Domestic dogs in protected areas: a threat to Brazilian mammals?

Lessa, I., Guimarães, T. C. S., de Godoy Bergallo, H., Cunha, A., & Vieira, E. (2016). Domestic dogs in protected areas: a threat to Brazilian mammals?.Natureza & Conservação.

The presence of domestic dogs (Canis lupus familiaris) in Brazilian protected areas is fairly frequent. The interaction of such dogs with native animals leads to population declines for many species, particularly carnivores. In this paper the main threats dogs bring about Brazilian biodiversity are assessed with a focus on protected areas. We collected information from papers on the interaction of dogs and wildlife species as well as from interviews with National Park managers. Studies in protected areas in Brazil listed 37 native species affected by the presence of dogs due to competition, predation, or pathogen transmission. Among the 69 threatened species of the Brazilian fauna, 55% have been cited in studies on dogs. Dog occurrence was assessed for 31 National Parks in Brazil. 

(A) Domestic dog sniffing a prey (Dasypus novemcinctus) in the Ilha Grande State Park. (B) A female dog with territorial marking behavior registered by a camera trap in the same Park; the dog was 3 km away from the nearest village. Photos: H.G. Bergallo and I.C.M. Lessa.

The presence of human residents and hunters in protected areas were the factors most often quoted as facilitating dog occurrence. These may be feral, street or domestically owned dogs found in protected areas in urban, rural or natural areas. Effective actions to control this invasive alien species in natural areas must consider dog dependence upon humans, pathways of entry, and the surrounding landscape and context.

Removal of feral dogs by befriending them

Morley, C. G. (2006). Removal of feral dogs Canis familiaris by befriending them, Viwa Island, Fiji. Conservation Evidence, 3(3).

On a Fijian island a decision was made to remove feral dogs Canis familiaris as they were predating
upon endangered fauna. Rather than trapping or shooting, by offering food and gradually habituating
them to people, almost all were captured unharmed and moved to the main island of Fiji. 

Toxoplasmosis in sea lions in NZ

Michael, S. A., Howe, L., Chilvers, B. L., Morel, P. C. H., & Roe, W. D. (2016). Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations. New Zealand Veterinary Journal, (just-accepted), 1-14.

AIMS: To investigate the seroprevalence to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure.
METHODS: Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was >30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples.
RESULTS: Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive.
CONCLUSIONS: Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.

Cat predation on wildlife in Haute Savoie, France

Vuagnat-Kolter, M. Prédation du chat domestique, Felis catus (linnaeus, 1758) sur la faune sauvage, dans une commune péri-urbaine de Haute-Savoie (74). Le Bièvre, 22.

Le chat domestique, Felis catus (Linnaeus, 1758) est une espèce invasive, un redoutable prédateur et un animal de compagnie qui ne dépend pas de la disponibilité des proies pour survivre. Ces trois aspects associés à l’importante densité de chats font de sa prédation sur la faune sauvage, un facteur important dans le fonctionnement des écosystèmes, qui peut entraîner localement le déclin d’espèces
indigènes. La présente étude a eu lieu en Haute-Savoie dans la commune de Feigères. Toutes les proies  ramenées au domicile par 44 chats domestiques ont été identifiées sur une durée de 3 mois. Un total de 163 proies ont été tuées (86 micromammifères, 69 oiseaux, 8 reptiles) pour une moyenne de 3,7 proies par chat. Neuf espèces d’oiseaux ont été identifiées, parmi lesquelles le moineau domestique (58 %) est le plus représentée devant le merle noir (13  %). Le moineau domestique est placé en première position car il est commensal de l’homme et vit dans toutes sortes de zones modifiées par celui-ci, notamment les jardins. L’extrapolation des résultats à l’échelle de la commune montre que 2068 proies dont 878 oiseaux ont été potentiellement tuées sur trois mois entre mi-avril et mi-juillet. Le suivi télémétrique réalisé sur une durée de cinq semaines sur cinq chats, a permis de démontrer que les chats sont inactifs la majeur partie du temps (77 %) et que leurs périodes d’activité privilégiées sont l’aube et le crépuscule, lorsque les températures sont les plus basses de la journée. Le domaine vital des chats est relativement petit, ils n’effectuent pas de grandes distances et occupent principalement leur foyer ainsi que le jardin attenant à celui-ci.

