Obstetrical Emergencies in Pets
Obstetrical emergencies are life-threatening medical emergencies that occur in pregnancy or during or after labor and delivery of fetus. Obstetrical emergencies are common in pet practice and require immediate intervention to prevent the mortality of the fetus as well as of the dam associated with it. Diagnosis and successful management of obstetrical emergencies at right time is critical for achieving high survival rate in pet practice. Management of obstetrical emergencies not only involves saving the life of dam and offspring but also conserving the future breeding soundness of the animal. Further, during any veterinary emergency, stress increases and thereby makes it difficult to know what steps to take and when. So in advance planning of possible pet emergencies makes it possible that the pet receives assistance it needs as quickly as possible. The most commonly encountered obstetrical emergencies in pet animals are:
- Dystocia
- Uterine torsion
- Uterine rupture
- Inguinal hernia
- RFM
- Metritis
- Hypocalcaemia
- Pregnancy toxemia
I. Dystocia
It is defined as the inability to expel fetus from the uterus and birth canal at the expected time of parturition. Dystocia, is from the Greek word “dys” which means “difficult, painful, disordered, or abnormal” and “tokos” which means birth, occurs when the process of parturition ceases to progress normally. This is an emergency which needs an immediate attention to reduce the risk of both the morbidity and mortality to the mother and fetus. Dystocia occurs in approx. 5% of all the parturitions in dogs and 3.3% to 5.8% of parturitions in queens. Dystocia can occur due to maternal or fetal factors, and in some cases, both factors may be involved.
Common causes for dystocia include uterine inertia, an oversized fetus, fetal mal-presentation or fetal death. Strong abdominal straining or tenesmus during second stage of labour is suggestive of pup presence in birth canal. Assistance may be necessary if the bitch does not deliver the pup within 30 minutes because fetus lodged in the birth canal can die if complete placental separation is not followed by delivery. Presence of lochia or utero-verdin (greenish–blackish vulvar discharge) indicates placental separation has begun and can be taken as a reliable sign for beginning of whelping. It has been reported that sometimes after the death of the caudal foetus in the uterus before term, lochia will pass and the remaining pups are born normally at term. For patients suffering from dystocia, any fluid, electrolyte, calcium, and glucose imbalances must be corrected.
IMPORTANT NOTE: Passage of lochia from a term bitch indicates whelping to commence within 1-2 hrs. Failure indicates a potential dystocia which could lead to the death of the entire litter of pups, if it is not relieved within 24 hrs. The mean gestation length in domestic cats is approximately 65 days (range 57–72 days), with the majority of parturitions (95-97%) occurring between 61 and 70 days.
Uterine Inertia
Uterine inertia is one of the common maternal causes of dystocia in dogs and cats and is of primary or secondary type with primary uterine inertia as the commonest causes of maternal dystocia. Primary uterine inertia occurs due to the failure to expel normal sized fetuses through a birth canal which is normal except for an incompletely dilated cervix. This occurs when parturition begins normally, but uterine contraction stops before expulsion of the puppy. Primary uterine inertia mostly happens due to inadequate uterine stimulation in one or two pup, hypocalcaemia, obesity, inadequate nutrition, uterine torsion etc. Secondary uterine inertia is in which the female dog gave birth to at least one pup but failed to expel all the fetuses or uterine contractions stopped before whelping was complete. Both fetal and maternal factors of dystocia may occur together e.g. Fetal oversize a fetal factor leads to secondary uterine inertia, a maternal factor.
Diagnostic evaluation
I. Complete history of animal like previous reproductive performance, breeding dates, past whelping & dystocia etc.
ii. Physical parameters like temperature, pulse, respiration rate, capillary refill etc.
iii. Confirmation that animal is pregnant and palpation of fetal movement and auscultation of fetal heart beats (absence does not confirm fetal death).
iv. Inspection of mammary gland for normal or abnormal secretion of milk.
v. Examination of vulva for lochia or blood.
vi. Digital examination of the vestibule and vagina in order to ascertain the relaxation of birth canal, presence or absence of foetus.
vii. Abdominal radiography to ascertain fetal number, size, position, signs of fetal death.
viii. Ultrasonographic examination for presence of fetus, fetal viability and prediction of fetal distress. Fetal heart rate of <130 beats/min gives indication of poor viability of pups if not delivered within next 2-3 hrs and <100 beats /min needs immediate veterinary intervention.
ix. Laboratory evaluation like complete blood count, serum chemistry (glucose, calcium) etc.
Treatment
1. Manipulative treatment
It includes extraction of mal-positioned or slightly oversized foetus from the dam using obstetrical forceps, sponge forceps etc. Lubrication of the birth canal should be done followed by grasping of the protruding puppy from vulva. Grasping tail or limb is not to be encouraged. Puppies obstructing the birth canal and barely protruding are to be recovered by caesarean section.
