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- How is FeLV transmitted?
Direct contact between cats is the most frequent method of FeLV infection. The virus is fragile and cannot survive longer than a few hours in the environment outside of the cat. A cat with FeLV sheds a large quantity of the virus in its saliva as well as in other bodily fluids such as urine and feces. However, FeLV is not a highly contagious virus, and transmission generally requires a prolonged period of close contact between infected and susceptible cats. Close contact activities include mating, mutual grooming, and sharing of litter trays and food bowls. Cat bites by an infected cat can readily transmit infection.
Another potential source of infection is when a pregnant cat infected with FeLV gives birth. In this situation, all the kittens will likely be born with FeLV virus. Fortunately, it is more likely that a queen infected with FeLV becomes infertile or there is pre-natal death of the kittens with abortion or resorption of the fetuses.
- Is there any treatment for FeLV infection or disease?
There is currently no specific treatment for FeLV-infected cats. There is no treatment to eliminate the virus from the body. Most FeLV-infected cats will eventually die or be euthanized because of diseases related to their infection. However, many cats showing FeLV-related disease will improve with symptomatic treatment, at least for a period of time. For example, if FeLV is causing immunosuppression and the patient develops secondary infections, the secondary infections may be treatable, leading to clinical improvement.
- How can infection be prevented?
Vaccines are available to protect cats against FeLV infection. Their use is highly recommended for any cat that goes outside at any time and therefore could have contact with FeLV- infected cats. As with other vaccines, an initial course of two injections is required, and regular boosters are necessary to maintain immunity. Your veterinarian will discuss the most appropriate options for your cat with you. All cats should be tested for FeLV prior to vaccination.
Although vaccination is very helpful in preventing infection with FeLV and thus controlling FeLV-related disease, no vaccine is 100% protective. Where possible do not allow your cat, particularly if a kitten, to come into close contact with known FeLV-infected cats or cats without a known history of proper vaccinations.
In larger colonies of cats, it is possible to control FeLV infection through a combination of routine FeLV testing, quarantine and vaccination programs. Fortunately, vaccinating a cat does not interfere with subsequent blood testing for FeLV.
FeLV is usually fatal. Studies have shown that 80-90% of FeLV-infected cats will die within three to four years of initial diagnosis.
Feline Immunodeficiency Virus
November 09th, 2010 | Category: Common Diseases,FAQS
- What is Feline Immunodeficiency Virus?
Feline Immunodeficiency Virus (FIV) is a virus specific to the cat family. It was first recognized in the mid 1980′s and it has been found in cats worldwide. Although widespread, it is not a common infection in cats. Only 1 – 2% of cats show evidence of exposure to the virus. In some cats exposure to the virus leads to clinical signs and symptoms that result in deficiency in the immune system. There are different strains of FIV and some seem more harmful than others.
- My cat has tested “positive” for FIV. Does my cat have feline AIDS?
Being FIV-positive is not the same as having feline AIDS. The FIV test (see below) detects antibodies that have been formed in the cat’s blood as a result of infection with the Feline Immunodeficiency Virus. “FIV-positive” means that your cat has been infected by the virus, but if it is not showing symptoms then it may be years, if ever, before the cat develops the clinical signs referred to as Feline AIDS (Acquired Immunodeficiency Syndrome of cats). Just being diagnosed with the FIV virus does not mean your cat has feline AIDS.
- Is my family at risk?
Absolutely Not! Although HIV (Human Immunodeficiency Virus, the cause of AIDS in people) belongs to the same family of viruses as FIV, the two viruses infect different species – HIV infects only humans and FIV infects only cats. The viruses are very specific for the species and there is no risk of cross infection between the immunodeficiency viruses of cats and people.
- Are other cats in the household likely to be already infected or to become infected?
Other cats in your household may already have been infected and should be tested. Spread between cats through normal social contact is unlikely so the majority of your cats may be FIV-negative when tested.
- How do cats get FIV?
