By Dr Clive Dalton & Dr Marjorie Orr
This chapter may put you off keeping cattle altogether, but don’t panic, as hopefully you’ll never see most of these diseases. It’s very much a selected list of diseases for reference, and is not a veterinary text. The diseases appear in an order you’ll most probably meet them if they arise. Your approach should be to keep them out of your property so they remain only names in this book.
Key points for good cattle health
- Health, welfare, production and profit are all related, so prevention of disease is always a better and cheaper option than finding cures. Veterinarians agree on this too.
- Good management prevents disease and minimises its impact and cost if and when disease occurs. So have an animal health programme worked out with your veterinarian each year, to review the most likely diseases that will occur and the most cost-effective ways to prevent them.
- There is now also the very important issue of your legal obligations, as it is illegal under the Animal Welfare Act 1999 to let an animal suffer any unnecessary or unreasonable pain or distress. You may not be able to tell if an animal is in pain, so if in doubt always err on the side of caution and seek veterinary help.
- All of us have a duty to report anything “abnormal” that we see in animals in case it is an “exotic disease” which can threaten our farming and export industries.
- The free NZ Exotic Disease hotline to call is 0800-809-966. If for any reason this number does not work, call the police to get through to them.
- Don’t worry if it turns out to be a false alarm. MAF would rather have to investigate these than a real exotic disease outbreak that was not diagnosed rapidly. You will not be sent a bill for your vigilance.
- If there is ever an outbreak of exotic disease, speed of reaction will save the nation.
Keeping your farm disease free
Plan to prevent disease ever getting near your farm. It’s all about developing a management plan with your veterinarian. Here are some issues to consider:
- Always buy or lease stock from reputable sources.
- Have good internal fences to keep stock under tight control.
- Double-fence your boundary with shade trees in between to keep stock from contacting neighbour’s stock.
- Have good farm hygiene plans especially for disposal of dead stock.
- Make stock trucks and trucks collecting dead stock, unload in a confined area or your farm.
- Make sure you (and any children) and anyone else working with animals have good personal hygiene to avoid “zoonoses” – diseases that humans can pick up from animals, e.g. campylobacter and leptospirosis.
- Provide a good protected offal hole for things like afterbirths.
- Have an isolation area to keep new arrivals on the farm separate for a few days. If they develop any health problems then at least you have not mixed them with the whole herd.
- Make sure all stock coming on to your property have the correct Tb documentation and any other documentation recommended by your veterinarian. This especially applies to bulls.
- Make sure visitors from other farms disinfect their footwear before walking your farm. Have a small bath and brush handy which will at least create a good talking point. Always go to other farms with clean boots and disinfect them again when you get home.
- Keep a detailed farm diary to record problems that occur, your diagnosis and treatment if you did not call a veterinarian, and full details of what the vet did if used. These data are very important when having a review with your vet.
- Check that all calves get sufficient colostrum at birth.
- Check the vaccination programme with your veterinarian for the diseases likely on your farm.
- Check the internal and external parasite programme with your vet. This is now vitally important.
- Have a plan to control pests – possums, mustelids, rats and mice, feral pigs and feral cats. Report stray dogs on your property to your nearest Animal Control Officer and keep your own dogs under control at all times.
- Have regular soil tests and occasional pasture tests carried out to check for trace elements and minerals. Also have regular blood and liver tests done on stock at critical times of the year e.g. before winter and before calving.
- It stands apart from the rest of the group.
- Looks dull and depressed with ears drooped and head down.
- Has an unusual posture and strains to pass urine, faeces or it has a discharge from the vulva coming from the uterus (womb).
- Loses its appetite and does not eat or drink with enthusiasm.
- Is scouring (diarrhoea).
- Breathing may be abnormal and you hear a wheezing sound. It may have a cough or catarrh from the nose.
- It has a raised heart rate and respiration.
- Slobbers saliva from the mouth.
- Has a dull, rough long matted coat, does not lick itself and the hair may be discoloured.
- Has scabby circular skin lesions especially on the head and neck.
- Is more agitated than normal and even aggressive.
- Is restless, kicks its belly showing pain, and it may keep looking around at its flank and licking it.
- Licking another area if the painful part cannot be reached.
- Grinds its teeth.
- Shakes its head – head tremours.
- Staggers, and moves in an odd way or with a circling action.
- Is very stiff with a rigid posture.
- Is lame and is reluctant to move.
- Vocalisation – especially when moved or the painful area is touched.
- Presses its head against a solid object like a fence post.
- Protection of the painful part.
- Is down on the ground (a “downer” cow) and refuses to get up.
- Has watery eyes or is blind and walks into objects or falls into holes when it loses contact with its mates.
- Has discoloured membranes of eyes and gums.
- The hair may be discoloured and have come out in certain areas.
- To examine a beast properly, you will need to hold it in a headbail or very tightly in a narrow race. You may be able to hold smaller stock like calves in the corner of a pen.
- You or the veterinarian will want to look at the sick animal’s mouth, tongue, teeth, and eyes, inside the ears, all over the skin, the joints and bones, under the tail, and between the digits of its feet. You will also need to feel the lymph nodes especially in the throat area. Add to this list any discharge from the ears, nose, eyes, mouth, anus, penis or vagina. All these should be noted.
