Diagnosis and Treatment of Endometritis

These cows typically have a creamy pussy discharge when 'Metrichecked' and may outwardly look to be in good health.  Even just a few flecks of pus on a 'Metricheck' device indicate that infection is present.  The longer these second stage infections remain undetected the greater the chance the cow will become infertile.

Long standing uterine infections cause permanent uterine scarring.  Recent trials have shown that those cows treated 1-3 weeks post calving have far better reproductive results than cows treated 4-8 weeks post calving.

The majority of uterine infections will have become undetectable 4 weeks post calving, even when using a 'Metricheck' device.  The infection however remains present deep inside the uterus.  These 'hard to detect' cows still have very poor fertility.  Early checking will considerably increase the chance of finding these 'dirty' cows.

All 'At risk' cows (RFM's, dead calvings, assisted calvings, vaginal discharge, twins) should be treated with a 'Metricure', 2-4 weeks post calving.

The rest of the herd should be 'Metrichecked' 7-28 days post calving.  Careful planning must be done to ensure calving groups can be identified for checking.  A sensible rational would be to identify cows calving up to the mid point and 'Metricheck' these 1-2 weeks after this date - e.g. August the 20th-25th.  The third quarter to calve is then marked again and checked 3 weeks later on about the 5th of September and the final quarter around another 3-4 weeks later on about the 5th of October.

Metricheck devices may be purchased or lent or you may use your vet to detect and treat during the same milking.

Calf Rearing Consultancy

The first of July has ticked over and our thoughts turn to getting ready for next calving.  Soon we will welcome a new batch of calves, representing a huge financial investment in the genetics of our herd.  If you have new staff involved in rearing your calves this year, are you confident they can........

• Safely stomach tube a calf to ensure they are getting essential colostrum within 12 hours?
• Safely care for and prepare your young calves for transport, maximising their welfare and meeting all the new requirements?
• Differentiate a hernia from an infected naval and know what to do with each?
• Spot that first scoury calf and know how to effectively halt the spread of the bugs?

If the answer to these, or any other calf related questions is no, then the Veterinary Centre is here to help.  We have ateam of veterinarians with a keen interest in calf rearing, headed up by veterinarian Nicola Neal, who has nearly 10 years of large scale calf rearing experience.  Utilising the latest ground breaking NZ research into calf health, we can provide tailored on-farm calf rearing training for staff, or individual management level advice to get your sheds and systems humming.  To get your calves off to a flying start and all your staff on the same page, give the Veterinary Centre a call today.

Rotavirus Scours

Now is the time to start considering the protection of this season's calves against Rotavirus scours. As we know, Rotavirus is the most common cause of infectious diarrhoea in young neonatal calves - and is easily spread from calf to calf by contaminated faeces in the calf pen. Successful calf rearing can be a real challenge, especially in the large herd situation. Overcrowding in sheds, especially in wet/cold weather, damp sheds, poor colostral transfer and overstretched staff can allow an environment for the proliferation of bugs that cause infectious diarrhoea i.e. Rotavirus, Salmonella, Coccidia.

Prevention of Rotavirus is a sound investment to protect your calves and their welfare. The vaccine Rotavec Corona is administered to the pregnant cow as a single shot between 3 and 12 weeks prior to calving. Therefore a herd should be vaccinated 3 weeks before the PSC to cover a 9 week calving spread.

A second option for cows which have already been vaccinated in previous years with Rotavec, is to boost these cows with Kolibin Neo, a new vaccine from AgriHealth. Kolibin Neo provides protection against the prevalent and NZ relevant rotavirus serotypes. Kolibin Neo has sound trial work, can be administered 2-12 weeks prior to calving, and offers a cost saving when used as a booster vaccine. If Kolibin Neo is used in previously unvaccinated cows, the cow will need two vaccinations in her first year. Therefore the net cost in year one, is slightly more than a single vaccination of Rotavec.

Long Acting Dry Cow Therapies - What's in a name?

Put simply all antibiotic intramammaries which are registered as Dry Cow therapies are long acting when compared to lactational intramammories.

The registered claims for these Dry Cow preparations stretch from 4 weeks to 10 weeks.  Cepravin for example is registered for up to 10 weeks based on clinical trials measuring udder residues (which were conducted in the Northern Hemisphere (NH)).  As dry periods in the NH do not tend to last longer than 10 weeks this trial finished measurements at 10 weeks.  Udder residues at this point in the study still exceeded levels required to control Strep bacteria.

Five years ago our practice in conjunction with MSD looked at Cepravin residues in springer cows with 14 week dry periods and found the majority still had protective levels in the pre-colostrum secretions. This is why it is the only DC antibiotic in NZ that can show proof in reducing early season BMSCC. The downside of course is that it is also by far the most commonly detected inhibitory substance in the early season, thus Cepravin treated cows must adhere to withholding the first 8 milkings from supply.

In short, a successful dry off strategy should cover 3 aims:

• Cure existing infections
• Prevent new infections immediately post-dry off
• Stop the establishment of new infections close to calving (springer period).

As the average dry period in Otago/Canterbury is between 85 and 90 days, few products registered in NZ (e.g. Cepravin) will provide significant protection close to calving.  There is little advantage in investing in products that provide protection for more than 4 weeks but less than 10 weeks if the dry period is going to be greater than 10 weeks.  This is because very few new infections are picked up in the mid-part of the dry period (see image below). If protection close to calving is desired in cows with longer dry periods we recommend Teatsealants.

"Fog Fever" - Cow Deaths

From a mob of in-calf heifers grazing regrowth rape, 3 heifers were noticed with an unusual grunting cough.  Twenty four hours later, two of these heifers died.  Post mortem of these affected heifers showed unusual inflammation in the lungs.  This was confirmed by the lab to be "Acute Bovine Pulmonary Emphysema and Odema" or "Fog Fever" for short.  The third heifer was treated symptomatically but died 36 hours later. Fog Fever is a James Herriot era name and the disease probably has nothing to do with fog and more to do with the fact the disease is more commonly seen in the autumn.  A rapid change in feed (also a risk factor for Vitamin B1 Deficiency) causes a particular gut bacteria to convert L-Tryptophan, a naturally occurring amino acid, to a toxic compound.  The toxin rapidly impairs lung function resulting in death.  No treatment is available but identifying the condition and removing affected animals from the paddock will prevent any new cases.