Canine Infectious Diseases
Canine Vaccination Recommendations
- Core Vaccines: Rabies Vaccine (IMRAB 3 TF) & DHPP Vaccine (Recombiteck C4(rDAPP)
- Non Core Vaccines: Bordetella Vaccine, Lyme Vaccine & Leptosporosis Vaccine
Rabies in Pets
Rabies is a viral disease that may infect any warm-blooded animal. Regardless of the initial site of virus introduction into the animal, the virus eventually invades the central nervous system. With rare exception, it is a fatal disease.
For domestic pets, such as cats and dogs, the greatest risk factor for contracting rabies comes from failing to receive proper rabies immunization and then coming in contact with a rabid animal.
Rabies is found on a worldwide basis. Even though all warm-blooded animals can become infected, some species are more susceptible than others. Skunks, raccoons, and bats are considered most susceptible, with cats, dogs, horses, and humans intermediate in susceptibility. Opossums and birds are relatively more resistant to the virus compared to other species. It is important to note that while wildlife represents the major reservoir of rabies in nature, cats and dogs are the principal source for rabies transmission to humans.
The usual source of rabies infection is the bite of an animal infected with the virus. The virus is found in high concentrations within saliva. Once inoculated into the victim, the virus travels up nerve endings to the central nervous system. There have been a few rare cases of humans contracting rabies by inhaling aerosolized virus in bat caves.
Rabies is classically divided into three distinct stages: prodromal, furious, and paralytic. The prodromal stage lasts 2-3 days and is characterized by major behavior changes. Normally friendly domestic animals, such as dogs and cats, become aggressive. In contrast, wildlife will lose their normal fear of humans. Also, wild animals that are normally seen only at night (nocturnal species) may be seen during the day. During the furious stage, dogs will typically become very vicious and lunge at any moving object. They may have muscle tremors and incoordination. During the final stage, the paralytic stage, paralysis sets in and death follows. Most dogs die from rabies within 2-7 days after they begin to show signs of the disease.
Rabies can be suspected based on clinical signs, but it can only be confirmed by microscopic examination of brain tissue. For this reason, animals suspected of having rabies are usually autopsied with a sample of brain tissue submitted to a pathologist. Although this can be upsetting for owners, remember that there is no room for error with rabies. If a human has been exposed and does not receive treatment, death is inevitable.
Whenever an animal without proper rabies vaccination bites a human, the animal is usually required to be confined and observed by a veterinarian for at least a 10 day period.
Treatment is not recommended for animals with rabies because of the potential risk for human exposure to the virus.
Rabies is always fatal in warm-blooded animals that develop the disease.
Transmission to Humans
Rabies can be transmitted to a human through the bite of an infected animal or inoculation of rabies-infected saliva into an open wound. Whenever a human is bitten by an animal, a physician should always be promptly contacted. In some areas, physicians are required to contact local animal control officials so that the vaccination status of the animal can be verified and an appropriate quarantine initiated.
Because rabies-immunized pets represent an important buffer between humans and the rabies reservoir found in wildlife, the importance of regular rabies boosters for pets cannot be overemphasized.
The first rabies vaccine is usually given at 12-16 weeks of age, followed by regular boosters. Depending upon state regulations, the boosters are given every year or every three years thereafter. These vaccines are considered safe and effective. Here at Phoenixville Animal Hospital we administer Merial Rabies Vaccine: IMRAB 3 TF.
Distemper in Dogs
Canine distemper is a contagious viral disease of dogs. It was a fairly common disease in the United States until the introduction of effective vaccines in the 1960’s. In some parts of the world, it remains an important and devastating disease.
Canine distemper virus (CDV) is present on a worldwide basis. In addition to dogs, other species can become infected. These other species include coyotes, foxes, raccoon, ferrets, mink and skunks.
Young dogs are more susceptible to the distemper virus than are more mature dogs. For dogs that become infected with CDV but survive, longstanding immunity usually results, but this immunity may decline with time.
Research statistics have shown that many more dogs are infected with CDV than actually show signs of the disease.
Dogs infected with the virus shed it in their feces, saliva, urine, ocular (eye), and respiratory secretions. New infection is established in a dog by inhalation of aerosolized respiratory secretions. Once the virus invades the dog’s respiratory tract, it begins to reproduce. If the dog does not initiate a strong immune response by the second or third week of the infection, cells infected with the virus begin to spread to other parts of the body. At this point, recovery from the disease becomes less likely.
