Tick Lyme
Canine Health: Parasites, A Dog Owner's Guide To Worms, Fleas, Mites & Ticks
How to treat and protect your dog.
Even the healthiest and best-kept dogs will suffer from parasites of some kind during their lives. This knol is a guide to the major threats and how to treat and protect against them.
Introduction
 |
Dogs are prone to infestation by two types of parasite: external parasites living on the outside of the dog, such as ringworm, lice, fleas and ticks, and internal parasites, primarily worms.
Internal Parasites
WormsWorms are an unfortunate fact of life. All dogs will have them at some point and most will have them during puppyhood, when they are most vulnerable to them. It can be a serious matter. Worm infestation can cause weight loss, vomiting, diarrhoea and a painfully swollen abdomen. In the worst cases they can even cause death. So it's important that dogs are treated - or wormed - from an early age.
There are four main types of worms, each of which live in the dog's intestine and feed on undigested food there.
Roundworms
 |
| A roundworm. Image: wikimedia.org |
Roundworms are the most common in puppies, indeed almost every puppy is born with them present. They look a little like a rubber band and can be several inches long. They are spread through the environment and other dogs' faeces. (Yet another reasons for owners to practice good hygiene by carrying a poop-scoop or plastic bag to clean up when out and about.) Roundworms mainly infest the small intestine. But they can also affect the large intestine, blood vessels and respiratory tract.
The worms are a real threat to puppies because they can penetrate the wall of its gut and pass via the bloodstream into organs like the liver and lungs. This in turn can lead to pneumonia, hepatitis and fits.
Owners should also be aware that roundworm can infect humans, particularly children whose eyes are vulnerable to the disease.
Tapeworms
 |
| A 'packet' of tapeworm eggs Dipylidium caninum. |
Hookworms
 |
| Egg from Trichuris vulpis (canine whipworm) seen through a microscope at 400x. Photo: Joel Mills |
Hookworms are relatively easy to diagnose because they can ordinarily be seen by the naked eye.
Whipworms
These thread-like parasites are around 5-7 centimetres long and live in the colon and small intestine. They are transmitted via eggs that have infested a dog's faeces and can only be passed on to dogs that ingest them directly. These too are bloodsuckers and, if present in large numbers in a dog, can cause bloody diarrhoea and lead to significant weight loss. In general, however, whipworms do not produce many eggs, which makes it one of the trickier forms of worms to detect even by a vet.
Other types of worm:
While most worms live in the intestine, there are a variety of parasites that develop in other organs. The main ones are:
Heartworms
This worm is spread by the mosquito and - as its name suggests - grows in the heart and the pulmonary arteries.
It is a problem in warmer climates, particularly in Australia.
Lungworms
There are two different types of this parasite, one of which is spread when dogs eat earthworms, the other passed on via the mother's saliva. Dogs in North America are also prone to a lung fluke, passed on by eating contaminated crayfish.
Kidney worms
This worm can grow to a considerable size and may require the removal of the kidney.
Treating Worms:
When to worm?
Worms can be passed from the mother either before birth or through her milk, so it's crucial treatment starts early, ideally when the puppy is two to three weeks old. If you are buying a new puppy, always check that the person who provides you with your puppy has begun this process. After that your dog should be wormed at least three times a year, throughout its life.
How to Worm?
The good news is that all worms are relatively easy to eliminate. And thanks to the wide range of modern treatments available at vets' surgeries, owners have a large range of options available now.
Deworming medicines now come in tablets, granules or liquids, each of which allows the owner to be exact in the dosages they give. The liquid medicines have the advantage of being administrable via a syringe which can be used to release the medicine into the dog's mouth.
External Parasites
It's a fact of life, that your dog will probably be affected by an external parasite at some point in its life. So, even at an early age, it is important to look out for the main nuisances, fleas, ticks, lice and mites.
Fleas
Life Cycle
A flea's life cycle is divided into four stages, egg, larva, pupa and adult. The eggs are laid by the female flea, which like all adult fleas live on the dog's coat. These eggs then fall off the "host" dog on to the home environment, perhaps on to the furniture or the carpet in their home. The eggs hatch into larvae, which feed on microscopic scraps, such as flea dirt and tapeworm eggs, before spinning a cocoon inside which the pupae develops into an adult.
The fleas are encouraged to hatch by warmth and vibration, either from the "host" pet or the environment around them. When the flea emerges it jumps back on to a "host" dog and the cycle begins all over again. The whole process from egg to flea can take as little as two weeks.
An adult flea lives for no more than seven or ten days, but during this time they cause immense discomfort and irritation to a "host" dog.