The virus of FIV is found primarily within certain cells inside infected cats. When virus is shed to the outside it is mainly in the saliva. Transmission of infection to another cat requires direct inoculation of the saliva, and a bite from an infected, shedding cat is the primary means of transmitting FIV. It is not surprising that many FIV-positive are known fighters, particularly those with a history of cat bite abscesses. Any cat bitten by a cat with an unknown medical history should be tested for FIV approximately two months after the bite.
The FIV organism is not able to survive for very long outside of living cat cells and this is another reason that casual infection is uncommon. Kittens may become infected at or soon after birth most likely through virus that is transmitted during pregnancy or through the queen (mother) cat’s milk. Around a quarter to a third of kittens born to an infected queen are likely to be infected themselves. Normal social interactions, such as grooming, have a very low risk of transmitting FIV.
- What type of disease does FIV cause?
FIV causes disease because it reduces the ability of the cat’s immune system to respond to other infections. Infections that would normally be overcome and cleared become prolonged, chronic or recurrent. This means that many of the clinical signs associated with FIV are due to other non-healing infections. Collectively the signs and symptoms seen as a consequence of FIV is sometimes called “Feline AIDS” or Acquired Immunodeficiency Disease of cats.
- Is there any treatment for FIV?
Secondary bacterial infections associated with feline AIDS can be effectively treated with antibiotics. Unfortunately this is usually only temporary until another infection occurs as a result of the suppressed immune system. No specific treatment for the virus is available. Some cats have been treated with interferon or with human anti-HIV drugs such as AZT with limited success. Evening Primrose oil seems to be helpful particularly in the earlier stages following infection.
- Should I have my cat euthanized?
Generally this is not necessary until the late stages of disease. Like people with HIV, cats with FIV have a long period where they can appear healthy and show no clinical signs. This period may last for two to five years or perhaps even longer, during which your cat can have a normal, happy life.
- How can I help my FIV-positive cat?
You can help your cat by ensuring it has a healthy lifestyle and feeding it a premium diet together with twice-yearly examinations and blood and urine tests to monitor immune status. Any infections should be treated promptly and aggressively. The better the general health of the cat, then the longer the asymptomatic (no obvious disease) period tends to be. Keeping an FIV-infected cat indoors is also a good idea as it reduces the likelihood of the cat picking up infections from other cats, as well as reducing the spreading of the virus from your cat to other cats.
- How can I prevent cats becoming infected and is there a vaccine?
As most cats become infected from bite wounds during fighting, the risk of FIV infection can be minimized by making sure your cat is neutered and, where possible, kept indoors. There is a new vaccine that has recently been released on the market and you should discuss if this vaccine is appropriate for your cat.
As the risk of infection spreading to your other cats by social contact is low, many people choose to keep the FIV-positive cat. In this case, the positive cat should have a separate feeding bowl from the other cats and food should not be left out for all cats to share.
- What causes heartworm disease?
Heartworm disease or dirofilariasis is a serious and potentially fatal disease in dogs. It is caused by a blood-borne parasite called Dirofilaria immitis.
Heartworms are found in the heart and adjacent large blood vessels of infected dogs. The female worm is 6 to 14 inches long (15 to 36 cm) and 1/8 inch wide (5 mm). The male is about half the size of the female. One dog may have as many as 300 worms.
- How do heartworms get into the heart?
Adult heartworms live in the heart and pulmonary arteries of infected dogs. They have been found in other areas of the body, but this is unusual. They live up to five years and, during this time, the female produces millions of offspring called microfilaria. These microfilariae live mainly in the small vessels of the bloodstream. The immature heartworms cannot complete their life cycle in the dog. The mosquito is required for some stages of the heartworm life cycle. The microfilaria are not infective (cannot grow to adulthood) in the dog although they do cause problems.
As many as 30 species of mosquitoes can transmit heartworms. The female mosquito bites the infected dog and ingests the microfilariae during a blood meal. The microfilariae develop further for 10 to 30 days in the mosquito and then enter the mouthparts of the mosquito. The microfilariae are now called infective larvae because at this stage of development, they will grow to adulthood when they enter a dog. The mosquito usually bites the dog where the hair coat is thinnest. However, having long hair does not prevent a dog from getting heartworms.
