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Cattle Health Concerns Post Flooding Events

We thought it would be useful to inform you of some post-flood problems that may arise in your cattle (Based on our experience from 2011).

There are several diseases to be aware of in the coming weeks:

1. Listeriosis

Water-damaged and mould affected hay and silage can promote the proliferation of Listeria monocytogens. This bacterium may cause abortions or neurological symptoms. Animals presenting with neurological signs often have an unsteady gait, circle to one side and have one side of the face affected by paralysis (drooping ear/tongue/ face).

Diagnosis is based often based on clinical presentation; however, some further testing is occasionally required for confirmation (particularly in the case of abortion).

Treatment involves a course of high dose penicillin, an anti-inflammatory course and supportive care.

Prevention is though avoiding feeding mould-spoilt hay/ silage.

1. Botulism

Water affected hay/silage may also lead to growth of Clostridium botulinum in mouldy sections. This bacterium can cause a neurological condition that can initially present as an unsteady gait before progressing to paralysis. Initially, it may look like milk fever, but the cattle fail to respond to treatment. These signs can develop 12 hours to 3 weeks post exposure.

Diagnosis is generally based on ruling out other conditions that could present in a similar manner.

There is no effective treatment other than supportive care. Unfortunately, it usually worsens with time and is inevitably fatal due to respiratory arrest.

Prevention of botulism relies on avoiding feeding mouldy or spoilt hay/silage and, in higher risk settings, vaccination. Different botulism vaccines have various claims for their effectiveness; Singvac claims to give three years of protection from a single dose and is relatively inexpensive.

1. Fungal pneumonia and abortions

Water affected hay and silage can lead to the ideal environment for fungal growth. There are many fungal species that can affect cattle. Affected cattle experience abortions and some cows that abort go on to develop severe pneumonia.

Again, prevention is achieved though avoiding feeding mould/ spoilt hay/ silage.

1. Leptospirosis

Leptospirosis is a bacterial disease spread from infected cows (L. hardjobovis) or pigs (L. Pomona). It is shed in the urine of infected cows and its survival in the environment improves in wet conditions.  Amongst other problems, it can cause abortions, sick cows with 4 quarter mastitis (colostrum-like in consistency) and severely sick calves with ‘red’ urine.

Diagnosis can be made through urine testing of affected animals and blood tests (usually 2 test 3 weeks apart).

Treatment involves a course of oxytetracycline using high doses, an anti-inflammatory course and supportive care.

Prevention relies upon adequate vaccination. Ensure all cattle are up to date with their Ultravac 7 in 1 vaccination as it contains both the common strains of Leptospira.

Note: Humans can get Leptospirosis from affected cattle. Urine splashing on mucosal surfaces (eyes and mouth) and through cut or abrasions of the skin. In humans, it can cause severe flu-like symptoms, headaches, severe lethargy and can affected unborn foetuses of pregnant women.

1. Dermatophilosis aka “Rain- scald”

Dermatophilosis is a skin condition caused by the bacterium, Dermatophilus congolensis. Prolonged wetting events such as cattle standing in water or muddy conditions can cause maceration of the skin and subsequent bacterial infection. It is most common at the back of the foot and legs. The infection can present as clumping of the hair or as wart-like granulating small (0.5-2cm) masses they may coalesce.

Diagnosis can be made on clinical presentation and sending samples away for culture.

Treatment involves cleaning and drying the affected areas as well as course of oxytetracycline and an anti-inflammatory.

Note: This is also a condition that humans can get from affected cattle. When dealing with suspect lesions, wears gloves and practice good hygiene.

1. Lame cows

With wet conditions and cattle having to spend a lot of time standing in water/ muddy conditions, they are at risk of developing foot rot as well and soft hooves which are prone to bruising as well as penetration for rocks/ stones.

It is worth lifting up the feet of lame cows to determine what treatment is necessary (generally paring lesions and applying a cowslip/wooden block to the unaffected claw). All lame cows should be given a course of an anti-inflammatory to reduce pain as lameness can become a welfare concern.

