Reproduction control in cats: new developments in non-surgical methods

Use of a slow-release GnRH implant in an adult billy goat

A 9.4 mg deslorelin slow-release implant was inserted into an adult, healthy billy goat to achieve temporary infertility and a reduction in sexual behavior. The implant was inserted in late autumn. No significant change in testis size was observed over the following 6 weeks. The endocrine function of the testis, which was examined by stimulation with human chorionic gonadotropin, was also unchanged after 6 weeks compared to the initial examination. Histological examination revealed a preserved spermatogenesis.In conclusion, the application of a GnRH analogue implant in the adult male goat has no influence on the investigated parameters - and thus probably also on its fertility.

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

This Scientific Report addresses a mandate from the European Commission according to Article 31 of Regulation (EC) No 178/2002 on the welfare of cats and dogs in commercial breeding establishments kept for sport, hunting and companion purposes. The aim was to scrutinise recent recommendations made by the EU Platform on Animal Welfare Voluntary Initiative on measures to assist the preparation of policy options for the legal framework of commercial breeding of cats and dogs. Specifically, the main question addressed was if there is scientific evidence to support the measures for protection of cats and dogs in commercial breeding related to housing, health considerations and painful procedures. Three judgements were carried out based on scientific literature reviews and, where possible a review of national regulations. The first judgement addressed housing and included: type of accommodation, outdoor access, exercise, social behaviour, housing temperature and light requirements. The second judgement addressed health and included: age at first and last breeding, and breeding frequency. Judgement 3 addressed painful procedures (mutilations or convenience surgeries) and included: ear cropping, tail docking and vocal cord resections in dogs and declawing in cats. For each of these judgements, considerations were provided indicating where scientific literature is available to support recommendations on providing or avoiding specific housing, health or painful surgical interventions. Areas where evidence is lacking are indicated.

Effectiveness of a Modified Administration Protocol for the Medical Treatment of Feline Pyometra

Pyometra is a common uterine disease of dogs and cats, typical of the luteal phase. Traditionally, ovariohysterectomy was considered the elective treatment for pyometra, but in some cases, such as breeding subjects or patients with a high anesthesiologic risk, medical treatment is preferred. Aglepristone is a progesterone receptor blocker and its use proved to be effective for the medical treatment of pyometra in bitches and queens. The aim of this work is to report the effectiveness, in the feline species, of a modified aglepristone administration protocol. Five intact queens were referred to veterinary care centers for pyometra. Aglepristone (15 mg/kg) was administered at D0, D2, D5, and D8, as described by Contri and collaborators for dogs. An antibiotic treatment (marbofloxacin, 3 mg/kg) was associated, and uterine conditions were checked with regular ultrasonographic exams. The uterus returned to its normal condition 10 days after starting the treatment and no adverse effects were reported. After treatment, three queens had an uneventful pregnancy. Even if the treated group was restricted and homogeneous, the proposed modified protocol proved to be useful and promising for the medical treatment of pyometra in cats; further studies are planned to verify its effectiveness in the long-term prevention of recurrence.

Reproductive Management in Catteries: Optimising health and wellbeing through veterinarian-breeder collaboration

PRACTICAL RELEVANCE

Many veterinarians - even those engaged in small animal reproduction - are uncomfortable with taking care of cat breeders or being in charge of catteries. Likely reasons for this are that feline reproduction is largely under-represented in undergraduate and graduate reproduction teaching, as well as in postgraduate education and science, whereas cat breeders themselves are often well informed and actively share knowledge with other cat breeders via the internet and social media.

CLINICAL CHALLENGES

A variety of problems can exist within a cattery, and collaboration between veterinarian and breeder to solve these is ultimately beneficial for the breeder, for the veterinarian, and for the health and wellbeing of the individual cats and of the cattery as a whole.

AIM

This review presents a comprehensive overview of aspects of cattery management that might negatively impact reproduction, including sanitation, hygiene and infectious disease control. It also discusses monitoring of reproductive performance, breeding recommendations, and the diagnostic and therapeutic approach to some common and specific problems.