There is great variation in the duration and severity of signs with distemper. In some dogs, distemper presents as a relatively mild disease with either no clinical signs or nonspecific signs, such as fever, depression, enlarged tonsils, or weight loss. More specific signs include ocular and nasal discharges, respiratory distress, coughing, diarrhea, vomiting. The ocular and nasal discharge usually starts out as clear and then changes to a more cloudy fluid. Some dogs develop skin infections or very thickened footpads. For this reason, distemper has been called “hard pad” disease. Puppies that have become infected while their permanent teeth are developing will often have defects in the tooth enamel.
In some dogs, CDV invades the central nervous system. Once this occurs, recovery from distemper is almost impossible. A variety of neurologic signs can be seen and include seizures (“chewing gum fits”), complete or partial paralysis, incoordination, visual problems, a head tilt or head bobbing, muscle tremors, and neck pain. In old dogs, progressive encephalitis called “old dog encephalitis” occurs rarely. It is thought to be caused by CDV. In these dogs, compulsive circling and head pressing are observed most commonly.
In many cases, a presumptive clinical diagnosis can be made by the particular clinical signs, evaluation of the vaccination history of the dog, and changes in bloodwork. To aid in the diagnosis, blood can be analyzed at special laboratories to determine rising levels of globulins (antibodies) in the blood over a period of a few weeks. When it is possible to obtain spinal fluid, this can also aid in the diagnosis.
Definitive diagnosis can be made by demonstration of the unique “inclusion” bodies seen microscopically in some cells. These inclusions can be seen in blood cells, bone marrow, and tissue samples.
No specific therapy is available. At best, good supportive care and control of any secondary bacterial infections is all that can be offered. Supportive care should be directed toward minimizing stress and meeting the need for fluids and nutrition.
The prognosis is uncertain because there is no effective antiviral medication for canine distemper once a dog has become infected. In most cases, once a dog shows clinical signs, the prognosis is guarded; many die of the disease.
Transmission to Humans
There is no health risk to humans caused by CDV.
Young puppies usually have protective immunity transferred from the mother through her milk. This immunity declines by six to eight weeks of age, however, and leaves the puppy susceptible to CDV. At this time (6-8 weeks), puppies should begin CDV vaccination with boosters given every 2-3 weeks until 14-16 weeks of age. These periodic boosters are recommended because some puppies may not begin to respond to the vaccine until after they are 6-8 weeks of age. Thereafter, yearly boosters are given.
No vaccine is considered 100% protective, but most dogs will respond to distemper vaccine and have adequate protection against CDV. Here at Phoenixville Animal Hospital we administer a Merial Vaccine: RECOMBITECK C4(rDAPP).
Infectious Canine Hepatitis
The word “hepatitis” is a nonspecific medical term describing any inflammatory process of the liver. A number of different diseases can cause hepatitis. One infectious cause is Infectious Canine Hepatitis, or ICH. This viral disease was first recognized as a unique disease of dogs in 1947.
ICH is found on a worldwide basis. It most commonly infects young dogs, but any dog without immunity is considered at risk for contracting the virus.
The ICH virus infects the dog by contact with the oral or nasal surfaces. Following viral reproduction in the tonsils and lymph nodes of the head and neck, it spreads to all parts of the body. It preferentially infects cells of the liver, eye, and kidney.
During this early stage of infection, the virus is shed in the urine, feces, blood, and oral and nasal secretions. Eventually, the virus localizes in the kidneys; it may be shed into the urine for up to a year.
Once the dog is infected with ICH virus, the incubation period lasts 4-7 days. In many cases, especially for adult dogs, the signs of ICH may be completely inapparent. Dogs with mild illness may be slightly depressed and run a low-grade fever, with complete recovery after a few days. Dogs who continue to run a fever and do not resolve the infection within this time period will go on to show other signs: enlarged lymph nodes and tonsils, abdominal tenderness, diarrhea, and coughing. Widespread hemorrhage and jaundiced skin develop in some of the more serious cases. Death from ICH is a possibility.
In some dogs, the virus invades the eye and stimulates the immune system. The inflammatory response that results leads to edema in the cornea, or the clear surface of the eyeball. This gives the cornea a bluish cast. For this reason, ICH is sometimes called “Blue Eye.”
A presumptive diagnosis can be made based on vaccination history, clinical signs, and laboratory findings. Conclusive diagnosis can be made when two separate blood samples (taken on different days) show a rise in antibody level to ICH virus.
