December 2010

added 22nd December 2010

One of the most common parasites in rabbits is probably the one that most people haven’t even heard of.  This is because although the majority of rabbits are infected, not all of them will show obvious symptoms.  However, it can cause extremely distressing problems and even be fatal, so it is vital that all bunny owners are aware of it and know how to prevent it.

E. Cuniculi (or Encephalitozoon Cunciuli, to give it it’s proper name) is a funny creature in that it is a single celled parasite and so behaves very differently to the ones we all know about like worms and mites. It can infect the kidneys, bladder, eyes and brain and cause a wide range of symptoms including urinary incontinence, cystitis, drinking and urinating more (due to kidney damage), conjunctivitis, cataracts, weight loss, muscle weakness and, probably the one most people are aware of, a head tilt and balance problems.  However, many rabbits show no symptoms at all, which is why it can spread between them so easily.

E. cuniculi is spread by spores excreted in an infected rabbits urine and so passes easily between rabbits living together.  It can be diagnosed by blood tests but as so many rabbits are infected and don’t have symptoms, these are not always accurate.  More often vets decide a rabbit is infected when they show the right signs of illness.

It is not an easy disease to treat and once a rabbit is showing severe symptoms, such as a head tilt, cataracts or kidney failure, they are often permanent.  However, the parasite can be eliminated with a long course of worming treatment and, provided the rabbit doesn’t come into contact with another infected individual, it will remain infection free.

If you have a lot of rabbits, the best thing to do is to treat every bunny for one month with a special worming product and ensure before any new rabbits join the group, they are isolated and treated for one month as well.

added 21st December 2010

 When you go to your vet with a problem they will explain what is wrong with your pet in terms you can understand.  However, really they have a lot of very long and complex words to describe exactly the same things, which to any normal person sounds like a whole new language.  So, I thought I would share a few of them with you, what they could mean and what they actually describe!

Defaecation – Doesn’t mean pretending you can’t hear, it is actually a posh word for pooing!

Emesis – No, not a ride at Alton Towers or your greatest enemy, actually the correct term for vomiting.

Melena – I have always thought this sounds like a rather pretty girl’s name and I bet there is some poor person out there called it, I just hope they don’t know that it really means bloody poo!

Tachycardia – Not the habit your Gran has for sending you cheap birthday cards but a way of describing a high heart rate.

Eructation – This is the proper word for burping, so next time you let one out at the dinner table you can say ‘Oh I do apologise for my eructation’ and your family will be so impressed with your language they will forget all about it!

Borborigmy – This is one of my all time favourite word, I just love the way it sounds, and it means a rumbling tummy.

Epistaxis – Not a fabulous cab, actually a nose bleed

Polydypsia & Polyuria – Could be a couple of parrots but really is the way of describing a pet who drinks too much and wees too much because of an underlying disease.

Varus & Valgus – Not a pair of great Greek gods; a description for wonky legs!  They are most often seen in pups with growth abnormalities or in some smaller breeds where it is considered ‘normal’.

Atrophy – Not an award, the proper word for wasting away, as in the way muscles atropy if people are bedridden.

Hypertrophy – Not an excitable award!  This is the opposite of Atropy and means getting bigger. Just like a body builders muscles when they have been working out.

So, next time you are in the surgery you can tell the vet ‘Oh, she is bound to have a tachycardia, she is always very nervous in here, in fact you are lucky she hasn’t defaecated all over the floor!’.  I am sure they will be very impressed!

Cat Henstridge BVSc MRCVS

added 10th December 2010

I wanted to talk a bit about how a bandage should be placed on a wound as this can be confusing for owners.  It is important to inform you of the correct method to bandage legs as I’m afraid I have seen some ghastly injuries to tendons and skin caused by over-tight bandaging…..

Why bandage wounds?

