This month’s pet of the month is Ruby, who has been suffering from tracheal collapse for the last nine years. She has been fortunate in that her symptoms have been limited to a chronic cough and have not progressed to more serious respiratory difficulty or distress.

Tracheal collapse is a progressive weakening of the tracheal cartilage, or “windpipe”, seen most commonly in middle-aged small breed dogs. As the trachea collapses it results in an obstruction to the passage of air. Certain breeds including Yorkshire Terriers, Bichon Frise and Pomeranians are more prone to this condition

How can I tell if my dog has tracheal collapse?

Tracheal collapse is characterised by a harsh “goose honking “cough that is often worsened by excitement. The disease is often worse in the summer months due to the heat. While the disease typically progresses over months or years, some dogs can present with a sudden onset difficulty breathing and require emergency therapy.  Dogs with tracheal collapse can often have other conditions including heart murmurs, pneumonia or problems with their larynx/palate.

How is tracheal collapse diagnosed?

Tracheal collapse is a dynamic process meaning that it can often be missed on normal chest radiograph (x-ray). Ideally, it is diagnosed using a combination of fluoroscopy – a video x-ray that allows visualisation of the trachea as the dog inhales and exhales – and bronchoscopy, where a camera is passed down the trachea to assess the degree of collapse and assess for other conditions, such as pneumonia.

How is tracheal collapse treated?

Medical management

The vast majority of dogs will respond to lifestyle changes (weight loss, being walked with a harness rather than a neck lead, avoidance of cigarette smoke or aerosols in the house) in combination with medications (corticosteroids, cough suppressants and antibiotics). Almost all dogs will have some improvement with the introduction of medication and up to 90% will be well controlled for 12-18 months.

Tracheal stenting

Tracheal stenting involves placing a metal (nitinol) mesh within the trachea under anaesthesia. The stent holds the trachea open and stops the airway obstruction. 90% of cases show a rapid improvement in clinical signs. It is important to know that dogs that have a tracheal stent placed will likely still require lifelong medications as outlined above.

What are the potential complications with tracheal stenting?

Tracheal stenting should only be performed by veterinary surgeons who have been properly trained in the technique. As the procedure requires fluoroscopy it is normally only performed at a referral practice. Many of the complications associated with stenting such as stent movement or fracture are more likely to occur if an incorrect size of stent has been placed. However, even when performed by appropriately trained personnel the complications seen with the technique can include inflammatory tissue growing through the stent and chronic infections. Up to 40% of cases that have a tracheal stent placed may require a second procedure at some point in their life. Following stent placement, most animals will be discharged within 24-28 hours.

Pet of the month for January is Max, who often accompanies his owner on long runs over the Downs. Last month unbeknown to his owner Max sustained an injury at the base of his tongue, which was not witnessed. Neither was there any evidence of blood or oral discomfort.

Understandably Max went off his food and became listless. A swelling became palpable below his jaw and on examination, bruising was discovered under the tongue. The injury became septic and was flushed under anesthetic. Max is now doing very well and has finished all his antibiotics.

Although we cannot be sure how Max sustained this injury, a number of dogs love to carry a stick and some will actively find their own stick when exercising off the lead on a walk. The majority of the time, this is harmless fun but sometimes part of a stick can go further into the mouth than planned! Stick injuries in dogs can be serious.

Occasionally, a section of twig can get lodged across the hard palate (this is the roof of the mouth), between the upper molar teeth.  If a dog has run at speed to pick up a stick then he/she may in effect ‘run onto the stick’, and there is potential for sections of stick or twig to penetrate deeper into the mouth, neck or throat.

Although not applicable in Max’ situation, a good tactic to try and avoid your pets chasing and carrying sticks is to provide other toys for them to play with whilst on their walks, and definitely, as pet owners, we should avoid the temptation to actually throw a stick for our dogs!

What is a zoonosis?
A zoonosis is a disease which can be passed between animals and humans.

