CASE NOTES


LAMENESS AND LOSSES IN CROSSBRED EWES AFFECTED BY FLOODWATER

Belinda Edmonstone, District Veterinarian, Lachlan LHPA, Forbes Office

This paper was first published in Skirting the Issues, the Official Newsletter of the Australian Sheep Veterinarians, Spring 2012 edition

Posted Flock & Herd December 2012

INTRODUCTION

At the end of February and beginning of March 2012, the Lachlan River catchment received heavy rain over what was already a saturated area. As a result, some areas received widespread flooding along the Lachlan River and also from local waterways. As the Lachlan River came down most producers had adequate warning to move stock to safe areas. However some local waterways rose rapidly in the Condobolin area catching some producers unaware.

CASE REPORT

Eight hundred 2 year old crossbred ewes were stranded in water for 5 days on red loam country from 6th March - 10th March. On 13th March the producer was able to access the sheep and bring them back to the shearing shed. Approximately 180 of the remaining 550 ewes were severely lame. As a property visit to examine the sheep was not possible due to floodwater, a phone diagnosis of interdigital dermatitis/foot abscess was made. The 70kg ewes were treated with oxytetracycline 300mg/mL given at a dose rate of 1mL/15kg. The sheep were reassessed by the producer one week later. He reported the skin was 'peeling off'.

On 29 March 2012 I examined the worse affected of the mob - approximately 200 head in paddocks around the shed. The badly affected ewes had skin peeling back up the leg following detachment from the coronary band. The lesions were like reverse degloving injuries. The claws were still firmly attached. Some wounds were fly struck. Some sheep were also struck in the axilla where the ewes had been sitting on their feet to keep flies away. Some ewes were in sternal recumbency however got up and moved off when approached. Other ewes were standing. The ewes were in good body condition with the majority in condition score 3. On the whole they appeared relatively bright.

We decided to treat them with another injection of oxytetracycline, a deep footbath of chlorhexidine and ivermectin jetting fluid for the treatment and prevention of fly strike. Although paddock feed was good, I advised supplementation with grain to minimise grazing time and maintain body condition. Daily inspection of the mob was required to assess and destroy any ewes that were deteriorating or suffering.

On 3 May 2012 I spoke to the producer and 200/550 ewes had been destroyed since my visit 5 weeks previously. On 7 August 2012 I revisited the property to examine the survivors at shearing. Approximately 50 had been destroyed since May and another 50 were to be destroyed after shearing as some ewes were still lame due to feet deformities and chronic foot abscess. Others had not healed properly and the producer was concerned about flies as the spring approached.

The final result - 250 ewes survived from a mob of 800.

Image 1: Example of wounds, 29 March 2012
Image 2: Example of wounds, 29 March 2012
Image 3: Example of wounds, 29 March 2012
Image 4: Example of wounds, 29 March 2012
Image 5: Examples of wounds, 7 August 2012. This sheep was destroyed.
Image 6: Examples of wounds, 7 August 2012. This sheep was destroyed.
Image 7: Examples of wounds, 7 August 2012. This sheep was destroyed.
Image 8: Examples of wounds, 7 August 2012. This sheep was destroyed.
Image 9: Example of healed wounds, 7 August 2012
Image 10: Example of healed wounds, 7 August 2012

DISCUSSION

While there are reports on assessing the welfare and prognosis of livestock standing in water (Read 2011), I was unable to find guidance on the management of survivors in a mob after they had been standing in water. Management of a single animal is different as more intensive nursing and wound management is possible. Management of a mob of approximately 500 ewes on a mixed farming property at the beginning of sowing presents a different scenario.

Although these ewes had some serious wounds, they were bright and in good body condition. As the wound was a reverse degloving injury there should be an adequate blood supply for healing. If infection and flies could be controlled, nutrition ensured and close monitoring achievable, we decided it was worth 'giving them a chance'. As time progressed, 300 of the 550 (55%) original survivors were destroyed. In total, 69% of the original mob perished in either the original flood event or due to wound complications.

CONCLUSION

When presented with a situation such as this it is difficult to make decisions on whether to advise destroying a large number of stock or 'give them a chance' particularly when resources to guide you are limited. With the benefit of hindsight, the producer and I feel that any ewe with noticeable detachment of skin from the coronary band should have been destroyed on initial examination. However, I feel that each situation needs to be assessed and managed according to the resources and attitude of the individual producer.

REFERENCE

  1. Read L (2011) "Water, water everywhere and not a spot to stand" Flock and Herd www.flockandherd.net.au accessed 19 October 2012
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