Most dogs infected with ICH will recover with good supportive care. This includes attention to nutrition, fluid intake, nursing care, and control of any secondary infections.
The more body systems that have become involved, the worse the prognosis.
Transmission to Humans
There is some serologic (blood test) evidence that ICH can infect humans. This still remains to be studied further. Even if this is proven true, there are no reported clinical signs of disease in humans related to ICH.
Although no vaccine assures 100% protection, the hepatitis vaccine is generally considered safe, effective, and very beneficial in preventing ICH. Following completion of puppy immunizations, mature dogs receive a booster once yearly during their annual vaccinations. Here at Phoenixville Animal Hospital we administer a Merial Vaccine: RECOMBITECK C4(rDAPP).
Parvovirus Infection in Dogs
Canine parvovirus (CPV) infection (sometimes called “parvo”) is a relatively new disease that struck the canine population in 1978. The classic signs are vomiting and bloody diarrhea. Because of the severity of the disease and its rapid spread through the canine population, CPV has aroused a great deal of public interest. The virus that causes it is very similar to feline distemper, and the two diseases are almost identical.
Therefore, it has been speculated that the canine virus is a mutation of the feline virus. However, that has never been proven. The virus has a selective effect on the most rapidly dividing cells of the body. For this reason, the lining of the small intestine and the cells of the bone marrow are most severely affected.
Several factors contribute to the clinical course of parvovirus infection in dogs. These include stress, vaccination history, age of the dog, concurrent infection with other diseases or parasites, and breed of the dog. Various studies have reported the breeds thought to be at increased risk for parvovirus; these breeds include the Rottweiler, Doberman pinscher, black Labrador Retriever, American Pit Bull Terrier, and the German Shepherd dog.
Parvoviral enteritis (intestinal inflammation) may affect dogs of all ages, but is most common in dogs less than one year of age. Young puppies less than five months of age are often the most severely affected and the most difficult to treat.
CPV has been regarded as reaching peak incidence in the spring and summer months, when puppies are losing the natural immunity conferred from the mother. A 1996 study of 283 dogs with CPV found the highest incidence in July, August, and September. Intact (non-neutered) male dogs were more likely to contract CPV than female dogs.
Canine parvovirus has been reported to exist in approximately 50 different countries.
The causative agent of CPV disease is a very hearty virus. Unlike most other viruses, CPV is stable in the environment and is resistant to the effects of heat, detergents, and alcohol. CPV has been recovered from dog feces even after three months at room temperature. Since the virus is so resistant to decay, it can survive for long periods and be transmitted to any dog by simple contact with a contaminated object (called a “fomite”). Examples of fomites include shoes, clothing, play toys, insects, and feet of the infected dog.
Feces of the infected dog contain millions of viral particles. Susceptible dogs become infected by ingesting (swallowing) the virus. There does not have to be direct contact between the two dogs. Dogs that become infected with the virus and show clinical signs will usually become ill within 7-10 days of the initial infection.
In a large percentage of dogs, there may be no signs at all; this is called an inapparent infection. These dogs are capable of shedding the virus in the feces.
When signs are present, they may be variable, but generally take the form of severe vomiting and bloody diarrhea. Vomiting is usually the first sign to develop after infection. Diarrhea usually begins about 24 hours later and may or may not contain blood. Some dogs exhibit anorexia, depression, and fever.
The clinical signs of CPV infection can mimic other diseases causing vomiting and diarrhea; consequently, the diagnosis of CPV is sometimes a challenge for the veterinarian. The positive confirmation of CPV infection requires the demonstration of the virus in the stool or the detection of anti-CPV antibodies in the blood serum. The detection of virus in the stool is easily done and takes just a few minutes. This test can be performed in the veterinarian’s office.
Occasionally, a dog will have parvovirus but test negative for virus in the stool; fortunately, this is not a common occurrence. A presumptive diagnosis may be based on the presence of a reduced white blood cell count (leukopenia). If
further confirmation is needed, stool or blood can be submitted to a veterinary laboratory for the other tests.
The absence of a leukopenia does not mean that the dog cannot have CPV infection. Some dogs that become clinically ill may not necessarily be leukopenic.
Unfortunately, there is no specific antiviral therapy that will kill the virus once it infects a dog. The most appropriate therapy focuses on treating the damage done by the virus. Since the lining of the intestine is compromised, diarrhea results. This can lead to severe dehydration, loss of sodium and potassium, and may provide intestinal bacteria with access to the blood stream (septicemia). Therefore, treatment involves intravenous fluid replacement, attention to electrolytes, and prevention of septicemia.