The following information sheet is designed to give an overview of some common or important diseases which can be passed from cats and dogs to humans, however, the list is not exhaustive.  Conditions which can be passed to humans from other domestic or exotic species are not included.  In general, these diseases are of most significance to immuno-compromised people.

What does immuno-compromised mean?
People who are immuno-compromised have immune systems which may not work very well.  This group would include the very old and very young, people recovering from severe illness or surgery, people with AIDS/HIV and people on chemotherapy drugs.

What skin diseases can be caught from cats and dogs?
Humans can be bitten by cat and dog fleas. The bites are seen as small, red, itchy lumps very often on the lower legs/ankles. It is important to keep cats and dogs regularly treated for fleas using a veterinary prescribed flea treatment. If humans are being bitten it is likely that the environment is infested, so the whole home should be treated as well. Make sure you follow any care and safety instructions when you spray your home.

Ringworm (dermatophytosis) is not a worm at all but a fungal infection of the skin. Many species of animals can carry this infection. It is often seen as patches of hair loss and scaling of the skin on cats and occasionally dogs. When humans pick up ringworm they develop red and often circular patches on their skin. This condition is treatable for both humans and pets.

Humans can also become irritated by mites that they acquire from their pets e.g. ‘fox mange’ (Sarcoptes scabei) and ‘walking dandruff’ (Cheyletiella). Infections in humans are usually self-limiting but it is advisable to visit the doctor. Cats and dogs can be treated under veterinary care after diagnosis in their owners.

Can worms affect humans?
We strongly recommend that pet cats and dogs are regularly wormed. Cat worms are currently not thought to cause problems for human health but we are not certain about this. Toxocara canis is a common round worm of dogs. If children are infected by this worm, the larva can occasionally ‘get lost’ on migration within the body and cause damage to the eyes, brain and elsewhere. Monthly worming of dogs with a good quality round wormer will prevent dogs becoming infected and spreading the worm.

Echinococcus granulosus is a dog tapeworm which also causes problems when larva ‘get lost’ on migration in the body, but this worm is thankfully only found in limited habitats (certain areas of Wales and the Hebrides). Hookworms (Ancyclostoma) which are passed occasionally in dog faeces can cause skin irritation when people have close contact with contaminated soil. Fortunately the condition is easily treated.

My pet has a tummy up-set can I catch anything from it?
Hand washing and basic hygiene should always be used when clearing up after a pet, especially when they have vomiting or diarrhoea. Giardia, Campylobacter, Salmonella and E. coli are just some of the infections which may be passed on to humans. If these bugs are suspected we will test for them but sometimes infections are not obvious, so care should always be taken in clearing up pets’ faeces.

I am pregnant, are there any specific zoonoses I should be concerned about?
Toxoplasmosis is of particular concern for pregnant women. This is a common single-cell parasite which only causes mild flu-like symptoms in most affected people – however, it can be critical to the health of both mother and fetus if a pregnant woman is infected. Many species of animal can be affected by toxoplasmosis, but only cats, the primary host, can spread the disease. When the spores pass out of the cat in its feces they are inactive. It takes about 24 hours of contact with air for the spores to become active or infective. This means that direct handling of an animal is not a great hazard, but pregnant women should not handle cat faeces or the litter tray. The greatest risk factors for Toxoplasmosis are gardening (i.e. handling soil), unwashed fruit and vegetables as well as undercooked meat. However, it is always recommended that pregnant women are especially careful to wash their hands after touching animals and before handling food. If you have any concerns about zoonoses during pregnancy you should discuss these with your midwife or doctor.

Can I catch Weil’s disease from my dog?
Weil’s disease is the severe human form of leptospirosis. This is an uncommon disease in humans and it is very rare for it to be passed by pet dogs. However, if a dog is affected its urine can be infective to humans. Both dogs and humans most commonly catch leptospirosis from stagnant or slow-moving water (specifically that which has been contaminated with rat urine). The disease causes sudden kidney and liver failure. We strongly recommend that dogs are vaccinated against leptospirosis annually. Care should be taken when handling dogs’ urine and, if leptospirosis is suspected, handlers should wash their hands and ideally wear gloves.

