Archive for the 'Veterinary articles' Category

Anal Furunculosis

Saturday, October 6th, 2007

Anal furunculosis is common and mostly affects German Shepherd Dogs(GSD) and GSD crosses. Anal furunculosis causes deep skin infection which results in skin ulceration and possibly open tracts running through the perianal (around the anus) skin. The breed predisposition is a result of physical factors including the low tail carriage, the humidity of the perianal area and the high number of apocrine glands around the anus, and possibly genetic factors causing an immune dysfunction. However we still cannot fully explain all the damage caused to the soft tissue of the perianal region.

Most dogs show extreme anal pain and have difficulty in passing feces. Initial investigation includes mapping the wounds around the anus +/- colonoscopy to determine if they have concurrent colitis (50% of cases do).

Treatment is difficult and frustrating, because relapses are frequent. There are medical and surgical options and often both need to be explored. Treating anal furunculosis with medicine would include either the use of steroid at a high dose with the view to tapering it down, or the use of  cyclosporin which is currently the favoured option for treatment however is a very expensive medicine. The dose of cyclosporin can be reduced by concurrently treating with another medicine called ketoconazole. Most recently there have been a few successful trials describing the use of a topical cream that acts in a similar way to cyclosporin although is considerably stronger and therefore is only used topically rather than as an oral pill or capsule form. This cream has been used as a follow up to cyclosporin once the lesions have started to shrink. If you and your vet decide to treat with any of these medicines, their side effects should be discussed and considered.

Surgical options include: sharp excision of the tracts, cryosurgery which involves freezing the tissue, and anal gland removal. These procedures may be of benefit in conjunction with the medical treatments listed above. There are possible complications to these surgeries and they should be discussed with your vet.

Please feel free to post any questions or personal experiences you may have had in treating your dog with this condition. We hope you find this article of use.

Dry Eye (Keratoconjunctivitis sicca)

Monday, September 17th, 2007

Dry Eye is a very common condition in dogs, and is seen more commonly in Cocker Spaniels, Westies, Cavalier King Charles Spaniels, Lhasos and Shihtzus.

The primary problem in Dry Eye is that your dog’s tear producing glands (lacrimal and nictitans glands) are unable to produce enough of the aqueous portion of the tear, leaving your dog with a dry, unlubricated eye. In the breeds listed above, the most common cause of dry eye will be as a result of their own immune system destroying (immune mediated) the glandular tissue to a point where they no longer produce any tears.

There are other possible causes such as drug reactions, neurological damage in dogs who have facial nerve paralysis, viral causes- the most common being distemper which is one of the viruses your dog will be vaccinated against, and congenital glandular abnormalities which will be a rare cause. However the most common cause is certainly as a result of immune mediated destruction of the glands.

There are a few clinical signs of Dry Eye and your dog may suffer from 1 or many of them: conjunctivitis (pink eye), blinking or rubbing there eye a lot, a pus/mucous discharge from their eye(s), crusting or even gluing together of the eye lids, dull looking cornea, and corneal ulceration.

Diagnosis of Dry Eye by your vet is made by observing the clinical signs, and a Schirmer Tear Test which is a simple test that measures the tear production over 1 minute.

The treatment for Dry eye is usually mangement rather than cure. The treatment of choice is with a medicine called cyclosporin. Cyclosporin comes in a small tube and contains the drug cyclosporine. Cyclosporin is used as a topical eye ointment and tends to have better results in animals who have been diagnosed earlier in the progression of Dry Eye. However even in cases where there is no tear production cyclosporin should be considered on a trial basis of 6-8 weeks. In addition to cyclosporin, tear replacement with a medicine such as Viscotears may be required. The cyclosporin will help combat against immune mediated destruction of the tear glands and Viscotears will help lubricate your dogs eye.

In cases where cyclosporin isn’t providing sufficient results and your dog is continually suffering from Dry Eye, your vet may offer the surgical treatment which involves moving one of your dog’s salivary gland ducts (parotid duct) into their lower eye lid to provide saliva as a substitute for tears. This is often a specialist proceedure and is not without post operative complications so is usually reserved for animals who are not benefiting from the use of cyclosporin.

