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Comments About Some Common Parasites of Your Dog and Cat

   Round worms, hook worms and whipworms are internal parasites, which live as adults in the digestive tract and cause general unthriftiness.  If they are allowed to exist in the body of your animal for any length of time they will cause the animal to become thin, inactive and much more susceptible to other diseases.  These three types of worms have a direct life cycle.  That is, the eggs leave an animal's body with the feces, enter the soil, and become infective larvae. These parasitic larvae are therefore constantly in the environment of your pet. They are highly contagious to dogs and cats.

   A dog which is kept in an outside pen, run, yard or on a rope can reinfect itself after being successfully wormed.  This is because of the infective larvae, which remain in the soil.  Hook worm and whipworm larvae are very difficult to kill in the soil.  If your dog lives in such an environment please discuss the problem with the veterinarian.

Roundworms can also be acquired by ingesting an animal of another species (mice, earthworms or roaches) which contains infective larvae.  Cats and dogs share whipworm infestation.

   Once ingested, larvae travel through an animal's body, passing through several stages before becoming egg-producing adults.  This travel takes various lengths of time for different parasites.  Since it is usually the adults that are killed by worming medication, the dose must be repeated when the larvae would reach adulthood.

   Therefore, hookworms are treated with two medication dosages, one month apart. A stool should be checked one month after the second injection.  Whipworms are treated by medication three times, at six-week intervals.  Roundworms, on the other hand, are usually treated with a single administration of medication.  Reminders will be mailed to you when second or third doses are needed.  Should you not receive one as anticipated, please call.

   It is good preventive care to bring a stool sample in every six months.  If you do not see your cat defecates, keep it in the house and provide a kitty litter. If all else fails, feel free to bring your dog or cat to the hospital where we will try to obtain some stool from the rectum.


Tapeworms are of different types.

1)  Taenids are tapeworms, which void segments from the bowels of dogs and cats.  An intermediate host (rabbit, pig, hare, goat, sheep, deer, cow, etc.) then ingests the segments.  Meat of the intermediate host is then eaten by a dog or cat, which is then infected with tapeworms.

2)  Dipylidiinae are tapeworms, which void segments from a dog or cat.  The segments contain eggs, which are then ingested by flea larvae or adult biting lice.  Another dog or cat ingests the flea or louse and is then infected with tapeworms.

3)  Dogs and cats obtain other tapeworms when they eat reptiles or birds.


   By far the most common tapeworm problem is infection with dipylidiinae via fleas.  You cannot rid your pet of these parasites without ridding its environment of fleas. Tapeworms are not as rapidly debilitating as other internal parasites, but will cause problems for your pet if you allow the infestation to remain for a long period of time. Because the eggs of tapeworms are not in your pet's feces, these parasites cannot be detected microscopically in a stool sample. You must diagnose this infection by observing "small rice kernel" size segments on your animal's fur (around the anus), or on the stool.


Ticks:  The brown dog tick (Rhipicephalus sanguineus) lives in the house (in cracks, bedding, carpeting and walls) and in kennels, and infects dogs and cats at all times of the year.  Wood ticks (dermacentor species) infect dogs only in their adult stage and do not infect houses or kennels. Deer ticks (Ixodes dammini ) are very problematic.  They are responsible for the spread of  Lyme disease (Borrelia burgdorferi – see below).  Ticks exist in three stages - laval, nymph and adult.  They may live for up to a year in each stage.

Ticks can jump onto a dog when it is outdoors in all seasons.  Wood ticks infect animals other than dogs and cats in larval and nymph stages, and attack pets in the adult stage.  These ticks can survive for many months without feeding.  If a brown dog tick infestation exists in your house an exterminator will be needed to eliminate it.  Care of the animal involves simple removal of the tick by pulling it with the fingernails.  Do not use matches or kerosene, etc.  Many times a small male tick is present alongside an engorged female.  With fingernail manipulation head and mouthparts will generally not be left in the skin.   If a persistent infestation exists in a dog, use fipronil (Frontline) a tick collar or spray.   (You can obtain Frontline, collars and spray at the hospital).  If you are having a problem with ticks, please discuss it with the veterinarian.

Lyme disease is an illness caused by a spirochete bacteria, Borrelia burgdorferi, which is transmitted to animals and man through the bite of infected ticks.

The disease is reported worldwide and throughout the United States. The states of New York, Massachusetts, Connecticut, Rhode Island and New Jersey account for the majority of cases in the United States. However, cases are reported from all geographic regions of the country. Different ticks are carriers in the different regions. Ixodes dammini (the deer tick) in the Northeast and Midwest.

Ixodes dammini is responsible for most of the cases of Lyme disease in the northeastern United States. These ticks are found in grassy areas (including lawns), and in brushy, shrubby and woodland sites, even on warm winter days. They prefer areas where some moisture is present. The tick has three life stages: larva, nymph and adult. Each stage takes a single blood meal. They feed on a variety of warm blooded animals including man, dogs, cats, horses and cows. The bite is painless so most victims do not know they have been bitten. The nymphal stage appears to be responsible for most Lyme disease cases. Both the larval stage (about the size of a grain of sand) and nymphal stage (about the size of a poppy seed) attach to a variety of small mammals, but prefer the white-footed mouse, the main reservoir of the Lyme disease bacteria. The adult ticks (about the size of a sesame seed) prefer to feed on white-tailed deer. The entire life cycle requires three separate hosts and takes about two years to complete.

Larval and nymphal deer ticks also attach to birds. Indeed, birds may be a primary means by which the ticks (some infected) are spread from one area to another. Some species of birds also function as a reservoir of infection.


Caution:  The presence of many small ticks on you dog means that you have a brown tick infestation in your house or kennel.  Ticks can transmit tick paralysis to dogs, and Rocky Mountain Spotted Fever as well as Lyme disease  and other diseases to man.  Eradicate ticks if they are a constant problem.

 Lyme disease has been described in dogs, cats, horses cows and goats. Symptoms can include fever, lameness and soreness, listlessness, loss of appetite, swollen glands and joints. Heart, kidney, liver, eye and nervous system problems are also described in animals. Laminitis is reported in horses and cows, as are poor fertility, abortions and chronic weight loss. Temperament changes have been reported in dogs and horses. Untreated animals can develop chronic progressive arthritis.

Primarily, lyme disease in dogs is manifested by lameness which often shifts from one leg to the other.  If a dog is lame and tets positive for Lyme antibodies the dog is treated as if it has Lyme disease.  Testing to ascertain surety of infection is expensive and, often, problematic, therefore, the dog is treated immediately.  Chronic infection can cause death.  Lyme is a disease of inflammation.  If the immune system is not in an inflammatory state the dog will most likely develop antibodies to the organism but not be chronically infected and will develop no inflammation.  Therefore, if a dog tests positive for lyme it should not be treated unless it is symptomatic.

Symptoms can be intermittent and vary in intensity from mild to quite severe and can mimic many other conditions.

 Lice:  Biting and sucking lice of dogs or cats are not common, but are seen in this area.  They are species specific - that is, they will not infect humans.  The complete life cycle of the louse, from nit (egg) to adult, lasts about three weeks and occurs entirely on the host animal.  Lice do not live off of their host.

Insecticides easily rid animals of these itchy pests (claws, bites and sucks cause itching).  Contact the hospital for an insecticidal shampoo to treat an animal with lice.

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