What should I do if I am scratched or bitten?
Cat and dog bites can be very serious. Wash all bites liberally under running water and always seek medical advice from your doctor as antibiotics are often required. There may also be legal implications if a dog has bitten a person – please see the UK Government website.

Cat scratches can also be nasty. All scratches should be thoroughly washed. Any scratch which becomes inflamed or painful should prompt a visit to a doctor. There is a bacterium which some cats have in their saliva and on their claws called Bartonella henselae which causes ‘cat scratch disease’ in humans – symptoms include swelling at the site of infection, fever, and swollen glands. Treatment may be required, especially in immuno-compromised patients.

If you have any queries concerns about your dog or cat and Zoonoses, please do not hesitate to contact us.

This month’s pet of the month is Fred who has sailed through his recent checkup and blood test for hyperthyroidism.

Hyperthyroidism is a relatively common disease of the aging cat. It is typically the result of a benign (non-cancerous) increase in the number of cells in one or both of the thyroid glands. The thyroid glands are located in the neck although there is occasionally additional tissue within the chest. In the image, the red shapes indicate approximately where the thyroid glands are located in a cat. The result of enlargement of the thyroid glands is an increased production of thyroid hormone within the body. Thyroid hormone controls the rate at which cells in the bodywork; if there is too much hormone, the cells work too fast. Despite many years of research, the exact cause of hyperthyroidism remains unknown.

Cats fed almost entirely canned food have been reported to have an increased risk of developing hyperthyroidism but it is likely that there are many causes.

What signs do cats with hyperthyroidism get?

Hyperthyroidism is a disease of middle-aged to older cats with an average age of onset of 12-13 years. Increased drinking and increased urination, weight loss, increased activity, vomiting, diarrhoea and increased appetite are often reported. Physical examination often reveals a small lump in the neck which represents an enlarged thyroid gland.

How is hyperthyroidism diagnosed?

A diagnosis of hyperthyroidism is made by the demonstration of increased levels of thyroid hormone in the bloodstream. Thyroxine (T4) measurement is the initial diagnostic test of choice.

How is hyperthyroidism in cats managed?

Medical treatment with either carbimazole or methimazole. These tablet medications are given once or twice daily lifelong. Side effects are uncommon but can occur. They include vomiting and reduced appetite. Very occasionally severe bone marrow or liver problems can be seen.

Dietary treatment. A specific prescription diet can be fed to hyperthyroid cats to control the disease. The diet is very low in iodine. Iodine is an essential component of thyroid hormone and less dietary iodine means less thyroid hormone is produced. The diet must be fed exclusively (i.e. the cat must eat no other food). Dietary treatment does not lower the thyroid hormone levels as much as the other treatment options

Surgical treatment. One or preferably both thyroid glands are removed with an operation. A short period of treatment with tablets is recommended prior to surgery. Anaesthesia can be a risk in older cats with hyperthyroidism that possibly has other concurrent diseases. There is a risk of a low blood calcium level after surgery if the parathyroid glands are removed with the thyroid glands. This can be a very serious problem if it is not recognised. Signs of a low blood calcium level can include facial rubbing, fits, tiredness, reduced appetite, and wobbliness. Low blood calcium levels are relatively easily managed with oral medication and treatment is rarely necessary lifelong.

Radioactive iodine treatment. Radioactive iodine is concentrated in the thyroid gland and destroys excessive thyroid tissue. The drug is given by injection under the skin. After the injection, cats need to spend 2-4 weeks in an isolation facility whilst they eliminate the radioactive material. Owners are not able to visit their pets whilst they are in isolation.

Hyperthyroidism can mask underlying kidney problems and these can become apparent after treatment. Blood tests are therefore necessary to assess kidney function as well as the thyroxine level during treatment.