The long term prognosis for your dog’s eye largely depends on how early their Dry Eye is diagnosed and how well they respond to cyclosporin. In most cases where their Dry Eye has been diagnosed early, and treated with cyclosporin +/- Viscotears at the dose your vet advises, your dog will maintain healthy corneas for life.

I hope this helps and we look forward to your comments.

Heaves, COPD in Horses

Thursday, September 6th, 2007

What is Heaves/COPD (Chronic Obstructive Pulmonary Disease)

COPD is the most common chronic lung disease of horses in Britain and Ireland. The reason for this is mainly due to the considerable amount of time horses spend indoors in this part of the world. More specifically it is because the usual forage and bedding (hay and straw) sometimes saved under damp and cold conditions contain factors that irritate the horses lungs leading to the signs that are characteristically associated with the disease.

How does my horse bedding and/or forage make my horse sick?

Forage and bedding materials that are saved in poor conditions are prone to overheating during storage. This can then lead to the growth of certain micro-organisms. Specifically COPD is a lung allergy to inhaled dust particles especially those containing spores of certain bacteria. Also associated with this disease is the fungus Aspergillus fumigatus. Loosely we can term the causative material as ?¢‚ǨÀúmoulds’, which appear abundantly in poorly conserved forage and bedding. When this material along with inhaled endotoxin enters the airways of the horse (especially those with more sensitive airways) it can lead to inflammation.

Are there any other factors associated with COPD in horses?

The destruction of cilia (the airways are lined my millions of hairlike projections called cilia ) is also a noteworthy factor as the hair like projections on the lining of the lung helps clear the lungs of foreign/unwanted material. In addition, boncho-spasm of airway muscles (not dissimilar to Asthma) can further lead to airway constriction and in some cases complete obstruction. Some horses have a history of suffering from respiratory infection(s) which may result in the initial compromise of the lung tissue allowing these irritants to cause COPD.

What are the typically expected clinical signs to expect with COPD?

  1. Coughing is the most sensitive indicator of lung disease in horses and is the commonest presenting sign (~85% incidence) in COPD cases.
  2. A nasal discharge is often noted (~55% cases). All cases of COPD have an increase in production of respiratory secretions in their lower airways. This discharge isn’t always evident as some horses swallow what is brought up before it is evident on the nostrils. Whereas others only have a discharge when they lower their head or when they cough.
  3. An increase in resting breathing rate that can be over 20 breaths per minute. This can be with or without an exaggerated abdominal expiratory effort or “heave”.
  4. Sometimes a rattling sound can be heard over the trachea at the approx entrance to the thoracic cavity. This is likely to be respiratory secretions moving with respect to inspiration and expiration

What if typical clinical signs are not conclusive in diagnosis of COPD?

Mildly affected animals may show only a few of the above-described signs and thus there may be insufficient clinical signs. Other tests that can aid diagnosis include bronchoscope examination of the lungs and/or tracheal secretion cytology as well as broncho-alveolar lavage fluid cytology.

What are the treatments available when a diagnosis has been made?

This disease is usually reversible even in long standing cases but only when the instigating cause has been determined and thus avoided. This usually involves removing hay and straw from the environment when the horse is kept. Where possible the horse should be permanently kept outdoors without any supplementary hay.

My horse can’t be kept outside all the time what can be done in cases like this?

If your horse has to be kept indoors then three inter-related aspects of management should be adhered to.

  1. Forage:
    1. Switch to a different source of forage, e.g. silage. Even soaked hay will have some spores that can be inhaled (despite extreme care) leading to breakdowns in the management of COPD and thus cases are a result of this. Remember soaked hay will drip onto the bedding and once dry spores will hatch and more of the causative agent will be present not less.
    2. Horses like silage despite what people will tell you, it merely takes a little time to get used to. Not only that it is often more nutritious than hay. However any soiled silage should be discarded, the potential for botulism is higher with silage than with other feedstuffs.
  2. Bedding
    1. Alternatives to straw such as wood shavings sawdust shredded paper or peat should be used.
    2. These must be kept dry as they also contain cellulose and can develop fungal growth if allowed to become damp.
  3. Stabling
    1. In general British stables are too small and poorly ventilated. Half doors of stables should be permanently open and the back wall of stables should have an air inlet of 0.5 sq metres/horse and also if possible a roof vent of 0.15 sq metres/horse.
    2. Forage for horses should never be kept lofts etc above stables.

