Tag Archives: bloody 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

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, 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.