2. Medical treatment
Medical treatment is indicated when the pet is in good health, cervix is dilated with fetal size normal and fetus are not in distress, labour has not been delayed for prolonged period and there is no obstruction to delivery. It is also important to identify placental separation, uterine disease and/or uterine rupture prior to start of medical treatment. It probably works best on females that have already given birth to at least one fetus and whose litter size is not higher than average.
The various medical treatments to be considered are:
Oxytocin: Since oxytocin is safe for both bitches and puppies, it is frequently utilized. However, excess dosing of it might cause fetal hypoxia, placental separation and tetanic and unproductive uterine contractions. However, Poor response of oxytocin may be seen when the extracellular calcium concentration is low.
Recommended dose in dogs is 5-20 units/dog, i/m at 30-40 min interval. In cats, recommended dose is 0.5-2 units/cat, i/m at 30 minutes interval with maximum of 2-3 doses.
Calcium: Calcium increases strength of uterine contractions in contrast to oxytocin which increase frequency of uterine contractions. Even in the presence of normal serum calcium concentrations, bitches who did not respond to oxytocin alone can benefit from calcium therapy. Calcium therapy might result in severe uterine contractions, it is used less frequently in queens.
Dose of 10% calcium gluconate is 0.2 ml/kg slow i/v over 3-5 min or 1-5 ml/dog s/c. In cats, the recommended dose for 10% calcium gluconate is 0.5-1.0 ml/cat by slow i/v. If the animal is restless or change in the heat rate and rhythm occurs, discontinue administration.
Approaches for treating dystocia
| History | Approach |
| 1 or 2 pup litter only or fetal oversize | Caesarean section |
| 5 or more pups remaining in uterus | Caesarean section |
| 4 or less pups remaining in uterus with non obstructed birth canal | Oxytocin at recommended dose. If pup is born within 30 minutes, repeat oxytocin at 30 minutes interval. If delivery slows, add calcium.If put is not born within 30 minutes of oxytocin administration, give 10% calcium gluconate 0.2ml/kg, i/v not exceeding 5 ml. Repeat oxytocin after calcium. If no pup is born after 30 minutes, go for caesarean section. |
II. Uterine Torsion
Uterine torsion in pets is relatively uncommon due to long and freely movable uterine horns. However, when it occurs, one or both horns can twist along the long axis or around the opposite horn, or the entire body can rotate. The common symptoms include severe pain with abdominal distension, hemorrhagic vulva discharge, tachycardia, signs of shock and dystocia. Severe torsions can lead to thrombosis or uterine vascular rupture, congestion, shock, and fetal and/or maternal death by blocking the uterine blood supply. Rupture may occur at parturition.
Diagnosis: Clinical signs, ultrasonographic examination and exploratory laparotomy
Treatment: Prompt surgical intervention (either a hysterectomy if thrombosis and gangrene are evident, or a hysterotomy to remove the fetus).
III. Uterine rupture
Uterine rupture is an uncommon condition in bitch and the condition may remain undiagnosed until dystocia occurs when puppies fail to enter the birth canal. In uterine rupture, death of foetus occurs immediately when fetus is expelled to abdominal cavity. After then, the fetus is either retained as a mummified fetus or resorbed (if fetal calcification has not taken place). Possible sequel to this condition is peritonitis.
IV. Inguinal Hernia
Pregnant uterine horn occasionally enters through inguinal ring and causing dystocia. It may be due to congenital defects in some breeds like Basset hound, White terrier etc.
Treatment
- • Surgical repair of the hernia for preventing ischemic compromise.
- • Caesarean section for delivery of term pups.
V. Retained Fetal Membrane
The persistence of green genital discharge after 12 hrs of birth of last puppy is indicative of a retained after birth. Vaginal exploration with finger is done followed by fiddling in order to bring out the umbilical cord & gentle traction is applied to withdrawal the placenta. Oxytocin is administered 0.5 hour after the last fetus is delivered so as to expel the terminal placenta if present. In no response by oxytocin administration or abdominal manipulation, laparotomy is indicated for milking the fetal membrane along the uterus towards the cervix. If this fails hysterotomy can be done to relieve them.
In cats, the treatment of choice is oxytocin (0.5 to 1.0 IU/cat, IM, every 30 minutes, maximum of 3 doses) within the 24 hours following delivery. Prostaglandin F2α (0.1 to 0.2 mg/kg, SC) or cloprostenol (1 to 2 μg/kg, SC) every 12 to 24 hours to effect can be used if oxytocin does not evacuate the uterus or parturition occurred more than 24 hours previously.
VI. Metritis
Acute puerperal metritis is a disease of immediate post partum period (0 to 7d post whelping) in which there is severe inflammation of the endometrium and myometrium that cause systemic illness in the bitch. It usually follows retained placenta, retained pups, macerated and decomposed pups, prolonged delivery etc. Bacteria thrive in retained or devitalized tissues leading to inflammation of endometrium and myometrium and if untreated leads to septicemia and toxemia. The animal shows symptoms of depression, high rectal temperature (103°-105°F), degenerative left shift of WBCs, putrid, reddish brown uterine discharge, hypo-volumic shock from dehydration, septicemia or endotoxemia etc.