A lot of clients say to me “I prefer to let the air get to a wound.”  This may be ok for small superficial wounds that have not gone full thickness through the skin, but for anything bigger than a graze, the wound should be covered.  We cover wounds for 3 main reasons:

1:         Wounds heal quickest in a MOIST environment- where all the good cells associated with healing can diffuse into the area.  With all the good will in the world, a little healing cell cannot pass through a hard crusty dry scab!  In addition, it has been shown that a wound that is allowed to heal without bandaging often forms a weaker scar (especially over areas of high motion such as the front of the knee or hock).  These weaker scars are more prone to splitting or re-opening several weeks or months later.

2:         Wounds heal quicker if there is restriction of movement across the skin edges.  As you can imagine, if you had a big wound on your knuckle and you constantly bent your finger backwards and forwards, it would take an age to heal as the movement would keep opening it up.  By bandaging the wound, we are able to restrict the movement of the skin across the wound.

3:         Bandaging helps suck discharge away from a wound, but also acts as a barrier to prevent bacteria and dirt getting into a wound.  NB.  This is only the case if the bandage is dry on the outside.  If you notice that the discharge from a wound has “wicked” and is showing a stain on the outer layer of the bandage, the barrier has effectively been broken, which allows bacteria to pass from the outside to the wound via the soggy bandage.  If you see this wicking, the bandage needs changing!

How to bandage a wound.

A good bandage consists of three main layers:

1:  The primary (contact) layer.

            This is the dressing that you apply directly to the wound.  These come in many forms. Your vet can advise you on what dressing to use, depending on the nature of the wound.

2:  The secondary layer.

            This is the padding for the bandage that also soaks up any discharge the wound may produce.  It can be cotton wool, gamgee or a conformable sponge bandage such as Soffban™. 

3:         The tertiary layer.

            This is the final layer that allows you to tighten the bandage to provide support to the limb and hold the whole thing in place.  It is often slightly elasticated and sometimes water-resistant, such as Vetwrap™.  This tertiary layer should ALWAYS go on over a layer of padding.  If you apply this layer directly to the skin, severe damage may result- including tendon damage and pressure sores.  NB. Don’t use exercise bandages for this layer as they can tighten if wet, causing bandage sores etc.  Stable bandages can be used.

Bandaging tips

Listed below are a few pointers to applying a good bandage:

• Place the dressing (primary layer) on the wound, then use the conformable soft bandage or cotton wool (secondary layer) to secure the dressing in place. 

• If you want to prevent movement across the wound, it is important to incorporate joints near the wound into the bandage. i.e. if the wound is on the mid cannon, the bandage should start from the coronet and go as far as the top of the cannon.  If in doubt, ask your vet.

• Apply the tertiary layer starting at the lower portion of the limb and working up, overlapping each turn of the bandage by a third. 

• Wrap the tendons to the INSIDE of the leg on the front legs and the OUTSIDE of the leg on the hind legs.   i.e.  If bandaging the right foreleg, wrap in a clockwise direction, if bandaging the left fore, wrap the bandage in an anti-clockwise direction.

• When using an elasticated tertiary layer, unravel extra bandage before wrapping round the leg, rather than just unrolling the bandage straight onto the leg- this allows you to control the amount of tightness in the bandage.

• Once complete, check the tightness of the bandage.  You should be able to fit your finger down the back of the bandage against the tendons with ease.  If you have difficulty in inserting your finger at the back of the bandage, it is probably on too tight.  In this case, you should remove it and re-apply.  Don’t just think..”oh, it’ll be ok till tomorrow”- pressure sores and tendon damage can develop within hours…

• The frequency of bandaging changes depends on the type of wound.  I would advise you follow your vet’s advice on this.  As long as the bandage has been well-applied (not too tight/ not too loose) and there is no evidence of “wicking” then it may be left on up to 72 hours (or even a day or two longer in some instances).  HOWEVER, I would always advise more frequent bandage changes in the early stages of wound-healing as you need to keep a handle on how the wound is progressing.