Detecting and Treating Fleas
Often your dog will be your best guide to whether fleas are present or not. When fleas move through a dog's coat they cause huge irritation and the dog will begin scratching, biting or licking at the area where the itching is concentrated. In other cases, dogs will be allergic to the bites of the flea and display obvious skin problems.
In some cases, however, there will be no obvious indication of fleas being present.
Fleas are hard to spot: they are small and hard for the naked eye to pick up, and they also move around the body quickly. Fleas do, however, tend to settle in the same region of the dog's body, usually around the base of the tail, the ears, neck and abdomen. One simple way of checking whether they are present is by combing through the dog's coat and shaking any loose matter on to a small piece of white tissue paper. If there are flecks of red then this is probably ingested blood from an infestation of fleas.
Left untreated, fleas can cause widespread problems, such as anaemia. They can also multiply at a terrifying rate and infest an entire household, not to mention all its occupants. So it is important to act when you detect them - and to do so quickly. Fleas are also hosts to tapeworms, so if they are present it's vital that the dog is treated for this as well.
There are a variety of flea controls, ranging from flea collars and powders, to shampoos and sprays. It used to be that you had to dust the dog's entire body, but thanks to modern medicine single "spot on" treatments can be applied to the back of the neck. The treatment spreads giving good protection to the whole of the body.
Ticks
Ticks are unpleasant, blood-sucking parasites that can afflict dogs everywhere. The most common varieties are the sheep and hedgehog ticks, which - as their names suggest - originate in other species then cross over to dogs as they roam in grass, woodland or overgrowth.
Ticks are generally less common than fleas, but they can cause abscesses and infections. In some parts of the world, including the United States, they can even transmit potentially lethal diseases like Lyme disease. It is vital, therefore, that they are treated quickly and effectively.
Life Cycle
The life cycle of a tick is thought to last up to three years and begins with the female tick laying thousands of eggs on the ground. When these eggs become larvae they settle on to grass and shrubbery ready to attach themselves on to animals - or indeed humans - as they brush by. Once they are attached to their host' they feed until they are ready to fall back off and develop into the next phase, the nymph. This process is then repeated as the nymph reattaches itself to a new host, feeding off it until it develops into a fully-grown tick. The tick will then climb on to grass and shrubland ready to attach itself to a final host. It is now that the real damage is done. The tick finds the point of least resistance in the dog's coat where it fixes itself on by its mouth. Often this is the face, the ears or the abdomen. It then begins to feed on the dog's blood supply, passing on any infections it is carrying at the same time. Because it burrows into the skin it can also leave nasty abscesses. Once the female tick has fed fully it falls off again, ready to lay eggs and start the cycle all over again.
How To Spot and Treat Ticks
The most obvious sign of ticks is a small, grey dot on the dog's skin. It is easy to mistake the dot for a wart or another lump, but the most obvious sign that it is a tick is that it will grow larger, often to the size of a pea.
Removing the tick can be a tricky process because it attaches itself to the dog's skin by its mouth. It is easy to remove the body but leave the mouth attached, which can lead to more severe problems. If ticks do turn up in your puppy you should see your vet as it can lead to anaemia and, occasionally, death. Ticks can also transmit infectious diseases to humans so it is important to act quickly.
You can treat your dogs in advance for ticks. If you live in a rural area and plan to walk your dog in open fields or woodland it is advisable to treat it in advance. If it is likely to come into contact with sheep it should also be treated.
Mites
Three types of mite are a cause of problems in dogs.
Demodex - this mite causes demodectic mange which can lead to juvenile pyoderma
Sarcoptes - these are the cause of scabies
Otodectes - this mite is the only one visible to the naked eye. It causes inflammation of the ear and can be seen in the shape of tiny white moving dots inside the canal of the ear.
How to Detect and Treat Mites
As with fleas, mites are tiny - almost microscopic - creatures almost always invisible to the human eye. The best way to detect them is by looking out for small specks of grit on the dog's coat during grooming.
Canine Hip Dysplasia
Canine Elbow Dysplasia
Dog Flu: An Owner's Guide to Dealing with Canine Influenza
British Veterinary Association
Life Cycle
A flea's life cycle is divided into four stages, egg, larva, pupa and adult. The eggs are laid by the female flea, which like all adult fleas live on the dog's coat. These eggs then fall off the "host" dog on to the home environment, perhaps on to the furniture or the carpet in their home. The eggs hatch into larvae, which feed on microscopic scraps, such as flea dirt and tapeworm eggs, before spinning a cocoon inside which the pupae develops into an adult.