EQUIPMENT AND TECHNICAL SKILLS

Reproductive management in the cattery requires no specialised equipment, as such. What it does need is an open mind, in terms of seeing how things are done, an open ear, for listening to the breeder, and the veterinarian's clinical skills in palpation, auscultation and, where required, further examination of the animals. Keeping abreast of the latest information on infectious diseases, disinfection and genetics ensures proper advice is provided.

EVIDENCE BASE

Current knowledge of reproductive management in catteries is summarised in order to apply an evidence-based approach, whenever possible. Notwithstanding, much of the information remains empirical.

Aglepristone and cloprostenol combination in the termination of late-term pregnancy in queens

OBJECTIVES

Termination rates for the highly recommended aglepristone (AGL) treatment are low in late-term pregnancy in queens. We studied the effects of an AGL and cloprostenol (CLO) combination in the termination of late-term pregnancy.

METHODS

Pregnant queens were assigned to two groups. Queens in the AGL group (n = 10) received AGL 10 mg/kg, twice, 24 h apart. Queens in the AGL-CLO group (n = 9) were additionally injected with a single dose of CLO (5 μg/kg) 24 h after the second dose of AGL. Progesterone, 17beta(β)-oestradiol, cortisol, oxytocin and prostaglandin F2alpha (PGF2α) metabolite were measured in sera obtained at days 0, 1 and 2, and on the day of abortion.

RESULTS

Average gestational age in both groups was similar (AGL 38.61 ± 0.91 days vs AGL-CLO 39.39 ± 1.35 days; P >0.05). Termination rates were 80% and 100% in the AGL and AGL-CLO groups, respectively (P <0.05). Fetal expulsion time was significantly longer (P <0.001) in the AGL group (96.9 ± 6 h) compared with the AGL-CLO group (69.8 ± 3.3 h). Duration of abortion was 19.8 ± 2.6 h and 12.6 ± 1.4 h in the AGL and AGL-CLO groups, respectively (P <0.05). Both treatments were well tolerated. Significantly (P <0.05) lower serum progesterone concentrations were observed in both groups at the day of abortion and concentrations in the AGL-CLO group (4.19 ± 0.80 ng/ml) were lower than in the AGL group (9.89 ± 2.21 ng/ml; P <0.05).

CONCLUSIONS AND RELEVANCE

AGL and CLO combination increases pregnancy termination rate in late-term pregnant queens. In addition, CLO contributes to a decrease in luteal function in AGL-treated late-term pregnant queens.

Mammary fibroadenomatous hyperplasia in a male cat

Case summary

Mammary fibroadenomatous hyperplasia (MFH) is a benign pathology characterised by extensive proliferation of the ductal epithelium and mammary stroma. It typically occurs in young female cats, and seems to result from hypersensitivity to progesterone. A 2-year-old entire male European Shorthair cat presented to the veterinary clinic with enlargement of several mammary glands, which had developed within the previous 10 days. There was no prior administration of progestin in the cat’s medical history. Diagnostic tests were performed to assess the basal progesterone concentration and the concentration after stimulation with gonadotropin-releasing hormone, which ruled out the presence of functional ovarian tissue. Histological examination of the testes excluded hormone-secreting testicular tumours. Histological examination of the mammary gland confirmed the diagnosis of MFH. Treatment was started with aglepristone, a selective competitor for progesterone receptors, administered subcutaneously at 15 mg/kg at days 1, 2, 8 and 15. A reduction in the size of the mammary glands was evident 6 days after the first administration, with complete remission observed after 4 weeks.

Relevance and novel information

To the best of our knowledge, this is the first full report of MFH in a male cat. Although the origin of the progestins responsible for MFH in this case could not be confirmed, in the light of the diagnostic tests performed and the results obtained, accidental contact with hormone-like substances seems to be the only plausible explanation for the cat’s clinical signs. Inhibitor therapy was successful.