• Bandaging is also a useful technique to employ if a wound on the leg is still bleeding.  By providing a firm, safe bandage you can help stop the bleeding until your vet arrives.  To stop bleeding, you can apply the bandage tighter than you would for a normal wound dressing.  A tight bandage should be applied for a minimum of 15 minutes to stop the bleeding, but no more than 1 hour as, any longer than this may lead to damage to the leg.  When applying a tight bandage- do not place excessive force on the bandage- it only needs to be a firm enough pressure to stem the flow of blood, over-excessive force could bruise or damage the underlying unaffected structures! 

I hope that helps explain a bit more about how to bandage and why you should do so.  I would advise that you practice bandaging on your horse, so that it is second-nature to you if faced with a wound.  Your vet or qualified riding instructor may also be able to show you how to do this properly, and I would never be to ashamed to ask if you are not sure how to do it!

Next time, I will discuss what you may want to keep in your first aid kit…..

By Charlie Briggs MRCVS

added 7th December 2010

It’s that time of year again.  Although we do see calf pneumonia all year round, particularly in year round calving dairy herds, the overall disease incidence does peak over the winter.  The increase in disease may be due to many reasons including bringing cattle inside, mixing of ages and the weather.

I approach all calf pneumonia outbreaks in the same manner.  Firstly the sick calves need to be treated promptly and effectively.  This means returning the calf to fitness as soon as possible with as little need to repeat the treatment as possible.  Anti-inflammatories are sometimes overlooked in the treatment of pneumonia but are essential to get the calf’s temperature down and to get it comfortable quickly thus allowing it to return to feeding and then recovery.  Pneumonia can be a very painful condition and so a longer-acting anti-inflammatory will be more benefit than a short-acting drug.  The other pharmaceutical arm of treatment is antibiotics which are used to combat the secondary bacterial infection that generally follows initial damage caused primarily by viruses.  The antibiotic needs to be effective against the bugs normally found in these cases including Mycoplasma bovis which is increasing in incidence.  Also the antibiotic will ideally be long-acting.  This is for 2 reasons: one is that the calf needs a course of antibiotics of at least 3-5 days to treat the infection and re-catching the calf to retreat within a few days is stressful to the calf, thus not aiding recovery; and secondly the damage caused by viruses means that the airways are susceptible to reinfection by bacteria for 7-10 days.  There are now many antibiotics designed specifically for use in calf pneumonia so please discuss with your vet which is likely to be the best for your farm.  The other major consideration in the treatment of acutely sick calves is good stockmanship and nursing to ensure that they get back to full food intake as soon as possible.

Once acutely sick calves have been treated the next group is the ‘in-contact’ calves which are in the same pen or airspace and thus exposed to the same bugs.  Whether to treat these calves or not will depend on a number of factors including the history of disease on the farm, severity of disease, proportion of affected versus unaffected calves and the building design and layout.  This is a matter to be discussed with the vet who knows your farm.  It should be remembered at all times that although ‘in-contact’ calves may not show signs of disease they will almost definitely have subclinical disease that will affect growth rates and their ability to fight off other infections.

After this I tackle the question of whether to seek a diagnosis of the specific agents causing disease which again is a decision relating to the individual farm and circumstances of the outbreak.  If you have mortalities then a post mortem examination of a fresh carcass that was acutely affected by disease can be very useful.  However a calf that has been chronically ill for days will be of little use in diagnosing the initiating agents involved in the outbreak.  A diagnosis may help in the discussion of future vaccine use on the farm to aid in the control of severe or consistent disease, and is part of the most important follow up stage which is how to control the disease both immediately and in the future. 

If they are homebred calves then ensure they receive adequate colostrum of good quality as soon as possible after birth, and if they are bought in try to ensure you buy from a reliable source to reduce the risk of them bringing any diseases onto your farm.  Many things may increase the chance of a pneumonia outbreak being initiated including stress, transport, routine procedures such as castration and debudding, weaning, malnutrition and concurrent disease, in particular BVD which can cause immunosuppression. 