When fully developed, the infective larvae enter the bloodstream and move to the heart and adjacent vessels where they grow to maturity in two to three months and start reproducing, thereby completing the full life cycle.
- Where are heartworms found?
Canine heartworm disease occurs all over the world. In the United States, it was once limited to the south and southeast regions. However, the disease is spreading and is now found in most regions of the United States and Canada, particularly where mosquitoes are prevalent.
- How do dogs get infected with them?
The disease is not spread directly from dog to dog. An intermediate host, the mosquito, is required for transmission. Spread of the disease therefore coincides with mosquito season. The number of dogs infected and the length of the mosquito season are directly correlated with the incidence of heartworm disease in any given area.
It takes a number of years before dogs show outward signs of infection. Consequently, the disease is diagnosed mostly in four to eight year old dogs. The disease is seldom diagnosed in a dog less than one year of age because the young worms (larvae) take up five to seven months to mature after infection.
- What do heartworms do to the dog?
Adult heartworms: Adult heartworms cause disease by clogging the heart and major blood vessels leading from the heart. They interfere with the valve action in the heart. By clogging the main blood vessels, the blood supply to other organs of the body is reduced, particularly blood flow to the lungs, liver and kidneys, leading to malfunction of these organs.
Most dogs infected with heartworms do not show any signs of disease for as long as two years. Unfortunately, by the time clinical signs are seen, the disease is well advanced. The signs of heartworm disease depend on the number of adult worms present, the location of the worms, the length of time the worms have been present, and the degree of damage to the heart, lungs, liver, and kidneys from the adult worms and the microfilariae.
The most obvious signs are a soft, dry cough, shortness of breath, weakness, nervousness, listlessness, and loss of stamina. All of these signs are most noticeable following exercise, when some dogs may even faint.
Listening to the chest with a stethoscope will often reveal abnormal lung and heart sounds. In advanced cases, congestive heart failure may be apparent and the abdomen and legs will swell from fluid accumulation. There may also be evidence of weight loss, poor condition, and anemia.
Severely infected dogs may die suddenly during exercise or excitement.
Microfilariae (Young heartworms): Microfilariae circulate throughout the body but remain primarily in the small blood vessels. Because they are as wide as the small vessels, they may block blood flow in these vessels. The body cells being supplied by these vessels are deprived of the nutrients and oxygen normally supplied by the blood. The lungs and liver are primarily affected.
Destruction of lung tissue leads to coughing. Cirrhosis of the liver causes jaundice, anemia, and general weakness because this organ is essential in maintaining a healthy animal. The kidneys may also be affected and allow poisons to accumulate in the body.
- How is heartworm infection diagnosed?
In most cases, diagnosis of heartworm disease can be made by a blood test that can be run in the veterinary hospital or by a veterinary laboratory. Further diagnostic procedures are essential to determine if the dog can tolerate heartworm treatment. Depending on the case, we will recommend some or all of the following procedures before treatment is started.
Serological test for antigens to adult heartworms: This is a test performed on a blood sample. It is the most widely used test because it detects antigens (proteins) produced by adult heartworms. It will be positive even if the dog does not have any microfilaria in the blood. This occurs in about 20% of the cases. Dogs with less than five adult heartworms will not have enough antigen to give a positive test result, so there may be an occasional false negative result in dogs with early infections. Because the detected antigen is only produced by the female heartworm, a population of only male heartworms will also give a false negative. Therefore, there must be at least five female worms present for the most common heartworm test to diagnose heartworm disease.
Blood test for microfilariae: A blood sample is examined under the microscope for the presence of microfilariae. If microfilariae are seen, the test is positive. The number of microfilariae seen gives us a general indication of the severity of the infection. However, the microfilariae are seen in greater numbers in the summer months and in the evening, so these variations must be considered. Approximately 20% of dogs do not test positive even though they have heartworms because of an acquired immunity to this stage of the heartworm. Because of this, the antigen test is the preferred test. Also, there is another blood parasite that is fairly common in dogs that can be hard to distinguish from heartworm microfilariae.
