Tag Archives: diarrhoea

Diseases of dogs, Dogs, Internal diseases of Dogs

Hookworm

Hookworms attach to the intestinal wall with hook-like mouthparts. They are hard to see because they are only about 3 mm long and very thin.

Dogs are infested with hookworms in one of three ways:

1. Hookworm larvae pass from the dam to the pups through the placenta before birth

2. Pups ingest larvae in the mother’s milk

3. Larvae penetrate the skin

 

What problems do hookworms cause?

Hookworms suck blood from the tiny vessels in the intestinal wall and cause anaemia especially in puppies.  Pale gums, lethargy and weakness are signs of anaemia.

Hookworm also cause bloody diarrhoea, weight loss and failure to grow.

Hookworm larvae burrow into the skin and cause itching and discomfort in a heavily infested environment such as kennels.

 

How do we diagnose hookworm infestation?

Hookworms produce a lot of eggs which are easily found in faeces under a microscope. Faecal examination is less reliable in very young puppies.

 

How is hookworm treated?

Most broad spectrum wormers, like Milbemax and Drontal, kill adult hookworms. We repeat the treatment 2-4 weeks later to kill the next wave of larvae maturing into adult worms.

 

Are canine hookworms infectious to people?

Adult hookworms do not infect humans. However, hookworm larvae can burrow into human skin and cause itching. They do not mature into adults. Wear shoes to avoid skin contact with hookworm infested soil especially in wet weather.

 

How do we prevent hookworm infection?

1. Deworm pups at six weeks of age

2. Deworm pets at high risk of reinfestation

3. Pick up and dispose of dog faeces, especially in yards, playgrounds, and public parks.

4. Do not allow children to play in potentially contaminated environments.

5. Treat nursing bitches concurrently with their pups.

6. Use broad spectrum worm treatments that are effective against hookworms.

 

Diseases of dogs, Dogs, Internal diseases of Dogs

Roundworm

Roundworms, also known as ascarids, have round bodies and are 7-12 cm long. They live in  dogs’ intestines on partially digested food.

Pups infested with roundworms lose weight and look pot-bellied. They lose their appetites and may vomit or develop diarrhoea. Serious roundworm infestations obstruct or twist the bowel.

Most puppies acquire roundworm infection from their mothers before birth and then through the milk afterward.

Both puppies and adult dogs are also infected by swallowing roundworm eggs from bowls, hair or dirt contaminated with faeces. They can also be infected by roundworm larvae encysted in the organs of prey like mice, cockroaches, earthworms and chickens.

Ingested larvae and eggs are activated in the dog’s stomach and small intestine and migrate through the muscle, liver, and lungs. After several weeks, the larvae make their way back to the intestine to mature. When these worms begin to reproduce, new eggs will pass in the dog’s faeces, and the life cycle of the parasite is completed.

Roundworm eggs in the faeces confirm roundworm infestation. Because roundworm don’t produce many eggs we sometimes have to examine several fecal samples before we find eggs. Occasionally, we see mature worms in the dog’s vomit or faeces.

Treatment with broad-spectrum wormers like Milbemax or Drontal eliminates adult roundworm. No treatment reliably kills the migrating larvae so we give two or three treatments 2 weeks apart catch them as they mature into adult worms.

The eggs are resistant to most disinfectants and survive in quite harsh environmental conditions. They remain infective to dogs and humans for years.

Regular removal of dog faeces and deworming as detailed below prevent reinfection.

Roundworms are a risk to human health.  Children and people who are immunosuppressed or on immunosuppressive drugs are particularly vulnerable. The roundworm eggs only develop as far as larvae in people. As the larvae migrate through the body they can cause damage, particularly to the eye. Worming people does not kill the larvae as only adult worms are susceptible to wormers. To prevention human infestation

  • Deworm pups fortnightly until 12 weeks of age, then monthly until 6 months of age. Adult dogs must be dewormed every 3 months
  • Remove and dispose of dog faeces promptly
  • Teach children to wash their hands thoroughly after playing with dogs
  • Deworm pregnant bitches in late pregnancy and then every time her pups are dewormed, as above
  • Discourage dogs from defecating in children’s play areas

 

Diseases of dogs, Dogs, Internal diseases of Dogs

Whipworm

Whipworms live in the large intestine of dogs and irritate the lining causing watery, bloody diarrhoea and weight loss.

