Dr. Brian J. Luria
University of Florida
Our awareness in human and veterinary medicine that certain insects and arthropods transmit disease has been established for many years. In recent years, our knowledge has increased dramatically, mostly due to advancements in our ability to diagnose these diseases. For a variety of reasons, ticks are appearing in greater numbers than ever. Ticks are a very important cause of debilitating and deadly diseases and conditions in both humans and domestic animals. Almost equal to the disease transmitting potential of ticks, is the fear and concern that arise among many owners and veterinary staff members when a tick is found on a dog or cat.
This discussion will focus on education regarding the diseases that ticks can transmit, how to diagnose and treat them, and how to prevent your dogs from acquiring ticks and the diseases they transmit.
Brief Review of Ticks
Ticks are blood feeding external parasites of mammals, birds, and reptiles throughout the world. Ticks are second only to mosquitoes as vectors of pathogens. A vector is simply an organism that transmits a pathogen. For this discussion, we will focus on four tick species, based on the diseases that they transmit.
1. The Black-legged or Deer Tick (Ixodes scapularisI)
This tick is concentrated in both the North and Southeastern United States as well as in areas surrounding the Great Lakes. It is the tick that transmits Borrelia burgdorferi, the causative agent of Lyme disease as well as the agents of Babesiosis.
2. The Brown Dog Tick(Rhipicephalus sanguineus)
This tick has a widespread distribution. It is the tick that transmits Ehrlichia canis, one of the causative agents of Ehrlichiosis as well as Babesia canis and Babesia gibsonii.
3. The American Dog Tick (Dermacentor variabilis)
This tick is widespread throughout the US as well as parts of Canada and Mexico. It is the most important vector of Rickettsia rickettsii, the causative agent for Rocky Mountain spotted fever in the eastern US.
4. Rocky Mountain Wood Tick (Dermacentor andersoni)
This tick is found mostly in the Northwestern parts of the United States. It is an additional vector for Rocky Mountain spotted fever.
Basic Tick Lifecycle
Depending on the tick and environmental conditions, the lifecycle of a tick can range from a few months to two years. Each developmental stage of a tick’s life requires a blood meal in order to reach the next stage. Some species can survive for years without feeding.
Female ticks lay eggs in secluded areas where vegetation is dense and several inches high. Adult females of some tick species lay about 100 eggs at a time; others lay 3,000 to 6,000 eggs per batch. Regardless of species, tick eggs hatch in about two weeks.
After hatching, the larvae move into grass or shrubs in search of their first blood meal. If you or your pet passes by, they attach themselves and crawl upward in pursuit of an area of the skin that they can feed from. Then they drop off the host, back into the environment.
After finding their first blood meal, the larvae molt into their nymph stage and begin searching for another host. Nymphs are the size of a freckle and often go undetected, increasing the chance for disease transmission.
Once the nymph has had its blood meal, it matures into adulthood. Adult female ticks feed on a host for eight to twelve days. In some cases, they will increase to 100 times their original weight while feeding. While still on the host, the female will mate, fall off and lay her eggs in a secluded place â€“ beginning the lifecycle again.
Review of Common Diseases
I. Lyme Disease (Lyme Borreliosis)
Lyme disease was named in 1977 when arthritis was observed in a cluster of children in and around Old Lyme, CT. The first case of canine Lyme disease was reported in 1984. Lyme disease is caused by the bacterium, Borrelia burgdorferi. These spiral shaped bacteria are transmitted to humans and animals by the bite of infected deer ticks in the genus Ixodes (Deer ticks). Ticks, small rodents, and other non-human vertebrate animals all serve as natural reservoirs for B. burgdorferi. This means that the Lyme disease bacteria can live and grow within these hosts without causing them to die.
1. Black-legged ticks, also known as Dear ticks (Ixodes scapularis) are responsible for transmitting Lyme disease bacteria to humans and animals in the northeastern and north-central United States. On the Pacific Coast, the bacteria are transmitted by the western black-legged tick (Ixodes pacificus). Ixodes ticks are much smaller than common dog ticks. In their larval and nymphal stages, they are no bigger than a pinhead. Ticks feed by inserting their mouths into the skin of a host and slowly taking in blood. Ixodes ticks are most likely to transmit infection via saliva after feeding for two or more days. This amount of time is needed for the Borrelia organism to travel from the tickâ€™s midgut to the salivary glands where it is ransmitted.
