Your Doctor

September 2010

East Port Veterinary Hospital

LOOK EAR, IT’S SPRING!

Many of our pets suffer from recurrent ear infections. Owners of affected animals may notice that their pet’s ear infections flare in springtime. This is because many ear infections are part of the big picture of allergic skin disease. As ‘spring’ springs into action, so do levels of pollens and dander that induce allergic reactions in predisposed animals. This form of allergy is called atopy and causes itching and redness of the ears, feet, armpits, groin and around the anal area. There is a strong hereditary predisposition, so we often see certain breeds affected more than others. Staffordshire Bull Terriers, Jack Russell Terriers and Retrievers are some of the more commonly represented breeds, although this condition can affect any dog.

Other causes of recurrent ear infections are:

Food allergy – where a reaction to the proteins in the food induces itchiness, particularly of the face, ears and anal area.

Ear mites – which tend to be a disease of younger animals and result in the production of copious amounts of brown crumbly discharge from the ears.

Swimming – Getting ears repeatedly wet macerates the skin in the ear canals and makes it inflamed and sensitive to secondary infection.

Hairy ear canals – Excessive hair prevents good aeration and creates a warm, moist environment suitable for the growth of bacteria and yeasts.

Foreign bodies – Australia is full of plants with sticky awns and burrs that can end up trapped down ear canals.

Ear conformation that prevents adequate ventilation. Certain breeds such as Sharpeis, with their narrow ear canals, and Cocker Spaniels, with their heavy floppy ears, have a predisposition to ear infections because of the anatomy of their ears. This can be further compounded by the presence of other causes of ear irritation such as allergies and foreign bodies.

Keratinisation defects and production of excessive wax. All of the above causes of ear infections can result in excessive wax production, however excessive wax production can be a cause of ear infections in its own right – a kind of chicken and egg situation!

Dogs with ear infections experience a range of symptoms. They may show no signs at all or may have mild itchiness with occasional head shaking. Severely affected animals will hold their head on one side and find handling of their ears painful. It is estimated that over 50% of dogs with chronic ear infections will experience a ruptured eardrum (or tympanic membrane – a thin membrane between the outer and inner ear). The skin of an affected ear will be reddened and the ear canal will become progressively narrower as the symptoms become more chronic. Most affected ears smell and produce excessive waxy or purulent secretions.

Diagnosis and treatment will depend on initial examination findings. Your veterinarian may need to perform swabs to obtain samples for examination under the microscope and for culture. As many infected ears are painful, a general anesthetic may be required in order to perform an adequate examination of the canals. It is important to establish whether the tympanic membrane is intact, as this will affect the choice of medications that can be safely administered into the ear. Whilst under anaesthetic, the ear canal can be flushed and cleaned. Once a diagnosis has been made, the treatment may be anything from a spot-on insecticide application, a food trial, medicated drops and cleaning solutions to oral tablets and anti inflammatories. Keep up with regular revisits, as ear infections often appear much improved on the surface but with a closer look, are still grumbling further down the canal.

Symptoms of disease

Endocardiosis – the heart of the matter

Endocardiosis is the most common cause of heart failure in dogs. It is a degenerative condition of the heart valves causing them to become thickened and knobbly. The affected valves are distorted and unable to form a seal as the heart contracts, allowing back-flow of blood. Initially the body compensates for this. However, with time and further degeneration, most animals will go on to develop heart failure.

Because of its degenerative nature, this tends to be a disease of middle aged to older dogs. It is seen most commonly in the smaller breeds such as Cavalier King Charles Spaniels, Chihuahuas, Poodles and Yorkshire Terriers. Affected dogs have a heart murmur that may be present for years before clinical symptoms of heart disease occur. Once in heart failure, dogs experience exercise intolerance, difficulty breathing, coughing and lethargy. Fainting episodes can occur, especially when the dog gets excited.

A diagnosis is considered if the vet hears a heart murmur. It can be confirmed with ultrasound and x-rays. Once a dog is in heart failure, medications and diet may help maintain quality of life. However, eventually the prognosis is poor and the animal may suddenly become ill and die. Luckily, most patients with a heart murmur due to endocardiosis still get to experience a long, happy life before their heart disease catches up with them.

Pica – when pets ingest the indigestible!!