What medical treatments can be used to speed up recovery once a diagnosis has been reached?

Partial and temporary clinical improvement can be obtained with NSAID’s and corticosteroids, the later non specifically decrease the lung inflammation of COPD. Drugs of this nature (steroids) can be inhaled or taken orally like prednisilone, which is usually administered at 1mg/kg/day. However they should be used with caution and under specific veterinary guidance as the potential for laminitis is considerably higher with this group of drugs

Bronchodilatory drugs such as clenbuterol give immediate temporary and partial relief by relaxing the spasming muscle in affected airways and by increasing mucus clearance. However they do not relieve bronchiolar inflammation, thus a combination of both drug groups may be required initially to resolve or improve clinical signs.

Equine Cushings Disease

Monday, October 9th, 2006

AKA Equine Pituitary Adenoma

As many owners of horses & ponies will testify the quality of life of our animals is paramount. Thus it is very perplexing as an equine veterinary surgeon in this animal loving country that so many cases of this distressing disease either go unnoticed or more alarmingly untreated when diagnosed.

This very simple blog is just a basic synopsis of what to look out for if you are suspicious that your horse has Cushing’s. Then at the end a short overview of the currently available medical treatments are briefly evaluated based on current veterinary evidence.

What is Cushing’s disease of the horse?

Put very simply Equine Cushing’s disease/syndrome is an excess production of steroid by the adrenal gland of the horse.

Why does it happen?

To explain why it happens one has to understand the normal production of steroid in the body, remember we all need some steroid to live and function properly and our horses are no different.

Cortisol (the steroid produced by the adrenal glands of the horse) is produced when it is told to do so by a hormone called ACTH released from the brain. This production of ACTH is stopped once cortisol is produced, so the cortisol acts as a controlling balance mechanism within the body telling the brain to reduce the production of ACTH.

When this mechanism goes wrong, as in Equine Cushing’s disease/syndrome, that’s when the problems start. In Cushing’s disease/syndrome it is usually a problem in the brain of the horse. A small tumour causes an unregulated production and therefore release of ACTH.

This then tells the adrenal gland to produce cortisol but unlike in the normal horse the newly produced cortisol does not tell the brain to shut down the ACTH production. Therefore ever increasing levels of ACTH allow more and more steroid to be produced and enter the blood leading to the disease of Equine Cushing’s disease/syndrome and all of its distressing clinical signs.

So what are the suspicious signs of Equine Cushing’s Disease/Syndrome and what horses are more likely to be affected?

The following are some of the more commonly seen signs with Equine Cushing’s disease/syndrome but it is by no means an exclusive list, nor will every horse with Cushing’s exhibit all of these signs. Indeed there are other clinical signs not mentioned and it is for these reasons that this blog should in no way replace the clinical judgement of your vet with whom you should liase closely.

Secondly if you are going to successfully get to the bottom of this disease then you, your vet and your farrier (most likely) will have to work very closely to treat and manage this disease.

Some frequently reported signs:

  • Not an uncommon disease of horses over 15 yrs (rare in the younger horse)
  • Greatest incidence amongst the 20-25 year olds
  • Mares seem to more affected (reasons not known)
  • Polydipsia (drinking more) & polyuria (peeing more) these often go unnoticed
  • Glycosuria (glucose in urine)
  • Hirsutism (abnormally dense or hairy coat)
  • Hair abnormally long, curly or brittle
  • Density of hair can be exceptionally high
  • Normal seasonal shedding of hair often does not happen
  • Sweating and or weight loss is often common
  • Not easy to notice amongst the dense coat
  • Infections (respiratory/tendon sheaths/joints/oral ulcers) are not uncommon
  • Minor wounds often fail to heal or heal poorly or very slowly
  • Dramatic weight loss/muscle weakness/lethargy are commonly noted
  • Reproductive cycles in mares are often interrupted or are abnormal length
  • Some mares will lactate while not pregnant or nursing foals
  • Laminitis (frequently) & colic are often seen in the later stages of this disease
  • Bulging fat pads are often seen above the orbits of the eyes
  • Some horses may even go blind (albeit this is not common)

So how do I find out if my horse has this disease?