Additional therapies can include administration of immune serum (serum from a dog who has recently recovered from parvovirus), anti-endotoxin serum (to bind to bacterial toxins), and a drug to increase the white blood cell count.
Most dogs with CPV infection recover if aggressive treatment is used and if therapy is begun before severe septicemia and dehydration occur. Prognosis is more guarded in the breeds listed above as “at risk.”
Transmission to Humans
There is no documented evidence to suggest that humans may become infected with CPV.
Proper vaccination offers the best protection against CPV. Puppies receive a parvo vaccination as part of their multiple-agent vaccine given at 8, 12, and 16 weeks of age. In some situations, veterinarians will give an additional booster at 18 to 20 weeks of age. After the puppy series of vaccinations, all dogs should be boostered at least once a year. Dogs in high exposure situations (i.e., kennels, dog shows, field trials, etc.) may be better protected with a booster every six months. Pregnant bitches should be boostered within two weeks of whelping in order to transfer protective antibodies to the puppies. The final decision about a proper vaccination schedule should be made by your veterinarian. Here at Phoenixville Animal Hospital we administer a Merial Vaccine: RECOMBITECK C4(rDAPP).
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 one cup of chlorine bleach in a gallon of water (500 ml in 4 liters of water). It is important that chlorine bleach be used because most “virucidal” disinfectants will not kill the canine parvovirus.
Kennel Cough in Dogs
Canine infectious tracheobronchitis, or “kennel cough,” is an important respiratory disorder because it is highly contagious between dogs. A number of different infectious agents may be involved with this disease. It is characterized by bouts of nonproductive (dry) coughing lasting from days to even weeks.
Kennel cough spreads rapidly between dogs housed in close proximity, such as a boarding kennel. Affected dogs usually have a history of recent boarding or some similar stressor, such as a trip to the groomer or a dog show. Some researchers report that there is an increased incidence of kennel cough in the fall.
As noted above, a number of different agents may be involved with kennel cough. The canine adeno-2 virus (CAV2), the parainfluenza virus (PIV), and the bacterium Bordetella bronchiseptica are the common primary pathogens (responsible for setting up the initial respiratory disease). Secondary invaders, such as Mycoplasma, become involved once an inflammatory process is present in the airway.
A dry, hacking cough is the hallmark of this disease. Many times, owners mistakenly believe that the dog is choking on a foreign body. Other than the cough, most dogs are still bright and alert with a good appetite. Fever and enlarged tonsils are occasionally found.
In most cases, the history and physical exam are adequate to provide a presumptive diagnosis of kennel cough. Rarely are specific diagnostic tests indicated, although they may be helpful in cases that are not resolving as expected. These additional tests might include a blood count and blood chemistries, chest xrays, and a sample of fluid from the trachea (windpipe) or bronchi.
Although antibiotic therapy can be helpful for the bacterial component of kennel cough, there is no specific therapy for the viruses. For dogs that cough continually, a mild cough suppressant can be prescribed. However, it is for short-term use only.
Dogs who are recovering from kennel cough should not be stressed with exercise or excitement for at least a week. Rest is recommended to avoid precipitation of the cough caused by increased activity.
The prognosis is usually good and, in most cases, has the potential to resolve without complication. Infrequently, long-term respiratory problems can result from kennel cough.
Transmission to Humans
Canine infectious tracheobronchitis does not pose any health risk for humans.
Vaccines are available to protect against the main infectious agents responsible for kennel cough. Bordetella vaccines are given intranasally (drops in the nose) because this route produces rapid immunity. Sometimes the intranasal vaccine can lead to a mild cough. Here at Phoenixville Animal Hospital we administer a Merial Vaccine: RECOMBITECK C4(rDAPP) and Intervet/Merck Animal Health NOBIVAC INTRA-TRAC KC.
Immunity against the two main viral diseases is covered with standard vaccine protocols (injection). Because the immunity offered is neither 100% protective nor permanent, boosters are needed on a periodic basis. These are especially important before a dog is placed into a kennel situation; many kennels require these boosters before allowing a dog to enter the facility.
Lyme Disease in Dogs
Lyme Disease (not Lyme’s Disease) is caused by a bacterium called Borrelia. It is transmitted to dogs through the bite of a tick. Once in the blood stream, it is carried to many parts of the body. It is especially likely to localize in joints. It was first thought that only a few types of ticks could transmit this disease, but now it appears that several common species may be involved. Lyme Disease is named after the city in which it was first discovered, Old Lyme, Connecticut. Thus, it is
called “Lyme Disease” and not “Lyme’s” Disease.