INDUÇÃO DE OVULAÇÃO COM SWAB VAGINAL EM GATAS DOMÉSTICAS E SEUS EFEITOS SOBRE A MORFOLOGIA UTERINA

Resumo A ovulação em gatas é induzida por um reflexo neuroendócrino atribuído à estimulação mecânica dos receptores sensoriais durante o coito. Esta estimulação pode ser simulada com auxílio do swab vaginal, desencadeando a pseudogestação. Objetivou-se verificar a eficiência da indução de ovulação com swab, a fim de estabelecer um tratamento contraceptivo natural para felinos domésticos, bem como os efeitos sobre o útero do uso repetido dessa técnica. Na primeira fase do trabalho, foram avaliados 12 animais em três ciclos estrais consecutivos. No primeiro ciclo (T1), houve estimulação vaginal com swab. No segundo ciclo (T2), foi utilizado macho vasectomizado para cópula. No último ciclo (T3), a ovulação foi acompanhada sem estímulo (controle). Na segunda etapa do trabalho, 13 gatas foram submetidas a sucessivos estados de pseudogestação com intuito de verificar os efeitos da estimulação mecânica sobre o útero. A confirmação da ovulação em todas as etapas do trabalho foi realizada por meio da mensuração dos níveis de progesterona. A estimulação vaginal com swab apresentou resposta similar à obtida por monta natural (P>0,05). Algumas gatas apresentaram modificações uterinas discretas; no entanto, nenhum desses achados foi considerado de relevância patológica. Desta forma, a indução de ovulação com swab mostrou-se segura e sem efeitos colaterais expressivos.

Progestins to control feline reproduction: Historical abuse of high doses and potentially safe use of low doses

RELEVANCE

The high fertility rate of cats means that methods to control feline reproduction are a requirement for cat breeders and pet owners, as well as for those involved in the management of feral cat populations. Progestins continue to be used to prevent queens from cycling, and also as an adjunct or alternative to surgical sterilization within trap-neuter-return (TNR) programs.

EVIDENCE BASE

A considerable body of information exists on megestrol acetate (MA) and medroxyprogesterone acetate (MPA), thanks to the many studies and case reports published in the scientific literature over the past 50 years documenting their clinical use in cats. Comparatively less is known about the use in cats of more recent progestins such as levonorgestrel, proligestone, delmadinone, chlormadinone and altrenogest.

DOSING, SAFETY AND EFFICACY

Based on a combination of dose, frequency and duration of treatment, MA can be categorized into low (0.625 mg/kg/week for up to 30 weeks), medium (0.625 mg/kg q24h for 1 week or q48h for up to 2 weeks) and high (0.625 mg/kg q24h or q48h for several weeks, or weekly for months or years) dosages. Studies suggest that low dosages can be used relatively safely in cats, while higher dosages increase the risk and severity of adverse reactions. Early work showing that an oral MPA dosage of 0.01 mg/kg administered q24h for 12 months suppresses oestrus in queens effectively and safely has not been considered, and much higher MPA dosages (>6.25 mg/kg q24h) have been used in cats over the past 40 years.

RECOMMENDATIONS

Progestins should always be used with caution. Using the lowest possible dosages, MA and MPA may, however, continue to be used safely in pet queens as well as (in conjunction with TNR programs) for the control of feral cat colonies. More recent progestins appear to be effective and safe, albeit their efficacy and safety need to be further investigated.

Treatment with Suprelorin in a pregnant cat

Suppression of oestrus is of major interest in feral cat populations, but also in breeding queens temporarily not intended for breeding. Slow release gonadotropin-releasing hormone (GnRH) agonist implants are a new off-label approach for reproduction control in cats. However, initially, oestrus induction may occur and no data exist regarding what happens if previously mated queens are treated. This case report presents a queen mismated 9 and 8 days before treatment with a 4.7 mg deslorelin implant. The queen delivered four healthy kittens 66 days after mismating, but showed no interest in the kittens and lactation was not adequate. Progesterone and oestradiol concentrations were monitored and the queen was followed until the return of oestrus and subsequent breeding. The next oestrus was observed 498 days after treatment and the queen was mated in the second oestrus afterwards, became pregnant and delivered two healthy kittens, both of which were raised successfully by the queen. This case report clearly shows that pregnancy following a GnRH-agonist implant may go to term, but maternal care might be influenced owing to hormonal changes induced by treatment. In addition, this is the first report demonstrating reversibility of effects induced by long-term treatment with a deslorelin implant (return to oestrus, fertility and normal maternal care).