Category Archives: Diseases of dogs

Heart care for dogs

Dogs suffer from heart failure, just like humans. If dog owners recognise the warning signs of heart failure they can seek help earlier and enjoy a healthy, happy pet for longer.

Research shows that most dog owners are not aware of the risk of heart failure in older dogs, even though 1 in 10 dogs presented to vets suffer from heart disease.

Boehringer Ingelheim has launched a Heart Failure Awareness Program to raise owners’ awareness of the signs of heart disease in dogs. The company wants to reduce the numbers of dogs suffering unnecessarily from this life threatening condition.

The Heart Failure Awareness Program is aimed at dog owners because they are most likely to notice changes in their dog’s health and behaviour.

Early signs of heart failure, like loss of appetite, are subtle and often overlooked.

The common signs of congestive heart failure include:

  • Coughing, especially at night
  • Poor appetite
  • Reluctance to exercise and tiring quickly on walks
  • Laboured or fast breathing
  • Fainting – often associated with exercise
  • Weight loss
  • Enlarged abdomen
  • Weakness

If your dog is aged seven or more and showing one or more of the above signs visit a vet without delay.

Effective treatment of heart failure is available and when started early greatly improves affected dogs’ quality of life.

If owners recognise the signs of heart failure early and seek veterinary advice before the heart deteriorates markedly, treatment has the greatest benefit.

Research has shown effective treatment allows dogs with heart failure to enjoy many healthy, good quality years of life.

And that’s something all dog owners want.

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.

 

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

 

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.

 

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.

 

Cushing’s disease

In dogs with Cushing’s disease the adrenal glands overproduce some of the body’s regulators, particularly cortisol.

What are the signs of Cushing’s disease?

The most common signs of Cushing’s disease are marked increases in appetite, water consumption and urination. Lethargy, panting and a poor hair coat are also common. We often see a pot-bellied or bloated abdomen due to increased fat within the abdominal organs and thinning of the muscular abdominal wall.

What causes Cushing’s disease?

The three major causes of Cushing’s Disease:

  1. A tumour of the pituitary gland, that stimulates the adrenal glands to produce excessive  amounts of cortisol.
  2. Excessive administration of synthetic cortisones cortisones such as prednisolone, triamcinolone or dexamethasone may cause Iatrogenic Cushing’s disease.
  3. An adrenal gland tumour is an uncommon cause of Cushing’s Disease.

If we suspect Cushing’s Disease we run a blood test to check your dog’s general health. An enzyme called Alkaline Phosphatase (ALKP) is often high in dogs with Cushing’s disease. A Low Dose Dexamethasone test (LDDT) confirms or denies Cushing’s disease.

To determine which type of Cushing’s disease your pet has, we ultrasound the adrenal glands and/or do an endogenous ACTH blood test.

What are the treatment options?

Pituitary Tumour: This is the most common cause of Cushing’s disease. There are two treatment options for it. Trilostane is our drug of choice. A daily capsule of Trilostane reduces the production of cortisone and another important hormone, aldosterone.  We monitor your dog’s response to Trilostane with a test called the ACTH stimulation test. Too little Trilostane won’t reduce appetite or water consumption but too much will cause illness.

If your dog has liver or kidney disease we may suggest treatment with Mitotane (also known as Lysodren). This drug destroys part of the adrenal gland. Careful monitoring and good communication with your vet is necessary during the initial intensive treatment to achieve good results and avoid life-threatening adrenal damage.

Although the pituitary tumour remains present and continues to stimulate the adrenal gland if the tumour is small successful control for many years in most dogs is possible.  If the tumour is large, it may invade surrounding brain tissue and cause other signs, but this is rare.

Iatrogenic Cushing’s Disease: To treat this type of Cushing’s disease we must stop the synthetic cortisone in a very controlled way. If we stop intensive cortisone treatment abruptly your dog may lose his appetite, vomit, develop diarrhea and collapse. The suppressed adrenal gland takes a while to regain normal production of cortisol.

Treatment of an Adrenal Tumour:

Adrenal tumours tend to invade surrounding tissue but if we can surgically remove it all and it is not malignant your dog will regain normal health. Otherwise we treat adrenal tumours with Trilostane also.

Itchy bottom?

Dogs scoot their bottoms along the ground when they have anal gland problems, tapeworms or allergies.

If you catch your dog rubbing along on the carpet, worm him with a good quality wormer such as Drontal or Milbemax that covers all worms, especially tapeworm.

If he still scoots or seems off colour then bring him in to the surgery. Many small dogs suffer from anal sac problems. The gland fills up with material too thick to empty through the small ducts near the anus. Usually we just express them and all is well.