The domestic cat Felix catus (Linn. 1758) is an invasive species, a formidable predator and a pet which is not dependent on the availability of prey for its survival. These three elements, plus the high density of cats, make its preying on wildlife a major factor in the functioning of ecosystems. This can lead to a decline in indigenous species locally. The present study took place in the Haute-Savoie department (France), in the commune of Feigères. All the prey brought home by 44 domestic cats were identified over a period of 3 months. There were 163 prey items in all (86 small mammals, 69 birds and 8 reptiles) for an average of 3.7 prey items per cat. 9 species of bird were identified, among which the House Sparow was the most numerous (58  %) followed by Blackbird (13  %). The House Sparrow came first because it is closely associated with man and lives in all sorts of places modified by him, notably gardens. Extrapolating the results to the scale of the commune produces 2068 prey items including 878 birds which were potentially killed over the three-month period from mid-April to mid-July. Radiotracking carried out on 5 cats over 5 weeks showed that cats are inactive most
(77  %) of the time. Their preferred periods of activity are dawn and dusk when the day temperatures are at their lowest. The cats’ territories are relatively small, not covering large distances, and mainly
occupy their homes and the adjacent gardens.

Demography of domestic dog population and its implications for stray dog abundance

Makenov, M. T., & Bekova, S. K. (2016). Demography of domestic dog population and its implications for stray dog abundance: a case study of Omsk, Russia. Urban Ecosystems, 1-14.

In cities of Russia, stray dog populations have been conserved for a long time, despite natural mortality and constant catching. We suggested that the overpopulation of owned dogs and their subsequent transition into stray dogs is a primary reason for the increase in the number of stray dogs. Information on owned dogs was obtained through a cross-sectional household survey of dogs owners in Omsk, Russia. Analysis of a vertical life table showed that the maximum mortality of owned dogs under 1 year of age was 53 %; in other age classes, the mortality was, on average, 5.6 %. Analysis of fecundity showed that 81 % of the owners do not mate their dogs; consequently, only 36 % of the adult females whelped at least once. Analysis of the Leslie matrix showed that the growth rate of the population of owned dogs was 1 % per year. This result shows minimum overpopulation. Previous dogs escaped or were lost or vanished in rare cases (approximately 0.5 %). However, in a megalopolis, even such low frequencies are significant (95 % CI: 1433–5473 individuals). Analyses of the demographic processes in a population of owned dogs showed that a transition from owned dogs to stray dogs exists. Overpopulation is not the key reason for the transition, but different accidents are: that is, pets are lost, run away, etc. The frequency of such events is small, but, because of the size of the city, the number of such dogs might be 10–39 % of the total number of stray dogs.

Canine pathogens among wolves from the Alaska peninsula

Watts, D. E., & Benson, A. M. (2016). Prevalence of antibodies for selected canine pathogens among wolves from the Alaska peninsula, USA. Journal of Wildlife Diseases.

We collected blood samples from wolves (Canis lupus) on the Alaska Peninsula, southwest Alaska, USA, 2006–2011 and tested sera for antibodies to canine adenovirus (CAV), canine coronavirus (CCV), canine distemper virus (CDV), canine herpesvirus (CHV), canine parainfluenza (CPI), canine parvovirus (CPV), Neospora caninum, and Toxoplasma gondii. Detected antibody prevalence was 90% for CAV, 28% for CCV, 12% for CDV, 93% for CHV, 0% for CPI, 20% for CPV, and 86% for T. gondii. Prevalence of CCV antibodies suggested a seasonal pattern with higher prevalence during spring (43%) than in fall (11%). Prevalence of CCV antibodies also declined during the 6-yr study with high prevalence during Spring 2006–2008 (80%, n=24) and low prevalence during Spring 2009–2011 (4%, n=24). Prevalence of N. caninum and T. gondii antibodies were highly variable in the study area during 2006–2011. Results suggested that some pathogens might be enzootic on the Alaska Peninsula (e.g., CAV and CHV) while others may be epizootic (e.g., CCV, N. caninum, T. gondii).