2. In the spring, about 35 percent of ticks are thought to be harboring Borrelia, whereas up to 50 percent of adult ticks may be infected with the Borrelia organism in the fall.
C. Signs of Disease
1. Within days of the initial tick bite, animals will show flu-like symptoms (fever, malaise) and possibly enlarged lymph nodes (in humans, a bulls-eye lesion can be seen on the skin at this stage). Up to two to three months later, signs of an acute inflammatory process is seen (joints, heart, brain, eyes can all be affected). Over years of being affected, chronic arthritic changes can be seen.
2. About 75 percent of dogs will get acute arthritis which usually lasts two to four days and will often resolve on its own. However, dogs can have recurrent bouts of arthritis. After about 100 days post tick exposure, signs of acute arthritis resolve, even though animals are still infected.
1. History, along with clinical signs, positive serology (see below), and prompt response to antibiotic therapy are usually the criteria for the diagnosis of Lyme disease in dogs. If animals are having acute arthritic signs, a sample of joint fluid can be taken for analysis. Affected animals often have high numbers of neutrophils (a white blood cell often present when fighting bacteria) in their joint fluid.
2. Serologic testing is the most common modality used for diagnosis. Serum is the liquid part of the blood that is left when the blood cells are removed. It is comprised of water (naturally) as well as a very high content of various proteins. These include albumin “ a protein that aids in the proper retention of water in the bloodstream and globulins “ which are antibodies. Serological tests refer to a laboratory test done on blood serum to measure antibodies to infections. a. The most common screening serologic test for Lyme disease, as well as many other infectious diseases, is called an enzyme-linked mmunosorbent assay (or ELISA) which quantifies the presence of specific antibody produced by the immune system against specific organisms, such as Borrelia. **A positive serology detecting antibodies directed against Borrelia burgdorferiI is merely an indication of exposure to the organism or to a vaccine which contains antigen (single subunit vaccine) or multiple antigens (bacterin) to the spiorchete. An antigen is a substance capable of stimulating an immune response. A positive serology by itself does not constitute a diagnosis of Lyme disease. Antibodies persist in infected animals and do not decrease after antibiotic therapy.
b. The ELISA test cannot distinguish between antibodies produced against exposure to a natural infection and those produced against the vaccine for Lyme disease. In order to separate these two, another serologic test called Western blot testing is traditionally done to confirm natural exposure.
c. Recently, a test has been developed that detects the presence of antibody directed against a very specific surface antigen of Borrelia burgdorferi that is produced only in response to active infection. This antigen is called the C6 antigen. The only commercially available test for this is made by IDEXX Laboratories, Inc., and is called the SNAP3DxTM. It is a combination test that also tests for Dirofilaria immitis antigen (Heartworm) and Ehrlichia canis antibody (see below). This test should help veterinarians determine if a dog
has anti-Borrelia burgdorferi antibody induced by infection, rather than by vaccination.
1. It is important to remember that prevention measures can be effective in reducing exposure to infected ticks, and most patients can be successfully treated with antibiotic therapy when diagnosed in the early stages of Lyme disease.
2. Antibiotics are the treatment of choice for Lyme disease in dogs, as in humans. Tetracyclines such as Doxycycline or lactam antiobiotics such as Amoxicillin have been found to be very effective. Animals should be treated for at least four weeks.
3. Dogs usually respond with clinical recovery within 24 â€“ 48 hours; however the organism can persist, hence the duration of antibiotic therapy. Evidence to date indicates that in spite of adequate antibiotic therapy, infected individuals may be infected for life.
4. Anti-inflammatory medications, such as carprofen or etodolac can be used to alleviate arthritic pain in the short term. Corticosteroids, such as prednisone, should be avoided because of their ability to suppress the immune system.
F. Prevention, Tick Control and Public Health Concerns
1. Vaccinating dogs for Lyme disease is still a controversial issue in veterinary medicine and arguments for and against have been postulated over time. There are strong arguments in favor of vaccinating dogs in endemic areas against Lyme disease.