Diagnosis
- History and clinical signs
- Ultrasonography
Treatment
- Replacing fluid deficit. Dextrose i/v (if hypoglycemia)
- Initiating broad spectrum antibiotics
- Supportive therapy
Surgery is necessary to remove any residual placenta and/or devitalized fetal or uterine material after the bitch has stabilized. Antibiotic infusions and antiseptic solution infusion may damage uterine neutrophils. Role of various ecbolic agents is uncertain in the treatment.
In cats intended for breeding, uterine evacuation is indicated if the uterus is not friable and thin walled and no retained fetuses or fetal membranes are present. Oxytocin (0.5 to 1.0 IU/cat, IM, every 30 minutes for 1 to 2 doses) is effective only upto 24 hours postpartum. After that time, there are no more uterine oxytocin receptors present. Other drug choices for uterine evacuation include prostaglandin F2 alpha (0.1 to 0.2 mg/kg, SC) or cloprostenol (1-2 μg/kg, SC) every 12 to 24 hours to effect. Treatment to evacuate the uterus may take several days and is not recommended in severely ill queens.
VII. Hypocalcaemia/Eclampsia/Puerperal tetany
Eclampsia is an emergency medical condition in which there is life threatening drop of blood calcium levels. It may occur prior to parturition and is far more common during the first few weeks post partum. It is observed generally in smaller breeds. The animal shows symptoms of restlessness, nervousness, elevated body temperature, dry mouth, panting pacing, reluctance to care for the pups, stiffness before the onset of muscle tremors, tetany and convulsions etc. In addition to having a fever, some afflicted cats may become confused, hostile, and restless, and they may pace excessively.
Diagnosis:
- History and clinical signs
- Hyperthermia- 105°F (due to increased muscle activity)
- Blood calcium level: In dogs < 7 mg/100ml (normal 9-11mg/100ml) and in Cats < 6mg/100ml is confirmative.
- Blood glucose- Normal (differentiating from pregnancy toxemia).
- Differential diagnosis of seizures – epilepsy, meningo-encephalitis.
Treatment
- Slow i/v administration of calcium. Calcium gluconate (10% solution) @ 0.5-1.5 ml/kg slow i/v over 10-30 minutes (5-20 ml is a typical dose in dogs) is an effective treatment for Eclampsia in dogs and cats resulting in clinical improvement within 15 minutes. Once the animal is stable, dose of 10% solution of calcium gluconate needed for initial treatment may be diluted in equal volume of normal saline and given S/C every eight hours to control clinical signs.
- Gluco-corticoids should not be used (as they decreases intestinal absorption, enhance the renal excretion of calcium).
- Oral administration of calcium or Vit-D may be of benefit after initial i/v treatment.
- Removing pups to reduce lactational drainage.
- In pregnancy Dietary cation–anion difference is more crucial than calcium intake so as to prevent hypocalcaemia. Feeding highly anionic (acidic) diet was more responsive to parathyroid hormone, enabling quick mobilization of calcium from bone.
- Feeding of diets during pregnancy which do not have excessive calcium.
VIII. Pregnancy Toxemia
Pregnancy toxemia is a life threatening condition for both the dam and fetuses and can occur days to weeks before parturition. It occurs due to inadequate nutrition, large litters and is also associated with prolonged gestation and dystocia. The condition is characterized by hypoglycemia, ketonemia, Ketonuria and hepatic lipidosis. Ketonuria without glucosuria is a hallmark of pre-partum pregnancy toxemia in bitch. The symptoms include weakness, inability to stand, seizures and coma etc. Repaid diagnosis and treatment are critical to safeguard maternal and fetal health.
Diagnosis: Urine ketones in the absence of urine glucose, hypoglycemia.
Treatment:
- Supplemental nutrition and correction of hydro electrolytic disorders
- I/v dextrose administration. Dextrose (5%) @ 10ml/Kg (i/v) 3 times at 8 hrs apart on 1st day and then daily. 50% glucose solution @ 0.5-1 ml/Kg (i/v).
- Supportive therapy like B-complex @ 1ml I/M.
- Medical induction of parturition.
FAQ’S
- The most common cause of dystocia in canine and feline is _______________.
- _________ is the recommended dose of oxytocin in feline for management of dystocia.
- Persistence of green genital discharge after ___________hrs of birth of last puppy is indicative of a retained after birth in female dog.
- Dose of 10% calcium gluconate is ____________ in dystocia in female dog.
- ____________without glucosuria is a hallmark of pre-partum pregnancy toxemia in bitch.
Ans. (i) Uterine inertia (ii) 0.5-2 units/cat (iii) 12 hrs(iv) 0.2 ml/kg slow i/v (v) Ketonuria