Can Non-invasive Hormone Profiling in Female Tigers (Panthera tigris) could Differentiate True Pregnancy and Pseudopregnancy

Abstract

Background: The tigers (Panthera tigris) being the world’s largest cat are one of the critically endangered species which are at the verge of extinction. The pseudopregnancy or false pregnancy or pseudocyesis is a syndrome which is characterized by the presence of signs of pregnancy in a non-pregnant animal. False lactation or nervous lactation are the terms which are used to refer pseudopregnancy as there is very low quantities of milk production is seen. This condition can be differentiated with true pregnancy by using hormones and by correlation of behavioral symptoms of pregnancy with hormonal profiles for confirmation of pregnancy in female tigers. Methods: Total seven animals were used in the experiment and was divided into three groups (G I, G II and G III). Group G I consist of 03 non-bred animals of less than 9 years of age, G II consisted of 03 non-bred animals of more than 9 years of age and G III was consisted of 03 animals after mating irrespective of their age. Faecal samples were collected non-invasively from enclosures weekly up to 14 weeks. Only fresh samples (deposited within 24 h) was chosen, urine puddles were aspirated from the floor. The extracted samples were then analysed for estimation of relaxin, progesterone and prostaglandin F2 alpha metabolite (PGFM) by enzyme linked immunosorbent assay (ELISA). Result: Relaxin the hormone for early detection of pregnancy in felines gives elevated concentration from 49 days after mating and attains a peak during parturition, whereas, no elevation or peak was observed in pseudopregnant animals. Progesterone, in true pregnancy remains elevated from 7th week onwards after mating, it gets dropped after 7th week with wide fluctuation in pseudopregnant animals. PGFM elevation observed after nine weeks of gestation in true pregnancy whereas, no elevation will be observed in pseudopregnant tigress.