Selective pressure agaisnt TNR efforts

Bohrer, E. (2016). Determining the Onset of Reproductive Capacity in Free-Roaming, Unowned Cats (Doctoral dissertation).Oregon State University. University Honors College

The purpose of this thesis was to determine if an underlying biological cause exists for the exuberant reproductive success in free-roaming unowned (FRU) cats. The hypothesis for this thesis was that FRU tom and queen cats have reproductively adapted to man-made sterilization efforts by lowering the age at which they enter puberty. For domestic cats, puberty is reported to occur around 8 months of age. Cats were presented for surgical sterilization at either a feral cat clinic or at a local Humane Society during August-October 2014 and 2015. Age was determined by records provided from feral cat colony managers and confirmed with dental eruption patterns. The age groups for tom cats were: 2-2.5 months (weanling; n=6), 3-4 months (juvenile; n=6), 5-6 months (pubertal; n=6), and 12-24 months (adult; n=6). Queens were grouped by age (<4 months (pet n=5, FRU n=10) and 4-6 months (pet n=2, FRU n=7)).
For tom cats, the penis was evaluated to determine if spines were present and the contents from both vasa deferentes were milked onto a microscope slide, mixed with eosin-nigrosin stain, spread with a spreader slide, allowed to air dry and evaluated at 1000X. The percentage of sperm with normal morphology was determined after evaluating 100 sperm/slide. Testicles were hemi-sectioned, formalin-fixed, paraffinembedded, cut into sections (6 µm), stained with hematoxylin and eosin (H&E), and evaluated at 200X for evidence of spermatogenesis and measurement of seminiferous tubule diameter. For queens, the total ovarian uterine weights from FRU queens were also recorded. Ovaries were hemi-sectioned, formalin-fixed, paraffin-embedded, cut into sections (6 μm), stained with H&E, and evaluated at 200X. Follicles were counted and classified as primary, secondary, or tertiary. More adult toms (16/16) than juvenile toms (4/13) had penile spines (p<0.05). Mean±SD morphologically normal sperm for the juvenile and adult tom cats was not significantly different (77±11% and 81±13%, respectively). Evidence of spermatogenesis in weanling, juvenile, pubertal, and adult toms was 0%, 17%, 67%, and 100%, respectively (p<0.05 between successive age groups). The seminiferous tubular diameter was significantly larger in each successive age group (weanlings 88.10±10.88 µm; juveniles 109.8±8.89 µm; pubertal 142.2±16.89 µm; adult 237.90±52.45 µm). FRU queen cats under 4 months old had more tertiary follicles compared to owned cats under 4 months of age (33% and 17%, respectively; p<0.05). Total ovarian uterine weights were significantly higher in 4-6 month old FRU queens compared to under 4 months (1.18±0.31 g vs 0.93±0.28 g, respectively).
These observations provide an explanation for why TNR efforts to reduce FRU cat populations have not successful. Selective pressures and a significantly shortened life span may be factors contributing to this finding.

Hematological reference values for stray colony cats of northern Italy

Spada, E., Proverbio, D., Baggiani, L., Canzi, I., & Perego, R. (2016). Hematological reference values for stray colony cats of northern Italy. Comparative Clinical Pathology, 1-8.

In additional to significant dietary, lifestyle and hormonal differences, stray cats may have different hematological parameters from pet cats. The objectives of this study are to determine hematological reference intervals (RIs) from a large population of stray cats in northern Italy, to establish whether published RIs for the general pet feline population are valid in stray cats and to evaluate the effects of age and sex on hematological parameters. Hematological data were analyzed retrospectively from the database of a trap-neuter-release program (performed in 2008–2010 in northern Italy) to generate normal RIs. RIs were determined and compared with established pet cat RIs according to the National Committee for Clinical Laboratory Standard guidelines and the American Society of Veterinary Clinical Pathology guidelines. Data from 90 healthy stray cats from 17 colonies were available for determination of hematological RIs. Based on the results of comparison with published feline RIs, new RIs were proposed for RBC count, Hct, MCV, MCHC, and WBC count in stray cats. Male cats had a statistically significant higher value than did females for RBC count (mean RBC count in females 6.5 × 1012 versus 7.4 × 1012/L in males, P = 0.001), Hb (mean Hb concentration in females 9.9 versus 10.9 g/dL in males, P = 0.004), and Hct (mean Hct in females 24.8 versus 28.2 % in males, P = 0.001). Significant differences in five hematological parameters were found between stray and pet cats, for most of which the most plausible explanation is probably anesthetic effect and infections or parasitism. It can therefore be assumed that there is no need to establish a specific RI for most of the CBC variables in stray cats.

Stray dog control and zoonotic disease prevention in Grenada

Marisa, D., Cotran, E. K., Bidaisee, S., & Keku, E. O. (2016). The Effectivenessof Stray Dog Control and Zoonotic Disease Prevention in Global Health: An One Health Approach from Grenada. J Translational Diagn Technol, 1(1), 1-6.