Pregnant ladies are not the only ones to occasionally experience cravings to eat non-food materials. This unusual activity, called pica, also occurs in our domestic cats and dogs. Affected animals can eat an amazing array of materials from rocks and kitty litter to their owner’s underwear. Cats with pica are particularly attracted to fabric and plastic bags. Oriental breeds such as Siamese and Burmese seem predisposed to this condition and often have a fetish for sucking and chewing on wool. Ingestion of these unusual objects can have disastrous consequences including gut obstruction.

Most cases of pica are the result of a behavioural problem. If the animal has been weaned too early or been hand-reared, the sucking on fabric may be an exaggerated nursing behaviour. A stressful event can precede a bout of pica and many animals with obsessive-compulsive disorder will have pica as part of their symptoms. For some affected animals, there may just be pleasure obtained from the texture and feel of these objects when they are ingested. Medical conditions such as anaemia, inflammatory bowel disease and low iron levels can also predispose an animal to pica.

The treatment for pica can be difficult and needs to be addressed from various directions. The animal should have a thorough vet check to rule out any underlying medical conditions. If these are clear, the behavioural component of the problem needs to be addressed. Enrich the environment using toys, increased exercise and interactive playtime. Cats benefit from visual enrichment using windows, fish tanks and bird feeders (placed outside the window!) Thin rawhide chews and food-dispensing toys that drop small biscuits when rolled around can help direct eating away from inappropriate items. There are special diffusers available that release pheromones (secreted hormones that affect the brain) into the air to help reduce stress. Finally, mood-modifying medications may be needed to suppress the obsessive nature of this strange activity.

Treat my pet!

The Flea Wars!

Owners hate fleas. Owner’s pets hate fleas. Owner’s pets’ vets hate fleas! Lets face it, it is not easy to like something that causes so much irritation and can be so difficult to get rid of. Quick on their feet and with an ability to evade visual detection for an incredibly long period, adult fleas cause the physical problems such as scratching. However, it is the juvenile forms of the flea that make up the bulk of the population!

With the weather warming up, now is the time to get your anti-flea commando plans in action. A visit to the practice is a good place to start. While many excellent products for fleas are now available online, in pet shops and in discount pet marts, the veterinary clinic is the best place to get advice on INTEGRATED flea control. This will form the strongest basis of success against the nimble beastie.

Contrary to popular belief, fleas don’t move from pet to pet, only from environment to pet. Once an adult flea is on your pet, it will stay there until it dies, is removed by grooming, or killed by insecticides. Why would they leave the’ pet hotel’ after all? If your dog or cat has fleas, their eggs will end up in their (your!) environment. Eggs can be damaged, swept away or vacuumed, but the majority will fall deep into carpets, pet beds, your bed, fabric furnishings, and cracks between floorboards, making them almost impossible to remove manually. Basically, the eggs will go wherever your pet does.

The female flea lays her eggs after enjoying a blood meal from your pet. One female may lay as many as 50 eggs per day, or up to 2000 eggs in her lifetime! The eggs are not sticky but designed to fall from your pet’s coat to the ground. Once the eggs hatch, the larvae actively head towards dark, damp and safe places. They will feed on the ‘flea dirt’ (digested blood) that fell from your pet at the same time! As the larvae grow, they moult twice and then form a cocoon for protection. The fleas pupate in these cocoons until the conditions are right. This can include the presence of heat, vibrations or exhaled carbon dioxide…all the signs of a nearby host in fact!

Fleas can stay in the cocooned pupal phase for months, which explains why they can suddenly attack you and your pet when the weather warms up. This also explains why fleas can suddenly bombard people moving into a house that has been empty for some time. The whole life cycle of the flea can take as long as two years or as little as two weeks so it is easy to see that a small beginning can develop into a big problem very quickly indeed.

Integrated flea control can consist of a combination of topical products to kill adult fleas, oral products to ‘desex’ any fleas that slip through the net, and products for the household. There are also products that are very useful for pets with flea allergies. There is no ‘right’ answer for every situation. Seeking professional advice and using high quality products is the best approach for beating fleas.

Spring Kittens

The increasing daylight hours of spring are one of the triggers that stimulate cats to begin reproductive cycling. As last season’s kittens are reaching sexual maturity, now is the time to get them sterilised. Most cats reach sexual maturity at about 6 to 9 months of age although there is significant breed variation. Oriental breeds, such as the Siamese, may start cycling as early as 5 months of age; while larger and longhaired breeds, such as the Persian, may be a year old.

