anesthesia is sometimes used for taking x-rays of other areas of the body, especially if the patient is painful and positioning for x-rays would result in more pain. General anesthesia tends to cause muscle relaxation, which has additional advantages when x-rays of the body are required.
Sometimes, local anesthesia and general anesthesia are used together for the same procedure. For example, some veterinarians use general anesthesia to place the patient into a state of unconsciousness, then inject a local anesthetic agent into the skin and underlying tissues where surgery will be performed. The numbing effect of the local anesthetic can reduce the amount of pain that the patient experiences when he or she eventually wakes up from general anesthesia.
How Is Anesthesia Performed?
Your veterinarian may recommend a pre-anesthetic evaluation before placing your pet under general anesthesia. This process is generally not necessary for local anesthesia. The pre-anesthetic evaluation may include a physical examination to ensure that your pet is healthy enough for anesthesia. Pre-anesthetic blood work may also be recommended to help identify medical problems that may increase the risks associated with surgery or anesthesia. Pre-anesthetic blood work can help identify medical conditions such as infection, anemia (a low number of red blood cells), low blood sugar, inadequate blood-clotting ability, liver disease, or kidney disease.
If your pet has any pre-existing medical issues, such as a heart problem, your veterinarian may recommend additional testing to determine if any precautions are recommended or if anesthesia should be postponed or cancelled due to health reasons.
Some practices perform the pre-anesthetic evaluation on the day of anesthesia. However, some veterinarians perform this testing a few days or weeks before the procedure is scheduled. This is a common practice before performing an elective surgical procedure such as a dental cleaning, spay surgery, or castration surgery.
Inducing and Maintaining General Anesthesia
The process of sedating a patient and preparing him or her for entering general anesthesia is called induction. Once induction is accomplished, the patient is maintained under general anesthesia until the procedure (surgery, x-rays, biopsy, dental cleaning, or other procedure) is completed and the patient is permitted to awaken.
Induction generally begins with administration of a sedative. This helps relax the patient so that the rest of the induction activities can proceed. During this time, an intravenous catheter may be placed to begin administration of intravenous fluids. Once the patient is relaxed, additional medications are given to induce a deeper level of sedation, leading to general anesthesia. If injectable anesthetic medication is used, this medication is continued until the patient is permitted to wake up. If inhalant anesthesia is chosen, a breathing tube is inserted into the patient’s main airway (or sometimes an anesthetic mask is placed over the mouth and nose) and connected to a machine that delivers a carefully calculated mixture of oxygen and inhalant anesthetic. The patient inhales this mixture until the procedure is completed and the patient is permitted to awaken.
Both methods of general anesthesia (injectable or inhaled) will safely keep your pet asleep and pain-free. Whichever method of anesthesia is chosen, your veterinarian will take every precaution to help ensure that your pet remains healthy and awakens safely from anesthesia. Veterinary technicians observe and monitor patients that are under general anesthesia. Additionally, monitoring equipment is generally used to constantly measure heart rate, breathing, oxygen use, and blood pressure.
When the procedure is completed, the anesthetic agent is discontinued and the patient is monitored until he or she is fully awake and recovered from anesthesia.
What Are the Benefits and Risks of Anesthesia?
Keeping patients pain-free during surgery is an important goal of anesthesia, but there are many other purposes for anesthesia. If a dog has an injury that is too painful to be examined while the dog is awake, anesthesia may be the best way to facilitate a thorough examination. Additional procedures, such as placing a splint or cast on a broken leg, taking x-rays of a painful injury, or cleaning and dressing a serious wound can frequently be accomplished more efficiently if the patient is under anesthesia.
Many dental procedures, including dental cleaning, extracting an infected or broken tooth, taking dental x-rays, or performing dental restoration, are generally not possible without anesthesia.
As with any medical procedure, anesthesia is not without its risks. Some patients may react negatively to the anesthetic medication or experience fluctuations in heart rate, breathing, or blood pressure. Your veterinarian is extensively trained in performing anesthesia, and your veterinary care team will take every possible precaution to help ensure that your pet awakens safely. Be sure to address any questions or concerns with your veterinarian.
What Is Canine Adenovirus Type 2?
Canine adenovirus type 2 (CAV-2) causes respiratory disease in dogs and is one of the infectious agents commonly associated with canine infectious tracheobronchitis, which is also known as kennel cough. Canine infectious tracheobronchitis is usually spread from dog to dog through coughing. Dogs that are around other dogs, such as at boarding facilities, grooming salons, or dog parks, are at increased risk for exposure.
After CAV-2 has been transmitted to a dog, the incubation (development) period of the disease is approximately 3 to 10 days. The infection is typically self-limiting (resolving without treatment); however, in some cases, it can lead to pneumonia.
Signs of Canine Adenovirus Type 2 Infection
Common signs of CAV-2 infection include:
Diagnosis and Treatment
Infectious canine tracheobronchitis is usually diagnosed based on clinical signs and a history of possible exposure (such as a recent trip to a grooming salon or boarding facility).
Treatment of CAV-2 infection is typically limited to supportive care, which may consist of fluids, rest, and antibiotics to treat secondary infections that may develop.
A vaccine is available to prevent CAV-2 infection. However, it is important to realize that the vaccine does not completely prevent a dog from contracting CAV-2. Rather, the vaccine limits the severity of infection so that vaccinated dogs typically experience a milder form of the disease.
The CAV-2 vaccine also protects against infection with canine adenovirus type 1 (CAV-1). CAV-1 causes infectious canine hepatitis—a dangerous and potentially fatal infection. Because CAV-2 is common and the CAV-2 vaccine cross-protects against CAV-1, the CAV-2 vaccine is considered a core vaccine by organized veterinary medicine, meaning that all dogs should receive this vaccine. The CAV-2 vaccine is typically given in a combination vaccine that also protects against other serious diseases, such as canine distemper and canine parvovirus infection. Your veterinarian will recommend a vaccination schedule for your pet.
Other preventive measures include:
Dogs with kennel cough should wear a harness rather than a neck collar when taken for walks during recovery. Collars can place pressure on the trachea (the large airway that runs from the back of the throat into the lungs), which can contribute to coughing.
Dr. Carlson is an avid contributor to her blog, make sure you check out her articles!