Whipworms produce microscopic eggs that pass out in the dog’s faeces. The eggs resist drying and heat, and can infect another dog years later. Dogs housed on dirt or grass that is not regularly cleaned of faeces risk whipworm infestation.

 

Whipworm eggs in the faeces confirm a whipworm infestation. However, they are often hard to find as the worms only produce small numbers of eggs on an irregular basis. Any dog with chronic diarrhoea could have whipworms despite negative faecal examinations. Response to treatment indicates that whipworms were present after all.

Most broad spectrum wormers, including Milbemax and Drontal are effective against whipworms.

Whipworms are not infectious to people. They are only parasites of the dog.

 

Diseases of dogs, Dogs, Internal diseases of Dogs

Parvovirus in dogs

Parvovirus causes severe vomiting and diarrhoea and is very contagious. The virus may infect a whole litter of pups from an unvaccinated bitch. Dogs less than one year old are the most vulnerable to the virus.

Dogs go off their food and start to vomit within a few days of infection. An astute owner will notice a drop in appetite, depression, and fever before the vomiting and diarrhoea start. The diarrhoea often contains blood and mucus, and many dogs suffer severe pain in the belly.

How does a dog become infected with parvovirus?

The faeces of an infected dog is high in virus. Direct contact between dogs is not required to spread the virus.

Another dog is infected by licking the virus off food dishes, hair, the ground, shoes, clothes, tyres or other objects.  The virus survives for years in backyards.

How do we know it is parvovirus?

We suspect parvovirus in any vomiting dog, particularly if they are unvaccinated and young.  A rapid test for virus in the faeces confirms the infection. Occasionally, even though a dog  has parvovirus the test is negative because the virus has not travelled all the way down the intestine. If we still strongly suspect parvovirus we treat the pup in the isolation ward and retest later.

Can it be treated successfully?

No treatment kills the virus. We treat the dog symptomatically to replace lost fluids, rebalance electrolytes and prevent septicaemia. The virus causes loss of the lining of the intestinal tract. This results in severe dehydration and electrolyte imbalances, and allows bacteria to get into the bloodstream and cause septicaemia.

Pain relief and drugs to control the vomiting are often necessary.

Most dogs with parvovirus recover with aggressive treatment as long as it is begun before severe septicaemia and dehydration occur. Some breeds, notably the Rottweiler, have a much higher fatality rate than other breeds.

Can it be prevented?

Routine vaccination provides excellent protection against parvovirus. We vaccinate pups at 6-8 weeks, 10-12 weeks and then again at 14-16 weeks. In a parvovirus epidemic vaccination at two week intervals is recommended. Rottweilers and pups in an infected yard may need an additional booster at 18 to 20 weeks of age. A booster 12 months after the initial series of vaccinations and then every 3 years protects most dogs against infection.

Bitches should be vaccinated before whelping so that puppies are protected for the first vulnerable weeks of life

How do we kill the virus in the environment?

Disinfect food and water bowls, floors, towels and other contaminated items with chlorine bleach or a glutaraldehyde-based disinfectant at the recommended dilution.

Parvovirus is not transmissible to cats or humans.

 

Diseases of dogs, Dogs, Internal diseases of Dogs

Inflammatory bowel disease

Inflammatory Bowel Disease (IBD) is a chronic disease of the gut, or gastrointestinal tract. Most affected dogs have a history of recurrent or chronic vomiting and/or diarrhoea. They may lose weight but are otherwise normal. Most eat well or have an increased appetite, and appear normal.

Cause

Inflammatory cells invade the lining of the bowel causing thickening of the bowel. This interferes with digestion and absorption of nutrients and with normal movement of the bowel.

When the cells invade the stomach walls or upper small intestine vomiting develops. Infiltration of the small intestine causes watery diarrhoea and weight loss. Infiltration of the large intestine causes diarrhoea coated with mucus and fresh blood. The entire gastrointestinal tract is sometimes affected.