If you are worried about your horse having Cushing’s then you must liase with your vet. He or she will be able to add to the details described above. They may also help rule out other common causes to the signs described above.

Your vet will have a fair clinical suspicion (as will you) that this is a possible cause and thus an accurate diagnosis may be sought. This will involve a blood sample(s).

There are many tests that can be done but from my experience the most accurate blood tests involve testing for these four parameters on an overnight fasted horse:

  1. Basal cortisol levels
  2. Insulin levels
  3. Glucose levels
  4. ACTH levels

1. This ACTH sample must be spun/separated and frozen within a half hour of sampling and must be sent frozen to the laboratory. This is the current Laminitis Trust recommended blood test method of diagnosing this form of Equine Cushing’s disease.

What can I do once my horse has been diagnosed with Cushing’s?

There is no surgical cure for Equine Cushing’s disease/syndrome as it is a tumour in a part of the brain that is extremely difficult to get access to. Thus medical and farrier management is the current treatment of choice although herbal treatments such as “Monks Pepper” may also be investigated. Further details of this possible option can be obtained on request, please email us at info@vetmedsplus.co.uk

Like all medical problems it is often better to treat earlier than later. There are a few treatments that are useful but unfortunately all are expensive. Another problem is that there are no currently licensed products for the treatment of this disease in this country. It is my understanding that this may change in future and we will post them if or when they become available.

There are a few human medicines that are not licenced for use in horses although have very good results in helping control Cushing’s Disease. As they are not licenced for use in horses we are unable to list their names in this article.

I hope you have found this useful. If you have any comments please submit them to our blog and we will publish them on the website. If you have any questions please feel free to email us at: info@vetmedsplus.co.uk

Sincerely, The Vetmedsplus Large Animal Vet

Cushing’s Disease in Dog’s

Friday, August 11th, 2006

We have decided to write our first client information sheet on Cushing’s due to the overwhelming amount of questions we have had from owners about the disease. I would strongly encourage owners of dogs who are suffering from Cushing’s to follow the link below and write in with their comments, suggestions and experience as I’m sure this will be a great help to people who have recently had their dog diagnosed with hyperadrenocorticism (Cushing’s Disease). Thank you.

Cushing’s disease is one of the most commonly diagnosed endocrinopathies in dogs but is very rare in cats. 85-90% of Cushing’s occurs from excessive ACTH (a hormone) released from the pituitary gland in the brain that stimulates the adrenal glands to produce corticosteroid. The other 10-15% of cases are from a tumour (which may be benign or malignant) of the adrenal gland. Cushing’s disease results from the side effects of too much corticosteroid circulating within your dog’s body.

The possible side effects are many and listed below:

Increased drinking and urinating (may be peeing in the house), enlarging/pot bellied abdomen, hair loss, tiredness/lethargy, increased appetite, muscle weakness, skin changes, neurological signs.

The diagnosis is based on clinical signs, and a range of other possible tests including urinalysis, Xrays or ultrasound that can check for a number of organ changes, blood tests for haematology and biochemistry, and then more specific blood tests called an ACTH stimulation +/or a low Dose Dexamethasone Suppression Test, High Dose Dex. Suppression Test.

Treatment: Medical management of Cushing’s can be very successful. Trilostane is currently the only licenced UK drug for the treatment of Cushing’s Disease. Trilostane interferes with the production of steroid by the adrenal gland, it is not toxic to cells and it’s effects are reversible on stopping treatment. The treatment must be continued for life and from personal experience the author has seen good long term control of Cushing’s Disease.

There is a surgical option for Adrenal dependant Cushing’s HOWEVER this should not be undertaken lightly as the post-operative complications can be very severe, and as a result this proceedure is very rarely done. Please speak with your vet to get more information about this proceedure if you have any questions.