2. There are currently 2 different types of Lyme vaccines for dogs:
a. Whole-cell bacterin vaccine (LymeVax, Fort Dodge; Galaxy Lyme, Schering-Plough Animal Health), which consists of a complete killed B. Burgdorferi. This vaccine has been available for several years, however, with recent advancements in vaccine technology, it is the less preferable vaccine if one is to vaccinate their dogs.
b. Recombinant vaccine (rLyme, Merial), which consists of only parts of B. burgdorferi that are thought to provide protection from infection and/or disease in dogs. This vaccine consists of outer surface protein A (OspA) of B. burgdorferi. The mode of protection appears to involve killing the bacteria in the tick, prior to its transmission into the host animal.
c. So, what dogs should be vaccinated? It is clear, based on the mode of action of these vaccines, particularly the recombinant vaccine, that vaccinating already infected or exposed dogs will not cure them and may not prevent them from being infected. Unexposed, dogs in endemic areas appear to be the best candidates for vaccines.
d. A fatal kidney infection by B. burgdorferi has been reported in some dogs in endemic areas where antibiotic treatment had little effect. There has been no convincing evidence that vaccines could be related to this disease, however, the possibility of a connection does exist.
3. Tick control is discussed in detail at the end of these notes.
4. Dogs do not appear to be reservoirs for human infection.
Canine ehrlichiosis is an infectious rickettsial disease of dogs caused by a variety of different ehrlichial species, the most notable one being Ehrlichia canis. Rickettsia are rod-shaped, coccoid, or diplococcus-shaped, often pleomorphic bacteria that cause various diseases. E. canis was first recognized in Algeria in 1935 and first reported in the United States in 1963. The disease gained prominence due to devastating losses of military working dogs stationed in Vietnam. Ehrlichiosis is an illness characterized by a reduction in cellular blood elements.
1. Ehrlichia canis is transmitted by the vector tick Rhipicephalus sanguineus, or brown dog tick. This tick is also responsible for spreading Babesiosis (see below). This tick prefers to feed on dogs over humans.
2. Canine infection occurs when salivary secretions from the tick contaminate
the attachment site during ingestion of a blood meal.
C. Signs of Disease
1. There are three phases of disease seen with Ehrlichiosis: acute, subclinical and chronic:
a. Acute: After an incubation period of 8 â€“ 20 days, the infected dog enters into the acute phase, which lasts about two to four weeks. During this time, the organism multiplies within circulating white blood cells and is transported to all areas of the body. Fever, depression, malaise, anorexia and weight loss, discharge from the eyes and nose, enlarged lymph nodes and occasionally swelling of the legs can all be seen during this time.
Platelets, a cell line responsible in part for blood clotting, often are decreased during this phase of disease by a variety of mechanisms.
b. Subclinical: Occurs six to nine weeks post-infection and is characterized by persistence of low platelet count, variably low white and red blood cell counts in the absence of obvious illness. Dogs with an adequate immune system may eliminate the infection during this phase.
c. Chronic: Dogs unable to effectively rid the organism become chronically infected. Elevated globulin levels in the blood are often seen. In this stage of disease, many dogs develop bone marrow suppression (the bone marrow is where the majority of our cells are made). Clinical signs in this stage are variable. Some dogs show no signs of illness, while others can show a variety of clinical signs, including many bleeding abnormalities, particularly from the nose.
2. Laboratory abnormalities that can be seen include deficiencies in all cell lines, red, white and platelet. Occasionally a dramatic increase in the lymphocyte white blood cell line is seen.
3. Bone marrow examination usually reveals low cell numbers with varying degrees of suppression of all cell lines. However, elevation in the number of plasma cells, another white blood cell, is a frequently reported finding.
4. Serum proteins are often abnormal. Elevated globulins are commonly seen. Sometimes this is seen as elevation of all of the globulins equally, or just one of them. If only one globulin is elevated, described as a monoclonal gammopathy, this can easily be confused with a type of cancer called Multiple Myeloma. Often plasma albumin is low.
1. Morulae (intracellular inclusions composed of clusters of organisms) are observed rarely and almost exclusively during the acute stage of infection. However, if these are observed, they are definitively diagnostic.
2. Serologic testing is again the most common means of diagnosing Ehrlichiosis. The indirect fluorescent antibody (IFA) technique is currently recommended. The only drawback is that there is often cross-reactivity amongst different species of Ehrlichia.
3. Polymerase chain reaction (PCR) can be used to confirm diagnosis, as this is a molecular test that tests for the presence of DNA of the ehrlichial organism.
