Ovarian cystic disease in guinea pigs

Rodent Dermatology

This article reviews the most common dermatologic conditions of the pet rodent population, including the prevalence, clinical signs, diagnosis, and treatment recommendations.

Mast cells and Kurloff cells - Their detection throughout the oestrous cycle in normal guinea pig ovaries and in guinea pigs with cystic rete ovarii

Mast cells (MCs) and Kurloff cells (KCs) were detected in guinea pig ovaries in the follicular and luteal phases of the oestrous cycle. The samples of ovaries were fixed in Mota's basic lead acetate. Toluidine blue was used for detection of MCs and periodic acid-Schiff for detection of KCs. The percentage of KCs in a differential leukocyte count was determined in blood smears stained according to the Pappenheim method. Non-pregnant females with normal ovaries and with cystic rete ovarii were included in the study and the numbers of MCs and KCs were compared in these two groups and in follicular and luteal phases of the oestrous cycle. MCs' distribution in ovaries was different in the guinea pig in comparison to previously studied species: MCs were found exclusively in the superficial layers of cortical stroma and no significant difference was found between the number of MCs in the follicular and luteal phases, neither in normal ovaries, nor in ovaries with cystic rete ovarii. Significantly lower numbers of MCs were found in ovaries with cystic rete ovarii (P < 0.01) in contrast to normal ovaries. A significantly higher percentage of KCs in the peripheral blood was found in the follicular phase (P < 0.05), whereas no significant difference was found in relation to the presence of cystic rete ovarii. Interestingly, no KCs were found in the samples of ovaries (either in the follicular or luteal phase, and with or without cysts). Thus, the expected role of KCs in ovarian physiology or in the aetiology of the cystic rete ovarii can be excluded.

Geriatric Care of Rabbits, Guinea Pigs, and Chinchillas

Specialized veterinary care needed for geriatric rabbits, guinea pigs, and chinchillas is described along with medical conditions common in this age group. Clinical signs of pain, safe analgesics, therapeutics, and alternative modalities are outlined along with guidelines for end-of-life care and decision-making. A handout containing advice for small mammal herbivore clients with geriatric pets is included.

Laparoscopic ovariectomy in guinea pigs: A pilot study

OBJECTIVE

To assess the feasibility and safety of laparoscopic ovariectomy in guinea pigs utilizing 3-mm minilaparoscopic instruments.

STUDY DESIGN

Experimental pilot study.

ANIMALS

Guinea pigs (n = 3).

METHODS

The guinea pigs were sedated, placed under general anesthesia, and intubated under endoscopic visualization. A 3-port technique was used with a 3.9-mm cannula for the endoscope and two 3.5-mm cannulas accommodating 3-mm endoscopic instruments including a 3-mm vessel sealing device, grasping forceps, and endoscopic scissors. The abdomen was insufflated with CO₂ to a pressure of 6-8 mm Hg. The guinea pigs were manually tilted 90° laterally to visualize the dorsally positioned ovaries.

RESULTS

The procedure was successfully performed in all 3 animals. The surgery times were 120, 45, 45 minutes for the 3 guinea pigs, and anesthesia times were 186, 90, and 76 minutes, respectively. Placing the animals in complete lateral recumbency was found to be critical to visualize and manipulate the ovaries. The guinea pigs recovered smoothly from anesthesia.

CONCLUSION

Laparoscopic ovariectomy with 3-mm minilaparoscopic instrumentation using a 3-port technique was feasible in guinea pigs.

CLINICAL SIGNIFICANCE

Laparoscopic ovariectomy can be considered as an alternative to open ovariectomy as an elective surgical technique to prevent reproductive disorders in guinea pigs.

Gonadotrophin-Releasing Hormone Agonists and Other Contraceptive Medications in Exotic Companion Animals

The use of a gonadotrophin-releasing hormone agonist slow-release implant (GnRH A-SRI) has become increasingly popular as an alternative for surgical contraception in many species. Although these implants have proven to be very effective in some species (eg, ferrets, rats, chicken, psittacines, and iguanas), they have been found less effective in other species (eg, male guinea pigs and rabbits, veiled chameleons, slider turtles, and leopard geckos). This review provides an overview of the available literature on the effects of GnRH A-SRIs in companion exotic animals.

Ovarian lesions in 44 rabbits (Oryctolagus cuniculus)

The clinical and pathological records of 44 domestic, female rabbits with an age ranging from 6-124 months (median age: 63.5 month) were assessed retrospectively for ovarian lesions. Included were all rabbits that underwent an ovariohysterectomy with a subsequent pathological examination of the genital tract between March 1997 and June 2016. Pathological examination revealed ovarian lesions in 12 of the 44 rabbits including follicular cysts (n=7), cystic rete ovarii (n=3), widespread ovarian necrosis with dystrophic calcification (n=2), ovarian adenoma (n=1). Clinical examination including radiographs only suggested ovarian disorders in two cases of ovarian necrosis with dystrophic calcification and in two cases of cystic rete ovarii. Clinical significance was only conclusive in a case of cystic rete ovarii.