The fleas are encouraged to hatch by warmth and vibration, either from the "host" pet or the environment around them. When the flea emerges it jumps back on to a "host" dog and the cycle begins all over again. The whole process from egg to flea can take as little as two weeks.
An adult flea lives for no more than seven or ten days, but during this time they cause immense discomfort and irritation to a "host" dog.
Detecting and Treating Fleas
Often your dog will be your best guide to whether fleas are present or not. When fleas move through a dog's coat they cause huge irritation and the dog will begin scratching, biting or licking at the area where the itching is concentrated. In other cases, dogs will be allergic to the bites of the flea and display obvious skin problems.
In some cases, however, there will be no obvious indication of fleas being present.
Fleas are hard to spot: they are small and hard for the naked eye to pick up, and they also move around the body quickly. Fleas do, however, tend to settle in the same region of the dog's body, usually around the base of the tail, the ears, neck and abdomen. One simple way of checking whether they are present is by combing through the dog's coat and shaking any loose matter on to a small piece of white tissue paper. If there are flecks of red then this is probably ingested blood from an infestation of fleas.
 |
| Excoriations and crusts on the coat of a dog with fleas. |
There are a variety of flea controls, ranging from flea collars and powders, to shampoos and sprays. It used to be that you had to dust the dog's entire body, but thanks to modern medicine single "spot on" treatments can be applied to the back of the neck. The treatment spreads giving good protection to the whole of the body.
Ticks
 |
| American Dog Tick. Image: wikimedia.org |
Ticks are generally less common than fleas, but they can cause abscesses and infections. In some parts of the world, including the United States, they can even transmit potentially lethal diseases like Lyme disease. It is vital, therefore, that they are treated quickly and effectively.
Life Cycle
The life cycle of a tick is thought to last up to three years and begins with the female tick laying thousands of eggs on the ground. When these eggs become larvae they settle on to grass and shrubbery ready to attach themselves on to animals - or indeed humans - as they brush by. Once they are attached to their host' they feed until they are ready to fall back off and develop into the next phase, the nymph. This process is then repeated as the nymph reattaches itself to a new host, feeding off it until it develops into a fully-grown tick. The tick will then climb on to grass and shrubland ready to attach itself to a final host. It is now that the real damage is done. The tick finds the point of least resistance in the dog's coat where it fixes itself on by its mouth. Often this is the face, the ears or the abdomen. It then begins to feed on the dog's blood supply, passing on any infections it is carrying at the same time. Because it burrows into the skin it can also leave nasty abscesses. Once the female tick has fed fully it falls off again, ready to lay eggs and start the cycle all over again.
How To Spot and Treat Ticks
The most obvious sign of ticks is a small, grey dot on the dog's skin. It is easy to mistake the dot for a wart or another lump, but the most obvious sign that it is a tick is that it will grow larger, often to the size of a pea.
Removing the tick can be a tricky process because it attaches itself to the dog's skin by its mouth. It is easy to remove the body but leave the mouth attached, which can lead to more severe problems. If ticks do turn up in your puppy you should see your vet as it can lead to anaemia and, occasionally, death. Ticks can also transmit infectious diseases to humans so it is important to act quickly.
You can treat your dogs in advance for ticks. If you live in a rural area and plan to walk your dog in open fields or woodland it is advisable to treat it in advance. If it is likely to come into contact with sheep it should also be treated.
Mites
Three types of mite are a cause of problems in dogs.
Demodex - this mite causes demodectic mange which can lead to juvenile pyoderma
Sarcoptes - these are the cause of scabies
Otodectes - this mite is the only one visible to the naked eye. It causes inflammation of the ear and can be seen in the shape of tiny white moving dots inside the canal of the ear.
As with fleas, mites are tiny - almost microscopic - creatures almost always invisible to the human eye. The best way to detect them is by looking out for small specks of grit on the dog's coat during grooming.
Medical And Homeopathic Treatments
Selamectin
A topical insecticide and antihelminthic, this is used widely to control outbreaks of hookworms, earmites, roundworms, heartworms and fleas. It is the active ingredient in the prescription drug Revolution, manufactured by Pfizer Canada. Selamectin disables and eventually kills parasites by allowing chloride ions to enter the parasite's nerve cells. Selamectin combats both internal and external parasites.
A 2003 report by E. Pipano in the Israel Journal of Veterinary Medicine describes positive results in testing of Selamectin for safety and effectiveness. [1]
Other Canine Health Knols
Canine Hip Dysplasia
Canine Elbow Dysplasia
Dog Flu: An Owner's Guide to Dealing with Canine Influenza
External Links:
American Veterinary Medical AssociationBritish Veterinary Association