Also a Disease of Humans
Humans also get Lyme disease; however they do not get it directly from dogs. They get it from being bitten by the same ticks that transmit it to dogs. Therefore, preventing exposure to ticks is important for you and your dog.
Many people having the disease develop a characteristic rash at the site of the bite within 3 to 30 days. For these people, the disease can be easily diagnosed at an early stage. However, symptoms of Lyme Disease are more difficult to detect in animals than in people.
This characteristic rash does not develop in dogs or cats. Because the other symptoms of the disease may be delayed or not recognized, and because the symptoms are similar to those of many other diseases, Lyme Disease in animals is often not considered until other diseases have been eliminated.
Many dogs affected with Lyme Disease are taken to a veterinarian because they seem to be experiencing generalized pain and have stopped eating. Affected dogs have been described as if they were “walking on eggshells.” Often these animals have high fevers.
Dogs may also become lame because of the disease. This painful lameness often appears suddenly and may shift from one leg to another. If untreated, it may eventually disappear, only to recur weeks or months later. Some pets are affected with the Lyme Disease organism for over a year before they finally show symptoms. By this time, the disease may be quite widespread in the body.
Dogs with lameness, swollen joints, and fever are suspected of having Lyme Disease. However, other diseases may also cause these symptoms. There are two blood tests than may be used for confirmation. The first is an antibody test. This test does not detect the actual bacteria in the blood, but detect the presence of antibodies created by exposure to the organism. A test can be falsely negative if the dog is infected but has not yet formed antibodies, or if it never forms enough antibodies to cause a positive reaction. This may occur in animals with suppressed immune systems. Some dogs that have been infected for long periods of time may no longer have enough antibodies present to be detected by the test. Therefore, a positive test is meaningful, but a negative is not.
The second test is the polymerase chain reaction (PCR) test, or DNA testing. It is very specific and sensitive. However, not all dogs have the bacteria in their blood cells. If a blood sample is tested, a false negative may occur. The best sample for testing is the fluid from an affected joint.
Because the Lyme spirochete is a bacterium, it can be controlled by antibiotics. However, a lengthy course of treatment is necessary to completely eradicate the organism. The initial antibiotic selected to treat an infected pet may not be effective against the disease, especially if the infection is long-standing. In this situation, a switch to another antibiotic is often effective.
Occasionally, the initial infection will recur, or the pet will become reinfected after being bitten by another infected tick.
The key to prevention is keeping your dog from being exposed to ticks. Ticks are found in grassy, wooded, and sandy areas. They find their way onto an animal by climbing to the top of a leaf, blade of grass, or short tree (especially Cedar trees). Here they wait until their sensors detect a close-by animal on which to crawl or drop.
Keeping animals from thick underbrush reduces their exposure to ticks. Dogs should be kept on trails when walked near wooded or tall grass areas.
Removing a Tick from Your Dog
Check your pet immediately after it has been in a tick-infected area. If you find a tick moving on your pet, the tick has not fed. Remove the tick promptly and place it in rubbing alcohol or crush it between two solid surfaces. If you find a tick attached to your pet, grasp the tick with fine tweezers near the dog’s skin and firmly pull it straight out. You may need another person to help restrain your dog. Removing the tick quickly is important since the disease is not transmitted until the tick has fed for approximately 12 hours. If you crush the tick, do not get the tick’s contents, including blood, on your skin. The bacterium that causes Lyme Disease can pass through a wound or cut in your skin.
A vaccine is now available for protecting dogs against Lyme Disease. This vaccine is initially given twice, at two or three week intervals. Annual revaccination is also necessary to maintain immunity. The vaccine has been shown to be safe and very effective. We recommend it for any dog that has exposure to ticks. Here at Phoenixville Animal Hospital we administer a Merial Vaccine: RECOMBITEK Lyme (rLyme).
Leptospirosis in Dogs
Leptospirosis is an important and relatively complex infectious disease of dogs. It can affect almost all species of warm-blooded animals, including humans. Recognition of the disease is sometimes difficult because clinical signs will vary depending upon the particular strain of the Leptospira organism that has infected the dog. At least ten different strains are known to infect dogs. Most commercial vaccines contain antigens (proteins) which stimulate immunity against the
icterohemorrhagiae and canicola serovars. The incidence of disease caused by these two strains has decreased because of vaccines; however, other strains are becoming more common in the animal population.
