Pancreatitis

The importance of parasites and parasite control may or may not be obvious to many people. Parasites can cause a variety of problems in animals ranging from mild to severe. In some instances, parasites can even cause death. In addition to the illness that they cause, parasites can transmit other diseases to the animals that they infect. For example, ticks can transmit Lyme disease or Ehrlichia. However, one of the biggest concerns of parasitism in animals is the potential for spread to humans. Many of the parasites that infect animals can cause disease or illness in people as well. 

The types of parasites can be divided into two main categories--external or ectoparasites and internal or endoparasites. The remainder of this article will discuss the common types of parasites that affect cats and dogs, the signs that they can cause, the methods for diagnosis, and the drugs that are used to treat them.

Ectoparasites

The ectoparasites, or parasites that live on the dog or cat, are probably the most common and most recognized of all parasites. Parasites within this category include fleas, ticks, mites, and lice. 

Fleas are probably the most common parasite in dogs and cats. In this area, fleas have been increasing and they can be a year-round problem. Favorable weather conditions, including warmer than average winters, are probably to blame. Fleas typically cause one or more of the 4 following problems: 1) mild to severe itching, scratching, biting, and chewing, 2) flea saliva hypersensitivity or allergy and resulting skin problems, 3) the transmission of tapeworms, and 4) anemia and possible death (most often in very young or small animals). Fleas can be detected by direct examination of the animal. The presence of adult fleas or flea dirt, or small black specks of dried flea feces on the animal, is confirmatory. The presence of a flea allergy can be detected by a blood test.

Ticks, like fleas, have also been a big problem in this area. Over the last several years, the tick season seems to have lengthened. This is presumably due to favorable environmental conditions, mainly mild winters. Ticks can cause signs that range from mild local irritation to severe anemia. In addition, ticks can transmit many other diseases to animals and humans. These diseases include Lyme Disease, Rocky Mountain Spotted Fever, and Erlichia, among others. Ticks can be detected by direct examination of the animal.

Mites and lice are less commonly seen in dogs and cats than fleas and ticks but do occur. The three main types of mites include sarcoptic mange, demodectic mange, and chyletiella. Signs of mites and lice may or may not include itching, hair loss, dandruff or crusty lesions, bleeding or oozing skin, etc. Some types of mites are transmissible to people. However, animal lice ARE NOT transmissible to people. Lice are species specific. This means that dog lice live only on dogs and human lice live only on humans. (Thus, you cannot blame the dog for giving your kids head lice!) Mites and lice can be detected 

through skin scrapings and direct examination of the animal.

Endoparasites

The endoparasites, or parasites that live within the dog or cat, are often less obvious to owners but typically cause more severe diseases than ectoparasites. The most common parasites within this category include heartworms, roundworms, hookworms, whipworms, and tapeworms. Other parasites that are not common within this area of the country include liver flukes, kidney worms, and lungworms. 

Heartworms are one of the most important endoparasites in this area. The number of animals that we find with heartworms has been increasing over the past several years. Heartworms are transmitted to dogs and cats through the bite of an infected mosquito. Adult heartworms primarily live in the major blood vessels of the heart and lungs. Immature heartworms circulate throughout the blood vessels in the rest of the body. The signs of heartworm infection can be vague. It is not uncommon for an animal infected with adult heartworms to exhibit no signs of illness until late in the course of the disease. Signs of heartworm can include coughing, difficulty breathing, panting, exercise intolerance, decreased activity level, and sudden death. Heartworms can be easily detected through a blood test. 

Roundworms, hookworms, and whipworms are among the most common internal parasites. These parasites live within the gastrointestinal (GI) tract of animals and can cause diarrhea, anemia, loss of body condition, etc. Transmission of these parasites from animal to animal can occur in several ways. The main means of transmission for all three of these parasites is fecal-oral contact. The eggs from the parasites are passed within feces and gain entry into the next animal when the eggs are ingested. In addition, some of these parasites, mainly roundworms, can be passed from mother to offspring (puppy or kitten) through the milk or across the placenta. These parasites can be easily detected through a fecal float. 

Tapeworms are another example of a gastrointestinal (GI) parasite. Tapeworms can also cause diarrhea, weight loss/poor body condition, etc. Tapeworms can be passed in two main ways. First, fleas can carry and transmit tapeworms to the animals that they infect. Second, tapeworms can be carried and transmitted by rodents and rabbits. Dogs and cats 

that hunt and eat these animals tend to pick up tapeworms fairly readily. The fecal float techniques used to detect roundworms, hookworms, and whipworms will often not detect tapeworms. Diagnosis is often made by direct observation of tapeworm segments in freshly passed feces or on the animal.

Parasite Treatments

Over the years, the number and types of parasite treatments for small animals have grown tremendously. There are two main approaches to parasite treatment--preventative treatments and curative treatments. Preventative treatments are given on a regular interval in an effort to keep animals from getting a large burden of parasites. Curative treatments are given only in response to the positive identification of parasites. As with most things, prevention is easier and better than treating a problem once it is present. Many of the newer anti-parasite medications aim at preventing a wide variety of parasites while many of the curative treatments only kill one or two types of parasites. A complete discussion of all of the available parasite medications is beyond the limitations of this article, thus only the newest, preventative, prescription products will be discussed. These include Advantage, Frontline, Revolution, Heartgard, Interceptor, Program, Sentinel, and Proheart.

Advantage and Frontline are monthly topicals that kill ectoparasites. Advantage will kill adult fleas and flea larva and Frontline will kill adult fleas and ticks. A new version of Frontline, called Frontline Plus, will soon be available. This product 

will kill adult fleas, larva, and eggs.

Revolution is a monthly topical that will kill adult fleas, eggs, ear mites, roundworms, and hookworms in cats and adult fleas, eggs, ticks, ear mites, and sarcoptic mange in dogs. 

Program is an oral monthly that will kill flea eggs only. Program is also available in a long-lasting injectable form.

Heartgard, Interceptor, and Sentinel are oral monthly tablets that will kill a variety of parasites. Heartgard will kill immature heartworms, roundworms, and hookworms. Interceptor will kill immature heartworms, roundworms, hookworms, and whipworms. Sentinel is the combination of Interceptor and Program and thus will kill immature heartworms, roundworms, hookworms, whipworms, and flea eggs. 

Proheart is the newest heartworm medication available for use in dogs. It is an injection that is given twice a year. Proheart will kill immature heartworms and hookworms.

The information provided is for educational purposes only and is not intended to take the place of your regular veterinarian. Please do not hesitate to contact your regular veterinarian if you have questions regarding your pet.