Prevention can be difficult at times due to wet environmental conditions. Having a separate lame cow herd close to the milking shed may be warranted to minimize walking distance, minimize time spent on concrete and speed up the recover.

1. Severe “toxic” mastitis

Many producers are experiencing issue with mastitis in their herds. During wet conditions there is an increased risk of infection with gram-negative bacteria such as E. Coli mastitis. As a consequence of infection with these bacteria, cows can occasionally experience severe “toxic” mastitis. Often these animals are very unwell, becoming lethargic and unable to get up.

Treatment usually involves administering an intramammary after stripping the affected quarters out, injectable antibiotic course, an anti-inflammatory course, oral or subcutaneous calcium +/- IV and oral fluids. It may take some time for affected cows to recover.

Some producers have considered pre-milking teat dipping/ spraying their herds. There are no products registered for this use and there is a risk of Iodine residues in milk. It would be best to contact your milk factory and speak to the Milk Quality officer regarding this practice. If you are concerned cows are coming in with wet and muddy teats, gently cleaning and drying them with clean paper towel may be useful.

1. Midge borne disease (arboviruses)

With the wet conditions and moving into warmer weather, it is the perfect conditions for mosquito and midge to breed. There are several viruses that are spread by midges. These viruses are Bovine Ephemeral Fever (BEF/ 3- day- sickness) and Akabane virus. These viruses are common to the northern regions of Australia but under favourable environmental conditions and prevailing winds blowing them down south, we may see the disease in Victoria. There is an active surveillance program that will assist in detecting these viruses and we will be notified if they are detected in sentinel cattle herds.

Bovine Ephemeral Fever (BEF/ 3- day- sickness) generally present as severe lethargy, lameness and swelling of the legs and often the affected animal does not want to stand. Treatment involves an anti-inflammatory course, adequate nursing, and supportive care (providing deep bedding, offering feed, lifting several times a day etc). Most animals recover after a few days however, some larger animals/ bulls may develop secondary muscle and nerve damage due to being down for an extended period.

Akabane virus is really a disease of importance to pregnant cattle. Pregnant cattle that get infected can have still born calves, calves borne with brain defects or fixed/ fused limbs (arthrogryposis) that require assistance to be delivered.

Please contact the practice to discuss any other concerns that you may have and please don’t hesitate to organise a veterinary farm visit if required.

RODENTICIDE TOXICITY
Case/patient of the week and timely reminder for everyone.
The mice and rats are on the move seeking out warm places to live which means an increase in people using mouse and rat baits.
Rat and mouse baits are (unfortunately) very tasty for our pets as well. This time of year is when we usually see in an increased incidence of rat bait toxicity in both cats and dogs mostly from eating the bait directly but secondary poisoning from eating the dead rodents has happened in our smaller pets.

Jedda presented to us weak, pale, cold and had an increased respiratory effort. Her owners were very worried she had eaten rat bait without them realising. We ran an in-house coagulation time  and haematology which showed she wasn’t clotting her blood properly and was anaemic. On physical exam we couldn’t hear her heart properly.
Jedda was in shock and in a critical condition. We were suspicious Jedda was bleeding in to her chest which was confirmed via X-ray. The blood in the chest cavity meant that she could not expand her lungs properly and hence was having trouble breathing

She was immediately started on intravenous fluids, active warming, nasal oxygen, vitamin K, which is the antidote for most rat bait toxicities, and a fresh frozen plasma transfusion to replace clotting factors.
After 48 hours of care Jedda was strong enough to eat, walk a small distance and be off nasal oxygen. She was still anemic but her body had started making new red blood cells and her clotting time was back to normal. The blood in her chest had significantly reduced so we did not need to drain it. Jedda went home for lots of TLC, rest and 4 weeks of vitamin K.

If you suspect your pet has eaten rat bait please call the practice on (03) 5484 2255. Other signs of rat bait toxicity, along with pale gums and weakness, are obvious  bleeding from the nose or mouth, blood in the urine and bruising on the skin and gums.

*case posted with permission from owner