Sometimes the material gets infected and the glands become swollen and painful.  Your dog might have trouble defecating or lick the area a lot. The glands may break through the skin and discharge foul smelling fluid. At the surgery we clip and clean them as well as starting antibiotics and pain relief. If your dog has repeated anal gland infections we recommend surgery to remove them.

In spring and summer many allergic dogs rub, lick and scratch all over including their bottoms. Some dogs allergic to food proteins also rub their bottoms on the ground. Treatment for the allergies usually stops the rubbing and licking.

 

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.

Hypothyroidism

The thyroid gland regulates the body’s metabolic rate. When it slows down the whole body slows down.

Hypothyroidism is a deficiency in production of the thyroid hormone. This deficiency is caused by immune-mediated destruction of the thyroid gland, most commonly, or by natural atrophy of the gland.

Signs of hypothyroidism include:

  • Weight gain
  • Lethargy
  • Cold intolerance
  • Dry coat and excessive shedding of hair
  • Very thin coat
  • Increased pigmentation of the skin
  • Failure to re-grow hair after clipping or shaving
  • A tragic expression because of thickening of the facial skin
  • Abnormal nerve function exhibited as non-painful lameness, dragging of the feet, lack of co-ordination and a head tilt
  • Loss of libido and infertility in intact males
  • Lack of heat periods, infertility, and abortion in females
  • Spots on the eyes
  • Dry eye because of inadequate tear production.
  • Anaemia

The thyroid glands are located in the neck either side of the trachea or windpipe. They are controlled by the body’s master gland, the pituitary gland, located at the base of the brain.

 

To confirm hypothyroidism we test blood to see if T4, the main thyroid hormone, is low. Unfortunately, dogs sick for some other reason or taking certain drugs like seizure medications, may have low levels too. Confirmation of hypothyroidism sometimes requires an additional test.

Hypothyroidism is treated daily with tablets containing a thyroid replacement hormone, thyroxine, for the rest of the dog’s life.

We check T4 levels again after a month of treatment to make sure we are giving the right dose. We test 4-6 hours after the morning dose. T4 levels are then checked every 6 months and the dose adjusted if necessary.

Overdosing produces signs of hyperthyroidism including hyperactivity, lack of sleep, weight loss, panting, nervousness, aggressive behaviour and an increase in water consumption. If any of these occur, please let us know immediately.

Demodectic mange

Demodectic mange is caused by the demodex mite, Demodex canis, which lives in normal skin and is present in small numbers in all dogs.  Humans have their own demodex mites (D. folliculorum, D. brevis) and the dog demodex mite never affects humans.

The entire life cycle of the demodex mite is spent on the skin. It lives in hair follicles and feeds on cells, serum and epidermal debris.

Transmission of mites from bitch to puppies occurs during nursing in the first 2 days of life.

Occasionally a puppy’s immature immune system allows the mites to multiply abnormally and mild localised skin disease results.  A small proportion of affected pups have a more depressed immune system and generalised demedicosis develops.

The signs of localised demodicosis include patchy hair loss and mild scaliness on the face.  Sometimes the skin is mildly red but in the early stages it is usually not itchy. Most cases occur before 6 months of age and heal spontaneously.

Up to 10% of affected dogs progress to the generalised form. It usually starts during puppyhood. With generalised demidicosis we see hair loss, inflammation and enlarged glands. Secondary bacterial infections cause scratching, redness, swelling and crusting of the skin.

Dogs with chronic generalised demodicosis have depressed immune T-cell responses. Eradication of the mites results in restoration of the T-cell function.

Breeds predisposed to generalised demodicosis include the Old English Sheep dog, Afghan Hound, Collie, German Shepherd, Staffordshire and Pit bull terrier, Doberman, Dalmatians, Great Dane, English Bulldogs, Boston terriers, Dachshunds, Chihuahua, Boxers, pugs, Sharpeis, Beagles and Pointers. Pure bred dogs have a much higher incidence than mongrels. There is evidence that it is an inherited problem.

To diagnose demodectic mange we scrape affected areas with the side of a scalpel blade and check for mites under the microscope.

We usually do not treat mild localised demidicosis as 90% of cases will clear spontaneously.

If the hair loss spreads and the skin becomes red, itchy or crusty then we treat the pup with a miticide. Regular skin scraping monitors the progress of eradication.  Treatment is continued for at least a month after a negative skin-scraping.

Secondary bacterial infections are treated with antibiotics and antiseptic shampoos as they arise.