Blood chemistries: Complete blood counts and blood tests for kidney and liver function may give an indication of the presence of heartworm disease. These tests are also performed on dogs diagnosed as heartworm-infected to determine the function of the dog’s organs prior to treatment.
Radiographs (X-rays): A radiograph of a dog with heartworms will usually show heart enlargement and swelling of the large artery leading to the lungs from the heart. These signs are considered presumptive evidence of heartworm disease. Radiographs may also reveal the condition of the heart, lungs, and vessels. This information allows us to predict an increased possibility of complications related to treatment.
Electrocardiogram: An electrocardiogram (EKG or ECG) is a tracing of the electric currents generated by the heart. It is most useful to determine the presence of abnormal heart rhythms.
Echocardiography: An ultrasonic examination that allows us to see into the heart chambers and even visualize the heartworms.
- How are dogs treated for heartworms?
There is some risk involved in treating dogs with heartworms, although fatalities are rare. In the past, the drug used to treat heartworms contained arsenic so toxic effects and reactions occurred more frequently. A newer drug is now available that does not have the toxic side-effects, allowing successful treatment of more than 95% of dogs with heartworms.
Some dogs are diagnosed with advanced heartworm disease. This means that the heartworms have been present long enough to cause substantial damage to the heart, lungs, blood vessels, kidneys, and liver. A few of these cases will be so advanced that it will be safer to treat the organ damage rather than risk treatment to kill the heartworms. Dogs in this condition are not likely to live more than a few weeks or months.
Treatment to kill adult heartworms: An injectable drug to kill adult heartworms is given. It kills the adult heartworms in the heart and adjacent vessels. These injections may be divided and given thirty days apart.
Complete rest is essential after treatment: The adult worms die in a few days and start to decompose. As they break up, they are carried to the lungs, where they lodge in the small blood vessels and are eventually reabsorbed by the body. This can be a dangerous period so it is absolutely essential that the dog be kept quiet and not be allowed to exercise for one month following treatment. The first week after the injections is critical because the worms are dying. A cough is noticeable for seven to eight weeks after treatment in many heavily infected dogs.
Prompt treatment is essential if the dog has a significant reaction in the weeks following the initial treatment, although such reactions are rare. If a dog shows loss of appetite, shortness of breath, severe coughing, coughing up blood, fever, and/or depression, you should notify us. Response to antibiotics, cage rest, and supportive care and intravenous fluids is usually good in these cases.
Treatment to kill microfilaria: Approximately one month following treatment to kill the adults, the dog is returned to the hospital for administration of a drug to kill the baby heartworms or microfilariae. Your dog needs to stay in the hospital for the day. Your dog is started on heartworm preventive after this treatment.
Other treatments: In dogs with severe heartworm disease, it may be necessary to treat them with antibiotics, special diets, diuretics to remove fluid accumulations, and drugs to improve heart function prior to treatment for the heartworms.
Dogs with severe heart disease may need lifetime treatment for the heart failure, even after the heartworms have been killed. This includes the use of diuretics, heart drugs, and special low salt, low protein diets.
Response to treatment: Dog owners are usually pleasantly surprised at the change in their dog following treatment for heartworms, especially if the dog had been showing signs of heartworm disease. The dog has a renewed vigor and vitality, improved appetite, and weight gain.
- What is distemper?
Distemper is a highly contagious viral disease of domestic dogs and other animals such as ferrets, skunks and raccoons. It is a contagious, incurable, often fatal, multisystemic viral disease that affects the respiratory, gastrointestinal, and central nervous systems. Distemper is caused by the canine distemper virus (CDV).
- How is the disease spread?
The disease is spread mainly by direct contact between a susceptible dog and a dog showing symptoms. Coughing and sneezing can spread the virus over short distances.
- What are the clinical signs?
As with all infectious diseases, clinical signs can vary. The main clinical signs are diarrhea, vomiting, a thick yellow discharge from the eyes and nose, cough and eventually seizures and neurological signs. Dogs that recover from the disease are often left with persistent nervous muscle twitches (chorea) and recurrent seizures.