Introduction: CranThe purpose of this study is to evaluate the effectiveness of stray dog control and disease prevention in Grenada by using a one health approach and address the associated global health implications.
Methods: A review of stray dog policy in Grenada, descriptive statistics analysis and interviews were conducted. World Organization for Animal Health’s and Grenada Dogs Registration and Control Act were reviewed. Quantitative data from 2008-2012 on registration, vaccinations, number of dog complaints filed and outcome of dog captures. Retrospective, oneon-one interviews with 14 stakeholders from three groups identified as being directly associated with the stray dog prevention
and control were performed.
Results: The Grenada Dogs Registration and Control Act provided an adequate framework for stray dog control. There was a decrease in the number of dogs registered and vaccinated and a steady increase in dogs captured and related complaints. Interview data suggested that community education, dog ownership, non-governmental organization involvement, and Grenada’s Stray Dog Control Program (SDCP) responsibility are needed to strengthen stray dog control programs and
disease prevention.
Discussion: Expansion of SDCP services is needed to reduce free-roaming dogs and disease risk to humans. A positive response from program users suggested that the SDCP is well-received by the community. Integration among stakeholders and increased access to the program's services in rural communities is needed. These findings have implication for further policy development to reduce global health risks associated with zoonotic diseases found in stray dogs.

Too feral to save?

Hutchison, M. (2016). Comments on the dilemma in the April issue: Too feral to save?. In Practice, 38(5), 254-254.

In the dilemma discussed in the April issue of In Practice, a feral cat had been brought into your practice. It had a simple fracture of the tibia that was eminently fixable, but the cat was feral to the point of being unhandleable. What was the best course of action? (IP, April 2016, vol 38, pp 198-199). David Mills suggested that there were three options: to euthanase; to perform surgical internal stabilisation followed by a rest period, then rehome or release; or to amputate the limb and then rehome or release. None of these options was ideal but a possible solution might be to consider the cat's values. While some suffering in any veterinary intervention was inevitable, this cat's suffering could be prolonged and severe. Consideration of the cat's values and applying ‘critical anthropomorphism’ might help to crystallise thoughts about the animal's welfare and interests. With the potential for severe suffering with no end gain, euthanasia might be the most ethically appropriate option in this case.

Focusing on specific age classes in spay programs

Lancaster, E. P., Lenhart, S., Ojogbo, E. J., Rekant, S. I., Scott, J. R., Weimer, H., & New Jr, J. C. (2016). Modeling Interventions in the Owned Cat Population to Decrease Numbers, Knox County, TN. Journal of Applied Animal Welfare Science, 1-12.

To find management strategies for controlling the owned cat population in Knox County, TN, the authors formulated a mathematical model using biological properties of such nonhuman animals and spay actions on certain age classes. They constructed this discrete-time model to predict the future owned cat population in this county and to evaluate intervention strategies to surgically sterilize some proportion of the population. Using the predicted population size and the number of surgeries for specific scenarios, they showed that focusing on specific age classes can be an effective feature in spay programs.

Epizootic of toxoplasmosis in several marsupials in Zoo

Patton, S., Johnson, S. L., Loeffler, D. G., Wright, B. G., & Jensen, J. M. (1986). Epizootic of toxoplasmosis in kangaroos, wallabies, and potaroos: possible transmission via domestic cats. Journal of the American Veterinary Medical Association, 189(9), 1166-1169.

Between July 28 and August 6 1984, adult marsupials kept at the Knoxville Zoo, USA, including 5 Potorous tridactylus, 3 Wallabia eugenii, 3 Macropus giganteus and 2 M. rufus, became lethargic, developed respiratory distress and died. Acute interstitial pneumonia was seen at necropsy in all 13 animals and multifocal granulomatous necrotizing hepatitis in 10; intracellular and free T. gondii tachyzoites were seen in both organs. Parasites were also found in gastrointestinal lesions and in the cells of the muscular tunica. Foci of necrosis and inflammation were seen in other viscera. One animal had T. gondii tachyzoites in the eye. Of the 3 animals from which blood was collected, 2 adult kangaroos were positive in the IHAT for T. gondii antibodies. All 12 mice inoculated with solutions from infected organs died 2 to 14 days later and T. gondii were seen in their liver and lung tissue smears and in the ascitic fluid of 4 mice. 8 of 11 surviving marsupials were seropositive; 2 animals had increasing titres during the 8 weeks of the epizootic. Blood and faeces of exotic cats kept near the marsupials were also investigated; only one Asian lion was found seropositive. Faecal oocysts were not found. 2 of 8 cats trapped in the zoo, but none of the 4 oppossums, were seropositive. One of the seronegative cats was shedding oocysts at the time of capture.