The presence of ovarian cysts in a captive Antillean manatee (Trichechus manatus manatus L. 1758)

Background

Several pathological changes associated with reproductive systems of marine mammals have been reported in primary literature. However, no such records exist regarding ovarian cysts in the Antillean manatee (Trichechus manatus manatus L. 1758).

Case presentation

A nulliparous female Antillean manatee, held in captivity at the Wroclaw Zoological Garden, died in April 2015. The animal was 370 cm long from nose to tail and weighed 670 kg. The width of manatee’s fluke was 80 cm. The post-mortem examination of the reproductive system showed the numerous pathological cysts on the external surface of the left and the right ovaries. Morphologically, the cysts had varying diameters and were attached to the ovaries by stalks. Some of the cysts were thin-walled and contained fluid, while several others were solid or contained a semi-solid mass. The structure of the ovaries displayed features of the polycystic ovary syndrome (PCOS). The cysts also exhibited positivity with cytokeratin and vimentin. There were no pathological changes within the uterus, uterine tube and vagina.

Conclusion

Although we were unable to definitively determine the exact source of the ovarian cysts in the studied manatee, we found that one of the causes may be age-related. Our study also revealed that ovarian cysts in the Antillean manatee form both types of corpora lutea (CL).

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-017-1164-7) contains supplementary material, which is available to authorized users.

Reproductive Medicine in Guinea Pigs, Chinchillas and Degus

Guinea pigs, chinchillas, and degus are hystricomorph rodents originating from South America. They are commonly presented as exotic pets in veterinary practice. Reviewing the anatomy and physiology of their reproductive tract helps to offer better client education about preventive medicine and helps to act faster in emergency situations. Choosing the right anesthetic protocol helps to prevent complications. This article should aid as a guideline on the most common reproductive problems of these 3 species and help in making decisions regarding the best treatment options.

Spontaneous reproductive pathology in female guinea pigs

Reproductive pathology of domestic guinea pigs is underreported to date. To provide a comprehensive review of uterine disease in guinea pigs, we performed a retrospective study of the pathology archives of the University of Tennessee, College of Veterinary Medicine. By histology, 13 of 37 uterine lesions in 23 animals were neoplastic; the other 24 nonneoplastic lesions included cystic endometrial hyperplasia (16 of 24), endometrial hemorrhage (3 of 24), pyometra (2 of 24), polyp (2 of 24), and mucometra (1 of 24). The most common guinea pig uterine neoplasms were uterine leiomyomas (6 of 13), followed by adenomas (3 of 13) and leiomyosarcomas (1 of 13). Other neoplasms included anaplastic tumors of unknown origin (2 of 13) and choriocarcinoma (1 of 13). Both anaplastic tumors and the choriocarcinoma were positive for vimentin. The choriocarcinoma was positive for HSD83B1, indicating a trophoblastic origin and its final diagnosis. All were negative for cytokeratin and smooth muscle. In multiple animals, more than 1 tumor or lesion was reported. Estrogen receptor and progesterone receptor expression was nearly 100% in uterine neoplasms. Nearly all animals for which data were available had cystic rete ovarii (18 of 19); the animal with no cystic rete ovarii had paraovarian cysts. In our study, female pet guinea pigs had a tendency to develop cystic endometrial hyperplasia and uterine neoplasia. Factors for the development of these lesions could be cystic rete ovarii, hormone dysregulation, and/or age. Other factors could contribute to the development of uterine lesions. As in other species, early ovariohysterectomy could decrease the prevalence of uterine lesions.

Unilateral flank ovariohysterectomy in guinea pigs (Cavia porcellus)

AIMS

To describe a simple, minimally invasive method of ovariohysterectomy via a unilateral flank approach in guinea pigs, for use in routine desexing of healthy female guinea pigs or treatment of ovarian cysts.

METHODS

The subjects of this retrospective study were 41 client-owned guinea pigs submitted for routine desexing or treatment of ovarian cysts. They included 16 healthy female guinea pigs aged 8-12 months (Group 1), and 15 females aged from 9 months to 3 years (Group 2), and 10 females aged from 3 to 7 years (Group 3) with different-sized ovarian cysts. Prior to surgery, the animals received clinical examination, blood testing (complete blood count and serum biochemistry profile) and examination of the abdomen using ultrasonography, to assess the condition of the reproductive tract and ensure the guinea pigs were fit for surgery. Ovariohysterectomy was performed via a unilateral flank incision made close to the erector spinae muscle starting approximately 1 cm caudal to the last rib. Both ovaries, uterine horns, and the uterine cervix were localised, ligated, and dissected through this unilateral retroperitoneal incision.

RESULTS

Ovariohysterectomy was successfully completed via a single flank incision in 38/41 (93%) guinea pigs. Three guinea pigs with ovarian cysts from Group 3, which were >6 years old died during surgery due to circulatory and respiratory failure under anaesthesia. In the remaining 38 cases, surgery proceeded without complications. A further two guinea pigs from Group 3 were reluctant to move or eat for the first 3 days after surgery but recovered after provision of supportive care. All 38 animals fully recovered and wound healing was normal.

CONCLUSIONS

This is the first report of ovariohysterectomy via a unilateral flank incision in guinea pigs. This approach is a simple, minimally invasive and safe alternative to the midline or bilateral flank approaches currently used for surgery of the reproductive tract in guinea pigs.