4. As discussed in the Lyme disease discussion, IDEXX Laboratories has marketed an in-house ELISA antibody test for E. canis that is calibrated at approximately 1:100. Again, it needs to be said that a positive test should be interpreted in combination with history, clinical signs, or laboratory abnormalities since a positive test does not necessarily mean that the dog has active disease.
1. Tetracyclines or Doxycycline, administered for at least three weeks is the treatment of choice for Ehrlichiosis. Dramatic clinical improvement generally occurs within 24-48 hours after initiation of appropriate antibiotics.
2. If an animal is in the chronic phase of the disease and has bone marrow changes, it can take up to 120 days for the bone marrow to regenerate following treatment.
F. Public Health Concerns
There is no evidence that direct transmission of ehrlichial species from dogs to humans occurs.
III. Rocky Mountain Spotted Fever
1. Rocky Mountain spotted fever (RMSF) is an infectious rickettsial disease of dogs, which is characterized by sever vascular damage. Canine susceptibility to Rickettsia rickettsii was demonstrated in 1933. Recent reports emphasize that, contrary to previous literature, untreated naturally-occurring RMSF can result in death. Clinical reports suggest that RMSF is a much more common cause of disease in dogs than was previously recognized.
2. Despite its name and original description as a disease of humans in the western United States, the majority of human cases of RMSF occur in the southeastern US. Human cases of RMSF have been reported from nearly every state in the US, western Canada, Mexico, and South America. Distribution of the disease is related to the distribution of the vector ticks Dermacentor variabilis, the American dog tick found in the eastern US, and Dermacentor andersoni, the wood tick, which is the principal vector in the western US. Canine RMSF has been recognized in most southeastern states, New York, Massachusetts, and Ohio.
3. Rocky Mountain spotted fever is caused by Rickettsia rickettsii, a very small bacterium that must live inside the cells of its hosts. They are difficult to see in tissues by using routing histologic stains and generally require the use of special staining methods. Rocky Mountain spotted fever was first recognized in 1896 in the Snake River Valley of Idaho and was originally called â€œblack measlesâ€ because of the characteristic rash. It was a dreaded and frequently fatal disease that affected hundreds of people in this area.
R. rickettsii is a small intracellular parasite in the family Rickettsiaceae. The organism is a member of the spotted fever group rickettsiae, which includes both pathogenic and nonpathogenic rickettsiae. Dogs and rodents comprise the mammalian reservoir for R. rickettsii. Following tick bite, infection may occur in humans, dogs and cats. Within the general tick population, few ticks contain infective R. rickettsii. However, there are geographic centers that contain large numbers of infective ticks. Attachment of a tick to a host for five to 20 hours is required before infection can take place.
C. Signs of Disease
1. R. rickettsii is transmitted to the dog by a tick bite. The rickettsiae enter the circulatory system and replicate. Rickettsiae cause direct damage to cells lining the vascular system, resulting in vascular inflammation and death of the cells, swelling of the skin, hemorrhage, which if severe can cause low blood pressure, shock and death. Central nervous system swelling may contribute to the development of neurologic signs, rapid clinical deterioration, and death. Fluid accumulation in the lungs may occur, and may be detected with an X-ray. Clinical signs include rapid breathing, difficult breathing or coughing in some
dogs. In severe cases, acute kidney failure may occur. Due to increased vascular permeability, fluid therapy should be used with caution, when treating dogs with Rocky Mountain spotted fever.
2. Some dogs develop mild illness following experimental and naturally occurring infection with R. rickettsii. In addition to the infective dose or strain variation in rickettsiae, breed predisposition may play a role in determining the severity of illness. For example, some have observed severe disease in Siberian Huskies, whereas Deerhounds sustain high antibody titers without prior evidence of associated illness.
3. Clinical signs in canine infection are identical to human cases of RMSF. Unlike Ehrlichiosis in which chronic infection can persist, the total duration of illness following R. rickettsii infection is generally short (two weeks or less). For this reason, canine RMSF is a disease that presents in the spring and summer (April to September). Fever, loss of appetite, depression, vomiting, diarrhea, and neurologic abnormalities are typically associated with the clinical presentation of the animal. Redness and discharge from the eyes, nasal discharge and coughing are frequent findings. In some dogs, weight loss is very severe, considering the short duration of illness. Joint pain and/or muscle pain may represent the only or most prominent clinical finding.
