Yearly Archives: 2011

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.

 

Cats, Diseases of cats, Internal Diseases of Cats, Today's News

Feline FIV and AIDS

FIV (Feline Immunodeficiency Virus) is prevalent in Australian cats but testing positive for FIV is not the same as having feline AIDS.

Feline AIDS describes the terminal stages of disease which may not occur for many years – or at all! A positive FIV test means that your cat has been infected by the virus.

 

Are my family at risk?

 

No. Although FIV belongs to the same family of viruses as HIV in people, it only infects cats. There is no risk of cross infection of either virus between species.

 

Are other cats in the household likely to be infected?

 

The virus is shed in the saliva of infected cats and spread by biting. Cats with a history of cat bite abscesses are more likely to test positive for FIV.

Spread between cats in a household is unlikely unless they fight. Normal social interactions such as grooming rarely transmit FIV.

The best way to minimise the chances of FIV infection is to confine uninfected cats indoors away from aggressive cats.

 

How is FIV diagnosed?

FIV is diagnosed with a blood test at the surgery which detects an immune response (antibodies) to the virus. If this test is positive your cat is infected.

Kittens with immunity passed on from their mother may test positive until 4 months of age. If a young kitten tests positive we retest them at six months of age.

Will my cat recover?

Once a cat is infected with the virus it remains infected for the rest of its life but not all infected cats  become ill.

 

What diseases does FIV cause?

Like HIV, FIV suppresses the body’s defences so that the cat is vulnerable to diseases it would normally  defeat. The cat is vulnerable to chronic or recurrent infections that fail to respond to regular treatment.

These include:

  1. Inflammation of the mouth and tongue leading to appetite loss, drooling and mouth pain
  2. Weight loss
  3. Poor appetite
  4. Fever
  5. Signs of brain dysfunction such as aggression, unequal pupils, convulsions and behavioural changes
  6. Swollen lymph glands
  7. Unusual infections like toxoplasmosis, cryptococcosis, chronic flu, pneumonia, skin disease
  8. Tumours especially those of the lymph system

The non specific signs of weight loss, poor appetite and fever occur in many diseases of cats and are usually unrelated to FIV. Cats with FIV are more likely to suffer from these signs and diseases more often and  be less able to throw them off even with treatment.

FIV positive cats have a shorter life expectancy on average than FIV negative cats.

Is there any treatment?

 

Secondary infections with bacteria or fungi are treated with antibiotics and anti-fungals but no specific treatment for the virus is available. Trials with anti-HIV drugs such as AZT have reduced mouth inflammation in affected cats but the cost and availability of AZT makes its use in general practice difficult at present.

Anti-inflammatory treatment reduces mouth inflammation and peps up the appetite in many cats.

 

Should I have my cat euthanased?

 

Certainly not on the basis of a positive FIV test!  Like humans with HIV, cats with FIV appear healthy and happy for a long time before getting sick.

On the other hand if your cat has succumbed to multiple infections, is no longer responsive to treatment or is suffering from a chronically painful mouth then euthanasia is the kindest solution.

 

How can I help my cat?

 

Confinement indoors of an FIV positive cat  reduces the risk of infection with other agents. It also reduces the risk of transmission of the virus to other cats.

A good quality, highly palatable diet as well as worming every 3 months and at least annual health checks will enhance the disease free period.

Infections require prompt and aggressive treatment.

 

How do we prevent FIV infection?

 

Desexing and confinement indoors, especially at night, reduces fighting and therefore the risk of infection. We recommend vaccination with FIV vaccine for all cats with access to the outdoors. Cats older than 6 months of age are tested for FIV before the first vaccination. A series of three primary vaccinations is given 2-4 weeks apart and then a booster is given annually.

 

Caring for your Cat, Cats, Diseases of cats

When to say goodbye…

This is one of the most difficult decisions a carer can ever make for their pet. Euthanasia is never easy but at the end of life it can be the kindest and most humane way to go.

Only you know when the time has come. This checklist might be helpful:

  • is your cat still interacting with you – lap time, dinner time – and with other people and pets in the family?
  • is any pain, especially arthritic or back pain, well controlled. There is a limit to the efficacy of medications and good nursing.
  • are the bad days starting to outnumber the good days?
  • does she still have her little routines and habits?
  • can she eat without assistance?
  • can she get around to water, sun, bed, litter on her own

If you have done all you can to make your cat comfortable and happy but life is just not good for her anymore then you can feel more confident in making your decision.

Diseases of dogs, Dogs, Internal diseases of Dogs

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.

Caring for your Cat, Caring for your Dog, Cats, Dogs, general

Boarding your pet

Holiday plans are not complete without accommodation arrangements for your pets, too. Many holiday accommodations are now pet friendly but most people have to leave their pets behind. Ideally, they should stay in their own home and yard with a friend, relative or house-sitter looking after them.

Many pets spend happy holidays at boarding facilities and even look forward to their own break from home routines. If possible visit the cattery or kennels beforehand, inspect the accommodation and meet the staff.

All commercial boarding establishments are licensed by the local authority but standards vary. Seek out recommendations from friends, neighbours or your veterinary surgeon. Some people like to trial board their dogs for a weekend or a few days and see how they settle.

Check that your pets’ vaccinations are up-to-date well before the holiday. Kennels insist upon current cover for distemper, hepatitis, parvovirus and kennel cough for dogs and enteritis, calicivirus and herpesvirus for cats.

A single intra-nasal kennel cough immunization at least 72 hours before boarding covers dogs previously unvaccinated for kennel cough for 12 months. Other vaccinations take at least ten days to take effect.

Caring for your Dog, Diseases of dogs, Dogs, general, Skin diseases of Dogs

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.

 

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.

Cancer in Cats, Cats, Diseases of cats, Internal Diseases of Cats

Hairballs?

Hairballs are overrated as a problem in cats.  A true hairball is hair wrapped in saliva and requires no treatment.  Hairballs almost never cause illness in pet cats.

On the other hand we should see your cat if she vomits frequently – whatever the vomitus is! If she is turning her nose up at her dinner or hiding then we should see her as soon as possible. Normal cats eat several times a day so even a single day of poor appetite is significant.

If she vomits a lot but doesn’t feel poorly she may still have a problem. Some cats are very sensitive to specific proteins like chicken, beef or lamb. A change to a diet free of the common proteins that cause hypersensitivity or to one that is specially treated to reduce reactions often helps these cats.

Often the only sign of inflammatory bowel disease or cancers of the bowel is frequent vomiting. Eventually affected cats lose weight or stop eating, but this is when the disease is well advanced. If a cat does not respond within a few weeks to a change of diet as mentioned above then we investigate more closely.

Diseases of dogs, Dogs, Internal diseases of Dogs

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.

Diseases of dogs, Dogs, Skin diseases of Dogs

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.