Downer cow syndrome

BAU

1. Definition A ‘Downer Cow Syndrome’ has been defined as a cow that has been in sternal recumbency for more than 24 hours

2. Characteristics Recumbent longer than 24 hours Usually occurs following parturient paresis No detectable specific diagnostic cause Animal in sternal recumbency Remain recumbent even after two successive treatment with calcium Occurs at any time but associated with parturition

3. Etiology Factors (immediately pre- and post-parturition and at calving) (1)Metabolic disorders: Hypocalcaemia Hypomagnesaemia Hypokalemia Acetonaemia Fat cow syndrom e Hypothermia Acidosis and bloat

4. CONTD… (2)Severe toxaemia : Acute coliform mastitis Acute septic metritis Acute diffuse peritonitis Aspiration pneumonia Traumatic reticulo -peritonitis Rupture of uterus

5. CONTD … (3)Traumatic injuries: Falls on hard surface Riding by other cows Rupture pelvis Fractured femur Rupture of the round ligament Dislocation of hip Rupture of muscle (abductor muscle, gastrocenemius ) Nerve damage

6. Epidemiology Downer cows are most commonly seen in the interval from two days before to 10 days after parturition Downer cows are usually between 5 to 8 years of age which are high producers Many have a history of Milk fever An incidence of 21.4 cases per 1000 cows, of these recumbent cows,33% recovered,23% were slaughtered and 44% died or required euthanasia

7. Pathogenesis Prolonged recumbency Compression/pressure damage Muscles Biceps femoris Semitendinosus Semimembranosus Abductor muscle Local muscle damage Lead to increase pressure within osteofacial compartment Internal filling of the compartment with blood or edematous fluid

8. Contd … A combined effects with external compression obstruction of blood supply Ischaemia (anoxia)= cell damage and inflammation Leading to ‘leaky’ blood vessels and post-compressed swelling Absorption of muscle damaged products in the circulation Myoglobinuria + Proteinuria + Brown discolored urine + Extremely high creatine phosphokinase Indicate muscle damage

9. Contd … Nerves Sciatic nerve damage Peroneal nerve damage Compression against the caudal Compression on the lateral side of aspect of the femur just distal to the stifle joint where it passes the point where the sciatic nerve over the proximal end of the transverses the hip joints fibula Recumbency Peronial paralysis Knuckles over the Fetlock when . attempting to walk Recumbency

10. Contd …

11. Clinical findings ( 1)Alert downer (a)Normal Bright and alert Eat and drink moderately Rectal temperature Heart rate Respiration rate Defection and urination

12. Contd … (b)Abnormal Sternal recumbency Unable to extend limbs to reach a standing position Some cows make frequent attempt to rise, resulting in the cow ‘creeping’ or ‘crawling’ along the ground with both hind limbs flexed and displaced posteriorly- the ‘frog-leg attitude’

13. Contd … ( 2)Non-alert downer Severely affected Do not usually eat or drink Lateral recumbency with head drawn back. Mucoid faeces with some times spots of blood With complications-cause death

14. Course Variable, depending on the nature and extent of the lesions and quality of the care About 50% downer cows will get up within 4 days Prognosis is grave if the cow is recumbent after 7 days Death may occur in 48 to 72 hours associated with myocarditis which may be due to repeated administration of calcium solution

15. Diagnosis (1)History and characteristic clinical signs The clinical sign of recumbency 24 its onset is the basis of diagnosis. Occurrence of parturient paresis Delayed or incomplete treatment of Milk fever Failed to rise within 24 hours following two successive course of treatment Hard and slippery floor

16. Contd … (2)Clinical examination Special examination on the caudal part the spine, including the tail, the pelvic ring and hind legs Rectal examination to detect any abnormalities Painful reactions to manipulation, abnormal mobility, lack of motor and sensory responses or audible crepitation may reveal the site and nature of the physical injuries responsible for prolonged recumbency

17. Contd … (3)Biochemical analysis Blood minerals and haematological values are within normal range Serum Aspirate Aminotranseferase (AST) and Creatininekinase (CPK) levels are usually elevated and indicate muscle damage. The CPK activity occurs after 48 hours and then falls rapidly, even though cows remained recumbent A marked proteinuria is usually present 24 hours after the onset of recumbency The urine may be brown because of severe myoglobinuria

18. Contd … (4)Necropsy changes No specific lesions at necropsy Haemorrhage and degeneration can be found in the upper hind leg musculature Some have myocarditis

19. Contd … (5)Differential diagnosis Maternal obturator paralysis Systemic diseases-Coliform mastitis, Acute diffuse peritonitis, Ephemeral fever Physical injuries-Pelvic and limb fractures, c oxofemoral dislocation, Spinal injuries, rupture of the gastro- cnemius muscle and radial paralysis

20. Treatment The main advice to give is that all cases of recumbency cows should be treated correctly, sufficiently and promptly The basic aim of treatment is to get the cow into her feet The treatment should be symptomatic and can be mad on the basis of biochemical tests and conditions There is no specific preferred treatment, although many have been described Cows that show relapse after treatment with calcium alone, a slow intravenous inj. of a solution containing calcium, magnesium, phosphorus and dextrose is given while the rate, rhythm and intensity of heart sounds are carefully monitored

21. Contd … Phosphorus containing solution eg . 30g Sodium acid phosphate in 300ml of water,5% solution 20 to 40 ml or Tonophosphan.20ml should be administrated intravenously because downer cows have been shown to have persistent hypophosphatemia Tripelennamine hydrochloride @10 to 15 ml should be administrated intravenously, which appears to act a potent, temporary CNS stimulate in cattle and is usually given before attempting to get the affected cow to rise It is essential to move downer cows from concrete floors or slippery, muddy yards before attempting to get them to stand

22. Contd … Affected cows should be kept in sternal recumbency , changed from side to side at least every 3 hours to minimize the degree of ischemic necrosis and para-analgesia which results from prolonged recumbency Adequate bedding is necessary to protect the bony prominences

23. Prevention As there is no single cause of the ‘Downer cow syndrome’ preventive measure should be aimed at eliminating the risk factors that predispose the cows to recumbency in the parturient paresis The aim is to prevent prolonged recumbency and muscle damage. However it is believed that most downer cows have been recumbent from parturient paresis The time interval between the onset of recumbency and treatment for Milk fever should be as short as possible Treatment of Milk fever must ensure that animals receive sufficient calcium in time

24. Contd … The amount of calcium required to effect a recovery seem to vary at least 12g of calcium given intravenously may be required to effect a cure. A solution of 25% Calcium borogluconate contains 10.4g Ca/500ml Under-dosing should be observed closely after treatment for possible relapse Close observation during calving and post calving