Leptospirosis occurs on a worldwide basis, especially in subtropical climates. Although the organism cannot reproduce outside of the host animal, it can survive for prolonged periods of time in water or wet soil. It is found in both urban and rural environments. Most cases in dogs are reported in the summer and early fall of the year.
Leptospirosis can develop in any age, breed or gender of dogs.
The leptospire organism is a unique type of bacterium called a “spirochete.” The name is derived from its slender, coiled (spiral) appearance under the microscope. The organism is shed in the urine of the infected animal. It enters the new host animal by penetrating mucous membranes or entering through abraded (open) skin. Infrequent routes of transmission to new hosts include venereal contact, through bite wounds, by ingestion of the organism, and through the placenta.
Once the organism has infected the dog, it can replicate (reproduce) in many different tissues. In dogs, the greatest numbers of organisms are usually found in the liver and kidneys. The signs can be dependent upon which strain of the organism is involved. For example, one particular strain of Leptospira primarily impacts the liver, whereas another involves the kidneys.
In many dogs, the disease is subclinical, meaning that there are no specific signs. Dogs who have a rapid onset of signs following infection will have fever, depression, weakness, vomiting, and muscle pain. The skin may have a jaundiced (yellow) tint and the mucous membranes (gums) will be pale. The pulse and respiration rates may be increased and shock will develop. If clotting problems occur because of damage to the lining of blood vessels, hemorrhage from the nose or bowel develops; obvious bruises will appear under the skin. If the disease progresses to this point, death can rapidly follow from liver or kidney failure.
Dogs who do not develop more acute infections or survive such infections may go on to develop chronic liver or kidney problems. In fact, the majority of dogs do not have the acute infection described above, but are chronically infected. The infection may be subclinical, meaning that there are no apparent signs.
In many cases, a presumptive diagnosis can be made based on the dog’s clinical signs, vaccination history, and potential exposure to the organism. Diagnosis is complicated because it is difficult to find the organism in tissue samples or urine. The most common laboratory test involves detection of increasing levels of antibody (protein) in the blood over a period of two to four weeks. The antibody is produced as an immune response against the organism. Some newer tests are on the horizon, such as the polymerase chain reaction test (PCR). This is a test to detect DNA of the organism. This particular assay is only available in a few laboratories at this time.
Treatment of infected dogs involves appropriate antibiotic therapy and good supportive care.
Antibiotic therapy involves two phases. The first phase is designed to inhibit reproduction of the organism, decrease shedding of it into the urine, and to protect the liver and kidneys from fatal complications. Most commonly, penicillin injections are given for about two weeks and are followed with another antibiotic. The second phase is aimed at eliminating residual organisms from the kidney using Doxycycline or Minocycline.
Supportive care of animals who show clinical signs will primarily involve intravenous fluid therapy. Fluids support the animal’s hydration status and blood pressure. Fluids also help preserve blood flow through the kidneys; this is important if kidney function is to be salvaged.
Because of the number of organ systems that can be affected by leptospirosis, blood work (cell counts and blood chemistries) need to be performed frequently during early stages of treatment.
The prognosis is dependent upon several factors, including the strain of the organism, the dog’s vaccination status, damage done to individual organ systems, and the dog’s response to treatment. In general, dogs that have an acute infection are more likely to die than those more chronically infected.
Transmission to Humans
There is risk of the infected dog transmitting leptospiral organisms to humans. As such, special precautions must be taken when handling these patients; in particular, contact with the dog’s urine must be avoided.
Even for dogs that appear recovered, the organism can be shed into the urine in large numbers for many months after treatment is completed. The Centers for Disease Control receives reports of about 50-100 human infections per year.
Most commercially available vaccines protect dogs against the icterohemorrhagiae and canicola strains, but they do not provide immunity against other important strains. Vaccines that protect against up to five strains are under development. Here at Phoenixville Animal Hospital we administer a Merial Vaccine: RECOMBITEK 4 Lepto (LCGIP), a vaccine that covers 4 strains of Leptospirosis.
In areas where leptospirosis is prevalent, vaccinations should be boostered frequently. Vaccines reduce the severity of the disease but do not prevent some dogs from becoming chronic carriers of leptospirosis. Some types of leptospirosis vaccines are associated with adverse reactions. For dogs that have had a reaction to the leptospirosis vaccines, recommendations are made by the veterinarian on an individual basis.