The other major consideration is the environment in which the calves are kept.  There are faults to be found with many calf houses including overstocking, mixing of age groups, inadequate ventilation, inadequate drainage and draughts on very young calves.  On the majority of farms there are improvements that could be made to some aspects of the calf rearing system that should decrease the risk of calf pneumonia occurring.  Often it takes a second pair of eyes to see these potential problems and so please involve your vet from the outset to reduce losses on your farm.

added 7th December 2010

I have seen a couple of cases of cobalt deficiency in store lambs this autumn.  Cobalt is required by ruminants for the manufacture of vitamin B12 which is used in the liver for energy production.  There are two reasons why it is seen in post-weaned lambs in particular – pre-ruminant animals have a lower requirement and so pre-weaning the lambs’ requirement is lower; also the cobalt requirement for growing animals is greater than it is for adults and so it is not so frequently seen in older animals.

Deficient animals present as poor, ill-thriven and often depressed lambs that have gone back a great deal post-weaning.  Despite there being no scouring the farmers have often wormed these animals regularly in the hope that this will rectify the ill-thrift.  Occasionally they will see a brief and limited response by using this strategy if the drench that they use contains added Cobalt.   However at the same time they are encouraging the development of anthelmintic resistance on their farm by the untargeted and unnecessary use of these drugs and this should be avoided.

On closer inspection of a group of lambs that are suffering from Cobalt deficiency a few will classically have runny eyes and then on individual handling it will be noted that many are anaemic and are often in an almost emaciated state with very little muscle mass and pot-bellys.  The farmer may have noticed that despite their poor condition the lambs are not always interested in eating supplementary feed and progressively get weaker.  There may have been some deaths in the group.

Diagnosing Cobalt deficiency is not always straight forward from blood results as very poor lambs may have normal blood levels and good lambs may have low blood levels.  However the history and clinical signs as described above when used in conjunction with at least 6 blood samples from the group should enable at least a tentative diagnosis that may be followed up by test treating some of the group and monitoring the response by weight gain compared to an untreated group a week to 10 days later.  It is also useful to rule out other causes of a few of the symptoms.  For example the Barber’s pole worm (Haemonchus contortus) can cause anaemia and ill-thrift but no scouring so faecal samples should be checked for worm eggs.  Also damage from chronic stomach worm infestation may cause inappetance and subsequent ill-thrift although generally scouring is also associated with this.  Other vitamin and mineral deficiencies may also be considered by your vet in
diagnosis.

Pasture cobalt uptake is lowest when grass growth is rapid and also in mature pasture.  This means that in a year like 2010 where we have had a dry summer, cobalt deficiency did not arise in many areas until later on in the autumn, once the wet weather had arrived to produce the autumn flush of grass.  Although the pasture content is difficult to predict and will fluctuate from year to year, if you have had cobalt deficiency diagnosed one year then it is prudent to either check the status yearly or to provide your lambs with supplementary vitamin B12 at weaning every year.

Treatment of Cobalt deficiency is generally achieved by injection or oral administration of vitamin B12.  In most cases it would be recommended to initially give both an injection and oral drench to the more severely affected animals.  Slow release boluses are also available but these are an expensive option, particularly if lambs only need to be supplemented for a couple of months until they are fit for slaughter.  Generally drenches need to be administered 3-4 weekly for prevention and more frequently for initial treatment of a severe deficiency problem.  You must treat the entire group as even lambs that are not showing the signs described are likely to have a subclinical deficiency that will deteriorate to a clinical problem if not corrected.  Licks are another option although these have the obvious disadvantage that not all animals take in an equal amount of lick and the most severely affected lambs are not likely to be interested in a lick until
they have had a boost of vitamin B12 from another source.

The most crucial thing to remember is not to suffer in silence when you have poor store lambs.  Please contact your vet to discuss why they may not be doing as well as expected.