US public opinion on humane treatment of stray cats

Chu, K., & Anderseon, W. M. US Public Opinion on Humane Treatment of Stray Cats. 2007. Alley Cat Allies: Bethesda, MD, 6.

An overwhelming majority of Americans believe that leaving a stray cat outside to live out his life is more humane than having him caught and put down, according to a nationally representative survey conducted for Alley Cat Allies by Harris Interactive in April and May 2007. These results reveal a significant disparity between the public’s humane ethic and the operating policy of most U.S. animal pounds and shelters.
 The current animal control policy is that it is more humane to kill a stray cat now than let him live out his life outdoors; however, this policy rests on untenable bases. While those bases will be discussed in detail below, what is most salient to note is that the socalled humane ethic of the animal control and sheltering system ends more cats’ lives than does any other documented cause of death.

Behavioral differences between urban feeding groups of neutered and sexually intact free-roaming cats

Finkler, H., Gunther, I., & Terkel, J. (2011). Behavioral differences between urban feeding groups of neutered and sexually intact free-roaming cats following a trap-neuter-return procedure. Journal of the American Veterinary Medical Association, 238(9), 1141-1149.

Objective—To examine behavioral differences during a 1-year observational period between urban feeding groups of neutered and sexually intact free-roaming cats following a trap-neuter-return procedure.

Design—Natural-setting trial.

Animals—Free-roaming cats (n = 184) living in 4 feeding groups in an urban region of Israel.

Procedures—Trap-neuter-return procedures were applied to 2 cat feeding groups (A and B). Their social and feeding behaviors and frequency of appearance at feeding time were compared with those of 2 unneutered cat groups (C and D). Behavioral data were obtained from weekly observations before and during feeding over a 1-year period.

Results—A lower rate of agonistic interactions was observed in the neutered groups than in the unneutered groups. Sexually intact male cats participated in more agonistic male-male encounters than did neutered male cats. Of 199 such encounters in the feeding groups, only 1 occurred between 2 neutered males. Neutered cats in group A appeared earlier and had higher frequencies of feeding and appearance at the feeding site, compared with unneutered cats.

Conclusions and Clinical Relevance—Less aggression was observed in the neutered groups, specifically, fewer agonistic neutered-neutered male encounters occurred. This reduced agonistic behavior of neutered males resulted in reduced fighting and vocalizations, potentially leading to fewer injuries and reduced transmission of fight-related infectious diseases and reduced noise disturbance from a human perspective. Regarding food delivery, the feeding groups were time-and-place dependent, exhibiting context-related social interactions. When competing for food resources, as neutered cats time their arrival in accordance with food delivery, they thereby gain access to the choicest items.

FeLV and FIV in free-roeaming cats

Lee, I.T., Levy, J.K., Gorman, S.P., Crawford, P.C. and Slater, M.R.2002. Prevalence of feline leukemia virus infection and serum antibodies against feline immunodeficiency virus in un-owned free-roaming cats. Journal of the American Veterinary Medical Association, 220: 620–622.

Objective—To determine prevalence of FeLV infection and serum antibodies against feline immunodeficiency virus (FIV) in unowned free-roaming cats.
Design—Cross-sectional serologic survey.
Animals—733 unowned free-roaming cats in Raleigh, NC, and 1,143 unowned free-roaming cats in
Gainesville, Fla.
Results—In Raleigh, overall prevalence of FeLV infection was 5.3%, and overall seroprevalence for FIV was 2.3%. In Gainesville, overall prevalence of FeLV infection was 3.7%, and overall seroprevalence for FIV was 4.3%. Overall, FeLV prevalence was 4.3%, and seroprevalence for FIV was 3.5%. Prevalence of FeLV infection was not significantly different between males (4.9%) and females (3.8%), although seroprevalence for FIV was significantly higher in male cats (6.3%) than in female cats (1.5%).
Conclusions and Clinical Relevance—Prevalence of FeLV infection and seroprevalence for FIV in unowned free-roaming cats in Raleigh and Gainesville are similar to prevalence rates reported for owned cats in the United States. Male cats are at increased risk for exposure to FIV, compared with female cats.