Something in the diet triggers the disease in some dogs. Bacterial proteins are involved in other cases. In most cases we cannot find any underlying cause.

Diagnosis

IBD is diagnosed by ruling out other diseases. Blood tests rule out liver or kidney disease, pancreatic insufficiency and diabetes. Faecal tests rule out parasites like whipworms or giardia.

X-rays or ultrasound rule out some tumours or cancers in the abdomen.

If these tests are all clear we trial special low allergy, low residue or high fibre diets, depending on the part of the bowel most involved.  If bacterial overgrowth is present we trial various antibiotics until we see improvement.

If there is no improvement we biopsy the bowel and a pathologist identifies the type of cells involved, assesses the severity of the inflammation and checks for cancer cells.

Treatment

If any diet has improved the condition we continue it.

Medication controls (not cures) the problem. We trial drugs like metronidazole, prednisolone and azathioprine until we find what suppresses the signs best. Most dogs stay on the appropriate drugs and diet for life.

Diseases of dogs, Dogs, general, Internal diseases of Dogs

Haemorrhagic gastroenteritis

Dogs affected with haemorrhagic gastroenteritis (HGE) vomit and pass diarrhoea with blood in it.  It develops rapidly and sometimes owners just find their dog collapsed.

HGE is more common in small breeds of dogs. A very high red blood cell concentration, measured as the packed cell volume, PCV, or haematocrit is characteristic of HGE. Most normal dogs have hæmatocrits of 37-55%. Dogs with HGE have hæmatocrits over 60%.

We don’t know the exact cause of HGE.

We rule out other causes of vomiting and bloody diarrhoea while we start emergency treatment for HGE.  These causes include stomach ulcers, trauma, worms, other gut parasites, gastrointestinal tumours, intestinal obstruction, foreign bodies, parvovirus, and coagulation disorders.

Dogs with HGE are very ill and if left untreated die. In most cases, it runs its course in a few days with intravenous fluid therapy to combat the dehydration and shock. We give other treatments like antibiotics, anti-ulcer medication and corticosteroids as indicated.

If intravenous fluid therapy is not given the haematocrit continues to rise and the blood becomes so thick that it can hardly flow. A clotting disorder called disseminated intravascular coagulation develops which is often irreversible and fatal.

Cancer in Dogs, Dogs, Medicines & Treatments

Chemotherapy And Cytotoxic Drugs

What is chemotherapy?

Cancer chemotherapy uses cytotoxic drugs to kill cancer cells. Unfortunately they also affects normal rapidly multiplying cells like those that line the gut and bone marrow cells that produce blood cells.

What is cancer?

Cancer is a disease of uncontrolled growth of cells. Cells are the basic structural units of the body. Normally they replicate to replace themselves as they age. In cancer a particular cell line multiplies in an inappropriate and uncontrolled manner.

What are cytotoxic drugs?

Many anti-cancer drugs are cytotoxic. Cytotoxic means “damaging to cells”. These drugs block cell growth and division and thus prevent cancer cells from multiplying. Cytotoxic drugs act only on rapidly dividing cells such as cancer cells but they can also harm normal body cells.

What side effects do cytotoxic drugs have?

Because cytotoxic drugs affect all rapidly dividing cells in the body, normal cells in blood-producing bone marrow, the gut, skin and reproductive organs are also affected.

Many animals on chemotherapy experience no side effects. However, they are more prone to infections, bleeding, vomiting, diarrhoea and loss of appetite.

Animals do not lose all their fur with chemotherapy drugs. Reproductive function is usually not relevant.

Some cytotoxic drugs cause liver, kidney or heart problems. The most serious side effect of chemotherapy is infection. We monitor for these problems with regular blood tests.

Am I at risk of exposure from these drugs?

Cytotoxic drugs are very potent and must be handled with care. We admit animals to hospital to administer most chemotherapy. Some are given by injection while other drugs are given as capsules or tablets.

Do not to handle urine or faeces after any chemotherapy session.

This information is of a general nature only, and must not be used as veterinary advice except where directed by your veterinarian. Hall Veterinary Surgery does not warrant the suitability of this information for specific cases. If your animal is unwell or you want to act on this information, please contact us on 6230 2223.