- It can be useful to take the body temperature, pulse rate and respiration rate, and note membrane colour, capillary refill time and hydration status.
- Remember the stress of handling, pain and physical activity can push pulse, respiration and body temperatures above normal.
- Use a proper veterinary thermometer. They are available as mercury-filled or digital ones. The digital ones are easier to read.
- Restrain the beast in a standing position. Small cattle can be restrained bodily in a corner of the yards but larger animals will need to be held in a narrow cattle crush.
- Shake a mercury thermometer down to below 35oC and lubricate the bulb with spittle or Vaseline to ease entry to the rectum.
- Stand to the side, lifts the animal’s tail and gently insert the thermometer rotating it slightly as it goes in to two-thirds of its length, and tilting it a little so that the bulb rests on the bowel wall. Use the same procedure for the digital model.
- Hold it in place for 1-2 minutes then remove and read the temperature. If the temperature is unexpectedly low, the process should be repeated as the bulb may have been embedded in faeces.
- The normal rectal temperature of cattle is 38.6° C (37.8 to 39.3). In calves the normal temperature tends to be at the top end of the normal range.
- An increase in temperature (hyperthermia or fever) may be caused by infections, toxins and/or acute inflammation. A slight increase may be caused by excessive exercise and/or a hot environment.
- A decreased temperature can be caused by a cold environment, especially in small or hungry cattle. The temperature also drops below normal in moribund (close to death) cattle, and in cattle with a sluggish thyroid gland (hypothyroidism).
Pulse and heart rate
- For heart rate, place a stethoscope on the left side of the chest just behind and above the elbow where there is relatively little hair.
- The pulse can be taken by feeling the femoral artery (inside the hind leg about a third of the way towards the back of the leg where the muscles meet the abdominal wall).
- It is important to use only a light finger touch, and the pulse is not easy to find especially in an animal that may be suffering from shock. Practise on normal animals to perfect the technique.
- Count the number of beats in 15 seconds and multiply them by 4 to give the heart rate for one minute. Table 23 shows some average heart rates for different ages of cattle. Note the high rate for a newborn calf
- The pulse should be relatively strong and steady. It may be weak and fast in cattle suffering from shock and/or haemorrhage, and with some types of heart disease the pulse is jerky and strong.
- It can be raised by fever or anaemia. But it can also be elevated by fear or pain, exercise and heat such as when stock are yarded.
- The pulse may be lowered by sleep or coma, by anaesthetics and certain poisons, and it is normally at the low end of the normal range in very fit animals.
- To record respiration rate, a beast must be relaxed and rested and not stressed or active. This is rarely possible after yarding and handling.
- Count respirations by observing the chest wall or flank rise and fall as the animal breathes.
- Count these for 15 seconds and multiply by 4 to give an estimate of the rate for 1 minute.
- Normal cattle breathe at the rate of 30 (range 27-40) breaths per minute.
- Respiration rate is increased by anxiety, pain, anger or exertion, shock, fever, heat stress, some drugs and poisons or because of difficulty with breathing caused by things like pneumonia. It is decreased during sleep or from a head injury or coma, or in some poisonings.
- Note any abnormal breathing behaviour such as laboured breathing, gasping, abdominal effort, unusual posture or neck position (head extended), grunting, coughing, choking or sneezing, one nostril may be more flared than the other, there may be a discharge of mucus or pus or blood.
- If the chest wall is hardly moving but the abdomen is (called abdominal breathing), this can be caused by painful chest conditions such as broken ribs or pleuritis (pleurisy is inflammation of the lining of the chest cavity).
- A beast with damaged alveoli in the lungs (emphysema) may make a double movement (chest then abdomen) when it exhales, and a beast with its nose blocked will breathe through its mouth
- The mucous membranes lining the mouth, eyes and nose should be a healthy pale pink colour (salmon mousse!). Some black cattle may have pigmented mucous membranes in their mouths so look at the lining inside their lower eyelid.
- If membranes are unusually pale - the animal may be anaemic.
- If pale blue (cyanotic) - the blood is not fully oxygenated so there may be heart or lung problems.
- If dirty dark pink - the animal may have toxaemia (toxic substances circulating in its blood).
- If yellowish (jaundice) - there may be liver disease.
- This can be a useful indicator of blood pressure.
- Press your thumb or forefinger gently on the mucous membrane on the gum inside the upper lip.
- When the pressure is released the gum will be white but the pink colour should return within 2 seconds.
- The capillary refill time is longer when blood pressure is low, e.g. after significant blood loss (haemorrhage) and/or shock.
- To check this, pinch or ‘tent’ the skin between the fingers and thumb on the neck.
- In normal cattle the skin returns to the normal flat state almost immediately, but in dehydrated animals it may take some seconds to return to normal.
- When there has been blood or fluid loss or lack of water intake the tissues become dehydrated.
- Pain is difficult to measure in animals like cattle that have no facial muscles to demonstrate fear or suffering as in humans.
- Assume that anything that would cause pain in humans will also cause pain in cattle.
- Another complicating factor is that cattle are herd animals and have evolved not to show signs of pain to avoid being attacked by predators.
- So the signs describing an unwell beast could be associated with either of acute or chronic pain. It is difficult to tell which so consult your veterinarian.
Disclaimer This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.