Cats are efficient breeders and ovulate in response to the stimulation of mating, ensuring the maximum chance of fertilisation. An unsterilised female cat or ‘queen’ can have at least three litters of 2 to 5 kittens a year and may be reproductively active for years. Thousands of unwanted cats are euthanased in shelters around Australia every year. Please sterilise your cat before it reaches sexual maturity to help reduce this statistic.

Rodent Barbers

When small mammals such as guinea pigs, rats or mice are kept with more than one other of their own kind, they have a charming way of establishing a hierarchy. The dominant animal will “barber” the subordinate animals by nibbling hair and whiskers from various parts of the body. The hair is cropped close to the skin, which remains undamaged. In mice, the variety of styles includes symmetrical ‘spectacles’ of hair loss around the eyes or a ‘crop circle’ on the head!

Guinea pigs are less formal and just nibble random patchy areas of fur. Barbering does not harm the affected animal. However, as some medical conditions can cause a similar appearance, any small furry with a funky hairstyle should be checked out by your vet.

Emergency!

Terrible Toxins: Drugs of Addiction

Over recent newsletters we have discussed house and garden toxins that can harm our pets. In our final ‘terrible toxins’ article, we raise a more controversial cause of poisoning – ‘drugs of addiction’ (DOAs) or recreational drugs. In these modern days, no one can deny the increasing use of such drugs in all segments of society. These drugs, if accidentally ingested by our pets, can cause serious and sometimes fatal symptoms.

Illegal drugs are a surprisingly common cause of severe signs in veterinary practice. Diagnosis can be challenging when owners are worried about ‘owning up’ to having the drugs. Sometimes a family member or friend may have brought illicit drugs into the home without the owner’s awareness. This is increasingly common in families with teenage children whose friends may be reluctant to ‘let on’ when the pet becomes ill. The most commonly used legal DOAs are cigarettes and alcohol.

Tobacco contains nicotine in varying amounts. The butt of the cigarette contains up to 25% of its total nicotine. Pets that ‘vacuum’ butts from the floor can exhibit signs within 15–45 minutes of ingestion. These include rapid heart rate, salivation, vomiting, diarrhoea, muscle weakness or twitching, coma and even death.

Alcohol is often accidentally ingested by pets. Occasionally, people under the influence of alcohol find it amusing to deliberately offer it to their pets. Low-level ingestion can lead to signs like staggering, excitability and decreased reflexes. Larger volumes may cause collapse and even death. Some research reports death in 50% of cases where the pet has ingested as little as 14mls of vodka per kg body weight or 55mls of wine per kg.

Marijuana is probably the most common illegal drug to cause intoxication in pets. The active toxin is called Tetrahydrocannabinol (THC) and is found in the leaves, buds and resin of the marijuana plant and in hash oil. Dogs that ingest THC will usually show signs within 30-90 minutes that can last up to three days. Signs include initial nervousness and disorientation followed by dilated pupils, flicking eyeballs, loss of control of urination and ‘wobbliness’. It can occasionally cause death. Cats rarely consume marijuana.

Barbiturates (‘downers’, ‘red devils’, ‘yellow jackets’) can cause lethargy or excitement, weakness, wobbliness, coma and death.

Gamma hydroxybutyrate (GHB, ‘liquid ecstasy’, ‘fantasy’) causes weakness, sedation, wobbliness, coma, slow heart and breathing rate and possible death.

Benzodiazepines (‘downers’, ‘roofies’, ‘roach’ or ‘rope’) may be prescribed or illicit. If ingested they act quickly (within 30 minutes) and have short and long-term effects. These include fatigue, wobbliness, low body temperature, low blood pressure, high heart rate, and nervous system excitement. If ingested at the same time as alcohol, these drugs can be fatal.

Opioids (morphine, heroin, codeine, methadone) are sometimes used for pain management in veterinary medicine. In accidental doses they can cause wobbliness, vomiting and slowed heart and breathing rate.

LSD has hallucinogenic properties in pets. Signs include disorientation, dilated pupils, racing heartbeat, high blood pressure and tremors.

Amphetamines cause high blood pressure and increased heartbeat, wobbliness, restlessness, tremors and seizures.

Cocaine causes excitement, hyperactivity, seizures, excess salivation, high heart rate, high temperature and coma. Death can occur due to cardiac arrest.

While vets are very good at treating pets that have ingested DOAs, treatment is safer and more effective if we know which drug has been taken. Urine-sampling kits to assess for DOA ingestion may not always be readily available in emergency. If you suspect at ANY time that your pet might have ingested any type of drug – legal or illegal – please let your vet know. It could save your pet’s life.