4. Bloody nasal discharge, blood in stools, blood in the urine and areas of bruising occur in some dogs, but may not develop unless diagnosis and treatment are delayed for five or more days after the onset of clinical signs. Bleeding into the eye is a consistent finding, even early in the course of the disease. Scrotal swelling, hemorrhage, and testicular pain are frequently observed in mail (sic)dogs. This finding correlates with the disease in man and experimental infections in rodents.
5. Neurologic signs including pain, loss of balance, tilting of the head, stupor, seizures, and coma may occur in dogs with RMSF. Similar to Ehrlichiosis, this presentation can mimic canine distemper in the young dog.
1. The marked variation in clinical presentation allows RMSF to mimic numerous other infectious and noninfectious diseases. Seasonal occurrence,history of tick infestation, fever, or the previously described clinical findings would suggest the possibility of RMSF.
2. Decreased platelets, generally mild in degree, are the most consistent finding in blood counts. Biochemical abnormalities reflect the effects of generalized vascular damage and vary with the severity and duration of infection. Low protein levels, elevated kidney function tests, and increased liver enzymes (serum alkaline phosphatase, alanine animotransferase) may occur in dogs with RMSF. In general biochemical abnormalities are mild. If joint swelling is present, inflammatory cells may be present.
3. Confirmation of a diagnosis requires either direct immunofluorescent testing for R. rickettsii antigen in tissue biopsies, or serologic testing utilizing an indirect fluorescent antibody test. Evaluation of acute and convalescent sera with greater than or equal to a fourfold increase in antibody titers confirms a diagnosis of RMSF. Timing of sample collection for acute and convalescent sera will greatly influence the serologic results. Cross reaction with other spotted fever group rickettsiae and persistent tick exposure to R. rickettsii complicates the interpretation of serologic results from clinical patients with suspected RMSF. Direct immunofluorescent testing of tissue biopsies provides the opportunity for rapid diagnosis of RMSF. R. rickettsii are generally more readily demonstrated in human patients in areas of hemorrhage prior to initiation of treatment. This also appears applicable to canine patients, although organisms may be more readily
identifiable in clinically unaffected skin from dogs. If acute phase sera are obtained several days after the onset of clinical signs, antibody titer to R. rickettsii antigens will be high.
Tetracycline or doxycycline is the treatment of choice. However, chloramphenicol and enrofloxacin are equally effective. A rapid clinical response occurs in dogs without neurologic signs following the initiation of treatment. If fever persists, another diagnosis should be considered likely. Delay in diagnosis and initiation of tetracycline of the use of antibiotics lacking efficacy for treating rickettsial diseases may result in a fatal outcome. Due to severe vascular damage, fluid therapy should be utilizes with caution.
1. Babesiosis is a tick-borne hemoprotozoan (blood) disease. The organism is called Babesia, the disease is called Babesiosis. There are two primary infecting species: Babesia canis and Babesia gibsonii. Babesia species can cause an acute hemolytic anemia in dogs. This is a low red blood cell count caused by the destruction of the red blood cells within the animal’s body. Babesia has worldwide distribution. In a high percentage of dogs with acute or potentially chronic babesiosis, it will contribute to an immune-mediated hemolytic anemia, where the red blood cells are destroyed by the animal’s own immune system. Babesiosis is a cyclical disease, similar to malaria. Dogs that recover from the initial infection show variable and unpredictable patent periods alternating with dormant periods.
2. Historically, Babesia gibsonii was considered endemic in Asia, Africa and the Middle East, but was not recognized in the United States until 1979. Subsequently, B. gibsonii infection was recognized in dogs from California and most recently in Pit Bull Terriers in the southeastern US. In most instances, the presenting problem was immune-mediated hemolytic anemia. To date, a competent tick vector for the organism has not been identified in the US; therefore, establishment of the organism within the tick population may not be possible. As the efficacy of currently available drugs for treatment of B. gibsonii
is limited, veterinarians should report any suspected cases to the State Veterinarian. Should B. gibsonii become established within a tick population in the US, the consequences could be serious.
Babesiosis is thought to be transmitted by the vector tick Thipicephalus sanguineus, or brown dog tick, the same tick that transmits Ehrlichia canis. This has not been definitively demonstrated.