- What is the treatment?
As with most viral infections, there is no specific treatment. Antibiotics are not effective against viruses, but do help in controlling the secondary bacterial infections that often occur with distemper. The treatment for distemper is aimed at helping reduce the signs and symptoms. This is accomplished with hospitalization providing rest and intensive nursing care, intravenous fluid therapy and symptomatic treatment for the vomiting, diarrhea, cough, etc.
- How can I prevent my dog from becoming infected?
Fortunately we have highly effective vaccines to use. These are given to puppies along with other routine vaccines. Although in the majority of dogs the protection from initial vaccination may last more than a year, annual revaccination may be recommended because some dogs may be at higher risk for contracting the disease.
- How common is distemper?
Canine distemper is seen worldwide but because of the widespread use of successful vaccines, it is much less common than it was in the 1970′s. It is still seen in populations where vaccination rates are low and in stray dogs. The virus may persist in recovered carrier dogs and in wildlife such as skunks and raccoons. It is essential to keep vaccinating our dog population to prevent canine distemper from returning as a major killer of dogs.
Canine Parvovirus, also known as CPV or simply parvo, is a highly contagious and often fatal disease in dogs. Unfortunately, it is common in north Texas. To lessen the chance of your puppy contracting this disease, we recommend starting a regular vaccination schedule at 8 weeks of age, with several boosters as your puppy grows to ensure he or she remains protected. Until your puppy is fully vaccinated, keep him or her away from areas where other dogs roam, including neighborhood parks and dog parks.
- What are the clinical signs of parvo?
The clinical signs and symptoms of CPV disease can vary, but generally they include severe vomiting and diarrhea. The diarrhea often has a very strong smell, may contain lots of mucus and may or may not contain blood. Additionally, affected dogs often exhibit a lack of appetite, marked listlessness and depression, and fever. Puppies under five months of age are usually the most severely affected, and the most difficult to treat.
- How does a dog become infected with parvovirus?
The main source of the virus is from the feces of infected dogs. Susceptible dogs become infected by ingesting the virus. Unlike most other viruses, CPV is stable in the environment and is resistant to the effects of heat, detergents, alcohol, and many disinfectants. A 1:30 bleach solution will destroy the infective virus. CPV has been recovered from surfaces contaminated with dog feces even after three months at room temperature. Due to its stability, the virus is easily transmitted via the hair or feet of infected dogs, contaminated shoes, clothes, and other objects or areas contaminated by infected feces. Direct contact between dogs is not required to spread the virus. Dogs that become infected with the virus and show clinical signs will usually become ill within six to ten days of the initial infection.
- Can parvo be treated successfully?
There is no treatment to kill the virus once it infects the dog. However, the virus does not directly cause death; rather, it causes loss of the lining of the intestinal tract, and destroys some blood cell elements. The intestinal damage results in severe dehydration (water loss), electrolyte (sodium and potassium) imbalances, and infection in the bloodstream (septicemia). When the bacteria that normally live in the intestinal tract are able to get into the blood stream, it becomes more likely that the animal will die. The first step in treatment is to correct dehydration and electrolyte imbalances. This requires the administration of intravenous fluids containing electrolytes. Antibiotics and anti-inflammatory drugs are given to prevent or control septicemia. Antispasmodic drugs are used to inhibit the diarrhea and vomiting that perpetuate the problems.
- Is there a way to kill the virus in the environment?
The stability of the CPV in the environment makes it important to properly disinfect contaminated areas. This is best accomplished by cleaning food bowls, water bowls, and other contaminated items with a solution of 1/2 cup of chlorine bleach in one gallon of water (133 ml in 4 liters of water). It is important that chlorine bleach be used because most disinfectants, even those claiming to be effective against viruses, will not kill the canine parvovirus.
- Does parvovirus pose a health risk for me? How about for my cats?
It is important to note that there is no evidence to indicate that CPV is transmissible to cats or humans.