C. Signs of Disease
Acute phase is of short duration, and is where the dog is initially infected with the disease. If the dog does not die outright from the infection, then it moves on to the next phase. Subclinical phase can last months or years. It is characterized by a fine equilibrium between the parasite and the immune system of the host. This equilibrium can be disturbed by a number of things: environmental stress, additional diseases/infections (especially Ehrlichiosis), immunodeficiency, spleen removal, surgery, stress, hard work, immunosuppressive treatment, or use of corticosteroids. The dog may exhibit few clinical symptoms during this phase, beyond intermittent fever and loss of appetite. If the equilibrium is disturbed, the parasite will begin to slowly grow in number and the dog will move into the next phase. In the chronic phase, if the dogâ€™s system remains unable to clear the parasite, it enters this final phase. The most obvious initial signs to an owner are
a cycle of: lethargy, loss of interest in food, and a gradual loss of body condition
especially evident around the eyes and along the spine. Other symptoms are:
upper respiratory problems (coughing or labored breathing), vomiting, constipation, diarrhea, ulcerative stomatitis (sores in the mouth), edema (swelling), abdominal swelling (ascites), bleeding under the skin or a rash (purpura), low white blood cell count, clotting problems, joint swelling, back pain, seizures, weakness, increased liver enzyme, low platelet count, hyper reflective eyes, enlarged lymph nodes, enlarged spleen, septic shock, depression.
1. A combination of a regenerative anemia, elevated bilirubin, low platelet count, elevated kidney values, elevated globulins and urinary casts are all common with Babesiosis.
2. Indirect fluorescent antibody tests are available and will demonstrate antibody
titers against the organism.
3. Definitive diagnosis is based on organism demonstration in red blood cells.
1. Until recently, there has not been an approved anti-babesia drug available in the United States for treatment of canine babesiosis. Imidocarb diproprionate (ImizolÂ®, Schering-Plough Animal Health) is currently available for the treatment of babesiosis in dogs. In acute babesiosis, the therapeutic response is rapid, with increasing production of new red blood cell values documented within 12 to 24 hours. In Africa and other regions of the world, imidocarb diproprionate is considered efficacious for treatment of E. canis, as well as B. canis infections. Some reports of success using metronidazole or clindamycin have been reported.
2. Although multiple therapies are being studied, there is no definitive treatment established for B. gibsonii infections in dogs.
V. Tick Control
A. Advancements in the products available to control fleas and ticks have revolutionized their prevention in veterinary medicine. In the past, we were recommending multiple products, from whole house flea bombs to topical powders, all containing chemicals less than ideal regarding exposure to our pets and to their owners. Now, more safe and effective products have been developed for use in dogs and cats.
B. Topical spot-on products
1. Frontline and Frontline Plus
A topical product which kills both fleas and ticks. The active ingredient is Fipronil. It is marketed to prevent fleas for up to three months, and prevent ticks for up to one month. Although not established, the label claims that ticks will die prior to beginning a blood meal. Frontline PLUS contains an insect growth regulator as well, which prevents eggs laid by fleas from developing into adults.
2. KillTix (Bayer)
a. Label claims a single application will repel and kill ticks for up to four weeks. Apply KillTix montly when ticks are a threat in your area. In more acute infestations, repeat applications can be made, but not more than every three weeks.
b. Can ONLY be used in dogs.
C. Tick Collars
Active ingredient is amitraz. Label claims that it kills ticks for up to three months. Studies have shown similar efficacy between fipronil and amitraz.
D. Revolution is not effective at preventing ticks.
Other than the Lyme disease vaccine discussed above, no other vaccines are available to prevent infection.
How do I remove ticks from my dog?
If possible, use blunt forceps or tweezers. Place tips around the tick where it is attached to the skin. Remove tick with a steady pull away from the skin. DO NOT JERK OR TWIST THE TICK. Take care not to crush or puncture the body of the tick or to get any fluids form the tick on you. After removing the tick, cleanse the area with mild soap and water and wash your hands with soap and water. Remedies such as matches, petroleum jelly or nail polish do not cause ticks to detach.
1. American College of Veterinary Preventive Medicine (ACVPM) www.acvpm.org
2. Centers for Disease Control and Prevention (CDC) www.cdc.gov
Dog Owners and Breeders Symposium
July 27, 2002
University of Florida
College of Veterinary Medicine